EP4247281A1

EP4247281A1 - Fastening devices, systems, and methods

Info

Publication number: EP4247281A1
Application number: EP21827478.5A
Authority: EP
Inventors: Richard Justin Hyer; Jonathan Bitter; Andrew Fauth; Raymond White; Matthew CAMUSO; Corey Johnson
Original assignee: RTG Scientific LLC
Current assignee: RTG Scientific LLC
Priority date: 2020-11-19
Filing date: 2021-11-19
Publication date: 2023-09-27
Also published as: CA3198252A1; JP2023551178A; WO2022109338A1; AU2021381430A1

Abstract

A femoral fixation device may include a shaft and a helical thread disposed about the shaft between a first location and a second location along the shaft. The helical thread may include a concave undercut surface. The femoral fixation device may be configured such that, when the femoral fixation device is implanted within a neck and a head of a femoral bone: the first location, the second location, and the helical thread therebetween may be disposed within the head of the femoral bone; the concave undercut surface may be oriented toward a proximal end of the femoral fixation device; and the concave undercut surface may be configured to transmit at least one force from the head of the femoral bone to the neck of the femoral bone.

Description

FASTENING DEVICES, SYSTEMS, AND METHODS

TECHNICAL FIELD

[0001] The present disclosure relates to fastening devices, systems, and methods. More specifically, the present disclosure relates to fastening devices with improved thread designs and fastening systems/methods utilizing fastening devices with improved thread designs.

BACKGROUND

[0002] Surgical procedures involving fasteners implanted within bone and other tissues can become lose over time due to multi-axial forces and off-axis loading scenarios that may be applied to the fastener during the healing process. Traditional fastener thread designs may not provide sufficient fastener fixation to overcome these multi-axial forces and off-axis loading scenarios.

[0003] Accordingly, fasteners with improved thread designs for increasing bone fixation and load sharing between a bone/fastener interface experiencing multi-axial and off-loading conditions would be desirable.

SUMMARY

[0004] The various fastening devices, systems, and methods of the present disclosure have been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available fastening devices, systems, and methods. In some embodiments, the fastening devices, systems, and methods of the present disclosure may provide improved bone fixation and load sharing between a bone/fastener interface under multi-axial and off-loading conditions.

[0005] In some embodiments, a femoral fixation device may include a shaft having a proximal end, a distal end, and a longitudinal axis. The femoral fixation device may also include a helical thread disposed about the shaft along the longitudinal axis between a first location and a second location along the shaft. The helical thread may include a first undercut surface and a second undercut surface. The femoral fixation device may be configured such that, when the femoral fixation device is implanted within a neck and a head of a femoral bone: (1) the first location, the second location, and the helical thread therebetween may be disposed within the head of the femoral bone; (2) the first undercut surface may be angled towards one of the proximal end and the distal end of the shaft; (3) the second undercut surface may be angled towards the other one of the proximal end and the distal end of the shaft; and (4) the first and second undercut surfaces may be configured to transmit at least one force from the head of the femoral bone to the neck of the femoral bone.

[0006] In some embodiments of the femoral fixation device, the first undercut surface may be angled towards the proximal end of the shaft and the second undercut surface may be angled towards the distal end of the shaft. [0007] In some embodiments of the femoral fixation device, when the femoral fixation device is viewed in section along a plane intersecting the longitudinal axis of the shaft, the helical thread may include at least one chevron shape oriented toward the proximal end of the shaft.

[0008] In some embodiments of the femoral fixation device, the helical thread may include a plurality of chevron shapes oriented toward the proximal end of the shaft.

[0009] In some embodiments of the femoral fixation device, when the femoral fixation device is viewed in section along a plane intersecting the longitudinal axis of the shaft, the helical thread may include at least one partial crescent shape oriented toward the proximal end of the shaft.

[0010] In some embodiments of the femoral fixation device, the helical thread may include a plurality of partial crescent shapes oriented toward the proximal end of the shaft.

[0011] In some embodiments of the femoral fixation device, the proximal end of the shaft may include a headless cylindrical shape.

[0012] In some embodiments, a femoral fixation assembly may include a femoral fastener and a femoral support member. The femoral fastener may include a shaft having a proximal end, a distal end, and a longitudinal axis. The femoral fastener may also include a helical thread disposed about the shaft along the longitudinal axis between a first location and a second location along the shaft. The helical thread may include a concave undercut surface. The femoral support member may include a proximal end, a distal end, a longitudinal axis, and a passageway formed through the femoral support member at an angle with respect to the longitudinal axis of the femoral support member. In some embodiments, when the femoral fastener is implanted within a neck and a head of a femoral bone and the femoral support member is implanted along a longitudinal axis of the femoral bone, at least a portion of the shaft may be slidingly received within the passageway of the femoral support member, and the concave undercut surface may be oriented toward the proximal end of the femoral fastener and configured to transmit at least one force from the head of the femoral bone to the neck of the femoral bone.

[0013] In some embodiments of the femoral fixation assembly, the concave undercut surface may include at least one substantially flat surface.

[0014] In some embodiments of the femoral fixation assembly, the concave undercut surface may include a plurality of flat surfaces that are angled relative to each other.

[0015] In some embodiments of the femoral fixation assembly, when the femoral fastener is viewed in section along a plane intersecting the longitudinal axis of the shaft, the concave undercut surface may include at least one chevron shape oriented toward the proximal end of the shaft.

[0016] In some embodiments of the femoral fixation assembly, the concave undercut surface may include at least one curved surface.

[0017] In some embodiments of the femoral fixation assembly, when the femoral fastener is viewed in section along a plane intersecting the longitudinal axis of the shaft, the concave undercut surface may include at least one partial crescent shape oriented toward the proximal end of the shaft. [0018] In some embodiments of the femoral fixation assembly, when the femoral fastener is viewed in section along a plane intersecting the longitudinal axis of the shaft, the concave undercut surface may include at least one bent shape having an intermediate portion that is oriented toward the proximal end of the femoral fastener.

[0019] In some embodiments, a femoral fixation assembly may include a femoral fastener, a femoral support member, and a stop member. The femoral fastener may include a shaft having a proximal end, a distal end, and a longitudinal axis. The femoral fastener may include a helical thread disposed about the shaft along the longitudinal axis between a first location and a second location along the shaft. The femoral support member may include a proximal end, a distal end, a longitudinal axis, and a passageway. The passageway may include a first opening and a second opening opposite the first opening. The passageway may be formed through the femoral support member at an angle with respect to the longitudinal axis of the femoral support member. The stop member may include a proximal end, a distal end, a longitudinal axis, and a stop member projection having a preselected length. In some embodiments, when the femoral fastener is implanted within a neck and a head of a femoral bone, and the femoral support member is oriented with respect to a longitudinal axis of the femoral bone: (1) at least a portion of the shaft may be slidingly received within the passageway through the first opening; (2) at least a portion of the stop member may be received within the passageway through the second opening; and (3) a space having a predetermined length may be formed within the passageway between the distal end of the stop member and the proximal end of the shaft based on the preselected length of the stop member projection.

[0020] In some embodiments of the femoral fixation assembly, the femoral support member may be a bone plate.

[0021] In some embodiments of the femoral fixation assembly, the femoral support member may be an intramedullary nail.

[0022] In some embodiments of the femoral fixation assembly, the angle of the passageway with respect to the longitudinal axis of the femoral support member may be an acute angle.

[0023] In some embodiments of the femoral fixation assembly, the predetermined length of the space within the passageway may be greater than zero.

[0024] In some embodiments of the femoral fixation assembly, the predetermined length of the space within the passageway may be zero.

[0025] In some embodiments, a method of implanting a femoral fixation device within a femoral bone may include forming a bone tunnel through a neck of the femoral bone and into a head of the femoral bone and inserting the femoral fixation device into the bone tunnel. The femoral fixation device may include a shaft having a proximal end, a distal end, and a longitudinal axis. The femoral fixation device may also include a helical thread disposed about the shaft between a first location and a second location along the shaft. The helical thread may include a concave undercut surface oriented toward the proximal end of the shaft. The method may also include placing a portion of the shaft comprising the helical thread within the head of the femoral bone such that the concave undercut surface may be positioned to transmit at least one force from the head of the femoral bone to the neck of the femoral bone.

[0026] In some embodiments, the method may also include forming a tapped bone thread about the bone tunnel that may be configured to receive the helical thread therein.

[0027] In some embodiments of the method, placing the portion of the shaft comprising the helical thread within the head of the femoral bone further may further include rotating the shaft to insert the helical thread into the tapped bone thread disposed about the bone tunnel.

[0028] In some embodiments, the method may also include inserting the proximal end of the shaft into a first opening of a passageway formed through a femoral support member that is oriented with respect to a longitudinal axis of the femoral bone.

[0029] In some embodiments, the method may also include inserting a distal end of a stop member into a second opening of the passageway opposite the first opening and forming a space having a predetermined length within the passageway between the distal end of the stop member and the proximal end of the shaft based on a preselected length of the stop member.

[0030] In some embodiments, a pedicle bone fastener may include a shaft and a helical thread. The shaft may have a proximal end, a distal end, a longitudinal axis, and a minor diameter. The helical thread may be disposed about the shaft along the longitudinal axis between the proximal and distal ends of the shaft. The helical thread may include a first undercut surface and a second undercut surface. The first undercut surface may be angled toward one of the proximal end and the distal end of the shaft, the second undercut surface may be angled toward the other one of the proximal end and the distal end of the shaft, and the minor diameter of the shaft may be constant.

[0031] In some embodiments, the attachment feature may be coupled to the proximal end of the shaft and configured to be secured to an implement.

[0032] In some embodiments, the attachment feature may include a polyaxial head having a first semi-spherical surface.

[0033] In some embodiments, the implement may include a discrete tulip having a second semi- spherical surface configured to engage the first semi-spherical surface of the polyaxial head to secure the discrete tulip to the polyaxial head at any of a variety of relative orientations.

[0034] In some embodiments, the discrete tulip may include at least one opening and a locking member configured to secure a rod received through the at least one opening to the discrete tulip.

[0035] In some embodiments, the attachment feature may include an integrated tulip having at least one opening configured to receive at least a part of the implement therethrough. [0036] In some embodiments, the implement may include a rod receivable through the at least one opening of the integrated tulip and the integrated tulip may include a locking member configured to secure the rod to the integrated tulip.

[0037] In some embodiments, a method of preventing bone blowout may include forming a hole in a bone, the hole having a bone hole diameter, and inserting a bone fastener into the hole. The bone fastener may include a shaft and a helical thread. The shaft may have a proximal end, a distal end, a longitudinal axis, and a minor diameter. The helical thread may be disposed about the shaft along the longitudinal axis between the proximal and distal ends of the shaft. The helical thread may include a first undercut surface and a second undercut surface. The first undercut surface may be angled toward one of the proximal end and the distal end of the shaft. The second undercut surface may be angled toward the other one of the proximal end and the distal end of the shaft, and the minor diameter of a main portion of the shaft may not be greater than the bone hole diameter to reduce a radial outward load force imparted on the bone and prevent bone blowout.

[0038] In some embodiments, the minor diameter of the main portion of the shaft may be equal to the bone hole diameter.

[0039] In some embodiments, the minor diameter of the main portion of the shaft may be less than the bone hole diameter.

[0040] In some embodiments, the minor diameter of the main portion of the shaft may be between 0mm and 0.1mm less than the bone hole diameter.

[0041] In some embodiments, the minor diameter of the main portion of the shaft may be at least 0.1mm less than the bone hole diameter.

[0042] In some embodiments, the minor diameter of the main portion of the shaft may be at least 0.2mm less than the bone hole diameter.

[0043] In some embodiments, the minor diameter of the main portion of the shaft may be constant.

[0044] In some embodiments, a bone fastener may include a shaft and a helical thread. The shaft may have a proximal end, a distal end, a longitudinal axis, and a minor diameter. The helical thread may be disposed about the shaft along the longitudinal axis between the proximal and distal ends of the shaft and defining a major diameter of the bone fastener. The helical thread may include a first undercut surface and a second undercut surface. The first undercut surface may be angled toward one of the proximal end and the distal end of the shaft. The second undercut surface may be angled toward the other one of the proximal end and the distal end of the shaft, and a ratio of the major diameter to the minor diameter may be less than 1.50.

[0045] In some embodiments, the ratio of the major diameter to the minor diameter may be less than 1.25.

[0046] In some embodiments, the ratio of the major diameter to the minor diameter may be less than 1.10. [0047] In some embodiments, the ratio of the major diameter to the minor diameter may be less than 1.05.

[0048] In some embodiments, at least a portion of the shaft may be configured to be received with an intramedullary canal of a bone.

[0049] In some embodiments, the bone fastener may also include an attachment feature at the proximal end of the shaft configured to be adjustably secured to an implement.

[0050] In some embodiments, a pedicle bone fastener may include a shaft, a helical thread, and an integrated attachment feature. The shaft may include a proximal end, a distal end, and a longitudinal axis. The helical thread may be disposed about the shaft along the longitudinal axis between the proximal and distal ends of the shaft. The helical thread may include a first undercut surface and a second undercut surface. The first undercut surface may be angled toward one of the proximal end and the distal end of the shaft and the second undercut surface may be angled toward the other one of the proximal end and the distal end of the shaft. The integrated attachment feature may be disposed at the proximal end of the shaft and configured to be adjustably secured to a spinal stabilization implement.

[0051] In some embodiments, the integrated attachment feature may include a polyaxial head having a first semi-spherical surface configured to be polyaxially-adjustably secured to the spinal stabilization implement.

[0052] In some embodiments, the spinal stabilization implement may include a discrete tulip having a second semi-spherical surface configured to engage the first semi-spherical surface of the polyaxial head to polyaxially-adjustably secure the discrete tulip to the polyaxial head at any of a variety of relative orientations.

[0053] In some embodiments, the discrete tulip may include at least one opening and a locking member configured to secure a rod receivable through the at least one opening to the discrete tulip.

[0054] In some embodiments, the integrated attachment feature may include an integrated tulip having at least one opening configured to receive at least a part of the spinal stabilization implement therethrough.

[0055] In some embodiments, the integrated tulip further may include a locking member configured to secure the rod to the integrated tulip.

[0056] In some embodiments, a pedicle fastener stabilization system may include a pedicle bone fastener, a tulip, and a spinal stabilization rod. The pedicle bone fastener may include a shaft having a proximal end, a distal end, and a longitudinal axis. The pedicle bone fastener may also include a polyaxial head at the proximal end of the shaft. The pedicle bone fastener may also include a first helical thread disposed about the shaft along the longitudinal axis between the proximal and distal ends of the shaft. The first helical thread may include a first concave undercut surface. The pedicle bone fastener may also include a second helical thread disposed about the shaft adjacent the first helical thread. The second helical thread may include a second concave undercut surface. The first concave undercut surface and the second concave undercut surface may be angled towards one of the proximal end and the distal end of the shaft. The tulip may be configured to be polyaxially-adjustably secured to the polyaxial head, and the spinal stabilization rod may be securable to the tulip.

[0057] In some embodiments, the polyaxial head may be integrally formed with the pedicle bone fastener.

[0058] In some embodiments, the polyaxial head may include a first semi-spherical surface.

[0059] In some embodiments, the tulip may include a second semi-spherical surface configmed to engage the first semi-spherical surface of the polyaxial head to polyaxially-adjustably secure the tulip to the polyaxial head at any of a variety of relative orientations.

[0060] In some embodiments, the tulip may include at least one opening configured to receive the spinal stabilization rod therethrough.

[0061] In some embodiments, the tulip may include a locking member configured to secure the spinal stabilization rod to the tulip.

[0062] In some embodiments, a minor diameter of the shaft may be constant.

[0063] In some embodiments, a method of implanting a bone fastener assembly may include: (1) inserting a bone fastener into a bone, (2) adjusting an orientation of an implement to a selected orientation relative to an attachment feature of the bone fastener, and (3) attaching the implement to the attachment feature at the selected orientation. The bone fastener may include a shaft, a helical thread, and the attachment feature. The shaft may include a proximal end, a distal end, and a longitudinal axis. The helical thread may be disposed about the shaft along the longitudinal axis between the proximal and distal ends of the shaft. The helical thread may include a first undercut surface and a second undercut surface. The first undercut surface may be angled toward one of the proximal end and the distal end of the shaft. The second undercut surface may be angled toward the other one of the proximal end and the distal end of the shaft. The attachment feature may be disposed at the proximal end of the shaft and configmed to be adjustably secured to the implement.

[0064] In some embodiments, the attachment feature at the proximal end of the shaft may be configured to be polyaxially-adjustably secured to the implement. Adjusting the orientation of the implement to the selected orientation relative to the attachment feature may comprise polyaxially- adjusting the orientation of the implement to a selected relative orientation, of a plurality of polyaxially- differentiated potential relative orientations, relative to the attachment feature.

[0065] In some embodiments, the attachment feature may include a polyaxial head having a first semi-spherical surface, and the implement may include a discrete tulip having a second semi-spherical surface configmed to engage the first semi-spherical surface of the polyaxial head to polyaxially- adjustably secure the discrete tulip to the polyaxial head at any of a variety of relative orientations.

[0066] In some embodiments, the discrete tulip may include at least one opening and a locking member configured to secure a rod received through the at least one opening to the discrete tulip. [0067] In some embodiments, the method may also include drilling a pilot hole into the bone and inserting the shaft of the bone fastener into the pilot hole.

[0068] In some embodiments, the method may also include tapping a bone thread in the bone to form a tapped bone thread about the pilot hole and inserting the helical thread into the tapped bone thread.

[0069] These and other features and advantages of the present disclosure will become more fully apparent from the following description and appended claims or may be learned by the practice of the devices, systems, and methods set forth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Exemplary embodiments of the present disclosure will become more fully apparent from the following description taken in conjunction with the accompanying drawings. Understanding that these drawings depict only exemplary embodiments and are, therefore, not to be considered limiting of the scope of the present disclosure, the exemplary embodiments of the present disclosure will be described with additional specificity and detail through use of the accompanying drawings in which:

[0071] FIG. 1A illustrates a front perspective view of a fastener, according to an embodiment of the present disclosure; FIG. IB illustrates a rear perspective view of the fastener of FIG. 1A; FIG. 1C illustrates a side view of the fastener of FIG. 1A; FIG. ID illustrates a cross-sectional side view of the fastener of FIG. 1 A taken along the line A- A shown in FIG. 1C;

[0072] FIG. 2A illustrates a front perspective view of a fastener, according to another embodiment of the present disclosure; FIG. 2B illustrates a rear perspective view of the fastener of FIG. 2A; FIG. 2C illustrates a side view of the fastener of FIG. 2A; FIG. 2D illustrates a cross-sectional side view of the fastener of FIG. 2A taken along the line B-B shown in FIG. 2C;

[0073] FIG. 3 illustrates a partial cross-sectional side view of a fastener comprising crescentshaped threading;

[0074] FIG. 4A illustrates a front perspective view of a fastener, according to another embodiment of the present disclosure; FIG. 4B illustrates a rear perspective view of the fastener of FIG. 4A; FIG. 4C illustrates a side view of the fastener of FIG. 4A; FIG. 4D illustrates a cross-sectional side view of the fastener of FIG. 4A taken along the line D-D shown in FIG. 4C;

[0075] FIG. 5 A illustrates a front perspective view of a fastener, according to another embodiment of the present disclosure; FIG. 5B illustrates a rear perspective view of the fastener of FIG. 5A; FIG. 5C illustrates a side view of the fastener of FIG. 5 A; FIG. 5D illustrates a cross-sectional side view of the fastener of FIG. 5 A taken along the line E-E shown in FIG. 5C;

[0076] FIG. 6A illustrates a front perspective view of a fastener, according to another embodiment of the present disclosure; FIG. 6B illustrates a rear perspective view of the fastener of FIG. 6A; FIG. 6C illustrates a side view of the fastener of FIG. 6A; FIG. 6D illustrates a cross-sectional side view of the fastener of FIG. 6A taken along the line F-F shown in FIG. 6C; [0077] FIG. 7A illustrates a front perspective view of a fastener, according to another embodiment of the present disclosure; FIG. 7B illustrates a rear perspective view of the fastener of FIG. 7A; FIG. 7C illustrates a side view of the fastener of FIG. 7A; FIG. 7D illustrates a cross-sectional side view of the fastener of FIG. 7A taken along the line G-G shown in FIG. 7C;

[0078] FIG. 8A illustrates a front perspective view of a fastener, according to another embodiment of the present disclosure; FIG. 8B illustrates a rear perspective view of the fastener of FIG. 8A;

[0079] FIG. 9A illustrates an exploded view of a pedicle fastener stabilization system, according to an embodiment of the present disclosure; FIG. 9B illustrates the pedicle fastener stabilization system of FIG. 9A assembled together with a spinal stabilization rod; FIG. 9C illustrates a top perspective view of the discrete tulip shown in FIG. 9A; FIG. 9D illustrates a bottom perspective view of the discrete tulip; FIG. 9E illustrates a side view of the discrete tulip; FIG. 9F illustrates a cross-sectional side view of the discrete tulip taken along the line H-H shown in FIG. 9E;

[0080] FIG. 10A illustrates a top view of a vertebral body with the pedicle fastener stabilization system of FIG. 9A inserted into pedicles of the vertebral body; FIG. 10B illustrates a cross-sectional side view of FIG. 10 A;

[0081] FIG. 11A illustrates a front perspective view of a threaded stem, according to an embodiment of the present disclosure; FIG. 1 IB illustrates a rear perspective view of the threaded stem of FIG. 11 A; FIG. 11C illustrates a side view of the fastener of FIG. 11 A; FIG. 1 ID illustrates a cross- sectional side view of the fastener of FIG. HA taken along the line I-I shown in FIG. 11C;

[0082] FIG. 12A illustrates a front perspective view of a threaded stem, according to another embodiment of the present disclosure; FIG. 12B illustrates a rear perspective view of the threaded stem of FIG. 12A; FIG. 12C illustrates a side view of the fastener of FIG. 12A; FIG. 12D illustrates a cross- sectional side view of the fastener of FIG. 12A taken along the line J-J shown in FIG. 12C; FIG. 12E illustrates a perspective side view of the threaded stem of FIG. 12A coupled to an implant; FIG. 12F illustrates a system comprising the threaded stem of FIG. 12A;

[0083] FIG. 13A illustrates a front perspective view of a threaded stem, according to another embodiment of the present disclosure; FIG. 13B illustrates a rear perspective view of the threaded stem of FIG. 13A; FIG. 13C illustrates a side view of the fastener of FIG. 13A; FIG. 13D illustrates a cross- sectional side view of the fastener of FIG. 13A taken along the line K-K shown in FIG. 13C;

[0084] FIG. 14A illustrates a front perspective view of a threaded stem, according to another embodiment of the present disclosure; FIG. 14B illustrates a rear perspective view of the threaded stem of FIG. 14A; FIG. 14C illustrates a side view of the fastener of FIG. 14A; FIG. 14D illustrates a cross- sectional side view of the fastener of FIG. 14A taken along the line L-L shown in FIG. 14C; FIG. 14E illustrates a front perspective view of a radial head component, according to an embodiment of the present disclosure; FIG. 14F illustrates a rear perspective view of the radial head component of FIG. 14E; FIG. 14G illustrates a side view of the radial head component of FIG. 14E; FIG. 14H illustrates a bottom view of the radial head component of FIG. 14E; FIG. 141 illustrates an assembly comprising the threaded stem of FIG. 14A and the radial head component of FIG. 14E;

[0085] FIG. 15A illustrates a rear perspective view of a femoral fastener, according to an embodiment of the present disclosure;

[0086] FIG. 15B illustrates a front perspective view of the femoral fastener of FIG. 15 A;

[0087] FIG. 15C illustrates a side view of the femoral fastener of FIG. 15A;

[0088] FIG. 15D illustrates a cross-sectional side view of the fastener shown in FIG. 15C, taken along the line B-B;

[0089] FIG. 16A illustrates perspective side view of a femoral support member, according to an embodiment of the present disclosure;

[0090] FIG. 16B illustrates another perspective side view of the femoral support member of FIG.

16 A;

[0091] FIG. 16C illustrates a front view of the femoral support member of FIG. 16 A;

[0092] FIG. 16D illustrates a rear view of the femoral support member of FIG. 16A;

[0093] FIG. 17A illustrates a front view of a stop member, according to an embodiment of the present disclosure;

[0094] FIG. 17B illustrates a rear perspective view of the stop member of FIG. 17A;

[0095] FIG. 17C illustrates a front perspective view of the stop member of FIG. 17A;

[0096] FIG. 17D illustrates a side view of the stop member of FIG. 17A;

[0097] FIG. 17E illustrates a side view of the stop member of FIG. 17A with a stop member projection;

[0098] FIG. 17F illustrates a side view of the stop member of FIG. 17A with another stop member projection;

[0099] FIG. 18 illustrates an exploded view of a femoral fixation assembly, according to an embodiment of the present disclosure;

[00100] FIG. 19 illustrates a side view of the femoral fixation assembly of FIG. 18, after it has been assembled;

[00101] FIG. 20 illustrates a side view of the femoral fixation assembly of FIG. 18 implanted in a femur;

[00102] FIG. 21 illustrates a front view of the femoral fixation assembly and femur shown in FIG. 20;

[00103] FIG. 22 illustrates cross-sectional side view of the femoral fixation assembly and femur shown in FIG. 21, taken along the line C-C;

[00104] FIG. 23 illustrates a perspective side view of a guide pin inserter assembly adjacent a femur, according to an embodiment of the present disclosure; [00105] FIG. 24 illustrates cross-sectional side view of a guide pin insert, according to an embodiment of the present disclosure;

[00106] FIG. 25 illustrates a side view of a guide pin inserted into a femur;

[00107] FIG. 26 illustrates a side view of a guide pin depth gauge adjacent a femur, according to an embodiment of the present disclosure;

[00108] FIG. 27 illustrates a side view of a tissue shield and reamer adjacent a femur, according to embodiments of the present disclosure;

[00109] FIG. 28 illustrates a side view of drill bit, adjustable depth stop, and centering sleeve, according to embodiments of the present disclosure;

[00110] FIG. 29 illustrates a side view of a tap device, according to an embodiment of the present disclosure;

[00111] FIG. 30A illustrates a close-up partial view of a connection feature between an inserter and a femoral fastener prior to engagement, according to an embodiment of the present disclosure;

[00112] FIG. 30B illustrates a side view of the connection feature of FIG. 30A after engagement;

[00113] FIG. 30C illustrates a side view of the connection feature of FIG. 30A showing an inserter coupler that is inside the inserter before it engages with an internal thread of the femoral fastener;

[00114] FIG. 30D illustrates a side view of the connection feature of FIG. 30C after the inserter coupler has been engaged with the internal thread of the femoral fastener;

[00115] FIG. 31 illustrates a side view of a centering sleeve and inserter facilitating placement of a femoral fastener within a femur;

[00116] FIG. 32 illustrates a side view of the inserter of FIG. 31 being utilized to couple a femoral support member to the femoral fastener;

[00117] FIG. 33 illustrates a side view the femoral support member and femoral fastener after the inserter has been removed;

[00118] FIG. 34 illustrates a side view of an impactor and mallet utilized to seat the femoral support member against the femur;

[00119] FIG. 35A illustrates a side view of a compression screw inserted into the femoral support member and the femoral fastener;

[00120] FIG. 35B illustrates a close-up view of the compression screw shown in FIG. 35A;

[00121] FIG. 36 illustrates a side view of a drill bit and drill bit guide forming bone tunnels in the femur, according to an embodiment of the present disclosure;

[00122] FIG. 37 illustrates a side view of a depth gauge utilized to measure a depth of a bone tunnel, according to an embodiment of the present disclosure;

[00123] FIG. 38 illustrates a side view of a driver installing one or more bone plate fasteners into the femur, according to an embodiment of the present disclosure; [00124] FIG. 39 illustrates a side view of a drill bit and drill bit guide forming bone tunnels into the head of the femur, according to another embodiment of the present disclosure;

[00125] FIG. 40 illustrates a side view of driver installing one or more support fasteners into the head of the femur;

[00126] FIG. 41 illustrates a side view of the femoral fixation assembly of FIG. 40 after the one or more support fasteners have been installed;

[00127] FIG. 42 illustrates a side view of an extension plate being coupled to the femoral support member, according to an embodiment of the present disclosure;

[00128] FIG. 43 illustrates a side view of the femoral fixation assembly of FIG. 42 after the extension plate has been coupled to the femoral support member and additional support fasteners have been inserted into the head of the femur;

[00129] FIG. 44 illustrates a side view of the femoral fixation assembly of FIG. 41 after a trochanter plate has been coupled to the femoral support member and additional support fasteners have been inserted into the head of the femur, according to another embodiment of the present disclosure;

[00130] FIG. 45 illustrates a side view of the femoral fixation assembly of FIG. 44 showing a drill bit forming one or more bone tunnels to receive one or more trochanter plate fasteners to secure the trochanter plate to the femur;

[00131] FIG. 46A illustrates a perspective side view of the femoral fixation assembly shown in FIG. 45 after the one or more trochanter plate fasteners have been installed;

[00132] FIG. 46B illustrates a perspective front view of the femoral fixation assembly shown in FIG. 46A;

[00133] FIG. 47 illustrates a perspective front view of a side plate guide, according to another embodiment of the present disclosure;

[00134] FIG. 48A illustrates a front perspective view of a fastener, according to another embodiment of the present disclosure; FIG. 48B illustrates a rear perspective view of the fastener of FIG. 48A; FIG. 48C illustrates a side view of the fastener of FIG. 48A; FIG. 48D illustrates a cross- sectional side view of the fastener of FIG. 48A taken along the line C-C shown in FIG. 48C;

[00135] FIG. 49A illustrates a front perspective view of a fastener, according to another embodiment of the present disclosure; FIG. 49B illustrates a rear perspective view of the fastener of FIG. 49 A; FIG. 49C illustrates a side view of the fastener of FIG. 49A; FIG. 49D illustrates a cross- sectional side view of the fastener of FIG. 49A taken along the line F-F shown in FIG. 49C;

[00136] FIG. 50A illustrates a front perspective view of a fastener, according to another embodiment of the present disclosure; FIG. 50B illustrates a rear perspective view of the fastener of FIG. 50A; [00137] FIG. 51 A illustrates a front perspective view of a fastener, according to another embodiment of the present disclosure; FIG. 5 IB illustrates a rear perspective view of the fastener of FIG. 51 A;

[00138] FIG. 52A illustrates a front perspective view of a fastener, according to another embodiment of the present disclosure; FIG. 52B illustrates a rear perspective view of the fastener of FIG. 52A;

[00139] FIG. 53A illustrates a front perspective view of a fastener, according to another embodiment of the present disclosure; FIG. 53B illustrates a rear perspective view of the fastener of FIG. 53A;

[00140] FIG. 54A illustrates a perspective side view of a fastener, according to another embodiment of the present disclosure; FIG. 54B illustrates a kit comprising the fastener of FIG. 54A;

[00141] FIG. 55 A illustrates a perspective side view of a fastener, according to another embodiment of the present disclosure; FIG. 55B illustrates a kit comprising the fastener of FIG. 55A;

[00142] FIG. 56A illustrates a perspective side view of a fastener, according to another embodiment of the present disclosure; FIG. 56B illustrates a kit comprising the fastener of FIG. 56A;

[00143] FIG. 57A illustrates a rear perspective view of a fastener, according to another embodiment of the present disclosure; FIG. 57B illustrates a rear perspective view of the fastener of FIG. 57A with a separate tool inserted through a cannula of the fastener;

[00144] FIG. 58 illustrates a front perspective view of a fastener, according to another embodiment of the present disclosure;

[00145] FIG. 59A illustrates a perspective top view of fasteners engaged with a plate, according to an embodiment of the present disclosure; FIG. 59B illustrates a perspective side view of the fasteners and plate of FIG. 59 A;

[00146] FIG. 60A illustrates a perspective view of fasteners engaged with a plate, according to another embodiment of the present disclosure; FIG. 59B illustrates a top view of the fasteners and plate of FIG. 59A implanted in a tibia;

[00147] FIG. 61 illustrates a perspective view of fasteners and a plate, according to another embodiment of the present disclosure;

[00148] FIG. 62A illustrates a perspective top view of a plate, according to another embodiment of the present disclosure; FIG. 62B illustrates a side view of a distal femur fracture; FIG. 62C illustrates a side view of the distal femur fracture of FIG. 62B repaired with fasteners and the plate of FIG. 62A;

[00149] FIG. 63A illustrates a side view of a fastener, according to another embodiment of the present disclosure; FIG. 63B illustrates a perspective view of a plate, according to another embodiment of the present disclosure; FIG. 63C illustrates a perspective view of a plate, according to another embodiment of the present disclosure; [00150] FIG. 64A illustrates a perspective view of fasteners coupling a plate to a proximal humerus, according to another embodiment of the present disclosure; and FIG. 64B illustrates a side view of the proximal humerus of FIG. 64B.

[00151] It is to be understood that the drawings are for purposes of illustrating the concepts of the present disclosure and may not be drawn to scale. Furthermore, the drawings illustrate exemplary embodiments and do not represent limitations to the scope of the present disclosure.

DETAILED DESCRIPTION

[00152] Exemplary embodiments of the present disclosure will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. It will be readily understood that the components of the present disclosure, as generally described and illustrated in the drawings, could be arranged, and designed in a wide variety of different configurations. Thus, the following more detailed description of the embodiments of the implants, systems, and methods, as represented in the drawings, is not intended to limit the scope of the present disclosure but is merely representative of exemplary embodiments of the present disclosure.

[00153] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. While the various aspects of the embodiments are presented in the drawings, the drawings are not necessarily drawn to scale unless specifically indicated. [00154] The following disclosure presents various fasteners for utilization in bone and other tissues as implantable devices (e.g., orthopedic implants, spine implants, etc.) for the purpose of streamlining the present disclosure. However, it will be understood that the various fasteners and helical threading concepts presented herein can be utilized in any medium beyond bones/tissues and/or for any application beyond surgical procedures.

[00155] Example applications/procedures that may utilize any of the fasteners described or contemplated herein, in any configuration and with any of the features described herein, may include, but are not limited to: spine procedures (e.g., SI fusion, facet fixation, etc.), extremity procedures, reconstruction procedures, trauma procedures, sports related procedures, bone fixation procedures, bone fusion procedures, joint arthroplasty procedures, veterinary procedures, procedures involving osteoporotic or compromised bone, etc.

[00156] Moreover, fastener types that may utilize any of the thread designs, morphology, and/or features described herein may include, but are not limited to: pedicle fasteners, cervical fasteners, threaded stems, threaded intramedullary canal stems, cortical fasteners, soft tissue fasteners, long fasteners, cannulated fasteners, joint stems, revision fasteners, compression fasteners (e.g., hip compression fasteners, etc.), veterinary fasteners, etc.

[00157] FIGS. 1A-1D illustrate various views of a fastener 100, implantable bone anchor, or bone screw, according to one embodiment of the present disclosure. Specifically, FIG. 1A is a front perspective view of the fastener 100, FIG. IB is a rear perspective view of the fastener 100, FIG. 1C is a side view of the fastener 100, and FIG. ID is a cross-sectional side view of the fastener 100 taken along the line A- A in FIG. 1C.

[00158] In general, the fastener 100 may include a shaft 105 having a proximal end 101, a distal end 102, and a longitudinal axis 103. The fastener 100 may also include a head 104 located at the proximal end 101 of the shaft 105, a torque connection interface 106 formed in/on the head 104 (in either a male/female configuration), and a self-tapping feature 107 formed in the distal end 102 of the shaft 105.

[00159] In some embodiments, the fastener 100 may include a first helical thread 110 disposed about the shaft 105, and a second helical thread 120 disposed about the shaft 105 adjacent the first helical thread 110.

[00160] In some embodiments, the fastener 100 may include a “dual start” or “dual lead” thread configuration comprising the first helical thread 110 and the second helical thread 120.

[00161] In some embodiments, a depth of the first helical thread 110 and/or the second helical thread 120 with respect to the shaft 105 may define a major diameter vs. a minor diameter of the shaft 105 alone.

[00162] In some embodiments, a major diameter and/or a minor diameter of the fastener 100 may be constant or substantially constant along the entire length of the fastener, or along a majority of the length of the fastener. In these embodiments, a constant minor diameter may help avoid blowout of narrow/delicate bones (e.g., a pedicle) when inserting a fastener into a bone. In some embodiments, a pilot hole may first be drilled into a narrow/delicate bone and then a fastener having a similar minor diameter in comparison to the diameter of the pilot hole may be chosen to avoid blowout when inserting the fastener into the bone, as will be discussed in more detail below.

[00163] In some embodiments, a depth of the first helical thread 110 and/or the second helical thread 120 with respect to the shaft 105 may vary along a length of the shaft 105 to define one or more major diameters of the fastener 100 and/or one or more regions along the fastener 100 may comprise a one or more continuously variable major diameters.

[00164] In some embodiments, a thickness of the shaft 105 may vary along a length of the shaft 105 to define one or more minor diameters of the fastener 100, and/or one or more regions along the fastener 100 may comprise one or more continuously variable minor diameters. In some embodiments, a thickness/height/width/length/pitch/shape, etc., of the first helical thread 110 and/or the second helical thread 120 (or any additional helical thread) may vary along a length of the shaft 105. For example, a thickness/height/width/length/pitch/shape, etc., of the first helical thread 110 and/or the second helical thread 120 may be greater towards the tip of the fastener and thinner towards the head of the fastener (or vice versa) in either a discrete or continuously variable fashion, etc. [00165] In some embodiments, the major and/or minor diameters may increase toward a proximal end or head of a fastener in order to increase bone compaction as the fastener is terminally inserted into the bone/tissue.

[00166] In some embodiments, a pitch of the first helical thread 110 and/or the second helical thread

120 may vary along a length of the fastener 100.

[00167] In some embodiments, the fastener 100 may include a plurality of helical threads disposed about the shaft 105. However, it will also be understood that any of the fasteners disclosed or contemplated herein may include a single helical thread disposed about the shaft of the fastener. Moreover, the fastener 100 may comprise a nested plurality of helical threads having different lengths (not shown). As one non-limiting example, the fastener 100 may include a first helical thread 110 that is longer than a second helical thread 120, such that the fastener 100 comprises dual threading along a first portion of the shaft 105 and single threading along a second portion of the shaft 105.

[00168] In some embodiments, the plurality of helical threads may include three helical threads (not shown) comprising a “triple start” or “triple lead” thread configuration (not shown).

[00169] In some embodiments, the plurality of helical threads may include four helical threads (not shown) comprising a “quadruple start” or “quadruple lead” thread configuration (not shown).

[00170] In some embodiments, the plurality of helical threads may include more than four helical threads (not shown).

[00171] In some embodiments, the fastener 100 may include first threading with any of the shapes disclosed herein oriented toward one of the proximal end and the distal end of the fastener 100, with the first threading located proximate the distal end of the fastener 100, as well as second threading with any of the shapes disclosed herein oriented toward the other one of the proximal end and the distal end of the fastener 100, with the second threading located proximate the head of the fastener 100 (not shown).

[00172] In some embodiments, the fastener 100 may include multiple threading (e.g., dual helical threading, etc.) with any of the shapes disclosed herein located proximate one of the proximal end and the distal end of the fastener 100, as well as single threading with any of the shapes disclosed herein with the second threading located proximate the other of the proximal end and the distal end of the fastener 100 (not shown).

[00173] In some embodiments, the first helical thread 110 may include a plurality of first concave undercut surfaces 131 and a plurality of first convex undercut surfaces 141.

[00174] In some embodiments, the second helical thread 120 may include a plurality of second concave undercut surfaces 132 and a plurality of second convex undercut surfaces 142.

[00175] In some embodiments, when the fastener 100 is viewed in section along a plane that intersects the longitudinal axis 103 of the shaft 105 (see FIG. ID), the plurality of first concave undercut surfaces 131 and the plurality of second convex undercut surfaces 142 may be oriented toward (i.e., point toward) the proximal end 101 of the shaft 105.

[00176] In some embodiments, the plurality of first convex undercut surfaces 141 and the plurality of second concave undercut surfaces 132 may be oriented toward (i.e., point toward) the distal end 102 of the shaft 105.

[00177] In some embodiments, at least one of the plurality of first concave undercut surfaces 131, the plurality of first convex undercut surfaces 141, the plurality of second concave undercut surfaces 132, and the plurality of second convex undercut surfaces 142 may comprise at least one substantially flat surface.

[00178] In some embodiments, when the fastener 100 is viewed in section along a plane intersecting the longitudinal axis 103 of the shaft 105, the first helical thread 110 may comprise a plurality of first bent shapes (comprising at least one surface that is angled relative to the longitudinal axis 103 of the shaft 105 and/or at least one undercut surface) with a plurality of first intermediate portions 151 that are oriented toward (i.e., point toward) the distal end 102 of the shaft 105. This may be referred to as “standard” threading, having a “standard” orientation.

[00179] In some embodiments, when the fastener 100 is viewed in section along a plane intersecting the longitudinal axis 103 of the shaft 105, the second helical thread 120 may comprise a plurality of second bent shapes (comprising at least one surface that is angled relative to the longitudinal axis 103 of the shaft 105 and/or at least one undercut surface) with a plurality of second intermediate portions 152 that are oriented toward (i.e., point toward) the proximal end 101 of the shaft 105. This may be referred to as “inverted” threading, having an “inverted” orientation.

[00180] In some embodiments, one or more helical threads may morph/transition between a standard orientation and an inverted orientation along a shaft of a fastener.

[00181] In some embodiments, at least one of the plurality of first concave undercut surfaces 131, the plurality of first convex undercut surfaces 141, the plurality of second concave undercut surfaces 132, and the plurality of second convex undercut surfaces 142 may comprise at least one curved surface. [00182] As shown in FIG. ID, the proximally -oriented and distally -oriented surfaces of the first helical thread 110 (i.e., the first concave undercut surfaces 131 and the first convex undercut surfaces 141 in the fastener 100 of FIG. ID) may not have mirror symmetry relative to each other about any plane perpendicular to the longitudinal axis 103 of the fastener 100. Rather, the first concave undercut surfaces 131 and the first convex undercut surfaces 141 may be generally parallel to each other. The same may be true for the second helical thread 120, in which the second concave undercut surfaces 132 and the second convex undercut surfaces 142 may not have mirror symmetry relative to each other but may be generally parallel to each other.

[00183] Conversely, as also shown in FIG. ID, the proximally -oriented surfaces of the first helical thread 110 may have mirror symmetry relative to the distally -oriented surfaces of the second helical thread 120. Specifically, the first concave undercut surfaces 131 may have mirror symmetry relative to the second convex undercut surfaces 142 about a plane 170 that bisects the space between them and lies perpendicular to the longitudinal axis 103.

[00184] Similarly, the distally-oriented surfaces of the first helical thread 110 may have mirror symmetry relative to the proximally -oriented surfaces of the second helical thread 120. Specifically, the second concave undercut surfaces 132 may have mirror symmetry relative to the first convex undercut surfaces 141 about a plane 172 that bisects the space between them and lies perpendicular to the longitudinal axis 103.

[00185] This mirror symmetry may be present along most of the length of the first helical thread 110 and the second helical thread 120, with symmetry across different planes arranged between adjacent turns of the first helical thread 110 and the second helical thread 120 along the length of the longitudinal axis 103. Such mirror symmetry may help more effectively capture bone between the first helical thread 110 and the second helical thread 120 and may also facilitate manufacture of the fastener 100.

[00186] In some embodiments, when the fastener 100 is viewed in section along a plane intersecting the longitudinal axis 103 of the shaft 105, the first helical thread 110 may include at least one partial crescent shape that is oriented toward (i.e., points toward) the distal end 102 of the shaft 105 and/or the proximal end 101 of the shaft 105. FIG. 3 illustrates a partial cross-sectional view of a fastener 300 comprising crescent shapes, as one non-limiting example of such an embodiment.

[00187] In some embodiments (not shown), when the fastener 100 is viewed in section along a plane intersecting the longitudinal axis 103 of the shaft 105, the first helical thread 110 may include at least one partial crescent shape that is oriented toward (i.e., points toward) the distal end 102 of the shaft 105, and the second helical thread 120 may include at least one partial crescent shape that is oriented toward (i.e., points toward) the proximal end 101 of the shaft 105.

[00188] In some embodiments (not shown), the first helical thread 110 may include a first plurality of partial crescent shapes that are oriented toward (i.e., point toward) the distal end 102 of the shaft 105, and the second helical thread 120 may include a second plurality of partial crescent shapes that are oriented toward (i.e., point toward) the proximal end 101 of the shaft 105.

[00189] In some embodiments (not shown), the first plurality of partial crescent shapes and the second plurality of partial crescent shapes may be arranged in alternating succession along the shaft 105 of the fastener 100.

[00190] In some embodiments, the first helical thread 110 may be bisected by the line 123 shown in FIG. 3 with each crescent shape including a plurality of first undercut surfaces 111, a plurality of second undercut surfaces 112, a plurality of third undercut surfaces 113, and a plurality of fourth open surfaces 114 similar to the helical threading shown in FIG. ID, except with curved surfaces in place of flat surfaces. [00191] In some embodiments, the plurality of first undercut surfaces 111 and the plurality of second undercut surfaces 112 may comprise concave curved surfaces. However, it will be understood that portions of the plurality of first undercut surfaces 111 and/or portions of the plurality of second undercut surfaces 112 may also comprise convex curved surfaces and/or flat surfaces (not shown in FIG. 3).

[00192] In some embodiments, the plurality of third undercut surfaces 113 and the plurality of fourth open surfaces 114 may comprise convex curved surfaces. However, it will be understood that portions of the plurality of third undercut surfaces 113 and the plurality of fourth open surfaces 114 may also comprise concave curved surfaces and/or flat surfaces (not shown in FIG. 3).

[00193] In some embodiments, the plurality of third undercut surfaces 113 and the plurality of fourth open surfaces 114 may be replaced by a ramped surface (such as that utilized in a standard buttress thread design) without any undercuts (not shown in FIG. 3). Likewise, any of the other thread designs disclosed herein may utilize a ramped or buttress thread design on at least one side of the helical thread.

[00194] In some embodiments, a fastener may have only standard threads or only inverted threads. The type of threads that are desired may depend on the type and/or magnitude of loads to be applied to the fastener. For example, a screw loaded axially away from the bone in which it is implanted may advantageously have a standard thread, while a screw loaded axially toward the bone in which it is implanted may advantageously have an inverted thread. A screw that may experience multi-axial loading and/or off-loading conditions may advantageously include at least one standard thread and at least one inverted thread in order to increase bone fixation and load sharing between a bone/fastener interface during multi-axial and off-loading conditions to reduce high bone strain and distribute multi- axial forces applied to the bone in a load-sharing, rather than load-bearing, configuration. Shear loads and/or bending moments may also be optimally resisted with any chosen combination of threading, threading morphology, and/or threading variations contemplated herein to optimally resist shear loads, bending moments, multi-axial loading, off-loading conditions, etc.

[00195] In some embodiments, fasteners with standard threads may be used in conjunction with fasteners with inverted threads in order to accommodate different loading patterns.

[00196] In some embodiments, a single fastener may have both standard and inverted threads, like the fastener 100. Such a combination of threads may help the fastener 100 remain in place with unknown and/or varying loading patterns.

[00197] In some embodiments, the geometry of the threading of a fastener (with standard and/or inverted threads) may be varied to suit the fastener for a particular loading scheme. For example, the number of threads, the number of thread starts, the pitch of the threading, the lead(s) of the threading, the shape(s) of the threading, any dimension(s) associated with the threading (e.g., any length(s)/width(s)/height(s), etc., associated with the threading), the major diameter(s), the minor diameter(s), any angulation/angles associated with any surfaces of the threading, the “handedness” of the threading (e.g., right-handed vs. left-handed), etc., may be varied accordingly to suit any specific medium of installation, loading pattern, desired radial loading force, pull-out strength, application, procedure, etc., that may be involved.

[00198] In some embodiments, the material(s) of any portion of a fastener described herein may include, but are not limited to: metals (e.g., titanium, cobalt, stainless steel, etc.), metal alloys, plastics, polymers, PEEK, UHMWPE, composites, additive particles, textured surfaces, biologies, biomaterials, bone, etc.

[00199] In some embodiments, any of the fasteners described herein may include additional features such as: self-tapping features, locking features (e.g., locking threading formed on a portion of the fastener, such as threading located on or near a head of the fastener), cannulation, any style of fastener head (or no fastener head at all), any style of torque connection interface (or no torque connection interface at all), etc.

[00200] In some embodiments, a tap (not shown) may be utilized to pre-form threading in a bone according to any threading shape that is disclosed or contemplated herein. In this manner, taps with any suitable shape may be utilized in conjunction with any fastener described or contemplated herein to match or substantially match the threading geometry of a given fastener.

[00201] In some embodiments, a minor diameter of the fastener may be selected to match, or substantially match, a diameter of a pilot hole that is formed in a bone to avoid bone blowout when the fastener is inserted into the pilot hole, as will be discussed in more detail below.

[00202] Additionally, or alternatively thereto, the type of threads and/or thread geometry may be varied based on the type of bone in which the fastener is to be anchored. For example, fasteners anchored in osteoporotic bone may fare better with standard or inverted threads, or when the pitch, major diameter, and/or minor diameter are increased or decreased, or when the angulation of thread surfaces is adjusted, etc.

[00203] In some embodiments, a surgical kit may include multiple fasteners with any of the different fasteners and thread options described or contemplated herein. The surgeon may select the appropriate fastener(s) from the kit based on the particular loads to be applied and/or the quality of bone in which the fastener(s) are to be anchored.

[00204] Continuing with FIG. ID, in some embodiments the first helical thread 110 may include a plurality of first undercut surfaces 111, a plurality of second undercut surfaces 112, a plurality of third undercut surfaces 113, and a plurality of fourth open surfaces 114.

[00205] In some embodiments, the second helical thread 120 may include a plurality of fifth undercut surfaces 125, a plurality of sixth undercut surfaces 126, a plurality of seventh undercut surfaces 127, and a plurality of eighth open surfaces 128. [00206] In some embodiments one or more of the plurality of first undercut surfaces 111, the plurality of second undercut surfaces 112, the plurality of third undercut surfaces 113, the plurality of fourth open surfaces 114, the plurality of fifth undercut surfaces 125, the plurality of sixth undercut surfaces 126, the plurality of seventh undercut surfaces 127, and the plurality of eighth open surfaces 128 may comprise at least one flat or substantially flat surface.

[00207] In some embodiments, the plurality of first undercut surfaces 111, the plurality of third undercut surfaces 113, the plurality of sixth undercut surfaces 126, and the plurality of eighth open surfaces 128 may be angled towards the distal end 102 of the shaft 105.

[00208] In some embodiments, the plurality of second undercut surfaces 112, the plurality of fourth open surfaces 114, the plurality of fifth undercut surfaces 125, and the plurality of seventh undercut surfaces 127 may be angled towards the proximal end 101 of the shaft 105.

[00209] In some embodiments, when the fastener 100 is viewed in section along a plane that intersects the longitudinal axis 103 of the shaft 105 (as shown in FIG. ID), the first helical thread 110 may include at least one chevron shape that is oriented toward (i.e., points toward) the distal end 102 of the shaft 105. Likewise, the second helical thread 120 may also include at least one chevron shape that is oriented toward (i.e., points toward) the proximal end 101 of the shaft 105.

[00210] In some embodiments, when the fastener 100 is viewed in section along a plane that intersects the longitudinal axis 103 of the shaft 105 (as shown in FIG. ID), the first helical thread 110 may include a first plurality of chevron shapes that are oriented toward (i.e., point toward) the distal end 102 of the shaft 105. Likewise, the second helical thread 120 may include a second plurality of chevron shapes that are oriented toward (i.e., point toward) the proximal end 101 of the shaft 105.

[00211] In some embodiments, the first plurality of chevron shapes and the second plurality of chevron shapes may be arranged in alternating succession along the shaft 105 of the fastener 100, (e.g., see FIG. ID).

[00212] In some embodiments, a plurality of first interlocking spaces 161 and a plurality of second interlocking spaces 162 may be formed between the first helical thread 110 and the second helical thread 120 along the shaft 105 of the fastener 100.

[00213] In some embodiments, the plurality of first interlocking spaces 161 may be formed intermediate the first concave undercut surfaces 131 and the second concave undercut surfaces 132.

[00214] In some embodiments, the plurality of second interlocking spaces 162 may be formed intermediate the first convex undercut surfaces 141 and the second convex undercut surfaces 142.

[00215] In some embodiments, the plurality of first interlocking spaces 161 may be larger in size than the plurality of second interlocking spaces.

[00216] In some embodiments, the plurality of first interlocking spaces 161 and the plurality of second interlocking spaces 162 may be shaped and/or configured to interlock with bone/other tissues received therein to increase fixation of the fastener 100 within the bone/other tissues and provide additional resistance against multi-axial forces that may be applied to the fastener 100 and/or the bone/other tissues.

[00217] In some embodiments, the plurality of second undercut surfaces 112 and the plurality of sixth undercut surfaces 126 may be angled toward each other to trap bone/other tissues within the plurality of first interlocking spaces 161 in order to increase fixation and resistance against multi-axial forces.

[00218] In some embodiments, the plurality of third undercut surfaces 113 and the plurality of seventh undercut surfaces 127 may be angled toward each other to trap bone/other tissues within the plurality of second interlocking spaces 162 in order to increase fixation and resistance against multi- axial forces.

[00219] In some embodiments, the plurality of first undercut surfaces 111 and the plurality of fifth undercut surfaces 125 may each form an angle a with respect to the longitudinal axis 103 of the shaft 105, as shown in FIG. ID.

[00220] In some embodiments, the angle a may be greater than 90 degrees.

[00221] In some embodiments, the plurality of second undercut surfaces 112 and the plurality of sixth undercut surfaces 126 may each form an angle (3 with respect to the longitudinal axis 103 of the shaft 105.

[00222] In some embodiments, the angle (3 may be less than 90 degrees.

[00223] In some embodiments, the plurality of third undercut surfaces 113 and the plurality of seventh undercut surfaces 127 may each form an angle 0 with respect to the longitudinal axis 103 of the shaft 105.

[00224] In some embodiments, the angle 0 may be approximately 90 degrees.

[00225] In some embodiments, the angle 0 may be greater than 90 degrees.

[00226] It will be understood that the fastener 100 may include any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. Moreover, it will also be understood that the fastener 100 may be utilized in conjunction with (or within) any system, method, or instrumentation described or contemplated herein.

[00227] FIGS. 2A-2D illustrate various views of a polyaxial screw, pedicle bone fastener, or fastener 200, according to another embodiment of the present disclosure. Specifically, FIG. 2A is a front perspective view of the fastener 200, FIG. 2B is a rear perspective view of the fastener 200, FIG. 2C is a side view of the fastener 200, and FIG. 2D is a cross-sectional side view of the fastener 200 taken along the line B-B in FIG. 2C. The fastener 200 may include a shaft 205 having a proximal end 201, a distal end 202, and a longitudinal axis 203. The fastener 200 may also include a polyaxial head 204 having a first semi-spherical surface 221 located at the proximal end 201 of the shaft 205, a torque connection interface 206 formed in/on the polyaxial head 204, and a self-tapping feature 207 formed in the distal end 202 of the shaft 205. In some embodiments, the fastener 200 may include a first helical thread 210 disposed about the shaft 205, and a second helical thread 220 disposed about the shaft 205 adjacent the first helical thread 210. In these embodiments, the fastener 200 may comprise a “dual start” or “dual lead” thread configuration. However, it will also be understood that the fastener 200 may include any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. Moreover, it will also be understood that the fastener 200 may be utilized in conjunction with (or within) any system, method, or instrumentation described or contemplated herein.

[00228] FIGS. 4A-4D illustrate various views of a polyaxial screw, pedicle bone fastener, or fastener 400, according to another embodiment of the present disclosure. Specifically, FIG. 4A is a front perspective view of the fastener 400, FIG. 4B is a rear perspective view of the fastener 400, FIG. 4C is a side view of the fastener 400, and FIG. 4D is a cross-sectional side view of the fastener 400 taken along the line D-D in FIG. 4C. The fastener 400 may include a shaft 405 having a proximal end 401, a distal end 402, and a longitudinal axis 403. The fastener 400 may also include a polyaxial head 404 having a first semi-spherical surface 421 located at the proximal end 401 of the shaft 405, a torque connection interface 406 formed in/on the polyaxial head 404, and a self-tapping feature 407 formed in the distal end 402 of the shaft 405. In some embodiments, the fastener 400 may include a single helical thread 410 disposed about the shaft 405, as shown in FIG. 4D. In some embodiments, the fastener 400 may comprise a “single start” or “single lead” thread configuration having a standard orientation, as shown in FIG. 4D. However, it will also be understood that the fastener 400 may include any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. Moreover, it will also be understood that the fastener 400 may be utilized in conjunction with (or within) any system, method, or instrumentation described or contemplated herein. [00229] FIGS. 5A-5D illustrate various views of a polyaxial screw, pedicle bone fastener, or fastener 500, according to another embodiment of the present disclosure. Specifically, FIG. 5A is a front perspective view of the fastener 500, FIG. 5B is a rear perspective view of the fastener 500, FIG. 5C is a side view of the fastener 500, and FIG. 5D is a cross-sectional side view of the fastener 500 taken along the line E-E in FIG. 5C. The fastener 500 may include a shaft 505 having a proximal end 501, a distal end 502, and a longitudinal axis 503. The fastener 500 may also include a polyaxial head 504 having a first semi-spherical surface 521 located at the proximal end 501 of the shaft 505, a torque connection interface 506 formed in/on the polyaxial head 504, and a self-tapping feature 507 formed in the distal end 502 of the shaft 505. In some embodiments, the fastener 500 may include a single helical thread 510 disposed about the shaft 505, as shown in FIG. 5D. In some embodiments, the fastener 500 may comprise a “single start” or “single lead” thread configuration having an inverted orientation, as shown in FIG. 5D. However, it will also be understood that the fastener 500 may include any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. Moreover, it will also be understood that the fastener 500 may be utilized in conjunction with (or within) any system, method, or instrumentation described or contemplated herein. [00230] FIGS. 6A-6D illustrate various views of a polyaxial screw, pedicle bone fastener, or fastener 600, according to another embodiment of the present disclosure. Specifically, FIG. 6A is a front perspective view of the fastener 600, FIG. 6B is a rear perspective view of the fastener 600, FIG. 6C is a side view of the fastener 600, and FIG. 6D is a cross-sectional side view of the fastener 600 taken along the line F-F in FIG. 6C. The fastener 600 may include a shaft 605 having a proximal end 601, a distal end 602, and a longitudinal axis 603. The fastener 600 may also include a polyaxial head 604 having a first semi-spherical surface 621 located at the proximal end 601 of the shaft 605, a torque connection interface 606 formed in/on the polyaxial head 604, and a self-tapping feature 607 formed in the distal end 602 of the shaft 605. In some embodiments, the fastener 600 may include a first helical thread 610 disposed about the shaft 605, and a second helical thread 620 disposed about the shaft 605 adjacent the first helical thread 610. In these embodiments, the fastener 600 may comprise a “dual start” or “dual lead” thread configuration. In some embodiments, a dual start thread configuration may allow quicker insertion of the fastener 600 into bone/other tissues by requiring fewer rotations of the fastener 600 during insertion. In some embodiments, the first helical thread 610 and the second helical thread 620 may each comprise “standard” threading having a “standard” orientation, as shown in FIG. 6D. However, it will also be understood that the fastener 600 may include any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. Moreover, it will also be understood that the fastener 600 may be utilized in conjunction with (or within) any system, method, or instrumentation described or contemplated herein.

[00231] FIGS. 7A-7D illustrate various views of a polyaxial screw, pedicle bone fastener, or fastener 700, according to another embodiment of the present disclosure. Specifically, FIG. 7A is a front perspective view of the fastener 700, FIG. 7B is a rear perspective view of the fastener 700, FIG. 7C is a side view of the fastener 700, and FIG. 7D is a cross-sectional side view of the fastener 700 taken along the line G-G in FIG. 7C. The fastener 700 may include a shaft 705 having a proximal end 701, a distal end 702, and a longitudinal axis 703. The fastener 700 may also include a polyaxial head 704 having a first semi-spherical surface 721 located at the proximal end 701 of the shaft 705, a torque connection interface 706 formed in/on the polyaxial head 704, and a self-tapping feature 707 formed in the distal end 702 of the shaft 705. In some embodiments, the fastener 700 may include a first helical thread 710 disposed about the shaft 705, and a second helical thread 720 disposed about the shaft 705 adjacent the first helical thread 710. In these embodiments, the fastener 700 may comprise a “dual start” or “dual lead” thread configuration. This dual start thread configuration may allow quicker insertion of the fastener 700 into bone/ tissue by requiring fewer rotations of the fastener 700 during insertion. In some embodiments, the first helical thread 710 and the second helical thread 720 may each comprise “inverted” threading having an “inverted” orientation, as shown in FIG. 7D. However, it will be understood that the fastener 700 may include any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. Moreover, it will also be understood that the fastener 700 may be utilized in conjunction with (or within) any system, method, or instrumentation described or contemplated herein.

[00232] FIGS. 8A and 8B illustrate various views of a pedicle bone fastener or fastener 800, according to another embodiment of the present disclosure. Specifically, FIG. 8A is a front perspective view of the fastener 800, and FIG. 8B is a rear perspective view of the fastener 800.

[00233] The fastener 800 may generally include a shaft 805 having a proximal end 801, a distal end 802, a helical thread 810, and self-tapping feature 807. The fastener 800 may also include an integrated attachment feature, such as an integrated tulip 840 located at the proximal end 801 of the shaft 805, and a torque connection interface 806 within the integrated tulip 840.

[00234] In some embodiments, at least a portion of a minor diameter of the shaft 805 and/or a major diameter of the helical thread 810 may be constant to help prevent bone blowout during insertion of the bone fastener, as will be discussed below in more detail.

[00235] The fastener 800 may also include a helical thread 810 disposed about the shaft 805. In some embodiments, the helical thread 810 may comprise standard threading. In some embodiments, the helical thread 810 may comprise inverted threading. However, it will be understood that the fastener 800 may include any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. For example, in some embodiments the helical thread 810 may comprise a first helical thread with standard or inverted threading comprising a first concave undercut surface, and the fastener 800 may also include a second helical thread (not shown) with standard or inverted threading adjacent the first helical thread comprising a second concave undercut surface, forming a “dual start” thread configuration. Moreover, it will also be understood that the fastener 800 may be utilized in conjunction with (or within) any system, method, or instrumentation described or contemplated herein.

[00236] In some embodiments, the integrated tulip 840 may include at least one opening 843 formed through one or more sides of the integrated tulip 840.

[00237] In some embodiments, the integrated tulip 840 may include two openings formed through opposing sides of the integrated tulip 840.

[00238] In some embodiments, the at least one opening 843 may be configured to receive at least a part of a spinal stabilization implement therethrough.

[00239] In some embodiments, the spinal stabilization implement may comprise a spinal stabilization rod or rod (e.g., see rod 930 shown in FIG. 9B).

[00240] In some embodiments, the integrated tulip 840 may be configured to adjustably secure at least a part of the spinal stabilization implement to the integrated tulip 840 through the at least one opening 843.

[00241] In some embodiments, the integrated tulip 840 may include a locking member opening 855 configured to receive a locking member therein (e.g., see locking member 950 shown in FIG. 9A). [00242] In some embodiments, the locking member may be configmed to secure at least a part of the spinal stabilization rod received through the at least one opening 843 of the integrated tulip 840.

[00243] FIGS. 9A-9F illustrate various views of a pedicle fastener stabilization system, according to an embodiment of the present disclosure. Specifically, FIG. 9A illustrates an exploded view of the pedicle fastener stabilization system, FIG. 9B shows the pedicle fastener stabilization system of FIG. 9A assembled together (including a spinal stabilization rod), FIG. 9C illustrates a top perspective view of a discrete tulip or tulip 940 of the pedicle fastener stabilization system shown in FIG. 9A, FIG. 9D illustrates a bottom perspective view of the tulip 940, FIG. 9E illustrates a side view of the tulip 940, and FIG. 9F illustrates a cross-sectional side view of the tulip 940 taken along the line H-H shown in FIG. 9E.

[00244] As shown in FIG. 9A, the pedicle fastener stabilization system may generally include a pedicle bone fastener or fastener 900, the tulip 940, and the locking member 950. In some embodiments, the pedicle fastener stabilization system may also include a spinal stabilization rod or rod 930 that may be securable to the tulip 940 (see FIG. 9B).

[00245] The fastener 900 may generally include a shaft 905 having a proximal end 901, a distal end 902, and a longitudinal axis 903. The fastener 900 may also include a helical thread 910 disposed about the shaft 905 along the longitudinal axis 903 between the proximal and distal ends 901, 902 of the shaft 905. The fastener 900 may also include an integrated attachment feature located at the proximal end 901 of the shaft 905 , such as a poly axial head 904 having a first semi-spherical surface 921. The fastener 900 may additionally include a torque connection interface 906 formed in/on the polyaxial head 904 and a self-tapping feature 907 formed in the distal end 902 of the shaft 905.

[00246] In some embodiments, the helical thread 910 may comprise standard threading. In some embodiments, the helical thread 910 may comprise inverted threading. However, it will be understood that the fastener 900 may include any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. For example, in some embodiments the helical thread 910 may comprise a first helical thread with standard or inverted threading comprising a first concave undercut surface, and the fastener 900 may also include a second helical thread (not shown) with standard or inverted threading adjacent the first helical thread comprising a second concave undercut surface, forming a “dual start” thread configuration. Moreover, it will also be understood that the fastener 900 may be utilized in conjunction with (or within) any system, method, or instrumentation described or contemplated herein.

[00247] In some embodiments, the polyaxial head 904 at the proximal end of the shaft 905 may be configured to be polyaxially -adjustably secured to a spinal stabilization implement.

[00248] In some embodiments, the spinal stabilization implement may comprise the tulip 940.

[00249] In some embodiments, the tulip 940 may include a second semi-spherical surface 922 that may be configured to engage the first semi-spherical surface 921 of the polyaxial head 904 to polyaxially-adjustably secure the tulip 940 to the polyaxial head 904 at any of a variety of relative orientations.

[00250] In some embodiments, the tulip 940 may include at least one opening 943 formed through one or more sides of the tulip 940.

[00251] In some embodiments, the tulip 940 may include two openings formed through opposing sides of the tulip 940.

[00252] In some embodiments, the at least one opening 943 may be configured to receive at least a part of a spinal stabilization rod or rod 930 therethrough, as shown in FIG. 9B.

[00253] In some embodiments, the tulip 940 may also include a locking member opening 955 configured to receive the locking member 950 therein.

[00254] In some embodiments, the tulip 940 may be configured to adjustably secure at least a part of the rod 930 to the tulip 940 by tightening the locking member 950 to compress the rod 930 between the tulip 940 and the locking member 950, as shown in FIG. 9B.

[00255] The fastener 900 may comprise any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a vertebra, or within any other bone/tissue. Moreover, it will also be understood that the fastener 900 may be utilized in conjunction with (or within) any system, method, or instrumentation described or contemplated herein.

[00256] FIG. 10A illustrates a top view of a vertebral body 980 with the pedicle fastener stabilization system of FIG. 9A inserted into the pedicles 982 of the vertebral body 980, and FIG. 10B illustrates a cross-sectional side view of the vertebral body 980 of FIG. 10A.

[00257] In some embodiments, a method of implanting a polyaxial bone fastener assembly (e.g., such as the pedicle fastener stabilization system shown in FIGS. 9A-10B, or the bone fastener assembly shown in FIGS. 12A-12F, etc.) may generally include: (1) inserting a bone fastener into a bone, (2) adjusting an orientation of an implement to a selected orientation relative to an attachment feature of the bone fastener, and (3) attaching the implement to the attachment feature at the selected orientation. [00258] In some embodiments, the bone fastener may include a shaft, a helical thread, and the attachment feature.

[00259] In some embodiments, the shaft may include a proximal end, a distal end, a longitudinal axis, and the helical thread disposed about the shaft along the longitudinal axis between the proximal and distal ends of the shaft.

[00260] In some embodiments, at least a portion of a minor diameter and/or a major diameter of the shaft/helical thread(s) may be constant to help prevent bone blowout during insertion of the bone fastener, as will be discussed below in more detail.

[00261] In some embodiments, the helical thread may include a first undercut surface and a second undercut surface. [00262] In some embodiments, the first undercut surface may be angled toward one of the proximal end and the distal end of the shaft, and the second undercut surface may be angled toward the other one of the proximal end and the distal end of the shaft. However, it will be understood that the bone fastener may include any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. For example, in some embodiments the bone fastener may comprise a first helical thread with standard or inverted threading, as well as a second helical thread with standard or inverted threading adjacent the first helical thread in a “dual start” thread configuration, etc.

[00263] In some embodiments, the attachment feature may be disposed at the proximal end of the shaft and configured to be adjustably secured to the implement.

[00264] In some embodiments, the attachment feature may be configured to be polyaxially- adjustably secured to the implement.

[00265] In some embodiments, the attachment feature may be coupled to the bone fastener or to the shaft of the bone fastener.

[00266] In some embodiments, adjusting the orientation of the implement to the selected orientation relative to the attachment feature may comprise polyaxially adjusting the orientation of the implement to a selected relative orientation, of a plurality of polyaxially -differentiated potential relative orientations, relative to the attachment feature.

[00267] In some embodiments, the attachment feature may be integrally formed with the bone fastener or the shaft of the bone fastener.

[00268] In some embodiments, the attachment feature may include a polyaxial head having a first semi-spherical surface and the implement may include a discrete tulip having a second semi-spherical surface configured to engage the first semi-spherical surface of the polyaxial head to polyaxially- adjustably secure the discrete tulip to the polyaxial head at any of a variety of relative orientations. For example, the second semi-spherical surface of the discrete tulip may be polyaxially adjusted to a selected orientation (of a plurality of polyaxially -differentiated potential relative orientations) relative to the first semi-spherical surface of the polyaxial head, and the discrete tulip may then be attached to the polyaxial head at the selected relative orientation.

[00269] In some embodiments, the discrete tulip may comprise at least one opening and a locking member configured to secure a rod received through the at least one opening to the discrete tulip at the selected relative orientation.

[00270] In some embodiments, the attachment feature may include a polyaxial head having a first semi-spherical surface, and the implement may include a radial head component having a second semi- spherical surface configured to engage the first semi-spherical surface and permit polyaxial articulation of the radial head component with respect to the polyaxial head, as will be discussed in more detail below with respect to FIGS. 12A-12F. However, in some embodiments the attachment feature may include a head that may rigidly couple with a radial head component, as will be discussed in more detail below with respect to FIGS. 14A-14I.

[00271] In some embodiments, the method may also include drilling a pilot hole (not shown) into the bone and inserting the shaft of the bone fastener into the pilot hole.

[00272] In some embodiments, the method may also include tapping (not shown) one or more bone threads in the bone to form one or more tapped bone threads about the pilot hole and inserting the helical thread(s) into the one or more tapped bone threads.

[00273] Bone blowout can occur when a bone fastener is inserted into a bone and generates a sufficient outwardly directed radial force on the bone to cause bone blowout due to the size/morphology of the bone fastener and/or the size/morphology of the bone hole receiving the bone fastener.

[00274] In some embodiments, a method of preventing bone blowout may generally include forming a hole in a bone (not shown), the hole having a bone hole diameter, and inserting a bone fastener into the hole having a minor diameter that is not greater than 5% larger the bone hole diameter. In this manner, an outwardly directed radial force applied to the bone by the minor diameter of the fastener may be reduced to prevent bone blowout.

[00275] In some embodiments, the shaft may include a proximal end, a distal end, and a longitudinal axis with at least one helical thread disposed about the shaft along the longitudinal axis between the proximal and distal ends of the shaft.

[00276] In some embodiments, at least a portion of the minor diameter of the shaft may be constant to help prevent bone blowout during insertion of the bone fastener. For example, a main portion of a bone fastener may exclude a pointed tip portion of the bone fastener (e.g., see the main portion 986 and the pointed tip portion 984 of the fastener 900 in FIG. 10B, as one non-limiting example). Moreover, in some embodiments, a main portion of a bone fastener may exclude a proximal portion of the bone fastener that may or may not be fully inserted into the bone (e.g., see the proximal portion 988 of the fastener 900 in FIG. 10B, as one non-limiting example). Thus, in some embodiments a minor diameter of a main portion of a bone fastener may be constant (e.g., see the minor diameter 960 of the main portion of the fastener 900 in FIG. 10B which is constant, as one non-limiting example).

[00277] In some embodiments, at least a portion of the major diameter of a fastener may also be constant to help prevent bone blowout from the threading of the bone fastener during insertion (e.g., see the major diameter 965 of the main portion of the fastener 900 in FIG. 10B which is constant, as one non-limiting example).

[00278] In some embodiments, the helical thread may include a first undercut surface and a second undercut surface.

[00279] In some embodiments, the first undercut surface may be angled toward one of the proximal end and the distal end of the shaft, and the second undercut surface may be angled toward the other one of the proximal end and the distal end of the shaft. However, it will be understood that the bone fastener may include any thread configmation, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. For example, in some embodiments the bone fastener may comprise a first helical thread with standard or inverted threading, as well as a second helical thread with standard or inverted threading adjacent the first helical thread in a “dual start” thread configuration, etc.

[00280] In some embodiments, the minor diameter of at least a main portion of the shaft may be greater than the bone hole diameter. For example, the minor diameter of at least a main portion of the shaft may be greater than the bone hole diameter, but not greater than 5% larger the bone hole diameter. [00281] In some embodiments, the minor diameter of at least a main portion of the shaft may not be greater than the bone hole diameter.

[00282] In some embodiments, the minor diameter of at least a main portion of the shaft may be equal to the bone hole diameter.

[00283] In some embodiments, the minor diameter of at least a main portion of the shaft may be less than the bone hole diameter.

[00284] In some embodiments, the minor diameter of the main portion of the shaft may be between 0mm and 0.1mm less than the bone hole diameter.

[00285] In some embodiments, the minor diameter of the main portion of the shaft may be at least 0.1mm less than the bone hole diameter.

[00286] In some embodiments, the minor diameter of the main portion of the shaft may be between 0.1mm and 0.2mm less than the bone hole diameter.

[00287] In some embodiments, the minor diameter of the main portion of the shaft may be at least 0.2mm less than the bone hole diameter.

[00288] However, it will be understood that at least a portion of the minor diameter of the shaft may any size that is less than, equal to, or greater than the bone hole diameter.

[00289] In these embodiments, the unique morphology of the thread designs disclosed herein allow for “over-drilling” a given bone hole to create a bone hole diameter that is equal to or greater than the minor diameter of at least a main portion of the shaft, while maintaining good bone purchase and loading characteristics provided by the unique morphology of the thread designs disclosed herein. In this manner, an over-drilled bone hole in combination with a smaller minor diameter and the unique morphology of the thread designs disclosed herein can achieve a lower radial outward load force that is placed on the bone by the minor diameter of the shaft in order to prevent bone blowout. This is in contrast to typical procedures that “under-drill” bone holes and rely on bone compaction by fasteners with larger minor diameters than the bone hole diameter in order to achieve sufficient bone purchase. However, this will result in higher radial outward load forces placed on the bone by the larger minor diameter of the shaft, thus increasing the risk of bone blowout. [00290] In some embodiments, the method may also include tapping (not shown) one or more bone threads in the bone to form one or more tapped bone threads about the hole in the bone, and then inserting the helical thread(s) into the one or more tapped bone threads to further reduce an outwardly directed radial force applied to the bone by the helical thread(s) as the bone fastener is inserted into the bone.

[00291] FIGS. 11 A-l ID illustrate various views of a threaded stem, bone fastener, or fastener 1100, according to another embodiment of the present disclosure. Specifically, FIG. 11 A is a front perspective view of the fastener 1100, FIG. 1 IB is a rear perspective view of the fastener 1100, FIG. 11C is a side view of the fastener 1100, and FIG. 1 ID is a cross-sectional side view of the fastener 1100 taken along the line I-I shown in FIG. 11C.

[00292] The fastener 1100 may generally include a shaft 1105 having a proximal end 1101, a distal end 1102, a longitudinal axis 1103, a helical thread 1110 disposed about the shaft 1105 along the longitudinal axis 1103, a head 1104, and a torque connection interface 1106 formed in/on the head 1104.

[00293] In some embodiments, the fastener 1100 may include the helical thread 1110 disposed about the shaft 1105 in a “single start” or “single lead” thread configuration having standard or inverted threading.

[00294] In some embodiments, the helical thread 1110 may include a first undercut surface, a second undercut surface, a third undercut surface, and a fourth open surface.

[00295] In some embodiments, the first undercut surface and the third undercut surface may be angled towards one of the proximal end 1101 and the distal end 1102 of the shaft 1105, and the second undercut surface and the fourth open surface may be angled towards the other one of the proximal end 1101 and the distal end 1102 of the shaft 1105.

[00296] However, it will be understood that the fastener 1100 may include any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. For example, in some embodiments the helical thread 1110 may comprise a first helical thread with standard or inverted threading, and the fastener 1100 may also include a second helical thread (not shown) with standard or inverted threading adjacent the first helical thread, forming a “dual start” thread configuration, etc. Moreover, it will also be understood that the fastener 1100 may be utilized in conjunction with (or within) any system, method, or instrumentation described or contemplated herein.

[00297] In some embodiments, at least a portion of the fastener 1100 may be sized, shaped, and configured for use within an intramedullary canal (IMC) of a bone. For example, in some embodiments the fastener 1100 may be sized, shaped, and configured for use within an IMC as a transfemoral stem (or transfemoral stem abutment), a humeral stem, a tibial stem, etc. However, it will also be understood that the fastener 1100 may be sized, shaped, and configured for use within any IMC of any bone, and/or for any other suitable procedure or application outside of an IMC of a bone.

[00298] In some embodiments, the fastener 1100 may include a minor diameter 1160 and a major diameter 1165, as shown in FIG. 1 ID.

[00299] In some embodiments, a ratio of the major diameter 1165 to the minor diameter 1160 may be less than 1.50.

[00300] In some embodiments, a ratio of the major diameter 1165 to the minor diameter 1160 may be less than 1.25.

[00301] In some embodiments, a ratio of the major diameter 1165 to the minor diameter 1160 may be less than 1.10.

[00302] In some embodiments, a ratio of the major diameter 1165 to the minor diameter 1160 may be less than 1.05.

[00303] In some embodiments, at least a portion of the minor diameter 1160 of the shaft 1105 may be constant to help prevent bone blowout during insertion of the fastener 1100.

[00304] In some embodiments, at least a portion of the major diameter 1165 of the shaft 1105 may be constant to help prevent bone blowout during insertion of the fastener 1100.

[00305] FIGS. 12A-12F illustrate various views of a threaded stem, bone fastener, or fastener 1200, according to another embodiment of the present disclosure. Specifically, FIG. 12A is a front perspective view of the fastener 1200, FIG. 12B is a rear perspective view of the fastener 1200, FIG. 12C is a side view of the fastener 1200, FIG. 12D is a cross-sectional side view of the fastener 1200 taken along the line J-J shown in FIG. 12C, FIG. 12E is a perspective side view of the fastener 1200 coupled to a radial head component 1220, and FIG. 12F shows a system/kit 1250 including the fastener 1200.

[00306] The fastener 1200 may generally include a shaft 1205 having a proximal end 1201, a distal end 1202, a longitudinal axis 1203, a helical thread 1210, a polyaxial head 1204, a torque connection interface 1206 formed in/on the polyaxial head 1204, and one or more self-tapping features 1207.

[00307] In some embodiments, the fastener 1200 may include the helical thread 1210 disposed about the shaft 1205 in a “single start” or “single lead” thread configuration having a standard or inverted orientation.

[00308] In some embodiments, the helical thread 1210 may include a first undercut surface and a second undercut surface.

[00309] In some embodiments, the first undercut surface may be angled toward one of the proximal end 1201 and the distal end 1202 of the shaft 1205, and the second undercut surface may be angled toward the other one of the proximal end 1201 and the distal end 1202 of the shaft 1205.

[00310] In some embodiments, the helical thread 1210 may include a first undercut surface, a second undercut surface, a third undercut surface, and a fourth open surface. [00311] In some embodiments, the first undercut surface and the third undercut surface may be angled towards one of the proximal end 1201 and the distal end 1202 of the shaft 1205, and the second undercut surface and the fourth open surface may be angled towards the other one of the proximal end 1201 and the distal end 1202 of the shaft 1205.

[00312] However, it will be understood that the fastener 1200 may include any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. For example, in some embodiments the helical thread 1210 may comprise a first helical thread with standard or inverted threading, and the fastener 1200 may also include a second helical thread (not shown) with standard or inverted threading adjacent the first helical thread, forming a “dual start” thread configuration, etc. Moreover, it will also be understood that the fastener 1200 may be utilized in conjunction with (or within) any system, method, or instrumentation described or contemplated herein.

[00313] In some embodiments, at least a portion of the fastener 1200 may be sized, shaped, and configured for use within an IMC of a bone. For example, in some embodiments the fastener 1200 may be sized, shaped, and configured for use within an IMC of a radial bone as a threaded radial stem, etc. However, it will also be understood that the fastener 1200 may be sized, shaped, and configured for use within any IMC of any bone, and/or for any other suitable procedure or application outside of an IMC of a bone.

[00314] In some embodiments, the fastener 1200 may include a minor diameter 1260 and a major diameter 1265, as shown in FIG. 12D.

[00315] In some embodiments, a ratio of the major diameter 1265 to the minor diameter 1260 may be less than 1.50.

[00316] In some embodiments, a ratio of the major diameter 1265 to the minor diameter 1260 may be less than 1.25.

[00317] In some embodiments, a ratio of the major diameter 1265 to the minor diameter 1260 may be less than 1.10.

[00318] In some embodiments, a ratio of the major diameter 1265 to the minor diameter 1260 may be less than 1.05.

[00319] In some embodiments, at least a portion of the minor diameter 1260 of the shaft 1205 may be constant to help prevent bone blowout during insertion of the fastener 1200.

[00320] In some embodiments, at least a portion of the major diameter 1265 of the shaft 1205 may be constant to help prevent bone blowout during insertion of the fastener 1200.

[00321] In some embodiments, an attachment feature may be located at the proximal end 1201 of the shaft 1205 and configured to be adjustably secured to an implement, such as the radial head component 1220 or a glenoid component (not shown), etc. [00322] In some embodiments, the attachment feature may comprise a polyaxial head 1204 that may be coupled to, or integrally formed with, the proximal end 1201 of the shaft 1205.

[00323] In some embodiments, the polyaxial head 1204 may include a first semi-spherical surface 1221.

[00324] In some embodiments, the radial head component 1220 (or a glenoid component, etc.) may be coupled to the polyaxial head 1204 of the fastener 1200 for utilization in a radial head arthroplasty procedure, a glenoid procedure, etc.

[00325] In some embodiments, the radial head component 1220 may include a second semi- spherical surface 1222 configured to engage the first semi-spherical surface 1221 and permit polyaxial articulation of the radial head component 1220 with respect to the polyaxial head 1204.

[00326] In some embodiments, the radial head component 1220 may include a concave articulation surface 1224 configured to receive a convex articulation surface (not shown) to form a prosthetic joint. [00327] In some embodiments, a system/kit 1250 may comprise one or more drill bits 1230 of varying sizes to form pilot holes of varying size in a radial bone (not shown). The system/kit 1250 may also comprise one or more fasteners 1200 of varying size, one or more radial head components 1220 of varying size, and one or more couplers 1240 for coupling a radial head component 1220 to a fastener 1200, etc.

[00328] FIGS. 13 A-13D illustrate various views of a threaded stem, bone fastener, or fastener 1300, according to another embodiment of the present disclosure. Specifically, FIG. 13A is a front perspective view of the fastener 1300, FIG. 13B is a rear perspective view of the fastener 1300, FIG. 13C is a side view of the fastener 1300, and FIG. 13D is a cross-sectional side view of the fastener 1300 taken along the line K-K shown in FIG. 13C.

[00329] The fastener 1300 may generally include a shaft 1305 having a proximal end 1301, a distal end 1302, a longitudinal axis 1303, a helical thread 1310 disposed about the shaft 1305 along the longitudinal axis 1303, a head 1304, and a torque connection interface 1306 formed in/on the head 1304.

[00330] In some embodiments, the fastener 1300 may include the helical thread 1310 disposed about the shaft 1305 in a “single start” or “single lead” thread configuration having standard or inverted threading.

[00331] In some embodiments, the helical thread 1310 may include a first undercut surface and a second undercut surface.

[00332] In some embodiments, the first undercut surface may be angled toward one of the proximal end 1301 and the distal end 1302 of the shaft 1305, and the second undercut surface may be angled toward the other one of the proximal end 1301 and the distal end 1302 of the shaft 1305.

[00333] In some embodiments, the helical thread 1310 may include a first undercut surface, a second undercut surface, a third undercut surface, and a fourth open surface. [00334] In some embodiments, the first undercut surface and the third undercut surface may be angled towards one of the proximal end 1301 and the distal end 1302 of the shaft 1305, and the second undercut surface and the fourth open surface may be angled towards the other one of the proximal end 1301 and the distal end 1302 of the shaft 1305.

[00335] However, it will be understood that the fastener 1300 may include any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. For example, in some embodiments the helical thread 1310 may comprise a first helical thread with standard or inverted threading, and the fastener 1300 may also include a second helical thread (not shown) with standard or inverted threading adjacent the first helical thread, forming a “dual start” thread configuration, etc. Moreover, it will also be understood that the fastener 1300 may be utilized in conjunction with (or within) any system, method, or instrumentation described or contemplated herein.

[00336] In some embodiments, at least a portion of the fastener 1300 may be sized, shaped, and configured for use within an intramedullary canal (IMC) of a bone. For example, in some embodiments the fastener 1300 may be sized, shaped, and configured for use within an IMC as a transfemoral stem (or transfemoral stem abutment), a humeral stem, a tibial stem, etc. However, it will also be understood that the fastener 1300 may be sized, shaped, and configured for use within any IMC of any bone, and/or for any other suitable procedure or application outside of an IMC of a bone.

[00337] In some embodiments, the fastener 1300 may include a pin hole 1391 formed through the shaft 1305 of the fastener 1300. The pin hole 1391 may be configured to receive an anti-rotation pin 1390 therethrough. In this manner, the anti-rotation pin 1390 may prevent the fastener 1300 from rotating and/or loosening once the fastener 1300 has been implanted within a bone.

[00338] In some embodiments, the fastener 1300 may be utilized in a limb salvage procedure to prevent amputation and/or mitigate the need for additional amputation.

[00339] In some embodiments, the fastener 1300 may include an attachment feature 1395 that may be configured to removably couple with an implement, such as a prosthetic component (not shown). For example, the fastener 1300 may be inserted within an intramedullary canal of a long bone (e.g., a femur, a humerus, etc.). Once the fastener 1300 has achieved sufficient osseointegration within the long bone, another prosthetic component such as an abutment (not shown), etc., may be removably coupled to the fastener 1300 via the attachment feature 1395 and may extend outside the skin of the patient to connect with a prosthetic limb (e.g., a prosthetic arm, leg, foot, etc., not shown), as one non-limiting example.

[00340] In some embodiments, the fastener 1300 may include a minor diameter 1360 and a major diameter 1365, as shown in FIG. 13D.

[00341] In some embodiments, a ratio of the major diameter 1365 to the minor diameter 1360 may be less than 1.50. [00342] In some embodiments, a ratio of the major diameter 1365 to the minor diameter 1360 may be less than 1.25.

[00343] In some embodiments, a ratio of the major diameter 1365 to the minor diameter 1360 may be less than 1.10.

[00344] In some embodiments, a ratio of the major diameter 1365 to the minor diameter 1360 may be less than 1.05.

[00345] In some embodiments, at least a portion of the minor diameter 1360 of the shaft 1305 may be constant to help prevent bone blowout during insertion of the fastener 1300.

[00346] In some embodiments, at least a portion of the major diameter 1365 of the shaft 1305 may be constant to help prevent bone blowout during insertion of the fastener 1300.

[00347] FIGS. 14A-14F illustrate various views of a threaded stem, bone fastener, or fastener 1400, according to another embodiment of the present disclosure. Specifically, FIG. 14A is a front perspective view of the fastener 1400, FIG. 14B is a rear perspective view of the fastener 1400, FIG. 14C is a side view of the fastener 1400, FIG. 14D is a cross-sectional side view of the fastener 1400 taken along the line L-L shown in FIG. 14C. FIG. 14E is a front perspective view of a radial head component 1420 that may be utilized with the fastener 1400, FIG. 14F is a rear perspective view of the radial head component 1420, FIG. 14G is a side view of the radial head component 1420, FIG. 14H is a bottom view of the radial head component 1420, and FIG. 141 is a side view of an assembly comprising the radial head component 1420 and the fastener 1400.

[00348] The fastener 1400 may generally include a shaft 1405 having a proximal end 1401, a distal end 1402, a longitudinal axis 1403, a helical thread 1410, an attachment feature or head 1404, and a torque connection interface 1406 formed in/on the head 1404.

[00349] In some embodiments, the fastener 1400 may include the helical thread 1410 disposed about the shaft 1405 in a “single start” or “single lead” thread configuration having a standard or inverted orientation.

[00350] In some embodiments, the helical thread 1410 may include a first undercut surface and a second undercut surface.

[00351] In some embodiments, the first undercut surface may be angled toward one of the proximal end 1401 and the distal end 1402 of the shaft 1405, and the second undercut surface may be angled toward the other one of the proximal end 1401 and the distal end 1402 of the shaft 1405.

[00352] In some embodiments, the helical thread 1410 may include a first undercut surface, a second undercut surface, a third undercut surface, and a fourth open surface.

[00353] In some embodiments, the first undercut surface and the third undercut surface may be angled towards one of the proximal end 1401 and the distal end 1402 of the shaft 1405, and the second undercut surface and the fourth open surface may be angled towards the other one of the proximal end 1401 and the distal end 1402 of the shaft 1405. [00354] However, it will be understood that the fastener 1400 may include any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. For example, in some embodiments the helical thread 1410 may comprise a first helical thread with standard or inverted threading, and the fastener 1400 may also include a second helical thread (not shown) with standard or inverted threading adjacent the first helical thread, forming a “dual start” thread configuration, etc. Moreover, it will also be understood that the fastener 1400 may be utilized in conjunction with (or within) any system, method, or instrumentation described or contemplated herein.

[00355] In some embodiments, at least a portion of the fastener 1400 may be sized, shaped, and configured for use within an IMC of a bone. For example, in some embodiments the fastener 1400 may be sized, shaped, and configured for use within an IMC of a radial bone as a threaded radial stem, etc. However, it will also be understood that the fastener 1400 may be sized, shaped, and configured for use within any IMC of any bone, and/or for any other suitable procedure or application outside of an IMC of a bone.

[00356] In some embodiments, the fastener 1400 may include a minor diameter 1460 and a major diameter 1465, as shown in FIG. 14D.

[00357] In some embodiments, a ratio of the major diameter 1465 to the minor diameter 1460 may be less than 1.50.

[00358] In some embodiments, a ratio of the major diameter 1465 to the minor diameter 1460 may be less than 1.25.

[00359] In some embodiments, a ratio of the major diameter 1465 to the minor diameter 1460 may be less than 1.10.

[00360] In some embodiments, a ratio of the major diameter 1465 to the minor diameter 1460 may be less than 1.05.

[00361] In some embodiments, at least a portion of the minor diameter 1460 of the shaft 1405 may be constant to help prevent bone blowout during insertion of the fastener 1400.

[00362] In some embodiments, at least a portion of the major diameter 1465 of the shaft 1405 may be constant to help prevent bone blowout during insertion of the fastener 1400.

[00363] In some embodiments, the attachment feature, or head 1404, may be located at the proximal end 1401 of the shaft 1405 and configured to be adjustably secured to an implement, such as the radial head component 1420 or a glenoid component (not shown), etc.

[00364] In some embodiments, the head 1404 that may be coupled to, or integrally formed with, the proximal end 1401 of the shaft 1405.

[00365] In some embodiments, the head 1404 may include a neck portion 1412 and a projection portion 1414.

[00366] In some embodiments, the projection portion 1414 may comprise a disc shape. [00367] In some embodiments, the projection portion 1414 may also comprise one or more beveled surfaces 1416.

[00368] In some embodiments, the radial head component 1420 (or a glenoid component, etc.) may be coupled to the head 1404 of the fastener 1400 for utilization in a radial head arthroplasty procedure, a glenoid procedure, etc., as shown in FIG. 141.

[00369] In some embodiments, the radial head component 1420 may include a concave articulation surface 1424 that may be configured to receive a convex articulation surface (not shown) to form a prosthetic joint.

[00370] In some embodiments, the radial head component 1420 may include an attachment feature 1430.

[00371] In some embodiments, the attachment feature 1430 may include a window 1432 that may be sized and shaped to receive the head 1404 and neck portion 1412 of the fastener 1400 therein, as shown in FIG. 141.

[00372] In some embodiments, the attachment feature 1430 may also include one or more set screw holes 1436 configured to receive one or more set screws (not shown) to removably couple the radial head component 1420 to the fastener 1400.

[00373] FIGS. 15A-D illustrate various views of a femoral fixation device or femoral fastener 4300, according to another example of the present disclosure. Specifically, FIG. 15A is a rear perspective view of the femoral fastener 4300, FIG. 15B is a front perspective view of the femoral fastener 4300, FIG. 15C is a side view of the femoral fastener 4300, and FIG. 15D is a cross-sectional side view of the femoral fastener 4300 taken along the line B-B in FIG. 15C.

[00374] In general, the femoral fastener 4300 may include a shaft 4305 having a proximal end 4301, a distal end 4302, and a longitudinal axis 4303, as well as a helical thread 4310 disposed about at least a portion of the shaft 4305.

[00375] In some embodiments, the shaft 4305 of the femoral fastener 4300 may be cannulated with a through bore 4390.

[00376] In some embodiments, the through bore 4390 may include an internal thread 4380 formed along at least a portion of a length of the through bore 4390.

[00377] In some embodiments, the internal thread 4380 may be located toward the proximal end 4301 of the shaft 4305.

[00378] In some embodiments, the proximal end 4301 of the femoral fastener 4300 may comprise a headless fastener design having an at least partially cylindrical shape.

[00379] In some embodiments, the proximal end 4301 of the femoral fastener 4300 may include one or more recesses 4370 which may extend along the shaft from the proximal end 4301 of the shaft 4305 toward the distal end 4302 of the shaft 4305. [00380] In some embodiments, the one or more recesses 4370 may be shaped and configured to couple with an inserter tool to form a torque connection interface that may facilitate insertion of the femoral fastener 4300, as will be discussed in more detail below.

[00381] In some embodiments, the femoral fastener 4300 may include one or more self-tapping or bone cutting features formed in a distal portion of the femoral fastener 4300 (not shown).

[00382] In some embodiments, the helical thread 4310 may be disposed about the shaft 4305 along the longitudinal axis 4303 between a first location 4321 and a second location 4322 along the shaft 4305.

[00383] Although the femoral fastener 4300 shown in FIGS. 15A-15D illustrates a single helical thread design, it will be understood that the femoral fastener 4300 may include any number of threads and/or any number of thread characteristics, shapes, or configurations that are described or contemplated herein, in any combination. For example, the femoral fastener 4300 may include a “dual start” or “dual lead” thread configuration comprising a first helical thread and a second helical thread as previously described herein, etc.

[00384] In some embodiments, a depth of the helical thread 4310 with respect to the shaft 4305 may define a major diameter vs. a minor diameter of the shaft 4305 alone.

[00385] In some embodiments, the major diameter, the minor diameter, and/or a pitch of the helical thread 4310 may be constant or substantially constant along a length of the femoral fastener 4300.

[00386] In some embodiments, the helical thread 4310 may include one or more concave undercut surfaces 4331 and/or one or more convex undercut surfaces 4341.

[00387] In some embodiments, the one or more concave undercut surfaces 4331 may be angled towards one of the proximal end 4301 and the distal end 4302 of the shaft 4305.

[00388] In some embodiments, the one or more convex undercut surfaces 4341 may be angled towards the other one of the proximal end 4301 and the distal end 4302 of the shaft 4305.

[00389] In some embodiments, the one or more concave undercut surfaces 4331 may be angled towards the proximal end 4301 of the shaft 4305 and the one or more convex undercut surfaces 4341 may be angled towards the distal end 4302 of the shaft 4305.

[00390] In some embodiments, the one or more concave undercut surfaces 4331 and/or the one or more convex undercut surfaces 4341 may include a plurality of flat surfaces that are angled relative to each other.

[00391] In some embodiments, the helical thread 4310 may include one or more first undercut surfaces 4311 and one or more second undercut surfaces 4312.

[00392] In some embodiments, the one or more first undercut surfaces 4311 may be angled toward the proximal end 4301 of the shaft 4305 and one or more second undercut surfaces 4312 may be angled toward the distal end 4302 of the shaft 4305. [00393] In some embodiments, the helical thread 4310 may also include one or more third undercut surfaces 4313 and one or more fourth open surfaces 4314. However, it will be understood that in other embodiments the one or more third undercut surfaces 4313 and the one or more fourth open surfaces 4314 may be replaced with any other shaped surface or surfaces (e.g., any buttress type thread shape, any flat surface that is angled toward or away from the one or more concave undercut surfaces 4331, or angled 90 degrees with respect thereto, any curved surface that is generally oriented toward or away from the one or more concave undercut surfaces, etc.) without departing from the spirit or scope of the present disclosure.

[00394] In some embodiments, when the femoral fastener 4300 is viewed in section along a plane intersecting the longitudinal axis 4303 of the shaft 4305, the helical thread 4310 may include at least one chevron shape oriented toward the proximal end 4301 of the shaft 4305.

[00395] In some embodiments, when the femoral fastener 4300 is viewed in section along a plane intersecting the longitudinal axis 4303 of the shaft 4305, the helical thread 4310 may include a plurality of chevron shapes oriented toward the proximal end 4301 of the shaft 4305.

[00396] In some embodiments, when the femoral fastener 4300 is viewed in section along a plane intersecting the longitudinal axis 4303 of the shaft 4305, the helical thread 4310 may include at least one partial crescent shape oriented toward the proximal end 4301 or the distal end 4302 of the shaft 4305.

[00397] In some embodiments, when the femoral fastener 4300 is viewed in section along a plane intersecting the longitudinal axis 4303 of the shaft 4305, the helical thread 4310 may include a plurality of partial crescent shapes oriented toward the proximal end 4301 or the distal end 4302 of the shaft 4305.

[00398] In some embodiments, when the femoral fastener 4300 is implanted within a neck 4710 and a head 4720 of a femoral bone or femur 4700, the first location 4321, the second location 4322, and the helical thread 4310 extending therebetween may be disposed within the head 4720 of the femur 4700.

[00399] In some embodiments, when the femoral fastener 4300 is implanted within a neck 4710 and a head 4720 of a femur 4700, at least one of: the one or more concave undercut surfaces 4331, the one or more convex undercut surfaces 4341, the one or more first undercut surfaces 4311, the one or more second undercut surfaces 4312, the one or more third undercut surfaces 4313, and/or the one or more fourth open surfaces 4314 may be configured to transmit at least one force from the head 4720 of the femur 4700 to the neck 4710 (or other portion) of the femur 4700. In this manner, the unique shape and configuration of the helical thread 4310 can help mitigate or prevent loosening of the femoral fastener 4300 over time due to multi-axial forces and off-axis loading scenarios that may be applied to the femoral fastener 4300. [00400] In some embodiments, one or more interlocking spaces 4361 may be formed between adjacent thread portions of the helical thread 4310 along the shaft 4305 of the femoral fastener 4300.

[00401] In some embodiments, the one or more interlocking spaces 4361 may be shaped and/or configured to interlock with bone/other tissues received therein to increase fixation of the femoral fastener 4300 within the bone/other tissues and provide additional resistance against multi-axial forces that may be applied to the femoral fastener 4300 and/or the bone/other tissues.

[00402] In some embodiments, when the femoral fastener 4300 is viewed in section along a plane intersecting the longitudinal axis 4303 of the shaft 4305, the helical thread 4310 may include one or more bent shapes (comprising at least one surface that is angled relative to the longitudinal axis 4303 of the shaft 4305 and/or at least one undercut surface) with one or more intermediate portions 4351 that are oriented toward (i.e., point toward) one of the proximal end 4301 and the distal end 4302 of the shaft 4305.

[00403] In some embodiments, at least one of: the one or more concave undercut surfaces 4331, the one or more convex undercut surfaces 4341, the one or more first undercut surfaces 4311, the one or more second undercut surfaces 4312, the one or more third undercut surfaces 4313, and/or the one or more fourth open surfaces 4314 may comprise at least one substantially flat surface.

[00404] In some embodiments, at least one of: the one or more concave undercut surfaces 4331, the one or more convex undercut surfaces 4341, the one or more first undercut surfaces 4311, the one or more second undercut surfaces 4312, the one or more third undercut surfaces 4313, and/or the one or more fourth open surfaces 4314 may comprise at least one curved surface.

[00405] FIGS. 16A-D illustrate various views of a femoral support member 4400, according to an example of the present disclosure. Specifically, FIG. 16A is a perspective side view of the femoral support member 4400, FIG. 16B is another perspective side view of the femoral support member 4400, FIG. 16C is a front view of the femoral support member 4400, and FIG. 16D is a rear view of the femoral support member 4400.

[00406] In general, the femoral support member 4400 may include an elongate body having a proximal end 4401, a distal end 4402, a longitudinal axis 4403, and a barrel 4405.

[00407] In some embodiments, the femoral support member 4400 may comprise a bone plate.

[00408] In some embodiments, the femoral support member 4400 may comprise an intramedullary nail (not shown).

[00409] In some embodiments, the femoral support member 4400 may include one or more bone plate apertures 4434, one or more inferior support apertures 4432, one or more superior support apertures 4431, and/or one or more extension plate apertures 4436.

[00410] In some embodiments, the barrel 4405 may include a passageway 4410 formed therethrough having a first opening 4411 and a second opening 4412 opposite the first opening 4411. [00411] In some embodiments, the passageway 4410 may also include an internal thread 4414 and a barrel shoulder 4416 located adjacent the internal thread 4414.

[00412] In some embodiments, the barrel 4405 and/or the passageway 4410 may be formed through the femoral support member 4400 with a longitudinal axis 4408 at an angle 4409 with respect to the longitudinal axis 4403 of the femoral support member 4400, as shown in FIG. 19.

[00413] In some embodiments, the angle 4409 of the barrel 4405 and/or the passageway 4410 with respect to the longitudinal axis 4403 of the femoral support member 4400 may be an acute angle. However, it will also be understood that in some embodiments the angle 4409 may be a right angle and/or an obtuse angle.

[00414] FIGS. 17A-F illustrate various views of a stop member 4500, according to an example of the present disclosure. Specifically, FIG. 17A is a front view of the stop member 4500, FIG. 17B is a rear perspective view of the stop member 4500, FIG. 17C is a front perspective view of the stop member 4500, FIG. 17D is a side view of the stop member 4500, and FIGS. 17E and 17F are side views of the stop member 4500 including a stop member projection 4510 having a preselected length 4505.

[00415] In general, the stop member 4500 may include a proximal end 4501, a distal end 4502, and a longitudinal axis 4503.

[00416] In some embodiments, the stop member 4500 may include a torque connection interface 4530. In some embodiments, the torque connection interface 4530 may comprise a hexagonal shape. However, it will be understood that the torque connection interface 4530 may comprise any shape suitable for receiving a torque force from a driver tool, as will be discussed in more detail below.

[00417] In some embodiments, the stop member 4500 may include an external thread 4525.

[00418] In some embodiments, the stop member 4500 may include a stop member shoulder intermediate the external thread 4525 and the stop member projection 4510.

[00419] In some embodiments, the preselected length 4505 of the stop member projection 4510 may be zero.

[00420] In some embodiments, the preselected length 4505 of the stop member projection 4510 may be greater than zero.

[00421] In some embodiments, the preselected length 4505 of the stop member projection 4510 may be 3mm, 5mm, 10mm, etc., as some non-limiting examples of a preselected length 4505 that is greater than zero. However, it will be understood that any length greater than or equal to zero may be utilized for the preselected length 4505 of the stop member projection 4510.

[00422] FIGS. 18-22 illustrate various views of a femoral fixation assembly 4600 comprising the femoral support member 4400, the femoral fastener 4300, and the stop member 4500, according to an embodiment of the present disclosure. Specifically, FIG. 18 illustrates an exploded view of the femoral fixation assembly 4600; FIG. 19 illustrates a side view of the femoral fixation assembly 4600 after assembly; FIG. 20 illustrates a side view of the femoral fixation assembly 4600 implanted into a femur 4700; FIG. 21 illustrates a front view of the femoral fixation assembly 4600 and femur 4700 of FIG. 20; and FIG. 22 illustrates cross-sectional side view of the femoral fixation assembly 4600 and femur 4700 of FIG. 21 taken along the line C-C.

[00423] With reference to FIG. 22, when the femoral fastener 4300 is implanted within the neck 4710 and the head 4720 of the femur 4700, and the femoral support member 4400 is oriented with respect to a longitudinal axis of the femoral bone, at least a portion of the shaft 4305 of the femoral fastener 4300 may be slidingly received within the passageway 4410 of the barrel 4405 through the first opening 4411 of the passageway 4410.

[00424] In this manner, the femoral fastener 4300 may be allowed to slide further into the passageway 4410 of the barrel 4405 as the femur 4700 collapses due to the bone remodeling process, the healing process, continued use of the femur over time, etc.

[00425] However, it may be desirable to limit the amount of collapse that the femur 4700 may undergo. Accordingly, in some embodiments, the stop member 4500 may be inserted into the passageway 4410 in order to set a predetermined limit to the amount of collapse that the femur 4700 may be permitted to undergo.

[00426] In some embodiments, at least a portion of the stop member 4500 may be received within the passageway 4410 through the second opening 4412.

[00427] In some embodiments, the stop member 4500 may be inserted into the passageway 4410 and coupled thereto by engaging the external thread 4525 of the stop member 4500 with the internal thread 4380 of the femoral fastener 4300.

[00428] In some embodiments, a stop member shoulder 4520 of the stop member 4500 may be configured to abut against a barrel shoulder 4416 of the passageway 4410 when the stop member 4500 has been fully inserted into the passageway 4410.

[00429] In some embodiments, a space 4610 having a predetermined length 4605 may be formed within the passageway 4410 between the distal end 4502 of the stop member 4500 and the proximal end 4301 of the shaft 4305 based on the preselected length 4505 of the stop member projection 4510. The predetermined length 4605 of the space 4610 may define the amount of collapse that the femur 4700 may be permitted to undergo.

[00430] In some embodiments, the preselected length 4505 of the stop member projection 4510 may be selected such that the predetermined length 4605 of the space 4610 within the passageway 4410 may be zero. In these embodiments, the distal end 4502 of the stop member 4500 may abut against the proximal end 4301 of the femoral fastener 4300 to prevent collapse.

[00431] In some embodiments, the preselected length 4505 of the stop member projection 4510 may be selected such that the predetermined length 4605 of the space 4610 within the passageway 4410 may be greater than zero. In these embodiments, the predetermined length 4605 of the space 4610 in the passageway 4410 may define the amount of collapse that the femur 4700 may be permitted to undergo.

[00432] FIGS. 23-47 illustrate various views of a surgical procedure that may be utilized to install the femoral fixation assembly 4600 into a femur 4700.

[00433] FIG. 23 illustrates a perspective side view of a guide pin inserter assembly 4800 placed adjacent a femur 4700, according to an embodiment of the present disclosure.

[00434] The guide pin inserter assembly 4800 may generally include a handle 4850, a side plate positioner 4810 coupled to the handle 4850, a side plate guide 4820 coupled to the side plate positioner 4810, and a guide pin insert 4840 coupled to the side plate guide 4820.

[00435] In some embodiments, one or more of the handle 4850, the side plate positioner 4810, the side plate guide 4820, and/or the guide pin insert 4840 may each be removably couplable with each other.

[00436] In some embodiments, one or more of the handle 4850, the side plate positioner 4810, the side plate guide 4820, and/or the guide pin insert 4840 may be integrally formed with each other. For example, in some embodiments the side plate positioner 4810 and the side plate guide 4820 may be integrally formed with each other.

[00437] The side plate guide 4820 may be placed against the lateral side of the femur 4700 by manipulating the handle 4850 to orient the side plate guide 4820 with respect to a longitudinal axis of the femur. Once the side plate guide 4820 has been properly located adjacent the lateral side of the femur 4700, one or more placement pins 4830 may be inserted through apertures 4827 formed in the side plate guide 4820 to pin the side plate guide 4820 to the femur 4700.

[00438] Once the side plate guide 4820 has been pinned to the femur 4700 at a desired location, the guide pin insert 4840 may be coupled to the side plate guide 4820 by inserting a distal end of the guide pin insert 4840 into one of the locating slots 4825 of the side plate guide 4820, depending on a desired superior/inferior location and/or trajectory for the guide pin 4730.

[00439] In some embodiments, an interior space 4845 of the guide pin insert 4840 may be substantially straight and/or cylindrical in shape in order to direct the guide pin 4730 along a single trajectory into the head 4720 of the femur 4700.

[00440] In some embodiments, the interior space 4845 of the guide pin insert 4840 may be flared and/or somewhat conical in shape in order to allow the surgeon some degree of latitude to choose a trajectory for the guide pin 4730 into the head 4720 of the femur 4700.

[00441] In some embodiments, the interior space 4845 of the guide pin insert 4840 may include an angle 4846 that allows the trajectory of the guide pin 4730 to be varied in at least an anterior-posterior direction.

[00442] In some embodiments, the angle 4846 may be about 9 degrees, as one non-limiting example. However, it will be understood that the interior space 4845 may comprise any angle. [00443] In some embodiments, once the guide pin 4730 has been properly placed within the head 4720 of the femur 4700, the guide pin inserter assembly 4800 may be removed from the femur without disturbing the guide pin 4730 by sliding the side plate guide 4820 superiorly. In these embodiments, the guide pin insert 4840 may be removed from the guide pin 4730, and then the side plate guide 4820 may be moved superiorly to allow the guide pin 4730 to exit the side plate guide 4820 inferiorly through the removal slot 4826 that is formed in the side plate guide 4820. In these embodiments, the removal slot 4826 may extend further superiorly (than what is illustrated in FIG. 23) in order to provide a channel through which the guide pin 4730 may exit the side plate guide 4820 inferiorly as the side plate guide 4820 is moved superiorly. For example, FIG. 47 illustrates a side plate guide 4820 comprising a removal slot 4826 extending superiorly to connect with the one or more locating slots 4825. In this manner, the guide pin 4730 may be allowed to exit the side plate guide 4820 inferiorly through the removal slot 4826 as the side plate guide 4820 is moved superiorly.

[00444] FIG. 25 illustrates a side view of a guide pin 4730 located in the femur 4700 after the guide pin inserter assembly 4800 has been removed.

[00445] FIG. 26 illustrates a side view of a guide pin depth gauge 4900 adjacent the femur 4700 in order to measure a depth of the guide pin 4730 inside the femur 4700. The guide pin depth gauge 4900 may include one or more markings 4910 configured to indicate a depth of the guide pin 4730 inside the femur 4700, which may then be utilized to determine a selected length for the femoral fastener 4300.

[00446] Once the depth of the guide pin 4730 has been determined, a reamer 41100 and a tissue shield 41000 may be placed adjacent the femur 4700 in order to ream a bone tunnel in the femur 4700 that may be configured to receive the barrel 4405 of the femoral support member 4400 therein.

[00447] In some embodiments, a distal end 41010 of the tissue shield 41000 may be notched to conform to a lateral side of the femur 4700.

[00448] In some embodiments, the reamer 41100 may include a flared portion 41110 that may be configured to provide a countersink in the femur to receive the base 4440 of the barrel 4405 therein (see FIG. 16D).

[00449] FIG. 28 illustrates a side view of drill bit 41300, an adjustable depth stop 41200, and centering sleeve 41400, according to embodiments of the present disclosure. The adjustable depth stop 41200 may be slid onto the drill bit 41300 while depressing the button 41210 on the adjustable depth stop 41200 until a previously measured femoral fastener length is seen in the window 41205. The button 41210 may then be released in order to couple the adjustable depth stop 41200 to the drill bit 41300 and hold its position. The centering sleeve 41400 may be slid over the drill bit 41300. The drill bit 41300 and centering sleeve 41400 may then be placed over the guide pin 4730. The centering sleeve 41400 may be slid down the guide pin 4730 until seated, and the drill bit 41300 may then be rotated to form a bone tunnel for the femoral fastener 4300. The drill bit 41300 may be advanced until the adjustable depth stop 41200 rests against the centering sleeve 41400. This may indicate that the bone tunnel has been formed to a proper depth corresponding to the depth shown in the window 41205 of the adjustable depth stop 41200.

[00450] FIG. 29 illustrates a side view of a tap 41500, according to an embodiment of the present disclosure. The adjustable depth stop 41200 may be placed on the tap 41500 in the same manner as the drill bit 41300 described above. The tap 41500 and centering sleeve 41400 may then be placed over the guide pin 4730 and advanced into the femur. The tap 41500 may then be rotated using the handle 4850 to form a tapped bone thread about the bone tunnel in the head 4720 of the femur 4700. The tapped bone thread may be configured to receive the helical thread 4310 of the femoral fastener 4300 therein. [00451] In some embodiments, the tap 41500 may be configured to pre-form threading in the femur 4700 according to any threading shape that is disclosed herein. In this manner, taps with any suitable shape may be utilized in conjunction with any fastener described or contemplated herein to match or substantially match the threading geometry of a given fastener.

[00452] FIGS. 30A-30D illustrate a connection feature formed between an inserter tool 41600 and the femoral fastener 4300, according to an embodiment of the present disclosure. Specifically, FIG. 30A is a close up partial view of the connection feature between the inserter tool 41600 and the femoral fastener 4300 prior to engagement; FIG. 30B is a side view of the connection feature of FIG. 30A after engagement; FIG. 30C is a side view of the connection feature showing an inserter coupler 41620 inside the inserter tool 41600 before it engages with the internal thread 4380 of the femoral fastener 4300; and FIG. 30D illustrates a side view of the connection feature after the external thread 41630 of the inserter coupler 41620 engages the internal thread 4380 of the femoral fastener 4300 to retain the femoral fastener 4300 to the inserter tool 41600. As shown in FIGS. 30A-30B, the inserter tool 41600 may include one or more projections 41610 that may be received within the one or more recesses 4370 of the femoral fastener 4300. In this manner, the femoral fastener 4300 may be coupled with the inserter tool 41600 to facilitate insertion of the femoral fastener 4300 into the bone tunnel formed in the femur 4700.

[00453] FIG. 31 illustrates a side view of the centering sleeve 41400 and the inserter tool 41600 facilitating placement of the femoral fastener 4300 within the femur 4700.

[00454] In some embodiments, a portion of the shaft 4305 of the femoral fastener 4300 comprising the helical thread 4310 may be placed within the head 4720 of the femur 4700, such that, a concave undercut surface of the helical thread 4310 may be positioned within the head 4720 of the femur 4700 to transmit at least one force from the head 4720 of the femur 4700 to the neck 4710 of the femur 4700. [00455] In some embodiments, placing a portion of the shaft 4305 comprising the helical thread 4310 within the head 4720 of the femur 4700 comprises rotating the shaft 4305 to insert the helical thread 4310 into a tapped bone thread that is disposed about the bone tunnel. [00456] FIG. 32 illustrates a side view of the inserter tool 41600 facilitating placement of the femoral support member 4400 against the femur 4700 with the proximal end 4301 of the shaft 4305 of the femoral fastener 4300 placed inside the passageway 4410 of the barrel 4405.

[00457] Thus, in some embodiments, the proximal end 4301 of the shaft 4305 of the femoral fastener 4300 may be inserted into the first opening 4411 of the passageway 4410 formed through the femoral support member 4400 when the femoral support member 4400 is oriented with respect to the longitudinal axis of the femoral bone.

[00458] Moreover, in some embodiments the distal end 4502 of the stop member 4500 may be inserted into the second opening 4412 of the passageway 4410 opposite the first opening 4411, such that a space 4610 having a predetermined length 4605 may be formed within the passageway 4410 between the distal end 4502 of the stop member 4500 and the proximal end 4301 of the shaft 4305 based on the preselected length 4505 of the stop member 4500 or stop member projection 4510. In some embodiments, the stop member 4500 may be placed within the passageway 4410 after the femoral support member 4400 has been secured to the femur 4700 (e.g., see FIGS. 38-46B).

[00459] FIG. 33 illustrates a side view the femoral support member 4400, the femoral fastener 4300, and the femur 4700 after the inserter tool 41600 has been removed.

[00460] FIG. 34 illustrates a side view of an impactor 41700 and a mallet 41800 that may be utilized to further seat the femoral support member 4400 against the femur 4700, in some embodiments.

[00461] FIG. 35A illustrates a side view of a compression screw 41900 being inserted into the femoral support member 4400 and the femoral fastener 4300 with a driver tool 42000, according to an embodiment of the present disclosure. FIG. 35B illustrates a close-up view of the compression screw 41900 shown in FIG. 35A. If desired, the compression screw 41900 may be utilized to generate a compression force across a fracture of the femur 4700 by threading the compression screw 41900 into the femoral fastener 4300 while a head of the compression screw 41900 presses against the barrel shoulder 4416 in the passageway 4410. The compression screw 41900 may be rotated until a desired compression force is achieved. To maintain the compression force, one or more support fasteners 42800 (e.g., see FIG. 41) may then be placed across the fracture while the compression screw 41900 is generating the compression force. The compression screw 41900 may then be removed after compression has been achieved and maintained by the one or more support fasteners 42800. However, in some embodiments the compression screw 41900 may left inside the femoral fixation assembly 4600. [00462] FIGS. 36-41 illustrate the installation of various bone screws to affix the femoral fixation assembly 4600 to the femur 4700. Specifically, FIG. 36 illustrates a side view of a drill bit 42100 and a drill bit guide 42200 forming one or more bone tunnels in the femur 4700; FIG. 37 illustrates a side view of a depth gauge 42300 measuring a depth of a bone tunnel to ascertain a required length for a bone screw; FIG. 38 illustrates a side view of a driver tool 42400 installing one or more bone plate fasteners 42500 into the femur 4700; FIG. 39 illustrates a side view of a drill bit 42600 and drill bit guide 42700 forming a bone tunnel into the head 4720 of the femur 4700; FIG. 40 illustrates a side view of a driver tool 42400 installing one or more support fasteners 42800 into the head 4720 of the femur 4700; and FIG. 41 illustrates a side view of the femoral fixation assembly 4600 after the one or more support fasteners 42800 have been installed.

[00463] FIG. 42 illustrates a side view of an extension plate 42900 being coupled to the femoral support member 4400 with a driver tool 43000, according to some embodiments of the present disclosure. FIG. 43 illustrates a side view of the femoral fixation assembly 4600 after the extension plate 42900 has been coupled to the femoral support member 4400 and support fasteners 42800 have been inserted into the head 4720 of the femur 4700 through the extension plate 42900.

[00464] FIGS. 44-46B illustrate installation of a trochanter plate 43100 to the femur 4700, according to some embodiments of the present disclosure. Specifically, FIG. 44 illustrates a side view of the femoral fixation assembly 4600 after a trochanter plate 43100 has been coupled to the femoral support member 4400 and additional support fasteners 42800 have been inserted into the head 4720 of the femur 4700 through the trochanter plate 43100; FIG. 45 illustrates a side view of the femoral fixation assembly 4600 with a drill bit 43300 forming one or more bone tunnels in the femur 4700 to receive one or more trochanter plate fasteners 43200 to secure the trochanter plate 43100 to the femur 4700; FIG. 46A illustrates a perspective side view of the femoral fixation assembly 4600 after the one or more trochanter plate fasteners 43200 have been installed into the femur 4700 through the trochanter plate 43100; and FIG. 46B illustrates a front view of the femoral fixation assembly 4600 of FIG. 46A.

[00465] The present disclosure presents various fasteners for utilization in bone and other tissues as implantable devices (e.g., orthopedic implants, spine implants, sports medicine implants, dental implants, trauma implants, reconstruction implants, extremity implants, craniomaxillofacial (CMF) implants, veterinary implants, etc.) for the purpose of streamlining the present disclosure. However, it will be understood that the various fasteners and helical threading concepts presented herein can be utilized in any medium beyond bones/tissues and/or for any application beyond surgical procedures.

[00466] Example applications/procedures that may utilize any of the fasteners described or contemplated herein, in any configuration and with any of the features described herein, may include, but are not limited to: trauma procedures, spine procedures (e.g., SI fusion, facet fixation, etc.), reconstruction procedures, sports related procedures, ACL/tenodesis procedures, extremity procedures, dental procedures, CMF procedures, veterinary procedures, fracture fixation plate procedures (e.g., distal femur plates, proximal humerus plates, tibial plates, etc.), supplemental Fixation for IBD procedures, intramedullary canal fixation procedures, nail fixation procedures, limb salvage and transfemoral procedures, amputee connection procedures, total shoulder fixation, reverse glenoid fixation, small bone fixation (e.g., podiatric, hand/wrist, etc.), joint fusions, single-tooth implant fixation, jaw/facial reconstruction, dentures fixation, veterinary trauma, species specific procedures (e.g., equine, canine, rabbit, etc.), TPLO, shear fixation, osteotomies, fusions, procedures involving osteoporotic or compromised bone, etc.

[00467] Moreover, fastener types that may utilize any of the thread designs, morphology, and/or features described herein may include, but are not limited to: cortical fasteners, soft tissue fasteners, long fasteners, cannulated fasteners, plate fasteners, locking/non-locking fasteners, dynamic hip fasteners, acetabular cup fasteners, Schanz pins, half pins, pedicle fasteners, cervical fasteners, threaded stems, threaded intramedullary canal stems, joint stems, revision fasteners, compression fasteners (e.g., headless/headed compression fasteners, hip compression fasteners, etc.), ACL fasteners, tenodesis fasteners, bone-tendon-bone graft fasteners, suture anchors, dental fasteners, mandibular tenting fasteners, veterinary fasteners, etc.

[00468] FIGS. 48A-D illustrate various views of a headless screw or fastener 5300, according to another embodiment of the present disclosure. Specifically, FIG. 48A is a front perspective view of the fastener 5300, FIG. 48B is a rear perspective view of the fastener 5300, FIG. 48C is a side view of the fastener 5300, and FIG. 48D is a cross-sectional side view of the fastener 5300 taken along the line C- C in FIG. 48C. The fastener 5300 may include a shaft 5305 having a proximal end 5301, a distal end 5302, and a longitudinal axis 5303. The fastener 5300 may also include a torque connection interface 5306 formed in the proximal end 5301 of the shaft 5305 and a self-tapping feature 5307 formed in the distal end 5302 of the shaft 5305. In some embodiments, the fastener 5300 may include a first helical thread 5310 disposed about the shaft 5305, and a second helical thread 5320 disposed about the shaft 5305 adjacent the first helical thread 5310. In these embodiments, the fastener 5300 may comprise a “dual start” or “dual lead” thread design with alternating standard and inverted threads. However, it will also be understood that the fastener 5300 may include any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue.

[00469] FIGS. 49A-D illustrate various views of a headless screw or fastener 5600, according to another embodiment of the present disclosure. Specifically, FIG. 49A is a front perspective view of the fastener 5600, FIG. 49B is a rear perspective view of the fastener 5600, FIG. 49C is a side view of the fastener 5600, and FIG. 49D is a cross-sectional side view of the fastener 5600 taken along the line F- F in FIG. 49C. The fastener 5600 may include a shaft 5605 having a proximal end 5601, a distal end 5602, and a longitudinal axis 5603. The fastener 5600 may also include a torque connection interface 5606 formed in the proximal end 5601 of the shaft 5605. In some embodiments, the fastener 5600 may include a single helical thread 5610 disposed about the shaft 5605. In these embodiments, the fastener 5600 may comprise a “single start” or “single lead” thread configuration having a standard orientation, as shown in FIG. 49D. However, it will also be understood that the fastener 5600 may include any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. In some embodiments, the fastener 5600 may be sized, shaped, and configured for use as an Anterior Cruciate Ligament (ACL) interference screw for utilization in an ACL reconstruction procedure. However, it will also be understood that the fastener 5600 may be sized, shaped, and configured for use in any bone-tendon-bone graft procedure, or any other procedure/application.

[00470] FIGS. 50A and 50B illustrate various views of an interference screw or fastener 5700, according to another embodiment of the present disclosure. Specifically, FIG. 50A is a front perspective view of the fastener 5700 and FIG. 50B is a rear perspective view of the fastener 5700. The fastener 5700 may include a shaft 5705 having a proximal end 5701 and a distal end 5702, a head 5704, and a torque connection interface 5706 formed in the head 5704. In some embodiments, the fastener 5700 may include a single helical thread 5710 disposed about the shaft 5705. In these embodiments, the fastener 5700 may comprise a “single start” or “single lead” thread configuration having a standard orientation. However, it will also be understood that the fastener 5700 may include any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. In some embodiments, the fastener 5700 may be sized, shaped, and configured for use as an Anterior Cruciate Ligament (ACL) interference screw for utilization in an ACL reconstruction procedure. However, it will also be understood that the fastener 700 may be sized, shaped, and configured for use in any bone-tendon-bone graft procedure, or any other procedure/application. In some embodiments, a system or kit may include at least one ACL interference screw with standard threading, and at least one ACL interference screw with inverted threading. In some embodiments, a system or kit may include a plurality of ACL interference screws of varying sizes with standard threading, and a plurality of ACL interference screws of varying sizes with inverted threading. In some embodiments, a surgeon may select an ACL interference screw with standard or inverted threading and repair an ACL with the selected ACL interference screw.

[00471] FIGS. 51A and 5 IB illustrate various views of a fastener 5800, according to another embodiment of the present disclosure. Specifically, FIG. 51 A is a front perspective view of the fastener

5800 and FIG. 5 IB is a rear perspective view of the fastener 5800. The fastener 5800 may include a shaft 5805 having a proximal end 5801, a distal end 5802, a self-tapping feature 5807 formed in the distal end 5802 of the shaft 5805, and a torque connection interface 5806 formed in the proximal end

5801 of the shaft 5805. In some embodiments, the self-tapping feature 5807 may comprise a forward cutting flute configured to facilitate insertion of the fastener 5800 into bone/tissue. In some embodiments, the fastener 5800 may also include a reverse cutting flute (not shown) configured to facilitate removal of the fastener 5800 from the bone/tissue after healing has occurred. In some embodiments, the fastener 5800 may include a first helical thread 5810 disposed about the shaft 5805, and a second helical thread 5820 disposed about the shaft 5805 adjacent the first helical thread 5810. In these embodiments, the fastener 5800 may comprise a “dual start” or “dual lead” thread design with alternating standard and inverted threads. However, it will also be understood that the fastener 5800 may include any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. In some embodiments, the fastener 5800 may be sized, shaped, and configured for use in dental/CMF procedures. However, it will also be understood that the fastener 5800 may be sized, shaped, and configured for use in any procedure or application.

[00472] FIGS. 52A and 52B illustrate various views of a fastener 5900, according to another embodiment of the present disclosure. Specifically, FIG. 52A is a front perspective view of the fastener

5900 and FIG. 52B is a rear perspective view of the fastener 5900. The fastener 5900 may include a shaft 5905 having a proximal end 5901, a distal end 5902, a self-tapping feature 5907 formed in the distal end 5902 of the shaft 5905, and a torque connection interface 5906 formed in the proximal end

5901 of the shaft 5905. In some embodiments, the fastener 5900 may include a single helical thread 5910 disposed about the shaft 5905. In these embodiments, the fastener 5900 may comprise a “single start” or “single lead” thread configuration having a standard orientation. However, it will also be understood that the fastener 5900 may include any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. In some embodiments, the fastener 5900 may be sized, shaped, and configured for use in dental/CMF procedures. However, it will also be understood that the fastener 5900 may be sized, shaped, and configured for use in any procedure or application.

[00473] FIGS. 53 A and 53B illustrate various views of a fastener 51000, according to another embodiment of the present disclosure. Specifically, FIG. 53 A is a front perspective view of the fastener 51000 and FIG. 53B is a rear perspective view of the fastener 51000. The fastener 51000 may include a shaft 51005 having a proximal end 51001, a distal end 51002, a self-tapping feature 51007 formed in the distal end 51002 of the shaft 51005, and a torque connection interface 51006 formed in the proximal end 51001 of the shaft 51005. In some embodiments, the fastener 51000 may include a single helical thread 51010 disposed about the shaft 51005. In these embodiments, the fastener 51000 may comprise a “single start” or “single lead” thread configuration having an inverted orientation. However, it will also be understood that the fastener 51000 may include any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. In some embodiments, the fastener 51000 may be sized, shaped, and configured for use in dental/CMF procedures. However, it will also be understood that the fastener 51000 may be sized, shaped, and configured for use in any procedure or application.

[00474] FIG. 54A illustrates a compression fastener or compression screw 51300, according to another embodiment of the present disclosure. In some embodiments, the compression screw 51300 may be utilized to repair bone fractures by compressing two or more bone fragments together to reduce one or more bone fractures. The compression screw 51300 may comprise any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. Moreover, the compression screw 51300 (or any other fastener described or contemplated herein) may comprise first threading with any of the shapes disclosed herein oriented toward one of the proximal end and the distal end of the compression screw 51300 with the first threading located proximate the tip of the compression screw 51300, as well as second threading with any of the shapes disclosed herein oriented toward the other one of the proximal end and the distal end of the compression screw 51300 with the second threading located proximate the head of the compression screw 51300. In some embodiments, the starts of the distal and proximal threads can be “timed” such that, during insertion, the proximal thread nests between the cut distal thread thereby reducing cross-cutting of the bone. In some embodiments, the compression screw 51300 may further comprise forward and/or reverse cutting flutes. In some embodiments, an outer diameter of a head of the compression screw 51300 may be greater than an outer diameter of the tip of the compression screw 51300 in order to increase cortical engagement proximate the head of the compression screw 51300. In some embodiments, the compression screw 51300 may comprise dual threading toward the tip of the compression screw 51300 (e.g., with greater pitch), and single threading toward the head of the compression screw 51300 (e.g., with smaller pitch) in order to achieve increased thread engagement with bone toward the tip of the compression screw 51300, but still allow for variable pitch between the tip and the head of the compression screw 51300. FIG. 54B illustrates a system/kit 51350 that may comprise one or more compression screws of varying size, as well as any suitable supporting instruments to prepare a bone and/or insert a compression screw 51300 into a bone

[00475] FIG. 55 A illustrates a long screw or long fastener 51400, according to another embodiment of the present disclosure. In some embodiments, the long fastener 51400 may be utilized to repair bone fractures and/or stabilize a bone (e.g., in pelvis, hip, and other applications). The long fastener 51400 may comprise any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. FIG. 55B illustrates a system/kit 51450 that may comprise one or more long fasteners 51400 of varying size, as well as any suitable supporting instruments that may be utilized to prepare a bone and/or insert a long fastener 51400 into a bone.

[00476] FIG. 56A illustrates a half pin or Schanz fastener 51500, according to another embodiment of the present disclosure. In some embodiments, the Schanz fastener 51500 may be utilized to stabilize a bone with an external fixator (not shown), such as a spatial external fixator, a temporal external fixator, etc., during various procedures that may utilize an external fixator. In some embodiments, the Schanz fastener 51500 may increase fixation and reduce infections in comparison to traditional bone pins utilized with external fixators. The Schanz fastener 51500 may comprise any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. FIG. 56B illustrates a system/kit 51550 that may comprise one or more Schanz fasteners 51500 of varying size, as well as any suitable supporting instruments that may be utilized to prepare a bone and/or insert a Schanz fastener 51500 into a bone. In some embodiments, the Schanz fastener 51500 and/or corresponding insertion tool may include any suitable drive feature configuration (e.g., a suitable AO quick connect feature, etc.). [00477] FIG. 57A illustrates a fastener 51600, according to another embodiment of the present disclosure. In some embodiments, the fastener 51600 may include a cannula 51630 extending through a shaft 51605 of the fastener 51600. In some embodiments, the cannula 51630 may be configured to receive a tool therethrough, such as a drill bit, a K-wire 51660, etc., as seen in FIG. 57B. The fastener 51600 may comprise any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/tissue. Moreover, any fastener described herein may also include a cannula. In some embodiments, a K-wire 51660 may be inserted into bone/tissue at a surgical site. In some embodiments, the K-wire may be utilized to guide a drill bit to the surgical site to drill a pilot hole. In some embodiments, a tap may also be utilized to pre-form threading in the pilot hole. Taps with any suitable shape may also be utilized in conjunction with any fastener described or contemplated herein to match or substantially match the threading geometry of a given fastener. Moreover, any tap can be configured to be self-tapping or non-self-tapping. In some embodiments, the K-wire 51660 may be inserted through the cannula 51630 of the fastener 51600 to guide the fastener 51600 to the surgical site over the K-wire for insertion into the pilot hole. The K-wire 51660 may have a shaft 51640 that is guided and/or retained within the cannula 51630 during insertion. In some embodiments, a minor diameter of the fastener 51600 may be selected to match, or substantially match, a diameter of the pilot hole to avoid bone blowout.

[00478] FIG. 58 illustrates a bone/soft tissue repair anchor or fastener 51700, according to another embodiment of the present disclosure. In some embodiments, the fastener 51700 may include a connection feature 51740 configured to couple a suture 51730 (or suture tape, etc.) to the fastener 51700 to facilitate bone/soft tissue repair procedures with the suture 51730. In some embodiments, the connection feature 51740 may be internally located within the fastener 51700. However, it will be understood that the suture 51730 may be coupled to the fastener 51700 in any suitable manner and at any location on/within the fastener 51700. The fastener 51700 may comprise any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a given bone/soft tissue. In some embodiments, an outer diameter of a head of the fastener 51700 may be greater than an outer diameter of the tip of the fastener 51700 in order to increase bone/tissue engagement proximate the head of the fastener 51700.

[00479] FIGS. 59A and 59B illustrate various views of fasteners 51800 engaged with a plate 51830, according to another embodiment of the present disclosure. In some embodiments, the plate 51830 may comprise a Lateral Distal Fibula Plate (LDFP) for repairing a distal fibula (not shown). In some embodiments, the fasteners 51800 may comprise any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within the distal fibula. In some embodiments, the LDFP may comprise a locking LDFP with bone plate holes configured to receive both locking and non-locking fasteners to achieve lower head prominence where desired. As previously discussed, any of the fasteners disclosed or contemplated herein may include locking features, such as locking threads located on or near a head of the fastener, to lock a fastener to an implant (such as a bone plate). The locking threads located on or near the head of the fastener may match the morphology (e.g., pitch, shape, etc.) of the main threading of the fastener. Moreover, any bone plate (or other implant or component) utilized in conjunction with the fasteners disclosed herein may also comprise threading formed in the bone plate that may match (or substantially match) the general morphology of the threading of the fastener (e.g., pitch, shape, etc.) in order to engage the threading of the fastener with the threading of the bone plate to couple the fastener with the bone plate.

[00480] FIGS. 60A and 60B illustrate various views of fasteners 51900 engaged with a plate 51930, according to another embodiment of the present disclosure. In some embodiments, the plate 51930 may comprise a proximal tibial plate configured to repair a proximal tibia 51940. In some embodiments, the proximal tibial plate may comprise a locking proximal tibial plate with bone plate holes configured to receive both locking and non-locking fasteners to achieve lower head prominence where desired. The fasteners 51900 may comprise any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within the proximal tibia 51940.

[00481] FIG. 61 illustrates fasteners 52000 and plate 52030, according to another embodiment of the present disclosure. In some embodiments, the plate 52030 may comprise a distal femur fracture repair plate configured to repair a distal femur (not shown). In some embodiments, the distal femur fracture repair plate may comprise a locking distal femur fracture repair plate with bone plate holes configured to receive both locking and non-locking fasteners to achieve lower head prominence where desired. The fasteners 52000 may comprise any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within a distal femur.

[00482] FIG. 62A illustrates a Periprosthetic Fracture Repair Plate (PFRP) or plate 52130, according to another embodiment of the present disclosure. FIG. 62B illustrates a side view of a femur 52140 that has been fractured, and FIG. 62C illustrates a side view of the femur 52140 after the fracture has been repaired with the plate 52130 coupled to the femur 52140 via fasteners 52100. In some embodiments, the plate 52130 may comprise a locking PFRP with bone plate holes configured to receive both locking and non-locking fasteners to achieve lower head prominence where desired. The fasteners 52100 may comprise any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within the femur 52140, or within any other bone that may require periprosthetic fracture repair.

[00483] FIG. 63A illustrates a fastener 52300, FIG. 63B illustrates a plate 52330, and FIG. 63C illustrates another plate 52340, according to embodiments of the present disclosure. In some embodiments, the plates 52330, 52340 may comprise pelvic bone repair plates (e.g., quad plates, etc.) configured for use with the fastener 52300. In some embodiments, the plates 52330, 52340 may comprise percutaneous pelvic bone repair plates. In some embodiments, the plates 52330, 52340 may comprise locking pelvic bone repair plates with bone plate holes configured to receive both locking and non-locking fasteners to achieve lower head prominence where desired. The fastener 52300 may comprise any thread configuration, feature, or morphology described or contemplated herein to achieve optimal compression and fixation within pelvic bone, or within any other bone.

[00484] FIGS. 64A and 64B illustrate various views of fasteners 52400 coupling a plate 52430 to a proximal humerus 52440, according to another embodiment of the present disclosure. In some embodiments, the plate 52430 may comprise a proximal humerus plate configured to repair a proximal humerus 52440. In some embodiments, the proximal humerus plate may comprise a locking proximal humerus plate with bone plate holes configured to receive both locking and non-locking fasteners to achieve lower head prominence where desired. The fasteners 52400 may comprise any thread configuration, feature, or morphology described or contemplated herein to achieve optimal fixation within the proximal humerus 52440, or within any other bone.

[00485] Any of the fasteners described or contemplated herein may be configured for removal and replacement during a revision procedure by simply unscrewing and removing the fastener from the bone/tissue in which the fastener resides. Moreover, the fasteners described herein may advantageously be removed from bone without removing any appreciable amount of bone during the removal process to preserve the bone. In this manner, implants may be mechanically integrated with the bone, while not being cemented to the bone or integrated via bony ingrowth, in order to provide an instant and removable connection between an implant and a bone. Accordingly, revision procedures utilizing the fasteners described herein can result in less trauma to the bone and improved patient outcomes. However, it will also be understood that any of the fasteners described or contemplated herein may also be utilized with cement, as desired.

[00486] Any procedures/methods disclosed herein comprise one or more steps or actions for performing the described method. The method steps and/or actions may be interchanged with one another. In other words, unless a specific order of steps or actions is required for proper operation of the embodiment, the order and/or use of specific steps and/or actions may be modified.

[00487] Reference throughout this specification to "an embodiment" or "the embodiment" means that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, the quoted phrases, or variations thereof, as recited throughout this specification are not necessarily all referring to the same embodiment.

[00488] Similarly, it should be appreciated that in the above description of embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the present disclosure. This method of disclosure, however, is not to be interpreted as reflecting an intention that any embodiment requires more features than those expressly recited in that embodiment. Rather, inventive aspects lie in a combination of fewer than all features of any single foregoing disclosed embodiment. [00489] Recitation of the term "first" with respect to a feature or element does not necessarily imply the existence of a second or additional such feature or element. Elements recited in means-plus-function format are intended to be construed in accordance with 35 U.S.C. § 112(f). It will be apparent to those having skill in the art that changes may be made to the details of the above-described embodiments without departing from the underlying principles set forth herein.

[00490] The phrases "connected to," "coupled to" and "in communication with" refer to any form of interaction between two or more entities, including mechanical, electrical, magnetic, electromagnetic, fluid, and thermal interaction. Two components may be functionally coupled to each other even though they are not in direct contact with each other. The term "coupled" can include components that are coupled to each other via integral formation, as well as components that are removably and/or non-removably coupled with each other. The term "abutting" refers to items that may be in direct physical contact with each other, although the items may not necessarily be attached together. The phrase "fluid communication" refers to two or more features that are connected such that a fluid within one feature is able to pass into another feature. Moreover, as defined herein the term “substantially” means within +/- 20% of a target value, measurement, or desired characteristic.

[00491] While specific embodiments and applications of the present disclosure have been illustrated and described, it is to be understood that the scope of this disclosure is not limited to the precise configuration and components disclosed herein. Various modifications, changes, and variations which will be apparent to those skilled in the art may be made in the arrangement, operation, and details of the devices, systems, and methods disclosed herein.

Claims

CLAIMS What is claimed is:

1. A femoral fixation device comprising: a shaft comprising: a proximal end; a distal end; and a longitudinal axis; and a helical thread disposed about the shaft along the longitudinal axis between a first location and a second location along the shaft, the helical thread comprising: a first undercut surface; and a second undercut surface; wherein, when the femoral fixation device is implanted within a neck and a head of a femoral bone: the first location, the second location, and the helical thread therebetween are disposed within the head of the femoral bone; the first undercut surface is angled towards one of the proximal end and the distal end of the shaft; the second undercut surface is angled towards the other one of the proximal end and the distal end of the shaft; and the first and second undercut surfaces are configured to transmit at least one force from the head of the femoral bone to the neck of the femoral bone.

2. The femoral fixation device of claim 1, wherein: the first undercut surface is angled towards the proximal end of the shaft; and the second undercut surface is angled towards the distal end of the shaft.

3. The femoral fixation device of claim 2, wherein, when the femoral fixation device is viewed in section along a plane intersecting the longitudinal axis of the shaft, the helical thread comprises at least one chevron shape oriented toward the proximal end of the shaft.

4. The femoral fixation device of claim 3, wherein the helical thread comprises a plurality of chevron shapes oriented toward the proximal end of the shaft.

5. The femoral fixation device of claim 1, wherein, when the femoral fixation device is viewed in section along a plane intersecting the longitudinal axis of the shaft, the helical thread comprises at least one partial crescent shape oriented toward the proximal end of the shaft.

6. The femoral fixation device of claim 5, wherein the helical thread comprises a plurality of partial crescent shapes oriented toward the proximal end of the shaft.

7. The femoral fixation device of claim 1, wherein the proximal end of the shaft comprises a headless cylindrical shape.

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8. A femoral fixation assembly comprising: a femoral fastener comprising: a shaft comprising: a proximal end; a distal end; and a longitudinal axis; and a helical thread disposed about the shaft along the longitudinal axis between a first location and a second location along the shaft, the helical thread comprising a concave undercut surface; and a femoral support member comprising: a proximal end; a distal end; a longitudinal axis; and a passageway formed through the femoral support member at an angle with respect to the longitudinal axis of the femoral support member; wherein, when the femoral fastener is implanted within a neck and a head of a femoral bone, and the femoral support member is implanted along a longitudinal axis of the femoral bone: at least a portion of the shaft is slidingly received within the passageway of the femoral support member; and the concave undercut surface is oriented toward the proximal end of the femoral fastener and configured to transmit at least one force from the head of the femoral bone to the neck of the femoral bone.

9. The femoral fixation assembly of claim 8, wherein the concave undercut surface comprises at least one substantially flat surface.

10. The femoral fixation assembly of claim 9, wherein the concave undercut surface comprises a plurality of flat surfaces that are angled relative to each other.

11. The femoral fixation assembly of claim 10, when the femoral fastener is viewed in section along a plane intersecting the longitudinal axis of the shaft, the concave undercut surface comprises at least one chevron shape oriented toward the proximal end of the shaft.

12. The femoral fixation assembly of claim 8, wherein the concave undercut surface comprises at least one curved surface.

13. The femoral fixation assembly of claim 12, wherein, when the femoral fastener is viewed in section along a plane intersecting the longitudinal axis of the shaft, the concave undercut surface comprises at least one partial crescent shape oriented toward the proximal end of the shaft.

14. The femoral fixation assembly of claim 8, wherein, when the femoral fastener is viewed in section along a plane intersecting the longitudinal axis of the shaft, the concave undercut surface

58 comprises at least one bent shape having an intermediate portion that is oriented toward the proximal end of the femoral fastener.

15. A femoral fixation assembly comprising: a femoral fastener comprising: a shaft comprising: a proximal end; a distal end; and a longitudinal axis; and a helical thread disposed about the shaft along the longitudinal axis between a first location and a second location along the shaft; a femoral support member comprising: a proximal end; a distal end; a longitudinal axis; and a passageway comprising: a first opening; and a second opening opposite the first opening; wherein, the passageway is formed through the femoral support member at an angle with respect to the longitudinal axis of the femoral support member; and a stop member comprising: a proximal end; a distal end; a longitudinal axis; and a stop member projection having a preselected length; wherein, when the femoral fastener is implanted within a neck and a head of a femoral bone, and the femoral support member is oriented with respect to a longitudinal axis of the femoral bone: at least a portion of the shaft is slidingly received within the passageway through the first opening; at least a portion of the stop member is received within the passageway through the second opening; and a space having a predetermined length is formed within the passageway between the distal end of the stop member and the proximal end of the shaft based on the preselected length of the stop member projection.

16. The femoral fixation assembly of claim 15, wherein the femoral support member comprises a bone plate.

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17. The femoral fixation assembly of claim 15, wherein the femoral support member comprises an intramedullary nail.

18. The femoral fixation assembly of claim 15, wherein the angle of the passageway with respect to the longitudinal axis of the femoral support member comprises an acute angle.

19. The femoral fixation assembly of claim 15, wherein the predetermined length of the space within the passageway is greater than zero.

20. The femoral fixation assembly of claim 15, wherein the predetermined length of the space within the passageway is zero.

21. A method of implanting a femoral fixation device within a femoral bone, the method comprising: forming a bone tunnel through a neck of the femoral bone and into a head of the femoral bone; inserting the femoral fixation device into the bone tunnel, the femoral fixation device comprising: a shaft having a proximal end, a distal end, and a longitudinal axis; and a helical thread disposed about the shaft between a first location and a second location along the shaft, the helical thread comprising a concave undercut surface oriented toward the proximal end of the shaft; and placing a portion of the shaft comprising the helical thread within the head of the femoral bone such that the concave undercut surface is positioned to transmit at least one force from the head of the femoral bone to the neck of the femoral bone.

22. The method of claim 21, further comprising: forming a tapped bone thread about the bone tunnel, the tapped bone thread configured to receive the helical thread therein.

23. The method of claim 22, wherein: placing the portion of the shaft comprising the helical thread within the head of the femoral bone further comprises: rotating the shaft to insert the helical thread into the tapped bone thread disposed about the bone tunnel.

24. The method of claim 21, further comprising: inserting the proximal end of the shaft into a first opening of a passageway formed through a femoral support member that is oriented with respect to a longitudinal axis of the femoral bone.

25. The method of claim 24, further comprising: inserting a distal end of a stop member into a second opening of the passageway opposite the first opening; and forming a space having a predetermined length within the passageway between the distal end of the stop member and the proximal end of the shaft based on a preselected length of the stop member.

26. A pedicle bone fastener comprising:

60 a shaft comprising: a proximal end; a distal end; a longitudinal axis; and a minor diameter; a helical thread disposed about the shaft along the longitudinal axis between the proximal and distal ends of the shaft, the helical thread comprising: a first undercut surface; and a second undercut surface, wherein: the first undercut surface is angled toward one of the proximal end and the distal end of the shaft; the second undercut surface is angled toward the other one of the proximal end and the distal end of the shaft; and the minor diameter of the shaft is constant.

27. The pedicle bone fastener of claim 26, further comprising: an attachment feature coupled to the proximal end of the shaft and configured to be secured to an implement.

28. The pedicle bone fastener of claim 27, wherein the attachment feature comprises a polyaxial head having a first semi-spherical surface.

29. The pedicle bone fastener of claim 28, wherein the implement comprises a discrete tulip having a second semi-spherical surface configured to engage the first semi-spherical surface of the polyaxial head to secure the discrete tulip to the polyaxial head at any of a variety of relative orientations.

30. The pedicle bone fastener of claim 29, wherein the discrete tulip further comprises: at least one opening; and a locking member configured to secure a rod received through the at least one opening to the discrete tulip.

31. The pedicle bone fastener of claim 27, wherein the attachment feature comprises an integrated tulip having at least one opening configured to receive at least a part of the implement therethrough.

32. The pedicle bone fastener of claim 31, wherein the implement comprises a rod receivable through the at least one opening of the integrated tulip, and wherein the integrated tulip comprises a locking member configured to secure the rod to the integrated tulip.

33. A method of preventing bone blowout comprising: forming a hole in a bone, the hole having a bone hole diameter; and inserting a bone fastener into the hole, the bone fastener comprising: a shaft comprising: a proximal end; a distal end;

61 a longitudinal axis; and a minor diameter; and a helical thread disposed about the shaft along the longitudinal axis between the proximal and distal ends of the shaft, the helical thread comprising: a first undercut surface; and a second undercut surface, wherein: the first undercut surface is angled toward one of the proximal end and the distal end of the shaft; the second undercut surface is angled toward the other one of the proximal end and the distal end of the shaft; and the minor diameter of a main portion of the shaft is not greater than the bone hole diameter to reduce a radial outward load force imparted on the bone and prevent bone blowout.

34. The method of claim 33, wherein the minor diameter of the main portion of the shaft is equal to the bone hole diameter.

35. The method of claim 33, wherein the minor diameter of the main portion of the shaft is less than the bone hole diameter.

36. The method of claim 35, wherein the minor diameter of the main portion of the shaft is between 0mm and 0.1mm less than the bone hole diameter.

37. The method of claim 35, wherein the minor diameter of the main portion of the shaft is at least 0.1mm less than the bone hole diameter.

38. The method of claim 35, wherein the minor diameter of the main portion of the shaft is at least 0.2mm less than the bone hole diameter.

39. The method of claim 33, wherein the minor diameter of the main portion of the shaft is constant.

40. A bone fastener comprising: a shaft comprising: a proximal end; a distal end; a longitudinal axis; and a minor diameter; a helical thread disposed about the shaft along the longitudinal axis between the proximal and distal ends of the shaft and defining a major diameter of the bone fastener, the helical thread comprising: a first undercut surface; and a second undercut surface, wherein: the first undercut surface is angled toward one of the proximal end and the distal end of the shaft; and the second undercut surface is angled toward the other one of the proximal end and the distal end of the shaft; and a ratio of the major diameter to the minor diameter is less than 1.50.

41. The bone fastener of claim 40, wherein the ratio of the major diameter to the minor diameter is less than 1.25.

42. The bone fastener of claim 40, wherein the ratio of the major diameter to the minor diameter is less than 1.10.

43. The bone fastener of claim 40, wherein the ratio of the major diameter to the minor diameter is less than 1.05.

44. The bone fastener of claim 40, wherein at least a portion of the bone fastener is configured to be received with an intramedullary canal of a bone.

45. The bone fastener of claim 44, further comprising an attachment feature at the proximal end of the shaft configured to be adjustably secured to an implement.

46. A pedicle bone fastener comprising: a shaft comprising: a proximal end; a distal end; and a longitudinal axis; a helical thread disposed about the shaft along the longitudinal axis between the proximal and distal ends of the shaft, the helical thread comprising: a first undercut surface; and a second undercut surface, wherein: the first undercut surface is angled toward one of the proximal end and the distal end of the shaft; and the second undercut surface is angled toward the other one of the proximal end and the distal end of the shaft; and an integrated attachment feature at the proximal end of the shaft and configured to be adjustably secured to a spinal stabilization implement.

47. The pedicle bone fastener of claim 46, wherein the integrated attachment feature comprises a polyaxial head having a first semi-spherical surface configured to be polyaxially -adjustably secured to the spinal stabilization implement.

48. The pedicle bone fastener of claim 47, wherein the spinal stabilization implement comprises a discrete tulip having a second semi-spherical surface configured to engage the first semi-spherical surface of the polyaxial head to polyaxially-adjustably secure the discrete tulip to the polyaxial head at any of a variety of relative orientations.

49. The pedicle bone fastener of claim 48, wherein the discrete tulip further comprises: at least one opening; and a locking member configured to secure a rod receivable through the at least one opening to the discrete tulip.

50. The pedicle bone fastener of claim 46, wherein the integrated attachment feature comprises an integrated tulip having at least one opening configured to receive at least a part of the spinal stabilization implement therethrough.

51. The pedicle bone fastener of claim 50, wherein the spinal stabilization implement comprises a rod receivable through the at least one opening of the integrated tulip.

52. The pedicle bone fastener of claim 51, wherein the integrated tulip further comprises a locking member configured to secure the rod to the integrated tulip.

53. A pedicle fastener stabilization system comprising: a pedicle bone fastener comprising: a shaft comprising: a proximal end; a distal end; and a longitudinal axis; a polyaxial head at the proximal end of the shaft; a first helical thread disposed about the shaft along the longitudinal axis between the proximal and distal ends of the shaft, the first helical thread comprising a first concave undercut surface; and a second helical thread disposed about the shaft adjacent the first helical thread, the second helical thread comprising a second concave undercut surface, wherein the first concave undercut surface and the second concave undercut surface are angled towards one of the proximal end and the distal end of the shaft; a tulip configured to be polyaxially -adjustably secured to the polyaxial head; and a spinal stabilization rod securable to the tulip.

54. The pedicle fastener stabilization system of claim 53, wherein the polyaxial head is integrally formed with the pedicle bone fastener.

55. The pedicle fastener stabilization system of claim 54, wherein the polyaxial head comprises a first semi-spherical surface.

56. The pedicle fastener stabilization system of claim 55, wherein the tulip comprises a second semi-spherical surface configured to engage the first semi-spherical surface of the polyaxial head to polyaxially -adjustably secure the tulip to the polyaxial head at any of a variety of relative orientations.

57. The pedicle fastener stabilization system of claim 53, wherein the tulip comprises at least one opening configured to receive the spinal stabilization rod therethrough.

58. The pedicle fastener stabilization system of claim 57, wherein the tulip comprises a locking member configured to secure the spinal stabilization rod to the tulip.

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59. The pedicle fastener stabilization system of claim 53, wherein a minor diameter of the shaft is constant.

60. A method of implanting a bone fastener assembly comprising: inserting a bone fastener into a bone, the bone fastener comprising: a shaft comprising: a proximal end; a distal end; and a longitudinal axis; a helical thread disposed about the shaft along the longitudinal axis between the proximal and distal ends of the shaft, the helical thread comprising: a first undercut surface; and a second undercut surface, wherein: the first undercut surface is angled toward one of the proximal end and the distal end of the shaft; and the second undercut surface is angled toward the other one of the proximal end and the distal end of the shaft; and an attachment feature at the proximal end of the shaft configured to be adjustably secured to an implement; adjusting an orientation of the implement to a selected orientation relative to the attachment feature; and attaching the implement to the attachment feature at the selected orientation.

61. The method of claim 60, wherein: the attachment feature at the proximal end of the shaft is configured to be polyaxially-adjustably secured to the implement; and adjusting the orientation of the implement to the selected orientation relative to the attachment feature further comprises: poly axially adjusting the orientation of the implement to a selected relative orientation, of a plurality of polyaxially-differentiated potential relative orientations, relative to the attachment feature.

62. The method of claim 61, wherein: the attachment feature comprises a poly axial head having a first semi-spherical surface; and the implement comprises a discrete tulip having a second semi-spherical surface configured to engage the first semi-spherical surface of the polyaxial head to polyaxially-adjustably secure the discrete tulip to the polyaxial head at any of a variety of relative orientations.

63. The method of claim 62, wherein the discrete tulip comprises: at least one opening; and

65 a locking member configured to secure a rod received through the at least one opening to the discrete tulip.

64. The method of claim 60 further comprising: drilling a pilot hole into the bone; and inserting the shaft of the bone fastener into the pilot hole.

65. The method of claim 64 further comprising: tapping a bone thread in the bone to form a tapped bone thread about the pilot hole; and inserting the helical thread into the tapped bone thread.

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