JP2021529583A - Modular screw system with adjustable length - Google Patents

Abstract

A system that includes anchors, anchor components, and anchor assemblies and subassemblies adapted for attachment to the bone structure of a clinical subject. For example, two or more such anchors in the form of a screw may be attached to a bone, eg, a vertebral structure such as a vertebral root, and each anchor connects to a stabilizer such as a surgical rod inserted between the anchors. Will be done. The anchors and assemblies are novel in many respects due to their modular nature and height adjustment capabilities, which allow the anchors to be modular and pre-assembled, as opposed to traditional systems. It will also be available to surgeons in a fully assembled form, allowing a wide range of choices in devising optimal planes for surgical bone fixation. [Selection diagram] Fig. 1

Description

Priority This Patent Cooperation Treaty patent application was filed on June 26, 2018 and is entitled "LENGTH ADJUSTABLE MODELAR SCREW SYSTEM". US Patent Application No. 16 / 018,942 Claim the priority and interests of the issue. The patent application is incorporated herein by reference in its entirety.

The present invention relates to modular and adjustable assemblies for achieving alignment and fixation of two or more bones or bone segments. In certain embodiments, the present invention relates to modular and adjustable assemblies for achieving bone fixation in the spine.

The human skeleton is made up of bones, each of which plays a structural role individually or collectively with other bones. For example, the spinal cord, which surrounds and protects the spinal cord and associated nerves, provides the body with structure and allows fluid movement in many planes. The spine is essentially composed of 24 stacked vertebrae, including 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae. A healthy spine is flexible in multiple directions to allow a wide range of body movements. The intervertebral discs are placed between adjacent vertebrae and provide cushioning and damping to protect the spinal column and nerves in response to various translational and rotational forces associated with body movement. Maintaining the structural integrity and approximate axial alignment of the vertebrae is one key to good health.

The spine of a clinical subject can be damaged or damaged by one of many methods. Abnormalities or injuries to the spine include scoliosis (abnormal lateral curvature), kyphosis, excessive kyphosis, spondylolisthesis, displacement, degenerative or ruptured discs of one or more vertebral bodies. Includes, but is not limited to, fractures and tumors. These and other possible spinal conditions have a direct adverse effect on mobility and also cause pain that can lead to moderate to extreme or even weakness, which can be accompanied by diminished or lost nerve function.

To improve the pain associated with spinal condition and recover from loss of function, two or more vertebrae are fixed in relatively fixed positions, stabilizing the spinal displacement and straightening along the spinal axis. Various conventional procedures have been developed using a range of mechanical surgical systems and implants that can be performed. The stabilization system can be used without spinal fusion therapy or in combination with spinal fusion therapy where one or more spacing devices are used to replace all or part of the disc. Typically, such disc implants are natural bone components, artificial bones, and other biological sources obtained from clinical subjects or donor sources to promote bone growth and fusion between adjacent vertebral bodies. Used with components. One or more such replacements can be achieved with spinal fusion surgery. The fixation system is a substantially rigid structure of bone and mechanical hardware that replaces damaged or affected vertebrae with or without fusion components and connects them to relatively healthy adjacent vertebrae. Works to create.

In general, spinal fusion systems use one or more rigid or substantially rigid surgical stabilizing elements, such as rods or plates, and means for fastening and fixing the stabilizing elements to the bone. Includes modes. Fastening means can include one or more bone anchors, such as screws or bolts, assembled with connectors that allow engagement with one or more stabilizing elements. The connector may include hooks, clamps, cross connectors, and one or more stabilizing elements and other structures that engage the anchor. These systems of anchor and connector assemblies and stabilizing elements are fixed and interconnected to two or more vertebrae to provide support, facilitate vertebra alignment or realignment, and achieve immobilization and fusion.

When spinal fusion surgery is performed from the front of the clinical subject, a stabilizing element in the form of a thin plate, typically made of metal, is attached to the adjacent vertebral body and the plate is secured using an anchor such as a screw. That is the conventional practice. When fusion surgery is performed from the posterior surface of the clinical subject, it is conventional practice to anchor the bone anchor to the vertebral body, typically the pedicle. Multiple levels of adjacent vertebrae can be fixed in this way. Interconnecting the anchored anchors with the stabilizing elements creates a firm fixation between adjacent vertebral bodies.

The mode of surgical access may be open, i.e., involving a relatively extensive excision of soft tissue to explicitly expose the vertebrae to be fixed. In some examples, the mode of surgical access can be minimal and less invasive surgical techniques are used to minimize tissue resection. Although these minimally invasive approaches have many advantages for clinical subjects, the associated reduction in direct access and visualization of vertebral tissue is, in fact, difficult to access, grip, and instrumentally manipulate anchor implants. This means that it complicates the surgeon's efforts and often prolongs the time the clinical subject is undergoing surgery.

Among the many challenges associated with the placement of vertebral stabilization systems is the fact that adjacent vertebrae are usually not perfectly aligned. In fact, along any particular part of the spine, a series of adjacent vertebrae can deviate significantly laterally from the central axis of the spine. Moreover, as a result of natural spinal curvature and any vertebral defects, the corresponding parts, such as the pedicles of adjacent vertebrae, are not in the same plane. In the context of implanting a spinal fixation system, these fluctuations can be adapted to some extent by introducing flexors or curves into the substantially rigid stabilizing elements used for fixation. However, adjusting the curvature of the stabilizing element is not a completely satisfactory solution if the therapeutic benefit is obtained by rearranging the adjacent spines. Therefore, surgeons and surgical teams typically have to manipulate the spine and system instruments in an attempt to align fixed anchors to attach to stabilizing elements. Often, the degree of misalignment in terms of both longitudinal and vertical plane position of the vertebrae along the spine causes failure of one or more of the system components, prolongs surgery, and is a clinical subject. It can cause damage to the spine and ultimately lead to unsatisfactory clinical results. Access challenges in minimally invasive procedures can exacerbate the difficulties associated with misaligned vertebral bodies.

Attempts have been made in the design of spinal fixation systems to address variability in the anatomical structure of the spine, such as the variability in the anatomical structure of the spine described above. In many examples of conventional systems, the anchor is adapted to achieve a range of positioning variation based on the pivotal rotation of the anchor so that the axis of the fixed anchor with respect to the stabilizing element can be changed. These are called multi-axis and uni-axis anchors. They are particularly useful for facilitating the attachment of stabilizing elements to two or more vertebrae that are not aligned along the spinal axis. There are other examples of systems adapted by features that facilitate the engagement of non-axially aligned vertebrae. However, there is no conventional system suitable for responding to relative height fluctuations of adjacent vertebrae, where the corresponding parts of the adjacent vertebrae are not in the same plane. In addition, the surgeon attaches the bone anchor to the bone and then chooses from a range of modal anchor components to achieve an optimization system for fixation that avoids or minimizes problems associated with anatomical differences in the spine. There is no traditional system that allows options. Other than the spine, there is similarly no system that offers either or both modular and length-adjustable options in bone and fragment fixation or reduction, for example for other bones and fragments in the body.

To address the above challenges, the height of the vertebral body does not share a common plane, providing adjustability, ideally modularity, while satisfying or exceeding the functionality of traditional anchors. Bone anchors and other implants are needed to address the variability of the. Thus, for example, in spinal situations, uniaxial, uniaxial, and multiaxial positioning is possible and is fairly vertical between the distal attachment point of the bone and the proximal position of the stabilizing element. A fixed system that includes one or more anchors that allow movement and can be locked to avoid further translation after the system has been implanted. Such anchors allow for simplified attachment of adjacent anchors to stabilizing elements by reducing the degree of height variation of adjacent anchors, thereby many faced in surgical settings. Avoid the challenges of.

The present invention describes various exemplary systems and methods of placement of one or more anchors and stabilizing elements adapted for height adjustability during spinal fusion surgery. The present disclosure discloses, in various embodiments both described and contemplated, assemblies, subassemblies, and modular components, and their use to achieve adjustable fixation and / or reduction of bone and bone fragments. And how to install it.

In various embodiments, a modular anchor system with adjustable length for engaging with bone is provided. In an exemplary embodiment, the length adjustable modular anchor system includes a length adjustable modular screw including a neck assembly and shank.

In various embodiments, the present disclosure provides length-adjustable modular screws that include: coaxially by sliding the expander component into the through channel of the collet component along a common axis. A neck assembly that includes an elongated expander and collet components that are engageable, and a threaded shank that includes a socket for coaxially receiving the neck assembly. Here, the length of the modular screw is changed by sliding the engaged neck assembly in the shank socket along the common axis, and the length of the modular screw together with the components of the neck assembly. Selected by compressing and unfolding some of the collet components within the shank socket.

In some embodiments, the neck assembly component is engageable from between the open and compressed configurations.

In some embodiments, the open neck assembly provides free movement of the expander component within the collet component along a common axis.

In some embodiments, the modular screw is engageable with a holding housing configured to accommodate the rod and rod compression set screw.

In some embodiments, the present disclosure provides a length-adjustable modular anchor system for engaging with bone, the length-adjustable modular anchor system includes:
(A) An elongated expander and an elongated expander that is at least one length adjustable modular screw that can be coaxially engaged by slidably inserting the expander component into the through channel of the collet component along a common axis. Includes a neck assembly containing collet components and a threaded shank containing sockets for coaxially receiving the neck assembly, the neck assembly components are engageable from between open and compressed configurations and open configurations. The neck assembly provides free movement of the expander component within the collet component along the common axis, and the modular screw length is engaged in the shank socket along the common axis. The length of the modular screw is changed by sliding the, and the length of the modular screw is selected by compressing the components of the neck assembly together and unfolding some of the collet components within the shank socket, at least one length. Adjustable modular screw;
(B) At least one surgical rod; and (c) Adjustable length modular screw and retaining housing and locking element for engaging and fixing the surgical rod.

In some embodiments, the length-adjustable modular anchor system further comprises a compression set screw, washer, bone anchor, and one or more additional components selected from a combination thereof.

In some embodiments, the expander component includes a head at the proximal end and a pin extending from the head at the distal end, and the collet component is a seat that can be fitted to the head of the expander component at the proximal end. Containing, at the distal end, including a collet extending from the seat, the collet is oriented parallel to a common axis, includes at least one through slot that runs along at least part of the collet and penetrates the distal end, and is a collet component. The penetrating channel begins in the seat and extends through the distal end of the collet, the shank contains a threaded portion between the proximal and distal ends, and at the proximal end, at least part of the collet of the neck assembly. Includes an aperture that communicates with a socket that extends into the shank along a length from the proximal end to the distal end to accommodate.

In some embodiments, the present disclosure provides a length-adjustable modular anchor system for engaging with bone, the length-adjustable modular anchor system includes:
Modular screw with adjustable length, including neck assembly and shank
The neck assembly contains an expander component and a collet component, some of the expander components can be inserted into the through channel of the collet component along a common axis, and each of the expander and collet components has a collet. Includes collaborative features that can be compressed together for spreading,
The expander component includes a proximal head and a pin extending from the distal head.
The collet component includes a seat that can be fitted to the head of the expander component at the proximal end and a collet that extends from the seat at the distal end, the collet being oriented parallel to a common axis and at least part of the collet. The penetration channel of the collet component begins in the sheet and extends through the distal end of the collet, including at least one penetration slot that penetrates the distal end.
The shank includes a threaded portion between the proximal and distal ends, at the proximal end to a length extending from the proximal end to the distal end to accommodate at least part of the collet in the neck assembly. Includes an aperture that communicates with a socket that extends along the shank
The neck assembly is a length-adjustable modular screw that is adjustable and engageable within the shank to achieve variable length of the length-adjustable modular screw.

In some embodiments, the expander and collet components of the neck assembly are engageable and displaceable between the open and mating configurations, and in the open configuration the pins of the expander component are collet components. Engaged coaxially with the through channel of the, and only partially inserted into it, the expander and collet components are free to move along a common axis, and the components of the neck assembly are actuated into a mating configuration. Then, the head of the expander component and the sheet of the collet component are fitted, and the pins of the expander component are completely inserted into the through channel of the collet component.

In some embodiments, at least one of the expander component and the collet component includes a lock feature that is engageable when the head of the expander component and the sheet of the collet component are fitted.

In some embodiments, the lock feature interferes with the distal end of the collet when the expander and collet components are in the mating configuration to limit displacement of the expander components on the pins of the expander components. Includes circumferential flange.

In some embodiments, the pins of the expander component include a detent area, the collet component contains one or more compression elements within the collet penetration channel, and one or more compression elements of the collet are expanders. And can be engaged within the detent area of the pins of the expander component when the collet component is mated.

In some embodiments, the compressive element is a shaped foot at the distal end, extending within the collet penetrating channel, with the foot being angled, rounded, and out of a square. It has a shape that is one of the above.

In some embodiments, the pins of the expander component include a taper between the detent area and the proximal portion of the pin, and one or more compression elements of the collet include a complementary taper. The complementary taper spreads the collet when pressed against the proximal taper of the detent area. In some embodiments, the taper is conical.

In some embodiments, the collet component is circumferentially arranged around the collet and includes a plurality of through slots extending through the distal end along at least a portion of the length of the collet.

In some embodiments, each of the collet and shank socket has a substantially square cross-sectional shape, the collet comprises four through slots, and each of the through slots is located on the side of the collet and has four legs. The collet contains at least one compression element on each leg.

In some embodiments, the head of the extender component and the sheet of the collet component are each hemispherical.

In some embodiments, the hemispherical head of the extender component comprises a foot having a nearly square cross-sectional shape, and the hemispherical sheet of the collet component has a nearly square cross-sectional shape to accommodate the foot of the extender component. Includes a seat recess with.

In some embodiments, the length-adjustable modular screw further comprises at least one locking feature on at least one of the collet component and the shank that engages to hold the neck assembly within the shank socket.

In some embodiments, the lock feature is located at the proximal end of the shank with a molded recess along at least a portion of the length of the collet component and extends into the shank socket to form a collet configuration. The locking features prevent the neck assembly from being pulled out of the shank socket, including the molded recesses of the element and the complementary protrusions that can be engaged.

In some embodiments, the pins of the expander component include an extension at its distal end, the shank socket comprises a floor and a cannula extending from the floor towards the distal end, and the cannula is an expander component. Fitted to accept an extension of.

In some embodiments, the present disclosure provides a length-adjustable modular anchor system for engaging with bone, the length-adjustable modular anchor system includes:
Modular screw with adjustable length, including neck assembly and shank
The neck assembly contains expander and collet components, at least some of the expander components can be inserted into the through channel of the collet component along a common axis, and each of the expander and collet components is a collet. Equipped with collaborative features that can be compressed together to expand
The expander component includes a proximal head and a pin extending from the distal head.
The collet component includes a seat that can be fitted to the head of the expander component at the proximal end and a collet that extends from the seat at the distal end, the collet being oriented parallel to a common axis and at least part of the collet. Includes at least one penetration slot through the distal end along, the penetration channel of the collet component begins in the sheet and extends through the distal end of the collet.
The shank contains a threaded portion between the proximal and distal ends, along a length at the proximal end from the proximal end to the distal end to accommodate at least part of the collet in the neck assembly. Includes an assembly that communicates with a socket that extends into the shank
Here, the neck assembly is a length-adjustable modular screw that is adjustable and engageable within the shank to achieve variable length of the length-adjustable modular screw;
At least one surgical rod;
Retaining housing and locking elements for engaging and fixing length-adjustable modular screws and surgical rods; and optionally one or more compressions for engagement between the rod and bone anchor Washer.

In some embodiments, the present disclosure provides a surgical method for installing a bone anchor system for spinal fusion, the method including:
(I) Two or more bone anchors, at least one of which is a length-adjustable modular anchor system according to the present disclosure;
At least one surgical rod that defines the longitudinal axis;
Two or more holding housings for engaging and fixing bone anchors and surgical rods;
Two or more locking elements to secure the rod to the bone anchor; and optionally, one or more compression washers for engagement between the rod and the bone anchor;
To select each of
(Ii) Assembling a length-adjustable modular screw system either before or after installing the neck assembly in the holding housing, including the following steps:
(A) Engaging the expander and collet components of the neck assembly into one of the open and mating engagements and inserting the neck assembly into the shank socket;
(B) Bringing the distal end of the shank into contact with the bone;
(C) Using a suitable screwdriver, engage the drive recess in the neck assembly to compress the expander and collet components and unfold the collet;
(D) Pushing the threaded portion of the shank into the bone under continuous compression;
(E) Release the drive compression in the drive recess of the neck assembly;
(F) Length-adjustable module by optionally sliding the neck assembly along a common axis within the socket, either before or after tentatively fixing the surgical rod to the holding housing. Adjusting the length of the formula anchor system;
(F) Tighten the fixing element in the holding housing, compress the rod against the neck assembly, drive the expander and collet components into a compressive engagement, and spread the collet in the shank socket.

In some embodiments, the vertical height (length) of the length-adjustable modular screw can be adjusted intraoperatively. In some embodiments, the length-adjustable modular anchor system is fully assembled before the threaded portion of the shank engages the bone. In some embodiments, the vertical height (length) of the length-adjustable modular screw can be continuously adjusted along the length of the shank to select height adjustment. In some embodiments, the length-adjustable modular screw comprises one or more secure stop features in the shank, and the length-adjustable modular screw has a vertical height (length). , Can exist incrementally along the length of the shank, the increment of which corresponds to one or more certain stop features. In some embodiments of this method, the length-adjustable modular anchor system is provided pre-assembled. In some embodiments of this method, at least the neck assembly of the length adjustable modular anchor system is provided pre-assembled with the holding housing.

Various embodiments of the invention disclosed herein will be considered with reference to the accompanying drawings. These drawings merely depict typical embodiments and do not limit the scope.

A front plan view and an alternative perspective view of a modular anchor system with adjustable length according to the present disclosure are shown. FIG. 1 shows an exploded and assembled perspective view of the neck assembly of the length adjustable modular anchor system shown in FIG. FIG. 1 shows a front plan view, an exploded perspective view, and an enlarged perspective view of the length-adjustable modular anchor system shown in FIG. An alternative top perspective view, side view, and partially enlarged side view of the expander component of the neck assembly shown in FIG. 2 are shown on the left side, and an alternative top perspective view, side view of the collet component of the neck assembly shown in FIG. The figure and the side sectional view are shown on the left side. An alternative side view, top perspective view, and side cross-sectional view of the shank components of the length-adjustable modular anchor system 10 shown in FIG. 1 are shown. A bottom view and a top view are shown above, and a side view and a cross-sectional view of the length-adjustable modular anchor system 10 shown in FIG. 1 below, and the holding housing 20, compression washer 30, and locking element according to the present disclosure. A side view and a cross-sectional view of an alternative embodiment of the length adjustable modular anchor system 10 including 40 are shown. Each of the holding housing 20, the compression washer 30, the locking element 40, and the protrusion 570 is shown separately in a separate figure.

The embodiments for carrying out the present invention describe exemplary embodiments based on the general concept of the invention, and are not intended to limit the scope of the present invention in any way. In fact, the invention described herein is broader than, and is not limited to, the exemplary embodiments described herein, and the terms used herein are their complete usual. Has the meaning of.

Here, general invention concepts are described with occasional reference to exemplary embodiments of the invention. However, this general concept of the invention can be embodied in different forms and should not be construed as being limited to the embodiments described herein. Rather, these embodiments are provided so that the present disclosure is thorough and complete and fully conveys the scope of the concept of the invention to those skilled in the art. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by experts in the art, including general invention concepts. The terms described in the embodiments for carrying out the present invention are for the purpose of describing a specific embodiment, and are not intended to limit the general concept of the invention. As used in this detailed description and the appended claims, the singular forms "a", "an", and "the" may also include the plural unless the context explicitly states otherwise. Intended.

The term "proximal" used in connection with any object refers to the part of the object closest to the operator (or other mentioned reference point) of the object, and the term "distal" refers to the object. Refers to the part of the object farthest from the operator (or other stated reference point) of. "Clinical subject" refers to a human or other animal subject to treatment with a bone fixation or reduction device according to the present disclosure. With respect to the criteria herein that can be made for a clinical subject, the term "cranial" refers to the direction towards the head of the clinical subject and the term "caudal" refers to the direction towards the foot of the clinical subject. The term "posterior" refers to the direction toward the back of the clinical subject, the term "anterior" refers to the direction toward the front of the clinical subject, and the term "lateral" refers to the direction toward the side of the clinical subject. show.

As specifically used herein, the term "height" relates to reference to the spine of a clinical subject and refers to the relative position of one or both of the vertebrae and anchors along the adjacent portion of the spine. Similarly, the terms "vertical" and "vertical adjustment" refer to the relative height variation of one or both of the vertebrae and anchors along the adjacent part or length of the spine in the context of a prone clinical subject. And with respect to its adjustment, the anchor length adjustment will then be within the anterior-to-rear vertical dimension. These descriptors are not intended to be limiting with respect to embodiments of modular adjustable assemblies, subassemblies, and components according to the invention that are useful outside the spine, and more generally "length" and. It can be replaced with an alternative descriptor containing "length adjustment", in which the orientation of the bone and implant is different from the clinical subject or body part.

As used herein in the embodiments described and illustrated, the term anchor typically refers to the screw components of an anchor assembly or subassembly, and the term anchor assembly refers to a retaining housing (conventional tulip head). Or an attachment feature, such as another type of attachment device, and one or more of compression washers and set screws, and optionally additional screw components. Subassemblies also refer to modular components of the screw, such as, for example, shank and head portions, as well as these subassemblies. More generally, anchor components, subassemblies, and assemblies can be adapted to include features suitable for use in any bone of the clinical subject, in which they are modular and adjustable. The features are as described and claimed herein.

Unless otherwise indicated, all numbers representing properties such as quantity, length, diameter, etc. of materials used herein and in the claims are to be modified by the term "about" in all cases. Should be understood. Therefore, unless otherwise indicated, the numerical properties described herein and in the claims are approximate values that may vary depending on the appropriate properties required to be obtained in the embodiments of the present invention. Although the numerical ranges and parameters that indicate the broad range of general invention concepts are approximations, the numerical values shown in a particular example are reported as accurately as possible. However, the numbers essentially contain specific errors due to the errors found in each measurement. With reference to the drawings here, embodiments of a modular and length-adjustable modular anchor system 10 for fixing a bone stabilizing element such as a spine stabilizing rod to the bone are shown in FIGS. 1-6. There is. As further described herein, the length-adjustable modular anchor system 10 includes a length-adjustable modular screw 100 that is variable in length.

According to the illustrated embodiment, the length-adjustable modular screw 100 has a head 310 portion with a hemispherical screw head at the proximal end 410 and a separate threaded shank with a threaded shank 500 at the distal end. Assembled to provide a structure similar to conventional screws, including 500 parts. According to the present disclosure, the components of the length-adjustable modular screw 100 are fitted for interconnection along a common elongated shaft to achieve fixation or variable length when implanted in bone. Therefore, vertical displacement is possible. In a conventional pedicle screw anchor, the pressure from a rod locked to the holding housing 20 (tulip head) by a threaded nut displaces the compression washer 30 in the tulip head 20 and compresses the screw head. Compressive force is transmitted to the screw by, which locks it in place within the tulip head 20 and prevents axial rotation (for uniaxial and multiaxial assemblies). FIG. 6 provides an example of such a system, including an embodiment of the length adjustable modular screw 100 according to the present disclosure. In use, the compressive force used to lock the rod to the conventional screw also serves to lock the embodiment of the length adjustable modular screw 100 according to the present disclosure, thereby selected by the surgeon. Fix the vertical position.

Modular Anchor System with Adjustable Length In an alternative embodiment, a modular anchor system 10 with adjustable length for engaging with bone is provided. In one embodiment, as shown in FIG. 1, the length adjustable modular anchor system 10 includes a length adjustable modular screw 100 including a neck assembly 200 and a shank 500. With reference to FIG. 2, the neck assembly 200 includes an expander component 300 and a collet component 400. Once assembled, a portion of the expander component 200 can be inserted into the through channel 430 of the collet component 400 along a common axis, as shown in FIG. The penetration channel 430 of the collet component 400 begins within the sheet 440 and extends through the distal end 530 of the collet 450. Upon engagement, the head 310 of the expander component 300 contacts the sheet of the collet component 400 and the pin 330 passes through the through channel 430. In some embodiments, as shown in the drawings, the expander component pins 300, 330 include an extension extending beyond the distal end 420 of the collet 450. In other embodiments, the expander component pin 330 may lack such an extension and therefore the pin 330 may not extend beyond the distal end 420 of the collet 450.

The expander component 300 and the collet component 400 are engageable in the open configuration, the mating configuration, and the compression configuration, respectively. In the open configuration, the expander component 300 and the collet component 400 engage without the head 310 contacting the seat 440, and the pin 330 of the expander component 300 is coaxial with the through channel 430 of the collet component 400. Fitted and only partially inserted into it, the expander and collet components 300, 400 are free to move along a common axis.

In the mating configuration, as shown in FIG. 3 (center image), the head 310 is in contact with the seat 440, and the head 310 of the expander component 300 and the seat 440 of the collet component 400 are fitted but compressed. Instead, the pin 330 of the expander component 300 is fully inserted into the through channel 430 of the collet component 400. The collet 450 is not unfolded in each of the open and mating configurations. In the compression configuration, the expander component 300 and the collet component 400 are fitted, the head 310 and the sheet 440 are contacted and compressed so that the collet 450 has an overall larger diameter 590 than the unexpanded configuration. Spread to. Each of the expander and collet components 300, 400 includes a collaborative feature that can be compressed together to expand the collet 450.

With reference to the left side of FIG. 4, the expander component 300 includes a head 310 at the proximal end 410 and a pin 330 extending from the head 310 at the distal end 420. Referencing the right side of FIG. 4 again, the collet component 400 includes a seat 440 that can be fitted to the head 310 of the expander component 300 at the proximal end 530 and a collet 450 extending from the seat 440 at the distal end 420. .. In some embodiments, the head 310 of the expander component 300 and the sheet 440 of the collet component 400 are each approximately hemispherical and fitted to form a 220, approximately spherical head 310 and are fitted. The features of the 220 pin 330 and the collet 450 form a substantially rod-shaped extension from the sphere. Of course, it will be appreciated that in some embodiments, the features of the head 310 and seat 440 can be non-hemispherical. As shown, the expander component 300 has a head 310 that is approximately hemispherical and includes a flat portion at its apex that includes a drive recess 360 for engaging the driver. Any suitablely shaped drive recess 360 can be used for engagement with any of the various drivers. As shown in the drawings, in some embodiments, the head 310 of the expander component 300 includes a foot 320 having a substantially square cross-sectional shape, and the seat 440 of the collet component 400 is a foot 320 of the extender component 300. Includes a complementary sheet recess 441 with a nearly square cross-sectional shape to accommodate.

In various embodiments, the collet 450 comprises at least one through slot 452 oriented parallel to the common axis, through the distal end 420 and along at least a portion of the collet 450. And in some embodiments, the collet 450 is arranged circumferentially around the collet 450 and extends through at least a portion of the length of the collet 450 through the distal end 420. 452 is included. As shown in the drawings, eg, FIG. 4, the collet 450 includes four through slots 452. In the illustrated embodiment, the collet 450 has a substantially square cross-sectional shape 490, and each of the through slots 452 is arranged on the side surface of the collet 450 to form four legs. As shown, the collet 450 has chamfered corners 482 and substantially flat sides on its outer surface. The collet 450 then includes an array of interference enhancers 454 on the outer surface of its distal end 420. As shown, the interference enhancer 454 contains a jagged texture. In other embodiments, the feature may include other texture elements or may include one or more grooves, depressions or ridges. The interference enhancer 454 may enhance contact with the wall 550 of the socket 540 in the shank 500 when the collet 450 is unfolded. The interference enhancer 454 can also increase the flexibility of the shank 500 to spread. It will be appreciated that in some embodiments, the collet 450 lacks such an interference enhancer 454. Then, as shown in the illustrated embodiment, the collet 450 is substantially block-shaped with a taper or angle directed proximally on each leg 456 at its distal end 420 and within the penetrating channel 430. Includes compression element 460 of.

Various conventional features of the collet 450 are known in the art and can be selected to facilitate locking and compression and / or frictional engagement between the collet 450 and the anchor components to be engaged. Will be understood. In some examples, the difference in wall thickness of one or more components can be used to achieve compressive engagement. In another example, the features of the collet 450 may include a taper along the length of the engaging component. The features described herein are intended to be non-limiting and can be modularly adjusted according to the invention using other features of the collet 450 known in the art. It will be understood that an inventive anchor can be achieved.

In some embodiments, at least one of the expander component 300 and the collet component 400 is a locking feature that can be engaged when the head 310 of the expander component 300 and the sheet 440 of the collet component 400 are fitted 220. Includes part. In some such embodiments, for example, as shown in FIG. 2, the lock feature is 220 fitted with expander and collet components 300, 400 to limit displacement of the expander component 300. Includes a circumferential flange 340 on pin 330 of the expander component 300 that interferes with the distal end 420 of the collet 450 when in place. As shown in the drawing, the circumferential flange 340 is located between the proximal and distal ends 410, 420 and is angled from proximal to distal towards a common axis and is approximately conical. Oriented with a nearly flat surface on the proximal edge abutting the taper 332 forming the taper 332 of the. And, as shown, the pin 330 has a diameter at its proximal end 410 that is greater than the diameter of the distal end 420.

In some embodiments, pin 330 of the expander component 300 also includes a detent region 350, as shown in FIG. As shown, the detent region 350 has approximately the same diameter as the pin 330 at the distal end 420. Then, as shown, the detent region 350 is angled from proximal to distal towards a common axis and abuts at its proximal end 410 by a taper 332 forming a nearly conical taper 332. Will be done. Referring again to FIG. 4, collet component 400 includes at least one compression element 460 in collet 450 through channel 430. As shown in the drawings, eg, FIG. 2, at least one compression element 460 of the collet 450 is a detent area of pin 330 of the expander component 300 when the expander and collet components 300, 400 are fitted 220. Engageable within 350. In various embodiments, the compression element 460 extends through the channel 430 into the collet 450 and has a shape that is one of diagonal, round, and square. In various embodiments, the compression element 460 can be continuously formed, interrupted only by through slots 452, can be dome-shaped, can have a flat circumferential flange 340 shape, and one or more. It can include cones or chamfered edges, and can be wedge-shaped. Then, there may be a plurality of compression elements 460 arranged along the length of the penetration channel 430.

With reference to the drawing again, eg, FIG. 4, the pin 330 has a cross-sectional shape 370 that is substantially cylindrical, and the through channel 430 of the collet component 400 has an inner wall 431 that has a cylindrical inner wall cross-sectional shape 432. .. It will be appreciated that in other embodiments, each of the cross-sectional shape 370 of the pin 330 and the cross-sectional shape 432 of the inner wall can be non-cylindrical.

It is understood that in other embodiments, the expander component 300 and the collet component 400 may include features that engage to fit and compress, located at positions other than those shown in the drawings. Will be done. For example, one or more of the circumferential flange 340 and the detent area 350 and the taper 332 on the pin 330 can be located more proximally or more distally, and the pin 330 is the circumferential flange 340 and the detent. It may not include more than one or more extensions of the region 350 and the taper 332. Similarly, one or more of the compression elements 460 may be located more proximally or more distally within the penetration channel 430 of the collet component 400. As shown in the drawing, the pin 330 of the expander component 300 includes a conical taper 332 between the detent region 350 and the proximal portion of the pin 330, where one or more compression elements 460 of the collet 450. Includes a complementary taper 332, which expands the collet 450 when pressed against the proximal taper 332 of the detent region 350.

With reference to FIGS. 1 and 3, the length-adjustable modular anchor system 10 also includes a shank 500 that includes a threaded portion 510 between the proximal and distal ends 520 and 530. As shown, the shank 500 includes, at its distal end 530, a distal tip 532, which can be bullet-shaped, 532', suitable for penetrating bone. The shank 500 includes an aperture at its proximal end 520 that communicates with the socket 540. The socket 540 extends in the shank 500 along the length from the proximal end 520 to the distal end 530 and is adapted to accommodate at least a portion of the collet 450 of the neck assembly 200. Once the length-adjustable modular anchor system 10 is assembled, the neck assembly 200 is adjustable and engageable within the shank 500 to achieve the variable length of the length-adjustable modular screw 100.

In various embodiments, the threaded portion 510 of the shank 500 may be continuous from proximal end 520 to distal end 530, or there may be unscrew gaps at both ends, or unscrew gaps. Can exist along the length. In various embodiments, the shank 500 includes at least a major axis and a minor axis 592, 594, the minor axis 594 is defined by the outer surface of the wall 550 of the shank 500 excluding the thread, and the major axis 592 is defined by the thread. In some embodiments, one or both of the major and minor diameters 592 and 594 can be straight or tapered. In some embodiments, there may be a step-down from proximal to distal, just as there may be more than one major axis 592 and / or more than one minor axis 594. In some embodiments, at least a portion of the length of the shank 500 can be continuously tapered 332 from proximal to distal, or it can be tapered 332 in stages. In some embodiments, threading can be varied to provide a proximal thread zone 524 that is different from the distal thread zone 534.

With reference to the drawings again, the depicted collet has a cross-sectional shape of 490 that is approximately square, the socket 540 of the shank 500 has a socket cross-sectional shape of 542 that is square, and the collet 450 and socket 540, respectively, Includes chamfered corners 482 and chamfered side walls 544, respectively. It will be appreciated that in other embodiments, each of the collet cross-section shape 490 and the socket cross-section shape 542 can be non-square and can be cylindrical.

For example, as shown in FIG. 3, the shank 500 includes at least one wall aperture and, as illustrated, projects through each to engage with the neck assembly 200, as further detailed below. Includes two wall apertures 560, 560' adapted to accept 570, 570'. It will be appreciated that in some embodiments, the protrusions 570 and 570'may be integrated with the shank 500. The drawings show pins 330 that can be inserted into apertures 560, 560'via the flange 598 of the shank 500, but in some embodiments the shank 500 may lack the flange 598.

According to some embodiments, the length-adjustable modular screw 100 engages the neck assembly 200 and the shank with at least one locking feature that engages to hold the neck assembly 200 within the shank sockets 500 and 540. Further included in at least one of 500. With reference to FIGS. 3 and 4, in some embodiments, the lock feature is a molded recess 470 along at least a portion of the length of the collet component 400 and a proximal end of the shank 500. Includes complementary protrusions 570 and 570'located at 520. The protrusions 570 and 570'extend within the shank sockets 500 and 540 and are engageable with the molded recesses 470 of the collet component 400. The lock feature prevents the neck assembly 200 from being pulled out of the shank sockets 500 and 540. The lock feature also limits the rotational movement of the neck assembly 200 within the socket 540. As shown, the molded recess 470 is approximately elliptical and elongated from the proximal end 520 to the distal end 530 of the collet component 400. The molded recess 470 includes proximal and distal stoppers 472 and 474. It will be appreciated that other shapes of the molded recess 470 can be used and the molded recess 470 may have a longer or shorter length along the collet 450.

Other features of the neck assembly 200 engage with the shank 500 to further stabilize the engagement. With reference to the drawings again, pins 300, 330 of the expander component include an extension at its distal end 420, and shank sockets 500, 540 are a floor 580 and a cannula extending from the floor 580 towards the distal end 530. Including 596 and. The distal end 530 of the collet 450 contacts the floor 580 to limit the distal passage of the neck assembly 200 within the socket 540, and the cannula 596 stabilizes the neck assembly 200 against off-axis movement with respect to the shank 500. It is adapted to accept an extension of the expander component 300 that assists. In some embodiments, the respective lengths of the extension of the expander component 300 and the molded recess 470 of the collet 450 are when the neck assembly 200 is displaced proximally to the limit of the distal stopper 474. The extension is held within the cannula 596 and is selected to maximize off-axis stabilization and limit shaft withdrawal. As shown in the drawing, the floor 580 of the shank 500 has a substantially conical floor taper 582. In some embodiments, the floor 580 may have a different shape, be flat, or have a spherical contour or another shape. It will be appreciated that in alternative embodiments, different or additional engagement features can be used to achieve a fixed engagement between the subcomponents. Such engagement is useful for allowing one or more components to be torsionally engaged and actuated, such as by a drive tool, while preventing the other component from being subjected to torsional forces. Similarly, it is advantageous to use an engaging feature that acts as a stopper to prevent the components from coming off due to the application of shearing forces, such as pulling out the components aligned in the axial direction.

With reference to FIG. 6 again, an embodiment of a length-adjustable modular anchor system 10 for engaging with bone is shown. The length-adjustable modular anchor system 10 includes at least a length-adjustable modular screw 100 with a neck assembly 200 and a shank 500, a rod (not shown), and a surgical rod for engaging and fixing. Includes one holding housing 20 and locking element 40. Optionally, the length-adjustable modular anchor system 10 also includes one or more compression washers 30 for engagement between the rod and the bone anchor. In use, one or more length-adjustable modular anchoring systems 10 include one or more conventional bone anchors and a surgical rod 50 (or other stabilizing member), a holding housing 20, a lock. It can be used with additional components, including optional components such as element 40 and compression washers 30. An array of anchors and rods 50 of adjacent anchors, for example, two each in the pedicle of the adjacent vertebral body, up to four or more anchor arrangements, and to provide stabilization along the length of the spine. It can be used to stabilize adjacent vertebral bodies, which may include the engagement of a surgical rod with each of the pairs.

Also provided in accordance with the present disclosure is a surgical method for installing a bone anchor system for spinal fusion. According to this method, in some embodiments, the step involves selecting each of two or more bone anchors, at least one of which bone anchors are as described above herein. The neck assembly 200 and shank 500, and at least one surgical rod defining the longitudinal axis, and two or more holding housings 20 for engaging and fixing the bone anchor and the surgical rod, and the rod to the bone anchor. Adjustable length modular anchor system including two or more locking elements 40 for fixation and optionally one or more compression washers 30 for engagement between the rod and the bone anchor It is 10. Further according to this method, the steps include assembling a length-adjustable modular screw 100 system either before or after seating the neck assembly 200 in the holding housing 20.

The steps for assembling the length-adjustable modular screw 100 system first engage the expander and collet components 300, 400 of the neck assembly 200 with one of the 220 engagements that are open and fitted. The neck assembly 200 is inserted into the socket 540 of the shank 500 and then the distal tip 532 of the shank 500 is brought into contact with the bone. Then, using a suitable screwdriver, the drive recess 360 of the neck assembly 200 is engaged to compress the expander and collet components 300, 400 and expand the collet 450. Then, under continuous compression, the threaded portion 510 of the shank 500 is pushed into the bone. When the shank 500 is inserted to the desired depth of bone, the step releases the drive compression in the drive recess 360 of the neck assembly 200, thereby relaxing the collet 450 from spreading, thereby within the shank 500. Includes allowing translation of the neck assembly 200 of the.

Then, either before or after tentatively fixing the surgical rod to the holding housing 20, the vertical height (length) of the length-adjustable modular anchor system 10 is within socket 540 of the shank 500. It can be adjusted by sliding the neck assembly 200 along a common axis. Once the desired length and vertical height for adjacent anatomical structures and / or other anchors or implants have been selected, this method tightens the fixing element within the retaining housing 20 and attaches the rod to the neck assembly 200. On the other hand, the expander component 300 and the collet component 400 are pushed into a compression engagement state, and the collet 450 is spread in the socket 540 of the shank 500. In some embodiments of the surgical procedure, the length-adjustable modular anchor system 10 is fully assembled prior to engaging the threaded portion 510 of the shank 500 with the bone. In yet another embodiment, the length-adjustable modular anchor system 10 is provided pre-assembled. And in yet another embodiment, at least the neck assembly 200 of the length adjustable modular anchor system 10 is provided pre-assembled with the holding housing 20. In some embodiments, the length-adjustable modular screw 100 can be adjusted within a displacement range of zero mm to 20 mm, more specifically between 0 mm and 10 mm, which is 0.1. Includes partial increments within 0.2, 0.3, 0.4, 0.5, 1.0, 1.5, 2.0, and 2.5 to 20.0 mm. Not surprisingly, other increments and range of movement are possible, the practice of which is well within the skills of the art.

It is understood that in each of the various embodiments according to the invention, a plurality of length adjustable modular screws can be provided that are of variable length and thus allow for an extended range of length adaptability. Will be done. Such possible embodiments, whether the length-adjustable modular screw components are of fixed length or are provided in several length ranges, are such possible embodiments. In some embodiments, options are provided to provide pre-assembled lower and upper loading anchor assemblies, as well as anchor assemblies and subassemblies that can be partially assembled by the manufacturer or partially or completely by the surgeon. It is particularly advantageous in that it provides and provides a range of options for achieving maximum flexibility in the surgical setting.

As described herein according to the illustrated embodiments, the components of the length-adjustable modular screw 100 assembly that achieve the locking of the length-adjustable modular screw 100 to the rod are also length-adjustable. Collet for fixing the neck assembly 200 of the possible modular anchor system 10 to the shank 500, and optionally for fixing the vertical position of the length-adjustable modular screw 100 with respect to the vertebral bone and fixation system elements. The 450 lock mechanism can be activated. Of course, in other embodiments, the means to achieve locking can be other than compression by the rod, and in yet other embodiments, the locking means can be the same, but the locking element 40, rod, and compression. Certain elements, such as the washer 30, can be modified.

As used herein, reference is made to a fixation system that includes an anchor in the form of a vertebral pedicle screw and a stabilizing element in the form of one or more surgical rods in the illustrated embodiment. The spine is only one example of a bone or bone system that can be the subject of surgical correction, and therefore pedicle screws and rods are merely examples of bone anchors and vertebral stabilization system components contemplated herein. It will be understood by those skilled in the art. In another example, the anchor can be a tether or other tensioning means, or a screw for engaging with one or more plates or rods, or a combination thereof. And the anchors and systems described herein may be suitable for other bones and bone systems in the body. In addition, it is understood that the mechanism for adjusting the length of the anchor can be adapted for use with other anchors and fixing and stabilizing elements used in orthopedic applications of the spine or other parts of the body. Will be done.

In one example, surgical rods allow for coordinated adjustment of rod length when adjustments such as adjustment of rod length are made during or after implantation and in the context of spinal healing and / or treatment of scoliosis. Therefore, it can be made adjustable according to the features disclosed herein. In yet another example, the adjustable anchor may be used in the reduction or fixation of other bones, such as the bones of the hand or foot, or elsewhere where it is desirable to adjust the length of the anchor or other fixing element. One such example is the dual threading of the adjustment features disclosed herein, along with other head and thread configurations used to interconnect and reduce fractured bone fragments or adjacent bones. With headless screw or screw, rod or pin. Such anchors adapted according to the present disclosure will allow harmonious adjustment of implant length to accommodate anatomical differences in clinical subjects and achieve optimized anchor placement. ..

The present invention is directed in various aspects to systems including assemblies and subassemblies, components including anchors and anchor components adapted for attachment to the bone structure of a clinical subject. In an exemplary embodiment in which use relates to spinal fixation, one, two or more such anchors in the form of a screw are attached to the bone, eg, a vertebral structure such as the pedicle, and each anchor. Is connected to a stabilizer such as a surgical rod that is inserted between the anchors. Anchors are novel in many respects due to their modular nature, and therefore the option to provide anchors in modular, pre-assembled, and assembled forms is an optimal surgical fixation plan. Provides surgeons with a wide range of options when devising.

In use by surgeons, the installation of the above-mentioned inventive components of the exemplary bone anchor system for spinal fusion includes: pre-assembled and including assemblies and subassemblies selected from upper and lower loading forms. Selecting two or more bone anchor assemblies or subassemblies, at least one anchor assembly containing a modular screw with adjustable length; selecting a stabilizing element; By using a suitable screwdriver to drive each of the two or more anchors or anchor subassembly into a fixed engagement with the corresponding vertebral bone, where at least one anchor or anchor subassembly is an anchor by the surgeon. Includes, or is adapted to engage with, modular components that allow length adjustment, including translation along the vertical axis of the anchor, to allow selection of the length of the anchor. That; the proximal portion of the modular adjustable anchor to provide a means of engaging the stabilizing element with the anchor (such a modular portion is from a pre-assembled or modular screw head and engagement sheet. Engage (selected); optionally adjust the length of the anchor stepwise to achieve engagement of the stabilizing element within the anchor; Slide to the position of; introduce a fixing element to at least temporarily fix the stabilizing element in the anchor; optionally, at least adjust the vertical position of the anchor to adjust the stabilizing element and adjacent Optimizing the orientation of the height with respect to the anchor; tightening the fixing element to compress the stabilizing element within the anchor assembly, thereby locking the modular component of the anchor in a fixed manner and locking the position of the anchor. And also lock its engagement with the stabilizing element. This process is repeated for each adjustable anchor in the system, and traditional methods are used with traditional anchors.

The length-adjustable modular screws described herein can be used with the components of a conventional spinal stabilization system and can be used on a single vertebra or across two or more vertebrae of the spine. It will be appreciated by those skilled in the art that it can be used in combination with fused or non-fused treatments. Not surprisingly, in various examples, anchors can be used alone or in systems that include two or more anchors, connectors, and stabilizing elements, other than placement along the spinal axis. Can be placed. Thus, in other use cases, two or more anchors are used to extend either laterally or from anterior to posterior to traverse the vertebral bodies, or wrap one or more vertebral bodies, or they. One or more stabilizing elements, which are a combination of the above, can be fixed. And, of course, in some examples, components, including assemblies and subassemblies, anchors and anchor components, can be used in body bones other than the spine, and therefore individually, as multiples, or as multiples. It can be used in combination with other devices and in combination of these.

10 Modular anchor system with adjustable length 20 Retention housing 30 Compression washers (eg caps)
40 Lock element (eg set screw)
Rod (not shown)
100 Adjustable length modular screw 200 Neck assembly 300 Expander component 310 Head (hemispherical)
320 Foot 322 Foot Cross Section Shape 330 Pin 332 Taper 334 Extension 340 Circumferential Flange 350 Detent Area 360 Drive Recess (Hexagonal)
330 pins 370 cross-sectional shape, eg (square / cylindrical)
400 Collet component 410 Proximal end 420 Distal end 430 Penetration channel 431 Inner wall 432 Inner wall cross-sectional shape (cylindrical)
440 sheets (hemispherical)
441 Seat recess 442 Seat recess Cross-sectional shape, eg (square / cylindrical)
450 collet 490 collet cross-sectional shape (eg square)
452 Penetration slot 454 Interference enhancer (eg groove / depression / ridge)
456 Leg 460 Compression Element 470 Molded Recess 472 Recess Proximal Stopper 474 Recess Distal Stopper 480 Outer Surface 482 Chamfering Corner 500 Shank 510 Threaded Part 520 Proximal End 522 Proximal Aperture 524 Proximal Thread Zone 530 Distal End 532 Distal Tip 532'Bullet tip 534 Distal thread zone 540 Socket 542 Socket cross-sectional shape (eg square / cylindrical)
544 Chamfered side wall 550 Wall 560, 560'Wall aperture 570, 570'Protrusion 580 Floor 582 Floor taper 590 Diameter (eg straight, tapered, stepped down)
592 Major Diameter 594 Minor Diameter 596 Cannula 598 Flange

Claims (18)

Modular anchor system with adjustable length for engaging with bone
To accommodate a neck assembly containing an elongated expander and collet component that can be coaxially engaged by slidably inserting the expander component into the through channel of the collet component along a common axis and the neck assembly. Includes a length-adjustable modular screw, including a threaded shank that includes a socket for the modular screw, the length of which slides the engaged neck assembly within the shank socket along the common axis. The length of the modular screw is selected by compressing the components of the neck assembly together and expanding a portion of the collet components within the shank socket. Adjustable modular anchor system. The neck assembly component can be engaged between an open configuration and a compression configuration, and the neck assembly in the open configuration is free to move the expander component within the collet component along the common axis. The length-adjustable modular anchor system according to claim 1. The length-adjustable modular anchor system according to claim 1, wherein the vertical height (length) of the length-adjustable modular screw is adjustable during surgery. The length-adjustable modular anchor system of claim 1, wherein the length-adjustable modular anchor system is fully assembled before the threaded portion of the shank engages the bone. The first aspect of claim 1, wherein the vertical height (length) of the length-adjustable modular screw can be continuously adjusted along the length of the shank to select height adjustment. Modular anchor system with adjustable length. The length-adjustable modular screw comprises one or more secure stop features in the shank, and the vertical height (length) of the length-adjustable modular screw is that of the shank. The length-adjustable modular anchor system according to claim 1, wherein it may exist incrementally along the length, the increment of which corresponds to said one or more reliable stop features. The length-adjustable modular anchor system of claim 1, wherein the modular screw is engageable with a rod and a holding housing configured to receive a rod compression set screw. Modular anchor system with adjustable length for engaging with bone
(A) An elongated expander and an elongated expander that is at least one length adjustable modular screw that can be coaxially engaged by slidably inserting the expander component into the through channel of the collet component along a common axis. The neck assembly component includes a neck assembly that includes a collet component and a threaded shank that includes a socket for coaxially receiving the neck assembly, the neck assembly component being engageable from between an open configuration and a compression configuration. The open neck assembly provides free movement of the expander component within the collet component along the common axis, and the length of the modular screw is the shank socket along the common axis. Changed by sliding the engaged neck assembly within, the length of the modular screw is such that the components of the neck assembly are compressed together and a portion of the collet component is portion of the shank socket. With at least one adjustable length modular screw, selected by unfolding within
(B) With at least one surgical rod
(C) A length-adjustable modular anchor system that includes the length-adjustable modular screw and a holding housing and locking element for engaging and fixing the surgical rod. The length-adjustable modular anchor system of claim 8, further comprising a compression set screw, a washer, a bone anchor, and one or more additional components selected from a combination thereof. The expander component includes a head at the proximal end and a pin extending from the head at the distal end, and the collet component includes a sheet at the proximal end that can be fitted to the head of the expander component. , A collet extending from the sheet at the distal end, the collet being oriented parallel to the common axis, including at least one through slot that runs along at least a portion of the collet and penetrates the distal end. The penetrating channel of the collet component begins within the sheet and extends through the distal end of the collet, the shank including a threaded portion between the proximal and distal ends, at the proximal end, said. 8. The eighth aspect of the neck assembly comprising an aperture that communicates with a socket extending into the shank along a length from the proximal end to the distal end to accommodate at least a portion of the collet. Modular anchor system with adjustable length. Modular anchor system with adjustable length for engaging with bone
Includes adjustable length modular screw including neck assembly and shank
The neck assembly includes an expander component and a collet component, and a part of the expander component can be inserted into a through channel of the collet component along a common axis, respectively, of the expander and collet components. Includes collaborative features that can be compressed together to spread the collet.
The expander component includes a head at the proximal end and a pin extending from the head at the distal end.
The collet component comprises a sheet at its proximal end that is matable to the head of the expander component and a collet that extends from the sheet at the distal end, the collet being oriented parallel to the common axis. Along at least a portion of the collet, including at least one penetrating slot through the distal end, a penetrating channel of the collet component begins within the sheet and extends through the distal end of the collet.
The shank includes a threaded portion between the proximal and distal ends, from the proximal end to the distal end to accommodate at least a portion of the collet of the neck assembly at the proximal end. Includes an assembly that communicates with a socket that extends into the shank along a length.
The neck assembly is a length adjustable modular anchor system that is adjustable and engageable within the shank to achieve variable length of the length adjustable modular screw. The expander and collet components of the neck assembly are engageable and displaceable between the open and mating configurations, in which the pins of the expander component are of the collet component. Engaged coaxially with the through channel and inserted only partially into it, the expander and collet components are freely movable along the common axis, and the components of the neck assembly are fitted. When actuated in, the head of the expander component and the sheet of the collet component are fitted and the pins of the expander component are completely inserted into the through channel of the collet component, claim 11. Described length adjustable modular anchor system. 12. The expander component and at least one of the collet components include a lock feature that can be engaged when the head of the expander component and the sheet of the collet component are fitted. Described length adjustable modular anchor system. A circle on the pin of the expander component, wherein the lock feature interferes with the distal end of the collet when the expander and collet component are in the mating configuration to limit displacement of the expander component. 13. The length-adjustable modular anchor system according to claim 13, including a circumferential flange. The pins of the expander component include a detent region, the collet component comprises one or more compression elements in the collet penetration channel, and the one or more compression elements of the collet are said to be the expander and 13. The length-adjustable modular anchor system of claim 13, wherein the expander component pins are engageable within the detent area when the collet component is fitted. The compression element is a molded foot at the distal end, extending within the collet penetration channel, the foot being one of cornered, rounded, and square. The pin of the expander component comprises a taper between the detent region and the proximal portion of the pin, and one or more compression elements of the collet have a complementary taper. 15. The length-adjustable modular anchor system according to claim 15, wherein the complementary taper expands the collet when pressed against the proximal taper of the detent region. Each of the extender component head and the collet component sheet is hemispherical, each of the collet and the shank socket has a substantially square cross-sectional shape, and the collet includes four through slots. The length-adjustable modular anchor according to claim 16, wherein each of the through slots is arranged on the side surface of the collet to form four legs, each of which comprises at least one compression element on each leg. system. The length-adjustable modular screw further comprises at least one locking feature that engages the neck assembly to hold it in the shank socket on at least one of the collet component and the shank. The features are formed recesses along at least a portion of the length of the collet component and located at the proximal end of the shank and extend into the shank socket to form the molding of the collet component. 17. The length-adjustable modular anchor system according to claim 17, wherein the locking feature comprises a recessed portion and an engageable complementary protrusion to prevent the neck assembly from being pulled out of the shank socket. ..

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