CN113133823A

CN113133823A - Intramedullary nail sighting device and bone treatment system comprising same

Info

Publication number: CN113133823A
Application number: CN202010061047.4A
Authority: CN
Inventors: 张松; 钱毅; 许志勇
Original assignee: Beijing Montagne Medical Device Co Ltd
Current assignee: Beijing Montagne Medical Device Co Ltd
Priority date: 2020-01-19
Filing date: 2020-01-19
Publication date: 2021-07-20

Abstract

The invention provides an intramedullary nail aiming device and a bone treatment system comprising the same, wherein the intramedullary nail aiming device is suitable for various intramedullary nails and comprises a proximal aiming arm, a distal aiming arm and a connecting device for connecting the proximal aiming arm and the distal aiming arm, wherein for any one intramedullary nail selected from the various intramedullary nails, in a state that the intramedullary nail and the connecting device are installed on the proximal aiming arm, the rotating axis of a rotating component of the connecting device is fixed relative to the proximal aiming arm and points to the front bow bending starting position of the intramedullary nail. And after the distal aiming arm is non-rotatably fixed to the rotation assembly at the proximal connection hole corresponding to the intramedullary nail, the distal aiming arm is translatable relative to the intramedullary nail to enable the distal aiming hole to align with the distal screw hole of the intramedullary nail.

Description

Intramedullary nail sighting device and bone treatment system comprising same

Technical Field

The present invention relates to a medical instrument for orthopedic surgery, and more particularly, to an intramedullary nail aiming device suitable for implanting various intramedullary nails into a medullary cavity of a patient and aiming screw holes of the intramedullary nails, and a bone treatment system including the same.

Background

Intramedullary nail fixation is one of the surgical techniques for treating large long bone fractures. The technology has the advantages of relatively minimal invasion, less bleeding, less complication, capability of early activity and the like. However, due to the irregular shape of the marrow cavity, the intramedullary nail with a single shape is forced to be deformed by compression after being implanted into the marrow cavity, especially to be inclined at the initial position of the anterior bow bend, thereby causing the position of the distal screw hole to change, and the position of the distal screw hole cannot be positioned, thereby causing the implantation of the distal locking screw to be very difficult, resulting in prolonged operation time, increased ray use and even risk of operation failure.

The existing remote screw hole aiming technology comprises a positioning platform positioning technology, an intraoperative adjusting technology and a magnetic navigation technology.

The positioning platform technology is characterized in that an external aiming frame and an implant are installed together in a mechanical mode, and the purpose of finding a nail hole is achieved. However, this method requires cutting an opening in the patient's body tissue at the platform location, but this opening is only used for aiming the instrument, which increases the bleeding and trauma of the patient, and due to the deformation of the implant in the body, there is a situation that the positioning platform cannot be found accurately, which results in that the aiming block and the implant cannot be mounted together, and thus cannot be aimed.

The magnetic navigation technology adopts a magnetic field induction principle, a magnetic source is placed in the implant, and an external induction device induces the position of the magnetic source, so that the aim of aiming at the nail hole is fulfilled. However, this method requires the distal screw to be implanted first and then the proximal screw, and is not suitable for the operation in which the proximal screw must be fixed first and then the distal screw must be fixed, such as the treatment of femoral neck fracture.

The intraoperative adjustment technology is that in the operation process, the C-shaped arm is used for imaging in an auxiliary mode, the position of the guide sleeve is finely adjusted continuously, and the guide sleeve is aligned with a nail hole in an implant. The adjusting mechanism is divided into two types, one is a sliding mechanism, and the other is a rotating mechanism. The difference between the motion mode of the existing sliding mechanism and the deformation actually generated by the implant is larger, and larger axial deviation is easily generated after the intramedullary nail is implanted. The position of the rotation center of the existing rotation mechanism may vary due to the length variation of the implant, so that the position of the aiming hole cannot be the same as the position of the distal screw hole of the intramedullary nail which is inclined after implantation even through rotation, that is, a large axial deviation is also generated. However, axial misalignment can cause the screw to be misaligned from the center of the hole and forcibly screwed in, causing the implant to scratch with the locking screw, resulting in reduced fatigue strength and even failure of the implant resulting in surgical failure.

Therefore, there is a need in the art for an intramedullary nail aimer that is capable of accurately positioning its screw holes, and particularly its distal screw holes, after intramedullary nail implantation.

Disclosure of Invention

In order to solve at least one of the above drawbacks of the prior art, according to one aspect of the present invention, an intramedullary nail aiming device is proposed, which is suitable for a plurality of intramedullary nails, wherein the intramedullary nail aiming device comprises:

a proximal aiming arm having an outer end and an inner end, wherein the inner end is adapted to engage any intramedullary nail selected from the plurality of intramedullary nails;

a connecting device comprising a housing assembly and a rotating assembly rotatably arranged in the housing assembly, wherein the housing assembly is fixed to the outer end portion such that the rotational axis of the rotating assembly is fixed with respect to the proximal aiming arm and points to its anterior bow bending starting position in a state where the intramedullary nail is joined to the inner end portion; and

a distal aiming arm having a distal aiming hole at a distal end thereof and a plurality of proximal connecting holes at a proximal end thereof corresponding to the plurality of intramedullary nails, wherein the distal aiming arm is non-rotatably fixed to the rotation assembly at the proximal connecting holes corresponding to the intramedullary nails and is adapted to translate relative to the proximal aiming arm in a plane perpendicular to the rotation axis such that the distal aiming hole is aligned with the distal screw hole thereof in a state where the intramedullary nail is coupled to the inner end portion.

Optionally, the rotation assembly comprises a rotation core rotatably disposed in the housing assembly and a rotation post non-rotatably fixed to and axially protruding from the rotation core, wherein the rotation core comprises a radial protrusion protruding radially therefrom and the distal aiming arm is non-rotatably fixed to the rotation post at a proximal connection hole corresponding to the intramedullary nail, and

the coupling device further includes an actuating assembly extending along a displacement axis perpendicular to the rotational axis and including spaced apart threaded portions and gripping portions, wherein threads of the threaded portions engage corresponding threads of the housing assembly, and the gripping portions are configured to grip free ends of the radial protrusions in a direction of the displacement axis.

Optionally, the free end of the radial projection is cylindrical, the grip portion comprises first and second spaced apart radial flanges and a radial annular groove defined therebetween, wherein the radial annular groove is configured to receive the free end and the first and second radial flanges are configured to remain in contact with the free end.

Optionally, the rotary core has a central opening defined therein, wherein the rotary post is non-rotatably fixed to the central opening and adapted to slide relative to the rotary core along an edge of the central opening in a first sliding direction perpendicular to the axis of rotation.

Optionally, the rotary column has a radial flange projecting radially therefrom, the edge of the central opening having defined therein a pair of grooves parallel to each other and extending along said first sliding direction, the two parallel edges of the radial flange being snap-fitted in said pair of grooves.

Optionally, the proximal connection hole is in the form of an elongated hole, the rotation post being adapted to slide in the proximal connection hole along a second sliding direction perpendicular to the rotation axis and at a non-zero angle to the first sliding direction.

Optionally, the second sliding direction is perpendicular to the first sliding direction.

Optionally, the spin column has a flat surface defined on a radially outer surface thereof, and the proximal connection hole has an opposing flat surface defined on a sidewall thereof extending along the second sliding direction, wherein the flat surface is configured to contact the opposing flat surface.

Optionally, the housing assembly comprises a threaded bore leading to the rotating assembly, and the connecting means further comprises a set screw, wherein the set screw is configured to be threadedly connected with the threaded bore such that rotation of the set screw can cause it to compress against the rotating assembly to prevent rotation of the rotating assembly.

According to another aspect of the present invention, a bone treatment system is proposed, wherein the bone treatment system comprises an intramedullary nail aimer as described above and a plurality of intramedullary nails to which the intramedullary nail aimer is adapted, wherein,

an intramedullary nail selected from the plurality of intramedullary nails is coupled to the inner end of the proximal aiming arm such that the rotational axis of the rotating assembly of the connecting device is aligned with the anterior bow bend start position of the intramedullary nail, and

the distal aiming arm is non-rotatably secured to the rotating assembly of the connection device at a proximal connection hole corresponding to the intramedullary nail and is adapted to translate relative to the intramedullary nail in a plane perpendicular to the axis of rotation such that the distal aiming hole is aligned with the distal screw hole of the intramedullary nail.

The invention may be embodied in the form of exemplary embodiments shown in the drawings. It is to be noted, however, that the drawings are designed solely for purposes of illustration and that any changes which come within the teachings of the invention are to be considered as included within the scope of the invention, which is defined solely by the appended claims.

Drawings

The drawings illustrate exemplary embodiments of the invention. These drawings should not be construed as necessarily limiting the scope of the invention. Like numbers and/or like reference numerals may refer to like and/or like elements throughout. In the various drawings:

fig. 1 is a schematic perspective view of an intramedullary nail sight according to the present invention in an exploded state;

fig. 2 is a schematic perspective view of an assembled state of the connecting device of the intramedullary nail sight according to the present invention;

fig. 3 is a schematic perspective view of the coupling device of the intramedullary nail sight according to the present invention in an exploded state;

fig. 4 is a schematic perspective view of the rotating core of the connecting device of the intramedullary nail sight according to the present invention;

fig. 5 is a schematic perspective view of a fastening assembly of the intramedullary nail sight according to the present invention; and

fig. 6 is a schematic illustration of the tilted state of the intramedullary nail after implantation and the operation of the prior art aiming mechanism.

Detailed Description

The present invention will now be described in more detail with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as necessarily limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided merely to illustrate the invention and to convey the concept of the invention to those skilled in the art.

As used herein, with reference to the human body and the components described herein that are intended to be implanted into the human body, the terms "proximal P" and "distal D" are defined relative to the torso of the patient at the time of the implantation procedure, wherein the term "proximal P" is the end closer to the torso and the term "distal D" is the end farther from the torso, and on the basis thereof, the term "proximal P" and the term "distal D" together define a proximal-distal direction DP; the term "medial end M" and the term "lateral end L" are defined relative to the sagittal plane of the patient, wherein the term "medial end M" refers to the side closer to the sagittal plane and the term "lateral end L" refers to the side farther from the sagittal plane, on the basis of which the term "medial end M" and the term "lateral end L" together define a medial-lateral direction ML; the term "anterior end F" and the term "posterior end B" are defined relative to the orientation of the patient, wherein the term "anterior end F" refers to the direction in which the patient is facing and the term "posterior end B" refers to the direction in which the patient is facing away, and, based thereon, the term "anterior end F" and the term "posterior end B" together define an anterior-posterior direction FB. In the above definition, a "sagittal plane" is an imaginary vertical plane passing through the middle of the body or body structure, which divides the body or body structure into left and right halves. It is to be noted, however, that the above definitions regarding relative orientations are only given for the purpose of better illustrating the technical solution of the present invention through the accompanying drawings and should not be construed as limiting the scope of protection of the present invention in any way. Additionally, as used herein, the term "non-rotatably fixed" means that the objects involved cannot rotate relative to each other, but can still slide and/or translate relative to each other.

Referring to fig. 1-5, according to one aspect of the present invention, an intramedullary nail aimer is provided that generally includes a connecting device 100 and distal and proximal aiming

arms

200 and 300 connected together by the connecting device 100. The respective constituent elements are described in detail next.

The proximal aiming arm 300 of the present intramedullary nail aimer is described below with reference to fig. 1. As shown in fig. 1, the proximal aiming arm 300 is generally U-shaped, with the opening of the U-shaped structure facing in the distal direction D in the situation shown in the figure. The proximal aiming arm 300 comprises an outer end 310 and an inner end 320 separated along the medial-lateral direction ML, wherein the outer end 310 is for engaging the connection device 100 and the inner end 320 is for engaging the intramedullary nail 400 to be implanted. Optionally, the proximal aiming arm 300 has one or more proximal aiming holes defined therein, when the intramedullary nail 400 to be implanted is secured (e.g., by threaded connection, snap fit, friction fit, etc.) to the inner end 320, the proximal aiming hole is aligned with a proximal screw hole in the intramedullary nail 400, by "aligned" is meant that the proximal aiming hole is coaxial with the proximal screw hole, thus, when the intramedullary nail 400 is implanted in a patient (e.g., in a fractured femur of a patient), the guide sleeve may be inserted into the proximal aiming hole and extended toward the proximal screw hole, with the guide sleeve, the proximal aiming hole, and the proximal screw hole being coaxial, thereby, the proximal bone screw may be advanced in the guide sleeve towards the proximal screw hole and finally screwed into the bone through the proximal screw hole, thereby fixating the intramedullary nail at its proximal end in the patient.

The distal aiming arm 200 of the instant intramedullary nail aimer is described below with reference to fig. 1. As shown in fig. 1, the distal aiming arm 200 has a generally cylindrical shape extending along the distal-proximal direction DP. The distal targeting arm 200 has a distal targeting hole 210 (four shown) therethrough at its distal end and a plurality of proximal attachment holes 220 therethrough at its proximal end, wherein the distal targeting hole 210 is for aligning a distal screw hole 410 in the bone screw 400 and the distal targeting arm 200 is attached to the attachment device 100 at one of the plurality of proximal attachment holes 220. In addition, the plurality of proximal connecting holes 220 are provided in order to enable the instant intramedullary nail sight to fit a variety of intramedullary nails, that is, the plurality of proximal connecting holes 220 correspond to a variety of intramedullary nails of different sizes (specifically, different sizes along the distal-proximal direction DP), wherein each proximal connecting hole 220 corresponds to an intramedullary nail of one size. Further, after the physician selects an intramedullary nail 400 to be implanted for the patient according to the pre-and/or intra-operative planning, the distal aiming arm 200 is connected to the connection device 100 at the proximal connection hole 220 corresponding to the selected intramedullary nail 400 to enable the distal aiming hole 210 to be aligned with the distal screw hole 410, and then a distal bone screw is implanted in a manner similar to the implantation of the proximal bone screw described above to enable the distal bone screw to be screwed into the bone through the distal screw hole 410 to be fixed in the patient at the distal end of the intramedullary nail. It is noted that although 9 proximal connecting holes 220 are shown, in other embodiments, the number of proximal connecting holes 220 may vary depending on the type of intramedullary nail chosen, for example, if there are 10 intramedullary nails chosen, then 10 proximal connecting holes 220 may be provided. Accordingly, embodiments in which any number of proximal connection holes 220 are provided should be considered within the teachings of the present invention and are therefore included within the scope of the present invention.

Optionally, a number of intramedullary nails corresponding to proximal connection holes 220 is provided adjacent each proximal connection hole 220, such as the numbers "30, 32, 34, 36, 38, 40, 42, 44, 46" shown on the upper surface of distal aiming arm 200. Therefore, after the physician selects the intramedullary nail to be implanted, the proximal connection hole 220 corresponding to the intramedullary nail can be found more conveniently according to the serial number of the intramedullary nail, so that the subsequent operation can be performed more quickly, and the operation efficiency can be improved.

Optionally, symbols representing whether it is applied to a left limb implant procedure or a right limb implant procedure are provided on the surface of the distal aiming arm 200. For example, in the case of the left limb implant procedure shown in fig. 1, a symbol "L" representing its application to the left limb implant procedure is provided on the surface of the distal aiming arm 200. Thus, when the surgeon is ready to perform a left limb intramedullary nail implantation procedure, the distal aiming arm 200 with the symbol "L" may be used; when the surgeon is ready for a right limb intramedullary nail implantation procedure, the distal aiming arm 200 with the symbol "R" may be used. Further optionally, the symbols face the physician when the present intramedullary nail sight is assembled. Thus, by the arrangement of the symbols described above, the physician can be assured of using the correct distal aiming arm 200, and thus can be assured of the implantation procedure being performed smoothly.

The following describes the connection device 100 of the intramedullary nail sight with reference to fig. 1-4. As shown in fig. 2, the coupling device 100 generally includes a housing assembly 110 and a rotation assembly 120 rotatably disposed in the housing assembly 110. Wherein the housing assembly 110 is configured to be fixed to the outer end 310 of the proximal aiming arm 300 such that after the intramedullary nail 400 to be implanted is mounted to the inner end 320 of the proximal aiming arm 300 as shown in fig. 1, the axis of rotation XX' of the rotation assembly 120 is fixed relative to the proximal aiming arm 300 and directed towards or through the anterior bow bend starting position S of the intramedullary nail 400; and the rotation assembly 120 is configured to be connected to the distal aiming arm 200 at the proximal connection hole 220 corresponding to the intramedullary nail 400 to be implanted, such that the rotation assembly 120 can bring the distal aiming arm 200 to rotate about its rotation axis XX ', and the distal aiming holes 210 can be aligned with the distal screw holes 410 of the intramedullary nail 400 after the intramedullary nail 400 to be implanted and the connection device 100 are mounted to the proximal aiming arm 300, i.e., the plurality of distal aiming holes 210 can be coaxial with the plurality of distal screw holes 410, as indicated by axis YY' in fig. 1. Although the arrangement of the intramedullary nail sight has been described above in relation to a selected one of the plurality of intramedullary nails to which it is adapted, it will be appreciated that the arrangement described above is applicable in relation to any of the plurality of intramedullary nails selected. That is, for any one of the intramedullary nails selected from the plurality of intramedullary nails, after the intramedullary nail and the connection device 100 are mounted to the proximal aiming arm 300, the rotational axis XX' of the rotating assembly 120 of the connection device 100 is fixed relative to the proximal aiming arm 300 and points (or passes) toward the anterior bow bend start position of the intramedullary nail; and further, after distal aiming arm 200 is coupled to rotation assembly 120 at a proximal coupling hole corresponding to the intramedullary nail, distal aiming hole 210 can be aligned with a distal screw hole of the intramedullary nail.

With the above-described solution, after a physician selects an intramedullary nail 400 for a patient who has encountered a fracture, or the like, for example, by preoperative and/or intraoperative planning, the instant intramedullary nail aimer may be assembled from the intramedullary nail 400 and the intramedullary nail 400 mounted thereon. Alternatively, intramedullary nail 400 may be installed prior to the present intramedullary nail sight assembly. At this time, according to the above-described solution, the rotation axis of the distal aiming arm 200 (i.e., the rotation axis XX' of the rotation assembly 120) points or passes through the anterior bow bending start position S of the intramedullary nail 400, and the distal aiming hole 210 of the distal aiming arm 200 is aligned with the distal screw hole 410 of the intramedullary nail 400. However, as can be seen from the foregoing, referring to the dotted line portion in fig. 6, after the intramedullary nail 400 is implanted in a patient (e.g., in the medullary cavity of a femur), the intramedullary nail 400 may be tilted at the anterior bow bending start position S due to the natural bending of the medullary cavity, thereby causing the positions of the plurality of distal nail holes 410 to change. When intramedullary nail 400 is implanted in the patient ' S medullary cavity, the patient ' S orientation may be adjusted such that intramedullary nail 400 is tilted about rotational axis XX ' of rotating assembly 120 at anterior bow bend starting position S after implantation in the patient. In this case, since the distal aiming hole 210 of the distal aiming arm 200 is aligned with the plurality of distal screw holes 410 when the intramedullary nail 400 is not implanted, and the distal aiming arm 200 can be rotated by means of the rotating assembly 120 about the rotation axis XX' directed to or passing through the anterior bow bending start position S, the distal aiming hole 210 can be aligned with the distal screw holes 410 after the aiming arm 200 is rotated by a proper angle, without causing a deviation between the axial position of the aiming hole and the axial position of the distal nail hole after the rotation, which may cause difficulty in the implantation of the bone screw, even failure in the implantation, or forced implantation of the bone screw by the doctor, thereby causing scratches on the surface of the intramedullary nail and thus affecting the service life thereof, as in the case of the aiming device in the related art shown by the two-dot chain line. In summary, with the intramedullary nail aiming device of the invention, after the intramedullary nail is implanted into a patient body, the position of the far screw hole of the intramedullary nail can be found, so that the implantation of the bone screw (especially the far bone screw) can be carried out smoothly, and the intramedullary nail is protected from being damaged by the bone screw, thereby prolonging the service life of the intramedullary nail.

The connection device 100 is described in detail below with reference to fig. 2-4. As shown, the rotation assembly 120 includes a rotation core 122 rotatably disposed in the housing assembly 110 and a rotation post 121 non-relatively rotatably fixed to the rotation core 122 and protruding from the rotation core 122 in a direction parallel to the rotation axis XX', wherein the rotation post 121 is configured to be connected to the distal aiming arm 200 at a proximal connection hole 220 corresponding to the intramedullary nail 400 to be implanted, such that the distal aiming hole 210 can be aligned with the distal screw hole 410 and the rotation assembly 120 can rotate the distal aiming arm 200. Alternatively, as shown in fig. 3 to 4, the rotary core 122 has a rotary core body 122a and a radial protrusion 122b protruding radially (in a direction perpendicular to the rotation axis XX ') from the rotary core body 122a, wherein the rotary core body 122a has a cylindrical radially outer surface 122a1, which radially outer surface 122a1 is in contact with a likewise cylindrical radially inner surface 115 of the housing assembly 110, so that the rotary core body 122a is radially held by the radially inner surface 115 and is rotatable about the rotation axis XX' within the housing assembly 110. Optionally, the rotary core 122 further has a central opening 122c defined in the rotary core body 122a, and the rotary column 121 is fixed in the central opening 122c so as not to be relatively rotatable. Further, the central opening 122c has two opposite grooves 122c2, 122c2 'parallel to each other defined in two opposite edges 122c1, 122c 1' thereof, the two opposite grooves 122c2, 122c2 'extending in a first sliding direction perpendicular to the rotation axis XX', and the rotary cylinder 121 has a rotary cylinder body 121a and a radial flange 121b radially protruding therefrom, the two parallel edges 121b1, 121b1 'of the radial flange 121b being snap-fitted in the two opposite grooves 122c2, 122c 2' so that the rotary cylinder 121 is slidable in the first sliding direction but not rotatable with respect to the rotary core 122. Although the figures show that the sliding in the first sliding direction is achieved in such a way that a groove is provided in the edge of the central opening 122c and the edge of the radial flange 121b is snapped into the groove, it will be understood by those skilled in the art that the sliding in the first sliding direction can also be achieved in such a way that a groove is provided in the edge of the radial flange 121b and the edge of the central opening 122c is snapped into the groove. As shown, the central opening 122c opens out of the rotary core 122 in a radial direction, which enables the rotary column 121 to be removably received into the central opening 122 c. Optionally, the rotating post body 121a has a threaded hole 121a1 defined in an axial (direction parallel to the axis of rotation XX') end thereof, wherein a fastener 510 (e.g., a bolt) may be threaded through the proximal connection hole 220 into the threaded hole 121a1 to secure the rotating post 121 to the distal aiming arm 200. Optionally, the spin column body 121a has a flat surface 121a2 defined on a radially outer surface thereof, the flat surface 121a2 being configured to contact and/or abut an opposing flat surface 221 of the proximal connection hole 220 to non-rotatably secure the distal aiming arm 200 to the spin column 121. Further optionally, as shown, the spin column body 121a may have two mutually parallel flat surfaces 121a2 defined on its radially outer surface, the two flat surfaces 121a2 being configured to contact and/or abut two mutually parallel opposing flat surfaces 221 of the proximal connection hole 220. Optionally, the rotating core 122 further has axial protrusions 122d (two axial protrusions 122d are shown distributed on either side of the central opening 122c) projecting axially from the axially outer surface of its rotating core body 122a, the axial protrusions 122d being configured to contact the distal aiming arm 200 when the rotating assembly 120 is connected to the distal aiming arm 200 to increase the contact area of the rotating assembly 120 with the distal aiming arm 200, thereby enabling the rotating assembly 120 to efficiently and reliably rotate the distal aiming arm 200. Optionally, the axial protrusions 122d have multiple rows of ridges on their axially outer surfaces to further increase the friction between the rotating assembly 120 and the distal aiming arm 200, thereby enabling the rotating assembly 120 to more efficiently and reliably rotate the distal aiming arm 200.

Returning to fig. 1, as mentioned above, the proximal connection hole 220 has a relatively flat surface 221 defined on a sidewall thereof, the relatively flat surface 221 for contacting the flat surface 121a2 of the spin column body 121a to non-rotatably secure the distal aiming arm 200 to the spin column 121, such that the spin column 121 can rotate the distal aiming arm 200. Optionally, the proximal connection hole 220 is in the form of an elongated hole and extends along a second sliding direction with respect to the flat surface 221, such that the rotation column 121 is slidable in the proximal connection hole 220 along the second sliding direction, wherein the second sliding direction is also perpendicular to the rotation axis XX' and at a non-zero angle, in particular perpendicular, to the first sliding direction. According to the above technical solution, after the intramedullary nail 400 and the connecting device 100 to be implanted are coupled to the proximal aiming arm 300 and the rotation column 121 of the rotation assembly 120 is inserted into the proximal connecting hole 220 corresponding to the intramedullary nail 400, since the rotation column 121 is slidable in the first sliding direction and slidable in the second sliding direction in the proximal connecting hole 220, the distal aiming arm 200 is movable in a plane perpendicular to the rotation axis XX' with respect to the intramedullary nail 400, and thus, the distal aiming hole 210 thereof can be aligned with the distal screw hole 410 of the intramedullary nail 400 by moving the distal aiming arm 200. Further, when aligned, a fastener 510 (e.g., a bolt) may be threaded through the proximal connection hole 220 into the threaded hole 121a1 of the rotation post 121 and tightened, the rotation post 121 being locked relative to the rotation core 122 due to the axial tension exerted by the fastener 510, and the distal aiming arm 200 being locked relative to the rotation post 121, while the distal aiming arm 200 is only able to rotate relative to the intramedullary nail 400, but not translate relative thereto. Then, as described above, after the intramedullary nail 400 is implanted in the patient and tilted about the rotational axis XX' at the anterior bow bend starting position S, the distal aiming arm 200 may be rotated by the rotation assembly 120 such that the distal aiming hole 210 of the distal aiming arm 200 is again aligned with the distal screw hole 410 of the intramedullary nail 400. With the above technical solution, since the distal aiming arm 200 can still translate in the plane perpendicular to the rotation axis XX' after the rotation component 120 is connected to the proximal connection hole 220 so that the distal aiming hole 210 is aligned with the distal screw hole 410, the proximal connection hole 220 does not need to be machined, and the distal aiming hole 210 can be aligned with the distal screw hole 410 after the rotation component 120 is connected to the proximal connection hole 220, which greatly reduces the requirement for machining accuracy of the proximal connection hole 220, thereby reducing the production cost and improving the productivity. Although the translation of the distal aiming arm 200 relative to the proximal aiming arm 300 (and thus relative to the intramedullary nail 400 coupled to the proximal aiming arm 300) in a plane perpendicular to the axis of rotation XX' is discussed above in terms of "sliding in a first sliding direction" and "sliding in a second sliding direction", it will be appreciated by those skilled in the art that the present invention is not limited to the specific manner in which translation is achieved, in other words, any manner in which translation is achieved should be considered to be within the scope of the present invention.

2-3, the connecting device 100 further comprises an actuating assembly 130, said actuating assembly 130 being in the form of a cylindrical member extending along a displacement axis ZZ ' perpendicular to the rotation axis XX ', and comprising a threaded portion 131 and a clamping portion 132 axially (in a direction parallel to the displacement axis ZZ '), spaced apart, wherein the threading of the threaded portion 131 engages with the corresponding threading of the threaded hole 114 of the housing assembly 110, so that rotating the actuating assembly 130 about the displacement axis ZZ ' causes the actuating assembly 130 to be displaced along the displacement axis ZZ '; the gripping portion 132 is configured to axially grip the free end 122b1 of the radial projection 122b, so that displacement of the actuation assembly 130 along the displacement axis ZZ 'causes the radial projection 122b, and therefore the entire rotation assembly 120, to rotate about the rotation axis XX'. Optionally, the actuation assembly 130 further includes an actuation tip 133, the actuation tip 133 configured to engage a surgeon's hand or tool such that the surgeon's hand or tool may drive the actuation assembly 130 in rotation.

According to the above solution, after the intramedullary nail 400 is implanted in the patient, the physician may rotate the actuating assembly 130 relative to the housing assembly 110, and since the threads of the threaded portion 131 engage with the corresponding threads of the housing assembly 110, the actuating assembly 130 will displace along the displacement axis ZZ ', and at the same time, the clamping portion 132 will also displace along the displacement axis ZZ ', and further since the free end portion 122b1 of the radial protrusion 122b is axially clamped in the clamping portion 132, the radial protrusion 122b will rotate around the rotation axis XX ' under the driving of the clamping portion 132. Further, the radial protrusion 122b will rotate the rotary core 122 about the rotation axis XX ', the rotary core 122 will in turn rotate the rotary post 121 about the rotation axis XX ', and the rotary post 121 will in turn rotate the distal aiming arm 200 about the rotation axis XX ', thereby enabling the plurality of distal aiming holes 210 to be aligned with the plurality of distal screw holes 410 that are tilted after implantation. In summary, relative rotation between the threads can be translated into rotation of the distal aiming arm by the coupling device 100, which allows the surgeon to make fine and precise adjustments to the angle of rotation of the distal aiming arm 200 by rotating the actuation assembly 130. Further, since the free end portion 122b1 of the radial projection 122b is clamped axially in the clamping portion 132, i.e. in the direction of the displacement axis ZZ ', the radial projection 122b is only able to exert a force on the clamping portion 132 in the direction of the displacement axis ZZ', whereas a force in the direction of the displacement axis ZZ 'is not able to rotate the threaded portion 131 around the displacement axis ZZ'. In other words, the distal aiming arm 200 can only be rotated by rotating the actuation assembly 130, but not the actuation assembly 130 by rotating the distal aiming arm 200, which allows the distal aiming arm 200 to be automatically locked in the current position after the surgeon rotates the distal aiming arm 200 to the desired position (e.g., the position where the plurality of distal aiming holes 210 are aligned with the plurality of distal screw holes 410) by rotating the actuation assembly 130, without rotating the distal aiming arm 200 out of the desired position due to gravity or accidental bumping of the surgeon onto the distal aiming arm 200, which greatly reduces the surgeon's burden during the procedure and further ensures that the procedure is performed successfully.

Alternatively, as shown in fig. 2-4, the free end 122b1 of the radial projection 122b is cylindrical, the clip portion 132 includes first and second axially spaced

radial flanges

132a, 132b and a radial annular groove 132c defined therebetween, wherein the radial annular groove 132c is configured to receive the free end 122b1, and the first and second radial flanges 132a, 132b1 are configured such that the axial end surfaces 132a1, 132b1 thereof remain in contact with the side surface of the free end 122b 1. Thus, as grip 132 carries free end 122b1 and ultimately distal aiming arm 200, the transfer of motion is continuous, which makes it easier to adjust distal aiming arm 200 to a desired angle using connecting device 100, thereby ensuring the smooth performance of the procedure.

Optionally, the radial dimensions of first and second

radial flanges

132a, 132b are greater than the radial dimensions of threaded portion 131 such that the threads of threaded portion 131 remain engaged with the corresponding threads of housing assembly 110. Thus, the inner side walls of casing assembly 110 on either side of clamping portion 132 may block first radial flange 132a and second radial flange 132b, which define the travel of displacement of actuating assembly 130 along displacement axis ZZ', and thus enable the threads of threaded portion 131 to be prevented from disengaging from the corresponding threads of casing assembly 110, that is, such that the threads of threaded portion 131 remain engaged with the corresponding threads of casing assembly 110, thereby preventing over-rotation of actuating assembly 130, which may cause it to become dislodged and even fall out of casing assembly 110.

Optionally, as shown in fig. 3, the housing assembly 110 also has a stop 116 disposed on an inner sidewall thereof, the stop 116 being configured to stop further rotation of the rotary core 122 after it has rotated beyond a threshold angle. This prevents the surgeon from rotating the distal aiming arm 200 to an unreasonable angle, thereby ensuring that the procedure is performed safely and smoothly.

As described above, the rotation assembly 120 is defined to rotate within a specific angular range. Thus, the displacement of free end portion 122b1 along displacement axis ZZ ' (i.e., the displacement of actuating assembly 130 along displacement axis ZZ ') is approximately linear with respect to the angle of rotation of rotating assembly 120 (i.e., the angle of rotation of distal aiming arm 200), and further, since the pitch of the threads of threaded portion 131 is constant, the number of revolutions that actuating assembly 130 rotates is linear with respect to its displacement along displacement axis ZZ '. Therefore, the number of rotations of the actuation assembly 130 is approximately linear with the angle of rotation of the distal aiming arm 200. By "approximately linear," it is meant that the ratio of change in the number of rotations of the actuation assembly 130 differs by less than 10% from the ratio of change in the angle of the distal aiming arm 200 caused by the same. Likewise, the angle of rotation of the distal aiming arm 200 is approximately linear with the change in height of its distal end. Thus, the surgeon may linearly and uniformly change the angle of rotation of distal targeting arm 200 and thus the height of distal targeting hole 210 by rotating actuation assembly 130. In particular, since the relationship between the number of rotations of the actuating assembly 130 and the angle of rotation of the distal aiming arm 200 is fixed, the relationship between the number of rotations of the actuating assembly 130 and the change in height of the distal aiming hole 210 is directly obtained after the intramedullary nail is selected (the distance between the distal screw hole in the intramedullary nail and the anterior bow bend start position is approximately equal to the distance between the distal aiming hole in the distal aiming arm and the axis of rotation XX'). Thus, the surgeon may know how many turns of the actuating assembly 130 are required if some change in the height of the distal targeting orifice 210 is desired, which greatly simplifies the procedure and relieves the surgeon of the burden, thereby enabling the procedure to be completed more smoothly and quickly.

Alternatively, as shown in fig. 2-3, the housing assembly 110 includes a housing body 111 and a securing protrusion 112 extending from the housing body 111, wherein the housing body 111 is configured to receive the rotating assembly 120 and the securing protrusion 112 is configured to be secured to an outer end 310 of the proximal targeting arm 300. For example, the fixation protrusion 112 has a through hole 112a defined therein, wherein a fastening assembly 520 may be inserted through the through hole 112a into the outer end 310 in order to securely fasten the fixation protrusion 112, and thus the housing assembly 110, to the proximal aiming arm 300.

Optionally, as shown in fig. 1-3, the housing assembly 110 further includes a stationary end cap 113 attached to the housing body 111 (e.g., by snap-fit, friction-fit, welding, gluing, etc.), wherein the stationary end cap 113 has a through-hole 113a defined therein, and the rotation post 121 is connectable to the distal targeting arm 200 through the through-hole 113 a. In this manner, the stationary end cap 113 may axially locate and support the rotating assembly 120.

Optionally, as shown in fig. 3, the housing assembly 110 further comprises a threaded hole 117 leading to the rotating assembly 120 (in particular, the rotating core 122), and the connecting device 100 further comprises a set screw 140, wherein the set screw 140 is configured to be threadedly connected with the threaded hole 117, such that the set screw 140 can be pressed against the rotating assembly 120 by rotation to prevent the rotating assembly 120 from rotating. Thus, after the surgeon rotates the distal aiming arm 200 to the desired position, the rotation assembly 120 may be compressed by the set screw 140 to prevent the distal aiming arm 200 from rotating out of the desired position. This enables avoiding a surgeon from accidentally rotating the actuation assembly 130, thereby causing the distal aiming arm 200 to rotate out of the desired position. Alternatively, the set screw 140 includes a threaded shaft 141 and a set seat 142 fixed to an end of the threaded shaft 141, wherein the threaded shaft 141 is threadedly coupled with the threaded hole 117, and the set seat 142 radially protrudes with respect to the threaded shaft 141 and is disposed inside the housing assembly 110 such that the set seat 142 can be pushed toward and pressed against the rotating assembly 120 by the threaded shaft 141. Because of the larger radial dimension of the retention seat 142, it has a larger contact area with the rotating assembly 120, which enables the retention seat 142 to more reliably press against the rotating assembly 120; furthermore, the locking seat 142 can prevent the threaded rod 141 from being accidentally screwed out of the threaded hole 117, thereby further ensuring that the operation can be performed smoothly.

Optionally, as shown in fig. 1 and 5, the present intramedullary nail sight further comprises a fastening assembly 520 for fixing the housing assembly 110 of the connecting device 100 to the outer end 310 of the proximal aiming arm 300, the fastening assembly 520 comprising a base 521 and a first pin 522 and a second pin 523 protruding from the base 521, wherein the base 521 is configured to be inserted into the housing assembly 110 (in particular, the through hole 112a of the fixing protrusion 112) and the first pin 522 and the second pin 523 are configured to be inserted into the outer end 310. Alternatively, one of first pin 522 and second pin 523 is a cylindrical pin and the other is a prismatic pin. Optionally, first pin 522 is a hollow expandable pin, and fastening assembly 520 further comprises a jackscrew 524, wherein jackscrew 524 is configured to be inserted into first pin 522 through base 521 to cause first pin 522 to expand in outer end 310, thereby securing housing assembly 110 to outer end 310.

Alternatively, as shown in fig. 1-3, the connection device 100 is symmetrical about a plane passing through its middle and perpendicular to the axis of rotation XX'. This allows the linking device 100 to be used not only for left limb implant surgery as shown, but also for right limb implant surgery.

According to another aspect of the present invention, there is provided a bone treatment system comprising an intramedullary nail sight as described above and a plurality of intramedullary nails to which the intramedullary nail sight is applicable, wherein a physician may select any one of the plurality of intramedullary nails as an intramedullary nail 400 to be implanted according to a preoperative and/or intraoperative plan, the intramedullary nail 400 to be implanted being coupled to the inner end 320 of the proximal aiming arm 300, the housing assembly 110 of the connection device 100 being fixed to the outer end 310 of the proximal aiming arm 300 such that the rotation axis XX' of the rotation assembly 120 of the connection device 100 is fixed with respect to the proximal aiming arm 300 and aligned with the anterior bow start position S of the intramedullary nail 400 to be implanted, the distal aiming arm 200 being non-rotatably fixed to the rotation assembly 120 of the connection device 100 at the proximal connection hole 220 corresponding to the intramedullary nail 400 to be implanted, and may translate relative to intramedullary nail 400 in a plane perpendicular to axis of rotation XX' such that distal aiming hole 210 of distal aiming arm 200 is aligned with distal screw hole 410 of intramedullary nail 400 to be implanted.

Preferred but non-limiting embodiments of an intramedullary nail sight and a bone treatment system comprising the same according to the present invention are described in detail above with the aid of the accompanying drawings. Modifications and additions to the techniques and structures may become apparent to those skilled in the art without departing from the scope and spirit of this disclosure as set forth in the following claims. Accordingly, such modifications and additions that may be contemplated under the teachings of the present invention are intended to be part of this disclosure. The scope of the present disclosure is defined by the following appended claims, and includes equivalents known at the time of filing this disclosure and equivalents not yet foreseen.

Claims

1. An intramedullary nail sight suitable for use with a plurality of intramedullary nails, wherein the intramedullary nail sight comprises:

a proximal aiming arm (300) having an outer end (310) and an inner end (320), wherein the inner end (320) is adapted to engage any intramedullary nail (400) selected from the plurality of intramedullary nails;

a connection device (100) comprising a housing assembly (110) and a rotation assembly (120) rotatably arranged in the housing assembly (110), wherein the housing assembly (110) is fixed to the outer end portion (310) such that an axis of rotation (XX') of the rotation assembly (120) is fixed with respect to the proximal aiming arm (300) and points towards its anterior bow bending starting position (S) in a state in which the intramedullary nail (400) is joined to the inner end portion (320); and

a distal aiming arm (200) having a distal aiming hole (210) at its distal end and a plurality of proximal connecting holes (220) at its proximal end corresponding to the plurality of intramedullary nails, wherein the distal aiming arm (200) is non-rotatably fixed to the rotation assembly (120) at the proximal connecting holes (220) corresponding to the intramedullary nails (400) and is adapted to translate relative to the proximal aiming arm (300) in a plane perpendicular to the rotation axis (XX') such that the distal aiming hole (210) is aligned with its distal screw hole (410) in a state where the intramedullary nail (400) is joined to the inner end portion (320).

2. The intramedullary nail sight of claim 1, wherein the rotation assembly (120) comprises a rotation core (122) rotatably disposed in the housing assembly (110) and a rotation post (121) non-rotatably fixed to the rotation core (122) and axially protruding from the rotation core (122), wherein the rotation core (122) comprises a radial protrusion (122b) radially protruding therefrom, and the distal aiming arm (200) is non-rotatably fixed to the rotation post (121) at a proximal connection hole (220) corresponding to the intramedullary nail (400), and

the connection device (100) further comprises an actuation assembly (130), the actuation assembly (130) extending along a displacement axis (ZZ ') perpendicular to the rotation axis (XX ') and comprising a spaced apart threaded portion (131) and a clamping portion (132), wherein the threads of the threaded portion (131) engage with corresponding threads of the housing assembly (110), and the clamping portion (132) is configured to clamp the free end portion (122b1) of the radial protrusion (122b) in the direction of the displacement axis (ZZ ').

3. The intramedullary nail sight of claim 2, wherein the free end (122b1) of the radial protrusion (122b) is cylindrical, the clamping portion (132) includes first and second spaced apart radial flanges (132a, 132b) and a radial annular groove (132c) defined therebetween, wherein the radial annular groove (132c) is configured to receive the free end (122b1), and the first and second radial flanges (132a, 132b) are configured to remain in contact with the free end (122b 1).

4. Intramedullary nail sight according to claim 2, wherein the rotation core (122) has a central opening (122c) defined therein, wherein the rotation post (121) is non-rotatably fixed to the central opening (122c) and adapted to slide relative to the rotation core (122) along an edge of the central opening (122c) in a first sliding direction, which is perpendicular to the rotation axis (XX').

5. An intramedullary nail sight according to claim 4, in which the rotation post (121) has a radial flange (121b) projecting radially therefrom, the edge of the central opening (122c) having defined therein a pair of grooves (122c2, 122c2 ') parallel to each other and extending along said first sliding direction, the two parallel edges (121b1, 121b1 ') of the radial flange (121b) being snap-fitted in said pair of grooves (122c2, 122c2 ').

6. Intramedullary nail sight according to claim 4 or 5, wherein the proximal connection hole (220) is in the form of an elongated hole, the rotation post (121) being adapted to slide in the proximal connection hole (220) along a second sliding direction perpendicular to the rotation axis (XX') and at a non-zero angle to the first sliding direction.

7. An intramedullary nail sight according to claim 6, wherein said second sliding direction is perpendicular to said first sliding direction.

8. The intramedullary nail sight of claim 6, wherein the rotation post (121) has a flat surface (121a2) defined on a radially outer surface thereof, the proximal connection hole (220) has an opposing flat surface (221) defined on a sidewall thereof extending along the second sliding direction, wherein the flat surface (121a2) is configured to contact the opposing flat surface (221).

9. The intramedullary nail sight of any one of claims 1 to 5, wherein the housing assembly (110) includes a threaded bore (117) leading to the rotating assembly (120), and the connection device (100) further includes a set screw (140), wherein the set screw (140) is configured to be threadedly connected with the threaded bore (117) such that the rotating assembly (120) is prevented from rotating by compressing the rotating assembly (120) by rotating the set screw (140).

10. A bone treatment system, wherein the bone treatment system comprises an intramedullary nail aimer according to any one of claims 1-9 and a plurality of intramedullary nails to which the intramedullary nail aimer is adapted, wherein,

an intramedullary nail (400) selected from the plurality of intramedullary nails is coupled to the inner end portion (320) of the proximal aiming arm (300) such that the rotational axis (XX') of the rotating assembly (120) of the connecting device (100) is aligned with the anterior bow bend start position (S) of the intramedullary nail (400), and

the distal aiming arm (200) is non-rotatably fixed to the rotating assembly (120) of the connection device (100) at a proximal connection hole (220) corresponding to the intramedullary nail (400) and is adapted to translate relative to the intramedullary nail (400) in a plane perpendicular to the rotation axis (XX') so that the distal aiming hole (210) is aligned with a distal screw hole (410) of the intramedullary nail (400).