ORTHOPEDIC INTRAMEDULLARY NAILS

Abstract

An intramedullary (“IM”) nail for internal fixation of a bone is disclosed. In one embodiment, the IM nail may be a retrograde femoral nail. Alternatively, in another embodiment, the IM nail may be a tibial IM nail. In one or more embodiments, the screw holes are arranged and configured to optimize placement of one or more screws, fasteners, or the like. In addition, and/or alternatively, an IM nail may be arranged and configured to facilitate removal of a broken screw.

Claims

1. A retrograde intramedullary femoral nail arranged and configured to be implanted into a patient's femur via a distal end of the femur, the retrograde intramedullary femoral nail comprising: a body including a leading proximal end portion and a distal end portion opposite the leading proximal end portion, the distal end portion includes first, second, third, and fourth screw holes, each of the first, second, third, and fourth screw holes arranged and configured to receive a fastener.

2. The retrograde intramedullary femoral nail of claim 1, wherein: the first screw hole is positioned closest to the distal end portion of the body, the first screw hole extends in a medial-lateral direction in situ; and the second, third and fourth screw holes are angled relative to the first screw hole.

3. The retrograde intramedullary femoral nail of claim 2, wherein each of the second, third, and fourth screw holes are angled between about ±15 degrees to about ±45 degrees relative to a medial-lateral plane.

4. The retrograde intramedullary femoral nail of claim 2, wherein each of the second and third screw holes are angled between about ±15 degrees to about ±45 degrees relative to a medial-lateral plane, the fourth screw hole being parallel to the first screw hole.

5. The retrograde intramedullary femoral nail of claim 1, wherein one or both of the second and third screw holes are elongated slots.

6. The retrograde intramedullary femoral nail of claim 1, wherein the first hole is positioned 10 mm from the distal end portion, the second screw hole is positioned 20 mm from the distal end portion, the third screw hole is positioned 30 mm from the distal end portion, and the fourth screw hole is positioned 40 mm from the distal end portion.

7. The retrograde intramedullary femoral nail of claim 1, wherein the leading proximal end portion further includes a plurality of anterior-posterior screw holes arranged and configured to receive a fastener in an anterior-posterior direction in situ, the leading proximal end portion further including a medial-lateral screw hole arranged and configured to receive a fastener in the medial-lateral direction in situ.

8. The retrograde intramedullary femoral nail of claim 7, wherein the medial-lateral screw hole is arranged perpendicular to the plurality of anterior-posterior screw holes.

9. The retrograde intramedullary femoral nail of claim 7, wherein the medial-lateral screw hole is in the form of an elongated slot.

10. The retrograde intramedullary femoral nail of claim 9, wherein the plurality of anterior-posterior screw holes include first and second anterior-posterior screw holes for receiving first and second fasteners, respectively, the elongated slot being positioned in-between the first and second anterior-posterior screw holes.

11. The retrograde intramedullary femoral nail of claim 10, wherein the first anterior-posterior screw hole is positioned between 5 mm and 10 mm from a proximal end of the body, the second anterior-posterior screw hole is positioned 35 mm from the proximal end of the body, and the elongated slot is positioned 25 mm from the proximal end of the body.

12. The retrograde intramedullary femoral nail of claim 10, wherein the first anterior-posterior screw hole is positioned between 5 mm and 10 mm from a proximal end of the body, the elongated slot is positioned approximately 7 mm from the first anterior-posterior screw hole, the second anterior-posterior screw hole is positioned approximately 7 mm from the elongated slot, the first anterior-posterior screw hole, the elongate slot, and the second anterior-posterior screw hole all positioned within a distance of 40 mm from the proximal end of the body.

13. The retrograde intramedullary femoral nail of claim 10, further comprising, in use, utilizing an electromagnetic field tracking system to track the elongated slot.

14. The retrograde intramedullary femoral nail of claim 1, wherein at least one of the screw holes extends through a first wall of the body and a second wall of the body, the at least one screw hole defines a proximal screw hole portion passing through the first wall and a distal screw hole portion passing through the second wall, the proximal screw hole portion comprising threads and the distal screw hole portion being non-threaded.

15. The retrograde intramedullary femoral nail of claim 14, wherein the proximal screw hole portion comprises a diameter D.sub.1 and the distal screw hole portion comprises a diameter D.sub.2 that is greater than the diameter D.sub.1.

16. The retrograde intramedullary femoral nail of claim 14, wherein the proximal screw hole portion comprises a diameter D.sub.1 and the distal screw hole portion comprises a diameter D.sub.2 that is equal to the diameter D.sub.1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] By way of example, a specific embodiment of the disclosed device will now be described, with reference to the accompanying drawings, in which:

[0037] FIG. 1 is a perspective view of an example of an embodiment of a retrograde femoral intramedullary (“IM”) nail in accordance with one or more features of the present disclosure;

[0038] FIG. 2 is an alternate perspective view of the retrograde femoral IM nail shown in FIG. 1;

[0039] FIG. 3 is a side view of the retrograde femoral IM nail shown in FIG. 1;

[0040] FIG. 4 is an alternate side view of the retrograde femoral IM nail shown in FIG. 1;

[0041] FIG. 5 is a detailed view of a proximal end portion of the retrograde femoral IM nail shown in FIG. 1;

[0042] FIG. 6 is a detailed view of a distal end portion of the retrograde femoral IM nail shown in FIG. 1;

[0043] FIG. 7 is a perspective view of an example of an embodiment of a tibial IM nail in accordance with one or more features of the present disclosure;

[0044] FIG. 8 is a side view of the tibial IM nail shown in FIG. 7;

[0045] FIG. 9 is an alternate side view of the tibial IM nail shown in FIG. 7;

[0046] FIG. 10A is a detailed view of a distal end portion of the tibial IM nail shown in FIG. 7;

[0047] FIG. 10B is an alternate detailed view of a distal end portion of the tibial IM nail shown in FIG. 7;

[0048] FIG. 11A is a detailed view of a proximal end portion of the tibial IM nail shown in FIG. 7;

[0049] FIG. 11B is an alternate detailed view of the proximal end portion of the tibial IM nail shown in FIG. 7; and

[0050] FIG. 12 is a cross-sectional view of a screw hole formed in an IM nail in accordance with one or more features of the present disclosure.

[0051] It should be understood that the drawings are not necessarily to scale and that the disclosed embodiments are sometimes illustrated diagrammatically and in partial views. In certain instances, details which are not necessary for an understanding of the disclosed methods and devices or which render other details difficult to perceive may have been omitted. It should be further understood that this disclosure is not limited to the particular embodiments illustrated herein. In the drawings, like numbers refer to like elements throughout unless otherwise noted.

DETAILED DESCRIPTION

[0052] Various features or the like of IM nails will now be described more fully hereinafter with reference to the accompanying drawings, in which one or more features of the IM nails will be shown and described. It should be appreciated that the various features or the like may be used independently of, or in combination, with each other. It will be appreciated that an IM nail as disclosed herein may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will convey certain features of the IM nails to those skilled in the art.

[0053] Disclosed herein are various IM nails including one or more features arranged and configured to optimize placement of one or more screws, fasteners, or the like (terms used interchangeably herein without the intent to limit). In addition, and/or alternatively, disclosed herein is an IM nail including one or more features arranged and configured to facilitate removal of a broken screw.

[0054] Referring to FIGS. 1-4, an example of an embodiment of a retrograde IM nail 100 in accordance with one or more features of the present disclosure is illustrated. In use, as previously mentioned, a retrograde IM nail 100 is arranged and configured to be implanted into the medullary canal of a patient's femur via the distal end of the patient's femur (e.g., via the patient's knee). As such, the retrograde IM nail 100 may also be referred to as a retrograde femoral nail.

[0055] As illustrated, the retrograde femoral nail 100 includes a body 102 such as, for example, a cannulated body. The body 102 includes a leading or proximal end portion 110 (leading proximal end portion) and a distal end portion 130. With reference to FIGS. 1-5, in accordance with one or more features of the present disclosure, the proximal end portion 110 includes a plurality of screw openings, holes, slots, etc. 112 arranged and configured to receive a fastener, screw, etc. (terms used interchangeably herein without the intent to limit) in the anterior-posterior direction in situ. In one embodiment, the screw openings, holes, slots, etc. can be threaded. Alternatively, the screw openings, holes, slots, etc. can be non-threaded, or have any other configuration now known or hereafter developed. As illustrated, in one embodiment, the proximal end portion 110 includes first and second screw holes 112, although more or less screw holes may be incorporated.

[0056] In addition, as illustrated, the proximal end portion 110 of the retrograde femoral nail 100 includes a screw opening, hole, slot, etc. 114 arranged and configured to receive a screw in the medial-lateral direction in situ. Thus arranged, the medial-lateral screw hole or slot 114 may extend in a direction substantially perpendicular to the first and second screw holes 112. In one embodiment, the medial-lateral screw hole 114 is in the form of a slot. By utilizing a slot, dynamization or micro-motion of the retrograde femoral nail 100 in situ is enabled.

[0057] Alternatively, and/or in addition, in one embodiment, the medial-lateral slot 114 may be utilized to enable a surgeon to position a fastener into a femoral neck and head of the patient's femur. In one embodiment, the retrograde femoral nail 100 would have a length sufficient to extend the retrograde femoral nail 100 into the patient's femur to target the femoral neck and head area. The medial-lateral slot 114 may have a larger size or height to enable improved positioning and/or angulation of the fastener into the femoral neck and head. In addition, in one embodiment, the medial-lateral screw hole or slot 114 may be non-perpendicular to the first and second screw holes 112. Thus arranged, the medial-lateral screw hole or slot 114 may be arranged and configured to enable some anteversion. In connection with this embodiment, the medial-lateral slot 114 may be positioned as proximal as possible to the proximal leading edge (e.g., the medial-lateral slot 114 may take the position of the first screw hole 112). Thus arranged, by positioning the medial-lateral slot 114 adjacent to the proximal leading edge, the medial-lateral slot 114 may provide enhanced neck targeting. In addition, and/or alternatively, it is envisioned that the retrograde femoral nail 100 may also include a second slot (e.g., one or more of the screw holes 112 may be converted to a slot). In addition, and/or alternatively, the slots need not extend purely in the medial-lateral direction.

[0058] As illustrated, the proximal end portion 110 of the retrograde femoral nail 100 may include first and second screw holes 112 extending in the anterior-posterior direction for receiving first and second screws, respectively. In one embodiment, the medial-lateral screw hole or slot 114 may be positioned in-between the first and second screw holes 112 extending in the anterior-posterior direction. Although this is but one example and it should be understood that the proximal end portion 110 of the retrograde femoral nail 100 may include more or less screw holes extending in the anterior-posterior direction and more screw holes or slots extending in the medial-lateral direction. In addition, the screw holes may include alternate configurations such as, for example, the screw hole or slot extending in the medial-lateral direction may be positioned above or below (e.g., proximal or distal) of the screw holes extending in the anterior-posterior direction.

[0059] As illustrated, in one embodiment, the first or proximal most anterior-posterior screw hole 112 may be positioned as close as possible to the leading proximal end of the retrograde femoral nail 100. For example, the first or proximal most anterior-posterior screw hole 112 may be positioned approximately 5 mm to 10 mm from the proximal end of the retrograde femoral nail 100. The medial-lateral screw hole or slot 114 may be positioned such that a center of a proximal end of the medial-lateral screw hole or slot 114 is at least 7 mm from the first or proximal most anterior-posterior screw hole 112. In addition, the second anterior-posterior screw hole 112 may be positioned at least 7 mm from a center of a distal end of the medial-lateral screw hole or slot 114.

[0060] Alternatively, and/or additionally, in one embodiment, the medial-lateral screw hole or slot 114 may be positioned approximately 25 mm from the proximal end of the retrograde nail 100 and the third screw hole may be positioned approximately 35 mm from the proximal end of the retrograde femoral nail 100, although these dimensions are merely example and other dimensions can be used. Preferably, in one embodiment, the first, second, and third screw holes 112, 114 are positioned as close as possible while maintaining structural integrity of the retrograde femoral nail 100. In one embodiment, the first, second, and third screw holes 112, 114 are positioned within 40 mm extending from the leading proximal end of the retrograde femoral nail 100.

[0061] By providing a medial-lateral screw opening, hole or slot 114 in the proximal end portion 110 of a retrograde femoral nail 100 improved fixation of the proximal end portion 110 of the retrograde femoral nail 100 can be achieved. In addition, and/or alternatively, providing one or more medial-lateral screw openings, holes or slots 114 in the proximal end portion 110 of a retrograde femoral nail 100 facilitates easier connection to a bone plate via, for example, a screw passing through the bone plate and through the medial-lateral screw opening, hole, or slot.

[0062] In use, the medial-lateral screw opening, hole or slot 114 can be targeted (e.g., located) utilizing, for example, a targeting device that includes a low-profile medial component. For example, the medial-lateral screw opening, hole or slot 114 can be targeted utilizing electromagnetic field tracking capabilities of the SureShot targeting system manufactured and sold by Smith Nephew, Inc. Alternatively, in an alternate embodiment, it is envisioned that the medial-lateral screw opening, hole or slot 114 formed in the proximal end portion 110 of the retrograde femoral nail 100 could be targeted utilizing an instrument that indexes from one or both of the screw holes 112 extending in the anterior-posterior direction.

[0063] In use, SureShot targeting system is a computer-based software system that provides perfect circle targeting providing continuous visual real-time feedback of drill position to ensure correct direction and angle. Utilizing SureShot targeting system, need for fluoroscopy during targeting of the medial-lateral screw opening, hole or slot 114 in the retrograde femoral nail 100 is eliminated. Given the unique slimline operation of the SureShot targeting system, the limitations of placing fluoroscopic equipment on the medial side of the retrograde femoral nail 100 (e.g., in patient's crotch area) can be overcome.

[0064] In one embodiment, in use, the SureShot targeting system includes a field generator for generating one or more magnetic fields, a removable probe with a first magnetic sensor, a landmark identifier, and a processor. The landmark identifier may include a second sensor, or, alternatively, the field generator. The processor can utilize sensor data and, if desirable, field generator and other information, to generate and display a position and orientation of the sensor(s) in preferably six degrees of freedom, and thereby, to generate and display the position and orientation of a landmark (e.g., screw hole) formed in an orthopaedic implant (e.g., retrograde femoral nail) positioned within the magnetic fields. The system allows for blind targeting of one or more landmarks. Additional information on the SureShot targeting system can be found in U.S. Pat. No. 8,623,023, filed Feb. 18, 2011, entitled Targeting an Orthopaedic Implant Landmark, the entire disclosure of which is hereby incorporated by reference in its entirety.

[0065] In one embodiment, the retrograde femoral nail 100 can be provided in a system. The system may include one or more retrograde femoral nails 100 including a medial-lateral screw opening, hole, or slot 114 formed in the proximal end portion 110 thereof. The system may further include a SureShot targeting system for identifying and placing a screw through the medial-lateral opening, hole, or slot 114. For example, in one embodiment, a retrograde femoral nail 100 may be implanted into the medullary canal of a patient's femur via the distal end or knee. Once properly implanted, one or more screws can be inserted into the proximal end portion 110 of the retrograde femoral nail 100 utilizing the SureShot targeting system. For example, a screw can be positioned and inserted into the medial-lateral slot 114 formed in the proximal end portion 110 of the retrograde femoral nail 100. In addition, and/or alternatively, one or more screws may be inserted into the anterior-posterior openings, holes, or slots 112 formed in the proximal end portion 110 of the retrograde femoral nail 100.

[0066] Referring to FIGS. 1-4 and 6, in accordance with one or more features of the present disclosure that may be used separately from or in combination with the novel proximal end portion 110 of the retrograde femoral nail 100 discussed above in connection with FIG. 5, the distal end portion 130 of the retrograde femoral nail 100 includes a plurality of screw openings, holes, slots, etc. 132 arranged and configured to receive a screw. As illustrated, the distal end portion 130 of the retrograde femoral nail 100 includes first, second, third, and fourth holes 132A, 132B, 132C, 132D.

[0067] In one embodiment, the first hole 132A may be positioned approximately 10 mm from the distal end of the retrograde femoral nail 100, the second hole 132B may be positioned approximately 20 mm from the distal end, the third hole 132C may be positioned approximately 30 mm from the distal end, and the fourth hole 132D may be positioned approximately 40 mm from the distal end, although these dimensions are merely examples and other dimensions can be used.

[0068] Thus arranged, by incorporating an additional or fourth screw hole in the distal end portion 130 of the retrograde femoral nail 100, additional screw fixation may be achieved enabling fixation to potentially more bone fragments.

[0069] In one embodiment, the first screw hole 132A (e.g., screw hole closest to the distal end of the retrograde femoral nail 100) may extend in substantially the medial-lateral direction in situ. Meanwhile, in one embodiment, the second, third and fourth screw holes 132B, 132C, 132D may be angled or oblique. For example, the second, third, and fourth screw holes 132B, 132C, 132D may be angled between about ±15 degrees to about ±45 degrees, preferably about ±25 degrees, from the medial-lateral plane (or relative to the first screw hole 132A), although other angles may be used. Alternatively, in one embodiment, the fourth hole 132D may be substantially parallel to the first screw hole 132A, and thus extend in a substantially medial-lateral direction in situ. The second and third screw holes 132B, 132C being angled or oblique. For example, the second and third screw holes 132B, 132C may be angled between about ±15 degrees to about ±45 degrees, preferably about ±25 degrees, from the medial-lateral plane (or relative to the first and fourth screw holes 132A, 132D), although other angles may be used.

[0070] In addition, and/or alternatively, one or more of the screw holes may be in the form of an elongated slot. In one embodiment, one or more of the screw holes formed in the distal end portion 130 of the retrograde femoral nail 100 may be in the form of an elongated slot. For example, in one embodiment, the second and third screw holes 132B, 132C (e.g., the second and third screw holes 132B, 132C from the distal end of the retrograde femoral nail 100) may be in the form of an elongated slot. Thus arranged, by forming the second and third screw holes 132B, 132C as an elongated slot, the second and third screw slots 132B, 132C may be used to compress a fracture. That is, as will be appreciated by one of ordinary skill in the art, fracture compression may be accomplished by using slotted holes in combination with a reduction instrument. In use, the reduction instrument may be any now known or hereafter developed reduction instrument.

[0071] In one embodiment, the reduction instrument includes a reducer, a buttress, and a locking device that engages a proximal bone fragment and a distal bone fragment. In use, the retrograde femoral nail 100 is secured to the distal bone fragment by the locking device. The buttress engages the retrograde femoral nail 100 through an opening (e.g., second or third screw slot 132B, 132C). The reducer includes a compressing screw that applies a force on the buttress, reducing the fracture. Additional information on the reduction instruction can be found in U.S. Pat. No. 8,628,531, filed Jun. 25, 2008, entitled Assemblies for the Reduction of a Fracture, the entire disclosure of which is hereby incorporated by reference in its entirety.

[0072] By utilizing the retrograde femoral nail with one or more elongated slots with a reduction instrument, compression of fibula fractures in the patient's bone may be accomplished.

[0073] Referring to FIGS. 7-9, an example of an embodiment of a tibial IM nail 200 in accordance with one or more features of the present disclosure is illustrated. In use, as previously mentioned, a tibial IM nail is arranged and configured to be implanted into the medullary canal of a patient's tibia.

[0074] As illustrated in FIGS. 7-9, the tibial IM nail 200 includes a body 202 including a proximal end portion 210 and a distal end portion 230 (e.g., distal end portion 230 now being the leading end portion). As illustrated in FIGS. 7-10B, in one embodiment, the distal end portion 230 includes a plurality of screw openings, holes, slots, etc. 232 arranged and configured to receive a screw. As illustrated, in one embodiment, the distal end portion 230 of the tibial IM nail 200 includes first, second, third, and fourth holes 232A, 232B, 232C, 232D. In use, the second and third screw holes 232B, 232C extend at oblique angles (e.g., second and third screws holes are angled relative to the medial-lateral plane by angle α as best shown in FIG. 10B). As such, as illustrated, the distal end portion 230 of the tibial IM nail 200 includes a first screw hole 232A and a fourth screw hole 232D extending substantially in the medial-lateral direction. Thereafter, the second screw hole 232B and the third screw hole 232C may extend at oblique angles. Thus arranged, by properly orientating the configuration and positioning of the second and third oblique screw holes 232B, 232C, anatomical structures may be avoided.

[0075] In one embodiment, the second and third screw holes 232B, 232C may be arranged and configured at an angle α between approximately ±30 to ±60 degrees from medial-lateral in either direction (e.g., rotated approximately ±30 to ±60 degrees relative to the medial-lateral plane).

[0076] In addition, in one embodiment, the second and third oblique screw holes 232B, 232C may be tilted (e.g., angled vertically), although the second and third screw holes 232B, 232C may be horizontally positioned (e.g., parallel with respect to the first and fourth screw holes 232A, 232D). That is, one or both of the oblique screw holes 232B, 232C may be angulated relative to a central longitudinal axis of the distal portion of the tibia IM nail 200.

[0077] In one embodiment, the first or distal most screw hole 232A may be positioned approximately 6 mm from the distal end of the tibial IM nail 200. The second oblique hole 232B may be positioned approximately 14 mm from the distal end of the tibial IM nail 200. The third oblique screw hole 232C may be positioned approximately 22 mm from the distal end of the tibial IM nail 200. The fourth medial-lateral screw hole 232D may be positioned approximately 30 mm from the distal end of the tibial IM nail 200. However, it should be appreciated that such dimensions are but one example and other dimensions may be used.

[0078] Thus arranged, by optimizing the position and angulation of the screw holes, maximum securement may be achieved while avoiding anatomic structures such as, for example, the nerves, vessels, and tendons.

[0079] Referring to FIGS. 7-9, 11A, and 11B, in accordance with one or more features of the present disclosure that may be used separately from or in combination with the novel distal end portion discussed above in connection with FIGS. 10A and 10B, the proximal end portion 210 of the tibial IM 200 nail may be arranged and configured with a plurality of screw openings, holes, or slots 212. In one embodiment, the first or most proximal hole 212A is arranged and configured to align a screw approximately parallel with a tibial plateau TP through which the tibial IM nail 200 is inserted. That is, in one embodiment, the first or most proximal screw hole 212A formed in the proximal end portion 210 of the tibia IM nail 200 is arranged and configured to achieve approximate parallel screw alignment with the tibial plateau TP.

[0080] As illustrated, in one embodiment, the first or proximal most screw hole 212A formed in the proximal end portion 210 of the tibia IM nail 200 may be tilted or angled downwards away from the proximal end of the tibial IM nail 200. That is, the first or proximal most screw hole 212A may be angled downwards so that a screw inserted therein is positioned substantially parallel to the tibial plateau TP through which the tibia IM nail 200 is inserted. In one embodiment, the first or proximal most screw hole 212A may be angled or tilted downwards by approximately 5 degrees. Alternatively, in alternate embodiments, the first or proximal most screw hole 212A may be angled or tilted downwards by approximately 7 to 10 degrees. Thus arranged, the screw inserted into the first or proximal most screw hole 212A may include a downward slope of between 5 and 10 degrees, plus or minus a degree.

[0081] In this manner, the first or proximal most screw hole 212A is arranged and configured to align a screw or other fastener approximately parallel with the tibial plateau TP or, at a minimum, to avoid penetration of the tibial plateau TP.

[0082] In addition, in one embodiment, the proximal end portion 210 of the tibial IM nail 200 may also include additional screw openings, holes or slots. For example, as illustrated, in one embodiment, the proximal end portion 210 of the tibial IM nail 200 may include a second, third and fourth screw opening, hole, or slot 212B, 212C, 212D. In one embodiment, as best illustrated in FIG. 11A, the second screw hole 212B from the proximal end of the tibia IM nail 200 may also be tilted or angled. In one embodiment, the second screw hole 212B may include a downward tilt or angle. Alternatively, the second screw hole 212B may include an upward tilt or angle. Thus arranged, angulation of the second screw hole 212B facilitates increased bone fixation in the cortical bone (e.g., increased screw lengths may be utilized to achieve increased bone fixation while avoiding penetration of the tibial plateau TP).

[0083] In addition, and/or alternatively, in accordance with one or more features of the present disclosure, as illustrated, the third screw hole 212C from the proximal end of the tibial IM nail 200 may be in the form of an elongated slot. Thus arranged, in use, compression at the proximal end portion 210 of the tibial IM nail 200 may be achieved. In addition, and/or alternatively, the second screw hole 212B from the proximal end of the tibial IM nail 200 may be in the form of an elongated slot so that the second screw hole 212B may be used to achieve compression.

[0084] Thus arranged, in accordance with one or more features of the present disclosure, by downwardly tilting or angling the first or proximal most first screw hole 212A, the potential for the first or proximal most screw to penetrate the tibial plateau TP is reduced. It is also beneficial to enable the first or proximal most first screw to avoid penetrating the tibial plateau TP without requiring supplemental components be added to the proximal end portion 210 of the tibial IM nail 200 to achieve the angulation required. In addition, the orientation enables improved cortical bone purchase without changing the fundamental structure of and instrumentation requirements for the nail. It is also advantageous to maintain the ability to perform proximal fragment compression using conventional techniques (e.g., incorporation of one or more slots, maintains the ability to achieve compression at the proximal end portion 210 of the tibial IM nail 200. Additionally, the tibial IM nail 200 avoids requiring significant changes to nail instrumentation or insertion methods).

[0085] Referring to FIG. 12, in connection with another feature of the present disclosure, that may be used separately or in combination with the other features described herein, a detailed cross-sectional screw hole of an IM nail such as, for example, a retrograde femoral nail 100, a tibial IM nail 200, or any other now known or hereafter developed IM nail is illustrated. In use, the IM nail 300 includes a body 302 (e.g., a cannulated body) including a screw hole 310 arranged and configured to facilitate easier removal of a distal portion of a broken locking screw.

[0086] As will be appreciated by one of ordinary skill in the art, inserting a screw through a screw hole formed in a cannulated IM nail requires the screw to pass through a first or proximal screw hole portion formed in a first or proximal wall of the IM nail and through a second or distal screw hole portion formed in a second or distal wall of the IM nail (e.g., proximal and distal referring to a trajectory of the screw path). In use, a locking screw inserted into a threaded screw hole formed in an IM nail may break when the IM nail is subject to loading or during screw insertion through the IM nail and into the patient's bone. However, if the screw is arranged and configured to engage threads formed in the first or proximal screw hole portion formed in the first or proximal wall and the second or distal screw hole portion formed in the second or distal wall, as is the case with known IM nails, removal of the distal portion of the broken locking screw is rendered difficult. That is, in use, a locking screw is arranged and configured to threadably engage both the first and second walls of the IM nail, thus the screw threadably engages the first or proximal screw hole portion and the second or distal screw hole portion. If the screw breaks distally of the first or proximal threaded screw hole portion, as is the usual case, removal of the distal portion of the broken screw is difficult since the distal portion is still threadably coupled to the second or distal threaded screw hole portion and detached from the head portion of the screw. As such, rotating the head portion of the screw does not remove the distal portion of the broken screw.

[0087] Presently, one method for removing the broken distal portion of the broken screw from the patient involves tissue removal and grasping and turning of the far distal portion of the screw (e.g., a second incision may be formed in the opposite side of the patient's leg to grasp and rotate the distal portion of the broken screw to threadably decouple it from the second or distal threaded screw hole portion formed in the second or distal wall of the IM nail). Alternatively, the far distal portion of the broken screw may be drilled (e.g., the portion of the screw where the distal portion of the screw contacts the IM nail). In either scenario, each of these solutions is problematic due to the potential for unwanted tissue damage and introduction of unwanted debris into the surgical site.

[0088] Thus, it would be beneficial to provide a more practical solution. For example, it would be advantageous to be able to merely drive out the distal portion of the broken screw with a punch or similar tool through the first or proximal hole portion formed in the first or proximal wall of the IM nail left by removing the proximal portion of the broken screw, which may be rotated out. However, this is not possible where the distal portion of the screw remains threadably coupled to the threads formed in the second or distal screw hole portion formed in the second or distal wall of the IM nail (e.g., in instances where the screw breaks distally of the first or proximal screw hole portion formed in the IM nail, the distal portion of the broken screw remains threadably coupled to the second or distal screw hole portion formed in the IM nail). In other words, it is not practical to require a surgeon to strike a proximal end portion of the distal portion of the broken screw with a punch or similar tool with adequate force to shear through the threads coupling the distal portion of the broken screw and the IM nail.

[0089] Referring to FIG. 12, in one embodiment, the IM nail includes a first or proximal wall 303 and a second or distal wall 304, the screw hole 310 formed in the IM nail 300 passes through both the first or proximal wall 303 and the second or distal wall 304. However, in accordance with one or more features of the present disclosure, threads 315 for engaging the threads of a locking screw are only provided in the first or proximal wall 303 (e.g., first or proximal screw hole portion 310A) of the IM nail 300 along the trajectory of the locking screw (e.g., the second or distal screw hole portion 310B formed in the second or distal wall 304 is devoid of any threads). Thus arranged, if the screw breaks distally beyond the threads 315 formed in the first or proximal screw hole portion 310A formed in the first or proximal wall 303 of the IM nail 300, the distal portion of the broken screw can be driven out of the patient along the trajectory or path of the screw, and it will only be necessary to overcome the purchase of the distal portion of the broken screw with the tissue in which it is implanted, not the threaded purchase between the distal portion of the broken screw with the second or distal screw hole portion 310B formed in the second or distal wall 304 of the IM nail 300 through which the screw is inserted.

[0090] As illustrated, in one embodiment, the first or proximal wall 303 of the IM nail 300 through which the locking screw is initially inserted is threaded (e.g., includes threads 315) while the second or distal wall 304 of the IM nail 300 is non-threaded. In addition, the second or distal screw hole portion 310B formed in the second or distal wall 304 of the IM nail 300 preferably includes a diameter D.sub.2 that is greater than a diameter D.sub.1 of the threaded portion of the locking screw so that the threaded portion of the screw can pass through the second or distal screw hole portion 310B formed in the second or distal wall 304 of the IM nail 300 (e.g., in FIG. 12, the locking screw is represented by dashed lines for clarity of visualization of the IM nail). Alternatively, in one embodiment, diameter D.sub.2 may be equal to diameter D.sub.1. In one embodiment, diameter D.sub.1 may be approximately 12 mm to 13 mm, diameter D.sub.2 may have a lower limit of 12 mm, although these dimensions are exemplary and other dimensions may be used.

[0091] Thus arranged, if the locking screw breaks anywhere distal of the first or proximal threaded screw hole portion 310A formed in the first or proximal wall portion 303 of the IM nail 300, the proximal portion of the screw may be backed out using the head of the screw (e.g., the proximal portion of the broken screw can be rotated out of the IM nail 300). The distal portion of the broken screw may be driven distally through the tissue with a punch or other instrument that fits through the second or distal non-threaded hole portion 310B formed in the second or distal wall 304 of the IM nail 300 left by the extracted proximal portion of the broken screw. By this method, the threads of the screw are only engaging tissue (not the IM nail 300 at any location) and the purchase in the tissue may be easily overcome.

[0092] In addition, an extractor that includes a hole saw type cutter may be advanced from the distal end of the broken screw to core a tissue plug around the cross-section of the broken screw to more easily remove the screw. With the proposed method, the hole saw type cutter would not have to cut through any implant material, only tissue.

[0093] In an alternate embodiment, the distal portion of the screw may also be non-threaded. For example, the distal portion (e.g., shaft portion) of the screw may be in the form of a pin. Thus arranged, easier extraction of the distal portion of the broken locking screw be achievable.

[0094] In either event, by arranging the second or distal wall 304 of the IM nail 300 with a non-threaded screw hole portion 310B, easier removal of the distal portion of a broken locking screw is achievable resulting in reduced tissue damage and eliminating, or at least reducing, inadvertent introduction of debris into a surgical site.

[0095] The foregoing description has broad application. Accordingly, the discussion of any embodiment is meant only to be explanatory and is not intended to suggest that the scope of the disclosure, including the claims, is limited to these example embodiments. In other words, while illustrative embodiments of the disclosure have been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed, and that the appended claims are intended to be construed to include such variations, except as limited by the prior art.

[0096] The term “a” or “an” entity, as used herein, refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Accordingly, the terms “including,” “comprising,” or “having” and variations thereof are open-ended expressions and can be used interchangeably herein. The phrases “at least one”, “one or more”, and “and/or”, as used herein, are open-ended expressions that are both conjunctive and disjunctive in operation.

[0097] All directional references (e.g., proximal, distal, upper, underside, lower, upward, downward, left, right, lateral, longitudinal, front, back, top, bottom, above, below, vertical, horizontal, radial, axial, clockwise, and counterclockwise) are only used for identification purposes to aid the reader's understanding of the present disclosure, and do not create limitations, particularly as to the position, orientation, or use of this disclosure. Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and may include intermediate members between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to each other. Identification references (e.g., primary, secondary, first, second, third, fourth, etc.) are not intended to connote importance or priority but are used to distinguish one feature from another. The drawings are for purposes of illustration only and the dimensions, positions, order and relative sizes reflected in the drawings attached hereto may vary.