Three-dimensional internal nail assembly

Abstract

A system, assembly, and method for inserting and securing a nail into the intramedullary canal of a bone is provided. The intramedullary nail assembly includes a body (201) and an inlay (200). The body has an outer surface (214) and an opposing inner surface. The outer surface extends from a leading end (202) of the body to a trailing end (204) of the body. The inner surface defines a cannulation portion extending toward the leading end and into the trailing end. The body includes an anterior body portion (206) defining the leading end and a posterior body portion (208) defining the trailing end. The inlay is positionable within the cannulation portion of at least one of the anterior and posterior body portions. The inlay includes an engagement member (250) configured to engage the body to releasably lock the inlay within the cannulation portion of the body.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to systems, assemblies, and methods for inserting and securing a nail in the intramedullary canal of a bone. [Background technology]

[0002] Intramedullary nails are commonly used to treat fractures of the long bones of the body, such as fractures of the femur, tibia, and humerus. To treat such fractures, the intramedullary nail is inserted into the medullary canal of the long bone, crossing one or more fractures and reaching the fragments of the long bone separated by one or more fractures. A set screw is then inserted perpendicularly or at an oblique angle through the bone into the intramedullary nail, thereby securing the intramedullary nail to the bone. The intramedullary nail can remain in the medullary canal at least until the fracture heals.

[0003] The foregoing background description is intended merely to assist the reader and is not intended to limit the innovations described herein. Thus, the foregoing description should not be construed to indicate that any particular element of conventional systems is not suitable for use with the innovations described herein, nor is it intended to indicate that any element is essential to implementing the innovations described herein. Summary of the Invention [Means for solving the problem]

[0004] Treatment of unstable tibial fractures is challenging. In recent years, intramedullary nailing has become the treatment of choice due to its advantages of high mechanical stability, short union time, minimal soft tissue damage, and short disability period. To improve distal fracture stability, nails are typically fixed with screws, but even slight differences in the diameter of the screw hole and screw can compromise stability. Therefore, a new intramedullary nailing system with angle-stable distal and proximal screw fixation and a screw pullout safety function is desirable.

[0005] One aspect of the present disclosure provides an intramedullary nail assembly. The intramedullary nail assembly includes a body and an inlay. The body has an outer surface and an opposite inner surface. The outer surface extends from an anterior end of the body to a posterior end of the body. The inner surface defines a cannulation portion extending toward the anterior end and into the posterior end. The body includes an anterior body portion and a posterior body portion. The anterior body portion defines the anterior end of the body, and the posterior body portion is offset from the anterior body portion along a posterior direction and defines the posterior end of the body. The inlay is positionable within the cannulation portion of at least one of the anterior and posterior body portions. The inlay includes an engagement member configured to engage with the body to releasably lock the inlay within the cannulation portion of the body.

[0006] Another aspect of the present disclosure provides an inlay for an intramedullary nail assembly. The intramedullary nail assembly includes a nail body having an outer surface and an opposing inner surface. The outer surface extends from a leading end of the nail body to a trailing end of the nail body. The inner surface defines a cannulated portion extending toward the leading end and into the trailing end. The inlay includes an inlay body positionable within the cannulated portion of the nail body. The inlay body includes an engaging member configured to engage the nail body to releasably lock the inlay within the cannulated portion of the nail body.

[0007] Another aspect of the present disclosure provides a method of manufacturing an intramedullary nail assembly. The method includes inserting a first inlay into a cannulated portion of the body in at least one of the anterior and posterior body portions, the inlay including an engagement member configured to engage with the body to releasably lock the inlay within the cannulated portion of the body after the inlay is inserted. The method further includes inserting a second inlay into the cannulated portion of the other of the anterior and posterior body portions, the second inlay including a second engagement member configured to engage with the body to releasably lock the second inlay within the cannulated portion of the body after the second inlay is inserted.

[0008] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description section. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Moreover, the claimed subject matter is not bound by limitations that solve any or all of the disadvantages noted anywhere in this disclosure. [Brief explanation of the drawings]

[0009] The foregoing summary and the following detailed description of exemplary embodiments of the present application will be better understood when read in conjunction with the accompanying drawings. For the purposes of illustrating the present application, there are shown in the drawings exemplary embodiments of the present disclosure. It should be understood, however, that the present application is not limited to the precise arrangements and instrumentalities shown. The drawings are as follows: [Figure 1] FIG. 1 is a perspective view of a fractured long bone defining a proximal bone segment and a distal bone segment separated from the proximal bone segment by a bone gap. [Figure 2] FIG. 1 is a perspective view of an intramedullary nail assembly according to one aspect of the present disclosure. [Figure 3] 3 is a cross-sectional view of a perspective view of the intramedullary nail assembly shown in FIG. 2 taken along line 3-3 of FIG. 4. [Figure 4] FIG. 3 is an elevational view of a first side of the intramedullary nail shown in FIG. 2. [Figure 5] 3 is an elevational view of a second side of the intramedullary nail shown in FIG. 2, opposite the first side. [Figure 6] FIG. 3 is an elevational view of a third side of the intramedullary nail shown in FIG. 2 according to one embodiment of the present disclosure. [Figure 7] 7 is an elevational view of a fourth side of the intramedullary nail shown in FIG. 6, opposite the third side. [Figure 8] FIG. 3 is an end view of the intramedullary nail shown in FIG. 2 according to one embodiment of the present disclosure. [Figure 9] FIG. 1 is a perspective view of a first inlay according to one embodiment of the present disclosure. [Figure 10] FIG. 10 is an elevational view of a first side of the first inlay shown in FIG. 9. [Figure 11] 10 is a cross-section of a perspective view of the first inlay shown in FIG. 9 taken along line 10-10. [Figure 12] 11 is an elevational view of a second side of the first inlay shown in FIG. 10 opposite the first side. [Figure 13] FIG. 10 is an elevational view of the third side of the first inlay shown in FIG. 9. [Figure 14] FIG. 10 is an elevational view of the fourth side of the first inlay shown in FIG. 9. [Figure 15] FIG. 10 is a perspective view of a second inlay according to one embodiment of the present disclosure. [Figure 16] FIG. 16 is an elevational view of the first side of the second inlay shown in FIG. 15. [Figure 17] 16 is a cross-section of a perspective view of the second inlay shown in FIG. 15 taken along line 16-16. [Figure 18] FIG. 17 is an elevational view of a second side of the second inlay shown in FIG. 16, opposite the first side. [Figure 19] FIG. 16 is an elevational view of the third side of the second inlay shown in FIG. 15. [Figure 20] FIG. 16 is an elevational view of the fourth side of the second inlay shown in FIG. 15. [Figure 21] FIG. 10 is a perspective view of an alternative inlay design according to one aspect of the present disclosure. [Figure 22] FIG. 22 is a perspective view of the alternative inlay shown in FIG. 21 positioned within a screw fixation hole of an intramedullary nail according to one embodiment of the present disclosure. [Figure 23] FIG. 10 is a perspective view of an alternative inlay according to one aspect of the present disclosure. [Figure 24] 24A and 24B are side and top views, respectively, of the inlay shown in FIG. 23 placed within a bone anchor fixation hole of an intramedullary nail, according to an embodiment of the present disclosure. [Figure 25] 24A and 24B are side and top views, respectively, of the inlay shown in FIG. 23 placed within a bone anchor fixation hole of an intramedullary nail, according to an embodiment of the present disclosure. [Figure 26]25 is a cross-sectional view of the inlay shown in FIG. 23 placed in a bone anchor fixation hole of an intramedullary nail taken along line 25-25 shown in FIG. 25. [Figure 27] FIG. 10 is a perspective view of an alternative inlay according to one aspect of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] Certain terminology used herein is for convenience only and is not intended to be limiting. The words "top," "bottom," "distal," "proximal," "leading," "trailing," "inner," "outer," "above," "below," "axial," "transverse," "circumferential," and "radial" refer to directions in the drawings to which reference is made. The term "substantially" is intended to mean to a large extent or to the majority, but not necessarily entirely, of what is specified. All ranges disclosed herein are inclusive of the recited endpoints and are independently combinable (e.g., the range "2 grams to 10 grams" includes the endpoints 2 grams and 10 grams, and all intermediate values). Terms include the above-listed words, derivatives thereof, and words of similar import.

[0011] FIG. 1 illustrates a substantially elongated long bone 20 fractured along its longitudinal direction to define a first or proximal bone segment 22 and a second, distal bone segment 24 separated from the proximal bone segment 22 by a longitudinal bone gap 26 at a fracture location 28. It will be understood that the fractured long bone 20 may define a single fracture location 28, as shown, or may define multiple fracture locations, with each fracture location separating additional bone segments from one another at a respective bone gap. While the long bone 20 is a humerus in the illustrated embodiment, the long bone 20 may be any long bone in the body defining a medullary canal 23 suitable for receiving an intramedullary nail, such as for securing the proximal bone segment 22 to the distal bone segment 24. The bone gap 26 defines a bone gap distance D1 extending along the longitudinal direction L, where the bone gap distance D1 is greater than a desired distance suitable for securely securing the proximal bone segment 22 to the distal bone segment 24. In one aspect, the intramedullary nail may include a compression feature configured to close the bone gap 26 to a distance that allows for secure fixation of the bone segments 22 and 24 across the bone gap 26 during healing, although in alternative examples, the intramedullary nail may lack a compression feature.

[0012] 2-4 illustrate a perspective view of an intramedullary nail assembly 100, a perspective view of a cross section of the intramedullary nail assembly 100, and an elevation view of a first side of the intramedullary nail assembly 100, respectively, according to an embodiment of the present invention. The cross section of the intramedullary nail assembly 100 shown in FIG. 3 is taken along line 3-3 shown in FIG. 4. The intramedullary nail assembly 100 includes an intramedullary nail 101 (e.g., a body) and may also include one or both of a first inlay 200 and a second inlay 300. The intramedullary nail 101 is elongated from a first end 102 (e.g., an insertion end or leading end) to a second end 104 (e.g., a trailing end). The first end 102 may be considered the distal end and may define a first or outermost end of the intramedullary nail 101. The second end 104 may be considered the proximal end and may define a second terminal or outermost end of the intramedullary nail 101. As used herein, the term "proximal end" refers to an end that is closer to a medical professional than the distal end during a medical procedure, and the term "distal end" refers to an end that is farther from a medical professional than the proximal end during a medical procedure. Additionally, the term "proximal direction" refers to a direction extending toward a medical professional during a medical procedure, and the term "distal direction" refers to a direction extending away from a medical professional during a medical procedure.

[0013] The intramedullary nail 101 is substantially elongated along a central pathway extending from the posterior end 104 to the anterior end 102. In at least some embodiments, the central pathway may be defined by a central axis C of the intramedullary nail 101 extending from the posterior end 104 to the anterior end 102. It will be understood that the central pathway or central axis C of the intramedullary nail 101 may be straight or curved. Thus, the intramedullary nail 101 may be straight or curved as it extends along the central pathway or central axis C from the posterior end 104 to the anterior end 102. The intramedullary nail 101 may be inserted into the medullary canal of a long bone such that the central pathway or central axis C extends along the length of the medullary canal.

[0014] The intramedullary nail 101 has an offset anterior or distal body portion 106 and a posterior or proximal body portion 108. The intramedullary nail 101 also has an intermediate body portion 110 between the anterior body portion 106 and the posterior body portion 108. The anterior body portion 106 may extend from the anterior end 102 toward the posterior end 104 of the intramedullary nail 101 along a posterior direction T, which may also be referred to as the proximal direction. Furthermore, the posterior body portion 108 may extend from the posterior end 104 toward the anterior end 102 along an anterior direction L, which may also be referred to as the insertion direction or distal direction. For example, the anterior body portion 106 may extend from the anterior end 102 to the intermediate body portion 110, and the posterior body portion 108 may extend from the posterior end 104 to the intermediate body portion 110. It will be understood that the forward direction L extends from the rear end 104 towards the front end 106, and the rearward direction T extends in the opposite direction to the forward direction L (e.g., from the front end 102 towards the rear end 104).

[0015] In one aspect, the posterior body portion 108 is approximately equal to the overall length L of the intramedullary nail 101. O For example, the total length L of the intramedullary nail 101 O For example, the total length L of the intramedullary nail 101 O Length L less than one-fourth of T Additionally or alternatively, in at least some embodiments, the anterior body portion 106 has a length L O For example, the total length L of the intramedullary nail 101 O For example, the total length L of the intramedullary nail 101 O Length L less than one-fourth of L It has.

[0016] The intramedullary nail 101 has an outer surface 114 extending from the anterior body portion 106 to the posterior body portion 108. The outer surface 114 may extend from the posterior end 104 to the anterior end 102. The outer surface 114 may define the outermost periphery of the intramedullary nail 101. Further, the outer surface 114 may have any suitable cross-sectional shape as desired. For example, the outer surface 114 may be substantially circular in cross-section along a plane substantially perpendicular to the central path or central axis C. Additionally or alternatively, the intramedullary nail 101 may define a plurality of recesses extending within the outer surface 114. The recesses may be circumferentially spaced from one another around the periphery of the intramedullary nail 101 and may be elongated as they extend between the anterior body portion 106 and the posterior body portion 108.

[0017] The intramedullary nail 101 has an inner surface 118 opposite the outer surface 114. Accordingly, the intramedullary nail 101 includes a tubular wall 122 between the inner surface 118 and the outer surface 114. The inner surface 118 defines a cannulation portion 120 that extends into the posterior end 104 in the anterior direction L. The cannulation portion 120 can extend to the anterior body portion 106. In one aspect, the cannulation portion 120 can extend through the anterior end 102. Alternatively, the cannulation portion 120 can terminate before the anterior end 102, such as in the anterior body portion 106 or the intermediate body portion 110. The cannulation portion 120 can be configured (e.g., sized and shaped) to receive a rod therein, such as a reaming rod, as the intramedullary nail 101 is guided along the rod into the medullary canal of the bone. The cannulation portion 120 can extend along a central path or axis C of the intramedullary nail 101. The inner surface 118 can have multiple cross sections along the central path or axis C, with each cross section defined in a plane perpendicular to the central path or axis C. The inner surface 118 at each cross section can have any suitable cross-sectional shape as desired. For example, the inner surface 118 at each cross section can define a closed cross-sectional shape, such as a circle, an oval, a square, a rectangle, or other shape.

[0018] The inner surface 118 may further include a receiving shoulder or body shoulder 119. The receiving shoulder may be defined by a shoulder surface 111. The shoulder surface 111 may be angularly offset from the central axis C, for example, substantially perpendicular to the central axis C. In alternative embodiments, the shoulder surface 111 may have a conical, curved, or other shape. The shoulder surface 111 is configured to face in a direction toward the rear end 104 such that a cross-sectional dimension (e.g., diameter) of the inner surface 118 proximal to the shoulder surface 111 is greater than a cross-sectional dimension (e.g., diameter) of an innermost edge of the shoulder surface 111.

[0019] FIG. 5 illustrates an elevational view of a second side of the intramedullary nail assembly 100 according to one embodiment of the present disclosure. The intramedullary nail 101 defines a plurality of fastener holes 124 (e.g., bone anchor fixation holes). Each bone anchor fixation hole 124 is configured to receive a fastener (e.g., a bone anchor, a screw, a bolt, or other fastener) to attach the intramedullary nail 101 to bone. The bone anchor fixation holes 124 can include at least one posterior bone anchor fixation hole 126 and at least one anterior bone anchor fixation hole 128. Each bone anchor fixation hole 124 can intersect with the cannulation portion 120. Each bone anchor fixation hole 124 is configured to receive a bone anchor extending therethrough to attach the intramedullary nail 101 to bone. In particular, each bone anchor fixation hole 124 extends into the outer surface 114 and can extend at least partially, e.g., entirely, through the intramedullary nail 101. For example, each bone anchor fixation hole 124 can extend into the outer surface 114 on a first side of the intramedullary nail 101 and extend out from the outer surface 114 on a second side of the intramedullary nail 101 opposite the first side. Thus, each bone anchor fixation hole 124 can extend from an opening 124 a on the first side of the intramedullary nail 101 to an opening 124 b on the second side of the intramedullary nail 101. Thus, each bone anchor fixation hole 124 can be considered a through-hole, although aspects of the present disclosure are not limited to through-holes. At least a portion of the bone anchor fixation holes 124 can extend through the tubular wall 122 on the first side of the intramedullary nail 101 and through the tubular wall 122 on the second side of the intramedullary nail 101 opposite the first side.

[0020] Each bone anchor fixation hole 124 extends through the intramedullary nail 101 along a central bone anchor axis A that is angled relative to a central axis C of the intramedullary nail 101. For example, the central axis C of the intramedullary nail 101 extends along a first direction adjacent each bone anchor fixation hole 124, and each bone anchor fixation hole 124 extends within the intramedullary nail 101 along a central bone anchor axis A that extends along a second direction, the second direction forming a non-zero angle with the first direction. Each bone anchor fixation hole 124 can extend through the intramedullary nail 101 along the central axis A that forms a non-zero angle, such as a right angle or an oblique angle, with the central axis C of the intramedullary nail 101. Each bone anchor fixation hole 124 can be unthreaded or can include female threads to receive male threads of a fastener (e.g., a bone anchor, screw, bolt, or other fastener). Each of the bone anchor fixation holes 124 may be pre-formed (eg, pre-drilled) in the nail 101 according to the core diameter of the bone anchor.

[0021] Each posterior bone anchor fixation hole 126 and each anterior bone anchor fixation hole 128 may be located in posterior body portion 108 and anterior body portion 106, respectively. It will be appreciated that bone anchor fixation holes 124 may be located in intermediate body portion 110.

[0022] At least one posterior bone anchor fixation hole 126 can have an axis A that is aligned with the axis A of an adjacent posterior bone anchor fixation hole 126 along the longitudinal direction L. For example, the axis A of at least one posterior bone anchor fixation hole 126 can be in-plane with the axis A of the adjacent posterior bone anchor fixation hole 126. Thus, the openings 124a and 124b of the posterior bone anchor fixation holes 126 can be aligned with the openings 124a or 124b of the adjacent posterior bone anchor fixation holes 126 along the longitudinal direction L. In one aspect, the central bone anchor axis A of each posterior bone anchor fixation hole 126 can be parallel to the central bone anchor axis A of the adjacent one of the posterior bone anchor fixation holes 126. Alternatively, the central bone anchor axis A of each posterior bone anchor fixation hole 126 can be angularly offset from the central bone anchor axis A of the adjacent one of the posterior bone anchor fixation holes 126, such that the central bone anchor axes A converge on one side of the intramedullary nail 101 and diverge on the other side.

[0023] Alternatively, the axis A of at least one posterior bone anchor fixation hole 126 may be angularly offset from the axis A of an adjacent posterior bone anchor fixation hole 126 along the longitudinal direction L. For example, the axis A of at least one posterior bone anchor fixation hole 126 may be out-of-plane with the axis A of an adjacent posterior bone anchor fixation hole 126. Thus, the openings 124a and 124b of each posterior bone anchor fixation hole 126 may be misaligned with the openings 124a and 124b of an adjacent posterior bone anchor fixation hole 126 along the longitudinal direction L. In other words, the openings 124a and 124b of each posterior bone anchor fixation hole 126 on the outer surface 114 may be circumferentially offset from the openings 124a and 124b of an adjacent posterior bone anchor fixation hole 126 on the outer surface 114. Thus, the central bone anchor axis A of each posterior bone anchor fixation hole 126 may be at a non-zero angle with respect to the central bone anchor axis A of an adjacent one of the posterior bone anchor fixation holes 126.

[0024] The plurality of bone anchor fixation holes 124 also includes at least one anterior bone anchor fixation hole 128. All of the at least one anterior bone anchor fixation hole 128 are offset from all of the at least one posterior bone anchor fixation hole 126 along the longitudinal direction L. Each of the at least one anterior bone anchor fixation hole 128 extends entirely through the anterior body portion 106 of the intramedullary nail 101. In one aspect, each of the at least one anterior bone anchor fixation hole 128 extends from the leading end 102 to the entire length L of the intramedullary nail 101. O For example, the total length L of the intramedullary nail 101 O For example, the total length L of the intramedullary nail 101 O The anterior bone anchor fixation holes 128 may extend into the intramedullary nail 101 a distance of no more than one-quarter of the length of the anterior bone anchor fixation holes 128. While multiple anterior bone anchor fixation holes 128 are shown, it will be understood that the intramedullary nail 101 may define only one anterior bone anchor fixation hole 128. In embodiments having multiple anterior bone anchor fixation holes 128, the multiple anterior bone anchor fixation holes 128 may be offset from one another along the longitudinal direction L.

[0025] Each anterior bone anchor fixation hole 128 can have an axis A that is aligned with the axis A of an adjacent anterior bone anchor fixation hole 128 along the longitudinal direction L. For example, an anterior bone anchor fixation hole 128 and an adjacent anterior bone anchor fixation hole 128 can be in-plane with each other. Thus, the openings 124 a and 124 b of an anterior bone anchor fixation hole 128 can be aligned with the openings 124 a and 124 b of an adjacent distal bone anchor fixation hole 128 along the longitudinal direction L. Furthermore, the central bone anchor axis A of each anterior bone anchor fixation hole 128 can be parallel to the central bone anchor axis A of an adjacent one of the anterior bone anchor fixation holes 128 or can be angularly offset from the central bone anchor axis A of an adjacent one of the anterior bone anchor fixation holes 128 such that the central bone anchor axes A converge on one side of the intramedullary nail 101 and diverge on the other side.

[0026] Alternatively, the axis A of at least one anterior bone anchor fixation hole 128 may be angularly offset from the axis A of an adjacent anterior bone anchor fixation hole 128 along the longitudinal direction L. For example, the anterior bone anchor fixation hole 128 and the adjacent anterior bone anchor fixation hole 128 may be out-of-plane with each other. Thus, the openings 124 a and 124 b of each anterior bone anchor fixation hole 128 may not be aligned with the openings 124 a and 124 b of the adjacent anterior bone anchor fixation hole 128 along the longitudinal direction L. In other words, the openings 124 a and 124 b of each anterior bone anchor fixation hole 128 may be circumferentially offset from the openings 124 a and 124 b of the adjacent anterior bone anchor fixation hole 128. Thus, the central bone anchor axis A of each anterior bone anchor fixation hole 128 may be at a non-zero angle with respect to the central bone anchor axis A of the adjacent one of the anterior bone anchor fixation holes 128.

[0027] Furthermore, the axis A of the at least one anterior bone anchor fixation hole 128 can be aligned with the axis A of the posterior bone anchor fixation hole 126 along the longitudinal direction L. For example, the axis A of the anterior bone anchor fixation hole 128 can be in-plane with the axis A of the posterior bone anchor fixation hole 126. Thus, the openings 124a and 124b of the anterior bone anchor fixation hole 128 are aligned with the openings 124a and 124b of the posterior bone anchor fixation hole 126 along the longitudinal direction L. Alternatively, the axis A of the at least one anterior bone anchor fixation hole 128 can be angularly offset from the axis A of the posterior bone anchor fixation hole 126. For example, the axis A of the anterior bone anchor fixation hole 128 can be out-of-plane with the axis A of the posterior bone anchor fixation hole 126. Thus, the openings 124a and 124b of the anterior bone anchor fixation hole 128 can be misaligned with the openings 124a and 124b of the posterior bone anchor fixation hole 126 along the longitudinal direction L. In other words, the openings 124a and 124b of the anterior bone anchor fixation hole 128 may be circumferentially offset from the openings 124a and 124b of the posterior bone anchor fixation hole 126. Thus, the central bone anchor axis A of the anterior bone anchor fixation hole 128 may be at a non-zero angle relative to the central bone anchor axis A of the posterior bone anchor fixation hole 126.

[0028] 6 and 7 show elevational views of a third and fourth side of the intramedullary nail 101 according to an embodiment of the present disclosure. The intramedullary nail 101 defines a compression slot 130 extending into and through the intramedullary nail 101 in a direction substantially perpendicular to the central axis C. The compression slot 130 can intersect with the cannulation portion 120. For example, the compression slot 130 can extend into the outer surface 114 on a first side of the intramedullary nail 101 and extend out from the outer surface 114 on a second side of the intramedullary nail 101 opposite the first side. The compression slot 130 is a self-retaining compression slot configured to at least temporarily retain a compression member therein. The compression slot 130 is configured to provide positional flexibility when the intramedullary nail assembly 100 is inserted into the medullary canal of the fractured long bone 20.

[0029] The compression slot 130 may be elongated along the anterior direction L. In the illustrated embodiment, the compression slot 130 extends into the posterior portion 108 of the nail 101. It will be understood that the compression slot 130 may alternatively extend into the anterior portion 106 of the nail 101, or into both the anterior portion 106 and the posterior portion 108 of the nail 101. The portion of the nail 101 defining the compression slot 130 may define a cross-sectional distance, e.g., diameter, that is larger than other portions. In other words, the portion of the nail 101 defining the compression slot 130, e.g., the posterior portion 108, may define a cross-sectional area, e.g., diameter, that is larger than the cross-sectional areas of one or both of the anterior portion 106 and the intermediate portion 110.

[0030] The compression slots 130 can be positioned adjacent to the posterior bone anchor fixation holes 126. One or more of the posterior bone anchor fixation holes 126 can be positioned longitudinally outward from the compression slots 130 along the posterior direction T, such that the compression slots 130 are longitudinally disposed between the posterior bone anchor fixation holes 126 and the anterior end 102. Alternatively or additionally, one or more, up to all, of the posterior bone anchor fixation holes 126 can be positioned longitudinally inward from the compression slots 130, such that the posterior bone anchor fixation holes 126 are longitudinally disposed between the compression slots 130 and the anterior end 102. Similarly, if the compression slots 130 are positioned in the anterior portion 106 of the intramedullary nail 101, the anterior bone anchor fixation holes 128 can be positioned longitudinally outward from the compression slots 130 along the anterior direction L, or alternatively or additionally, the anterior bone anchor fixation holes 128 can be positioned longitudinally inward from the compression slots 130.

[0031] The intramedullary nail 101 can define an anterior receiving slot or element 121 (see FIG. 5 ). The receiving slot 121 extends from a respective one of the anterior bone anchor fixation holes 128. For example, an edge 123 of the tubular wall 122 of the intramedullary nail 101 that defines one of the anterior bone anchor fixation holes 128 can extend around the tubular wall 122 to further define the anterior receiving slot 121. The anterior receiving slot 121 extends into and through the intramedullary nail 101 in a direction substantially perpendicular to the central axis C. In one aspect, the anterior receiving slot 121 extends from the anterior bone anchor fixation hole 128 in the anterior direction L. The anterior receiving slot 121 can have a width that is different from, e.g., smaller than, a width of a respective one of the anterior bone anchor fixation holes 128. It will be appreciated that the anterior receiving slot 121 may alternatively be defined by the edge of a compression slot in substantially the same manner that the anterior receiving slot 121 is defined by the anterior bone anchor fixation hole 128. Thus, the anterior receiving slot 121 may be said to extend from a hole extending in the outer surface of the intramedullary nail 101, which may be, for example, a bone anchor fixation hole or a compression slot.

[0032] The intramedullary nail 101 can define a posterior receiving slot or element 131 (see FIG. 6 ). The receiving slot 131 extends from the compression slot 130. The receiving slot 131 can have a width that is different from, e.g., smaller than, the width of the compression slot 130. For example, an edge 132 of the tubular wall 122 of the intramedullary nail 101 that defines the inlay compression slot 130 can extend around the tubular wall 122 to further define the posterior receiving slot 131. The posterior receiving slot 131 extends into and through the intramedullary nail 101 in a direction substantially perpendicular to the central axis C. In one aspect, the posterior receiving slot 131 extends from the compression slot 130 in the posterior direction T. It will be understood that the posterior receiving slot 131 may alternatively be defined by an edge of at least one of the bone anchor fixation holes 124 in a manner substantially similar to the manner in which the posterior receiving slot 131 is defined by the compression slot 130. Thus, the posterior receiving slot 131 can be said to extend from a hole extending into the outer surface of the intramedullary nail 101, which hole can be, for example, a bone anchor fixation hole or a compression slot.

[0033] 8 illustrates an elevational view of a fifth side of the intramedullary nail assembly 101 according to one embodiment of the present disclosure. The inner surface 118 of the intramedullary nail 101 can define a recess 140 extending from the second end 104 in the anterior direction L. The recess 140 is configured to receive therein an alignment member 262 of the first inlay 200, as described further below.

[0034] 9-11 show a perspective view of a first inlay 200, an elevational view of a first side of the first inlay 200, and a perspective view of a cross-section of the first inlay 200 taken along line 10-10 of FIG. 10, according to an embodiment of the present disclosure. As described in further detail below, the first inlay 200 is configured to be inserted into the cannulated portion 120 of the intramedullary nail 101. The first inlay 200 includes a first inlay body 201 elongated from a first end 202 to a second end 204. The first end 202 may be considered the distal or leading end and may define a first end or outermost edge of the first inlay body 201. The second end 204 may be considered the proximal or trailing end and may define a second end or outermost edge of the first inlay body 201. The first inlay 200 may include a polymeric material.

[0035] The first inlay body 201 is substantially elongated along a central path C' extending in an anterior direction L' from the posterior end 204 to the anterior end 202. In at least some embodiments, the central path can be defined by a central axis C' of the first inlay body 201 extending from the posterior end 204 to the anterior end 202. The anterior direction L' can be substantially parallel to the central axis C'. It will be understood that the central path or central axis C' of the first inlay body 201 can be linear or curved. Thus, the first inlay body 201 can be linear or curved as it extends along the central path or central axis C' from the posterior end 204 to the anterior end 202. The first inlay body 201 can be inserted into the cannulated portion 120 of the intramedullary nail 101 such that the central axis C' of the first inlay body 201 is substantially aligned with and / or coaxial with the central axis C of the intramedullary nail 101.

[0036] The first inlay body 201 has an anterior body portion 206 and a posterior body portion 208 adjacent to the anterior portion 206 along a central axis C'. The interface between the anterior body portion 206 and the posterior body portion 208 defines an inlay shoulder 209. The shoulder 209 may be defined by a difference in cross-sectional dimension (e.g., diameter) of the posterior body portion 208 that is greater than the cross-sectional dimension (e.g., diameter) of the anterior body portion 206. The shoulder 209 defines the anterior end of the posterior body portion 208, including a shoulder surface 211. The shoulder surface 211 may be angularly offset from the central axis C', for example, substantially perpendicular to the central axis C'. In alternative embodiments, the shoulder surface 211 may have a conical, curved, or other shape. It will be understood that the shoulder surface 211 corresponds to the shoulder surface 111 of the intramedullary nail 101 such that when the first inlay body 201 is positioned within the cannulated portion 120 of the intramedullary nail 101, the shoulder surface 211 of the first inlay body 201 is configured to be substantially flush with the shoulder surface 111 of the intramedullary nail 101.

[0037] The first inlay body 201 has an outer surface 214 that extends from the anterior body portion 206 to the posterior body portion 208. In one aspect, the shoulder surface 211 constitutes a portion of the outer surface 214. The outer surface 214 can extend from the posterior end 204 to the anterior end 202. The outer surface 214 can define the outermost periphery of the first inlay body 201. Furthermore, the outer surface 214 can have any suitable cross-sectional shape as desired. For example, the outer surface 214 can be substantially circular in cross section along a plane substantially perpendicular to the central axis C'. It will be appreciated that the outer surface 214 can be configured to correspond to the inner surface 118 of the intramedullary nail 101 such that, when the first inlay body 201 is inserted into the cannulated portion 120 of the intramedullary nail 101, the first inlay body 201 can be axially movable along the central axis C of the intramedullary nail 101.

[0038] Referring to FIG. 11 , the first inlay body 201 has an inner surface 218 opposite the outer surface 214. The first inlay body 201 includes a tubular wall 222 between the inner surface 218 and the outer surface 214. The inner surface 218 defines a cannulation portion 220 extending through the first inlay body 201 from the posterior end 204 to the anterior end 202. The cannulation portion 220 can extend along a central axis C′ of the first inlay body 201. The inner surface 218 can have multiple cross sections along the central axis C′, with each cross section defined in a plane perpendicular to the central axis C′. The inner surface 218 in each cross section can have any suitable cross-sectional shape as desired. For example, the inner surface 218 in each cross section can define a closed cross-sectional shape, such as a circle, an oval, a square, a rectangle, or other shape.

[0039] 12 illustrates an elevational view of a second side, opposite the first side, of a first inlay 200 according to one embodiment of the present disclosure. The first inlay body 201 defines a plurality of bone anchor fixation holes 224. Each bone anchor fixation hole 224 is configured to receive a bone anchor for attaching the intramedullary nail 101 to bone when the first inlay 200 is positioned within the intramedullary nail 101. The bone anchor fixation holes 224 may include one or more holes that may intersect with the cannulated portion 220 of the first inlay body 201. In particular, each bone anchor fixation hole 224 extends within the outer surface 214 and may extend at least partially through, e.g., entirely through, the first inlay body 201. For example, each bone anchor fixation hole 224 can extend into the outer surface 214 on a first side of the first inlay body 201 and extend out from the outer surface 214 on a second side opposite the first side of the first inlay body 201. Thus, each bone anchor fixation hole 224 can extend from an opening 224a on the first side of the first inlay body 201 to an opening 224b on the second side of the first inlay body 201. Thus, each bone anchor fixation hole 224 can be considered a through-hole, although aspects of the present disclosure are not limited to through-holes. At least a portion of the bone anchor fixation holes 224 can extend through the tubular wall 222 on the first side of the first inlay body 201 and through the tubular wall 222 on the second side opposite the first side of the first inlay body 201.

[0040] In one aspect, each bone anchor fixation hole 224 of the first inlay body 201 is configured to align with a corresponding bone anchor fixation hole 126 defined by the posterior portion 108 of the intramedullary nail 101 when the first inlay body 201 is positioned within the cannulated portion 120. Thus, a through hole is formed through the intramedullary nail assembly 100, extending through the bone anchor fixation hole 224 of the first inlay body 201 and the corresponding bone anchor fixation hole 126 of the intramedullary nail 101. In one aspect, the bone anchor fixation hole 224 may have a shape that substantially matches the shape of the corresponding bone anchor fixation hole 126. In one aspect, the cross-sectional dimension (e.g., diameter) of the bone anchor fixation hole 224 is smaller than the cross-sectional dimension (e.g., diameter) of the corresponding bone anchor fixation hole 126 of the intramedullary nail 101. The cross-sectional dimensions of the bone anchor fixing holes 224 allow bone anchor screws inserted into the intramedullary nail assembly 100 through the bone anchor fixing holes 224 of the first inlay body 201 and through each bone anchor fixing hole 124 of the intramedullary nail 101 to come into contact with the first inlay body 201, further securing the screw to the intramedullary nail assembly 100.

[0041] 13 and 14 show front and back views, respectively, of a first inlay 200 according to an embodiment of the present disclosure. The first inlay body 201 defines an inlay compression slot 230 extending into and through the first inlay body 201 in a direction substantially perpendicular to the central axis C'. The inlay compression slot 230 can intersect the cannulation portion 220. For example, the inlay compression slot 230 can extend into the outer surface 214 on a first side of the first inlay body 201 and extend out of the outer surface 214 on a second side opposite the first side of the first inlay body 201. The inlay compression slot 230 is a self-retaining compression slot configured to at least temporarily retain a compression member therein.

[0042] The inlay compression slot 230 of the first inlay body 201 is configured to align with the compression slot 130 defined by the posterior portion 108 of the intramedullary nail 101 when the first inlay body 201 is positioned with the cannulated portion 120. Thus, a slot is formed through the intramedullary nail assembly 100 extending through the inlay compression slot 230 of the first inlay body 201 and the corresponding compression slot 130 of the intramedullary nail 101. The inlay compression slot 230 may be releasable to fit the compression slot 130. In one aspect, the inlay compression slot 230 may have a shape that substantially matches the shape of the corresponding compression slot 130. The inlay compression slot 230 may have cross-sectional dimensions (e.g., diameter and / or width) that are substantially the same as the cross-sectional dimensions (e.g., diameter and / or width) of the corresponding compression slot 130 of the intramedullary nail 101. In alternative embodiments, the cross-sectional dimensions (e.g., diameter and / or width) of the inlay compression slot 230 may be smaller than the cross-sectional dimensions (e.g., diameter and / or width) of the corresponding compression slot 130 of the intramedullary nail 101. The alignment of the inlay compression slot 230 with the compression slot 130 provides positional flexibility when the intramedullary nail assembly 100 is inserted into the medullary canal of the fractured long bone 20.

[0043] The first inlay 200 includes at least one engagement feature configured to engage with the intramedullary nail 101 to limit one or both of (1) translation of the first inlay 200 relative to the intramedullary nail 101 along the central axis C′ and (2) rotation of the first inlay 200 relative to the intramedullary nail 101 about the central axis C′. The at least one engagement feature may include one or more, and up to all, of the engagement member 250, the protrusion 260, and the alignment member 262. Each engagement feature may extend from the outer surface 214 of the first inlay 200, for example, outwardly from the outer surface 214. However, it will be understood that each engagement feature may alternatively extend inwardly from the outer surface 214.

[0044] The first inlay 200 can include an engagement member 250. In one aspect, the engagement member 250 is positioned adjacent the inlay compression slot 230. In alternative aspects, the engagement member 250 may be positioned adjacent at least one of the bone anchor fixation holes 224 or another location on the outer surface 214 of the first inlay body 201. The engagement member 250 can have a shape that matches the shape of the receiving slot 131 of the intramedullary nail 101. The engagement member 250 is configured to be received within the receiving slot 131 and limit one or both of translation of the first inlay 200 relative to the intramedullary nail 101 along the posterior direction T and rotation of the first inlay 200 about the central axis C'. The engagement member 250 extends radially outward from the outer surface 214. The engaging member 250 may be resiliently attached to the first inlay body 201 such that when the first inlay body 201 is inserted into the cannulated portion 120 of the intramedullary nail 101, the engaging member 250 flexes radially inward toward the central axis C', and when the engaging member 250 aligns with the receiving slot 131, the engaging member 250 flexes radially outward to be received in the receiving slot 131. Thus, the engaging member 250 can be biased radially outward.

[0045] The first inlay body 201 can define an engagement slot 252. The engagement slot 252 can extend from at least one of the bone anchor fixation holes 224 or the inlay compression slot 230. For example, an edge 232 of the tubular wall 222 of the first inlay body 201, which defines the opening to the inlay compression slot 230, can extend around the tubular wall 222 to further define the engagement slot 252. The engagement slot 252 extends into and through the first inlay body 201 in a direction substantially perpendicular to the central axis C'. The engagement member 250 can extend from the edge 232 into the engagement slot 252. In one aspect, the engagement member 250 extends from the edge 232 into the engagement slot 252 in an anterior direction L'. The engagement member 250 can be attached to the body 201 to form a hinge that allows the engagement member 250 to flex radially inward and outward.

[0046] The first inlay body 201 can further include at least one radial protrusion 260. The radial protrusion 260 is configured to contact the inner surface 118 of the intramedullary nail 101 to further limit one or both of translation of the first inlay 200 along the posterior direction T and the anterior direction L and / or rotation of the first inlay 200 about the central axis C. The radial protrusion 260 extends radially outward from the outer surface 214 on the anterior body portion 206. The radial protrusion 260 has a cross-sectional dimension (e.g., diameter) that is greater than the cross-sectional dimension (e.g., diameter) of the outer surface 214 of the anterior body portion 206. In one aspect, the radial protrusion 260 can be disposed about the outer surface 214 that defines the bone anchor fixation hole 224 closest to the anterior end 202 of the first inlay body 201. For example, the radial protrusion 260 can be aligned with the bone anchor fixation hole 224 around the circumference of the outer surface 214. In some examples, the at least one radial protrusion 260 may include a pair of radial protrusions extending radially outward in opposite directions from the outer surface 214 .

[0047] The first inlay body 201 can further include an alignment element 262. The alignment element 262 is configured to be received within a recess defined by the inner surface 118 of the intramedullary nail 101 to rotationally align the first inlay body 201 with the intramedullary nail 101. The alignment element 262 extends radially outward from the outer surface 214 of the posterior body portion 208. The alignment member 262 has a cross-sectional dimension (e.g., diameter) that is greater than the cross-sectional dimension (e.g., diameter) of the outer surface 214 of the posterior body portion 208.

[0048] 15-17 show a perspective view of a second inlay 300, an elevational view of the second inlay 300, and a perspective view of a cross section of the second inlay 300 taken along line 16-16 in FIG. 16 , according to an embodiment of the present disclosure. The first inlay 300 includes a second inlay body 301 elongated from a first end 302 to a second end 304. The first end 302 may be considered the distal or leading end and may define a first end or outermost edge of the second inlay body 301. The second end 304 may be considered the proximal or trailing end and may define a second end or outermost edge of the second inlay body 301. The second inlay 300 may include a polymeric material.

[0049] The second inlay body 301 is substantially elongated along a central pathway extending in an anterior direction L" from the posterior end 304 to the anterior end 302. The central pathway may be defined by a central axis C" of the second inlay body 301 extending from the posterior end 304 to the anterior end 302. The anterior direction L" may be substantially parallel to the central axis C". It will be understood that the central pathway or central axis C" of the second inlay body 301 may be straight or curved. The second inlay body 301 may be inserted into the cannulated portion 120 of the intramedullary nail 101 such that the central axis C" of the second inlay body 301 is substantially aligned with and / or coaxial with the central axis C of the intramedullary nail 101.

[0050] The anterior end 302 of the second inlay body 301 can define a protrusion 309. The protrusion 309 extends radially outward from an outer surface 314 of the second inlay body 301 such that a cross-sectional dimension (e.g., diameter) of the protrusion 309 is greater than a cross-sectional dimension (e.g., diameter) of the outer surface 314. The protrusion 309 is configured to substantially prevent further axial movement of the second inlay body 301 into the cannulated portion 120 of the intramedullary nail 101. The anterior end 302 can also define an alignment member 311. The alignment member 311 extends radially outward from the outer surface 314. In one aspect, the alignment member 311 is positioned adjacent to the protrusion 309 along the anterior direction L″. The alignment member 311 is configured to rotationally align the second inlay body 301 with the intramedullary nail 101.

[0051] The outer surface 314 of the second inlay body 301 extends from the anterior end 302 to the posterior end 304. The outer surface 314 may define the outermost periphery of the second inlay body 301. Furthermore, the outer surface 314 may have any suitable cross-sectional shape as desired. For example, the outer surface 314 may be substantially circular in cross-section along a plane substantially perpendicular to the central axis C″. It will be appreciated that the outer surface 314 may be configured to correspond to the inner surface 118 of the intramedullary nail 101 such that, when the second inlay body 301 is inserted into the cannulated portion 120 of the intramedullary nail 101, the second inlay body 301 is axially movable along the central axis C of the intramedullary nail 101.

[0052] Referring to FIG. 17 , the second inlay body 301 has an inner surface 318 opposite the outer surface 314. The second inlay body 301 includes a tubular wall 322 between the inner surface 318 and the outer surface 314. The inner surface 318 defines a cannulation portion 320 extending through the second inlay body 301 from the posterior end 304 to the anterior end 302. The cannulation portion 320 can extend along a central axis C″ of the second inlay body 301. The inner surface 318 can have multiple cross sections along the central axis C″, with each cross section defined in a plane perpendicular to the central axis C″. The inner surface 318 in each cross section can have any suitable cross-sectional shape as desired. For example, the inner surface 318 in each cross section can define a closed cross-sectional shape, such as a circle, an oval, a square, a rectangle, or other shape.

[0053] 18 shows a bottom view of a second inlay 300 according to one embodiment of the present disclosure. The second inlay body 301 defines a plurality of bone anchor fixation holes 324. Each bone anchor fixation hole 324 is configured to receive a bone anchor for attaching the intramedullary nail 101 to bone when the second inlay 300 is positioned within the intramedullary nail 101. The bone anchor fixation holes 324 may include one or more holes that can intersect with the cannulated portion 320 of the second inlay body 301. In particular, each bone anchor fixation hole 324 can extend into the outer surface 314 and at least partially through, e.g., entirely through, the second inlay body 301. For example, each bone anchor fixation hole 324 can extend into the outer surface 314 on a first side of the second inlay body 301 and extend out from the outer surface 314 on a second side opposite the first side of the second inlay body 301. Thus, each bone anchor fixation hole 324 can extend from opening 324a on a first side of second inlay body 301 to opening 324b on a second side of second inlay body 301. Thus, each bone anchor fixation hole 324 can be considered a through-hole, although aspects of the present disclosure are not limited to through-holes. At least a portion of bone anchor fixation holes 324 can extend through tubular wall 322 on the first side of second inlay body 301 and through tubular wall 322 on a second side of second inlay body 301 opposite the first side.

[0054] In one aspect, each bone anchor fixation hole 324 of the second inlay body 301 is configured to align with a corresponding bone anchor fixation hole 128 defined by the anterior portion 106 of the intramedullary nail 101 when the second inlay body 301 is positioned within the cannulated portion 120. Thus, a through hole is formed through the intramedullary nail assembly 100, extending through the bone anchor fixation hole 324 of the second inlay body 301 and the corresponding bone anchor fixation hole 128 of the intramedullary nail 101. In one aspect, the bone anchor fixation hole 324 may have a shape that substantially matches the shape of the corresponding bone anchor fixation hole 128. The shape of the opening 324 a and the bone anchor fixation hole 324 allows for dynamization during the bone healing process. In one aspect, the cross-sectional dimension (e.g., diameter) of the bone anchor fixation hole 324 may be smaller than the cross-sectional dimension (e.g., diameter) of the corresponding bone anchor fixation hole 128 of the intramedullary nail 101.

[0055] 19 and 20 show elevational views of the third and fourth sides, respectively, of the second inlay 300, according to an embodiment of the present disclosure. In an alternative example (not shown), the second inlay body 301 can define an inlay compression slot (not shown) extending into and through the second inlay body 301 in a direction substantially perpendicular to the central axis C". The inlay compression slot can intersect the cannulation portion 320. For example, the inlay compression slot can extend into the outer surface 314 on a first side of the second inlay body 301 and out of the outer surface 314 on a second side opposite the first side of the second inlay body 301. The inlay compression slot is a self-retaining compression slot configured to at least temporarily retain a compression member therein.

[0056] The inlay compression slot of the second inlay body 301 is configured to align with a compression slot (not shown) defined by the anterior portion 106 of the intramedullary nail 101 when the second inlay body 301 is positioned with the cannulated portion 120. Thus, a slot is formed through the intramedullary nail assembly 100 extending through the inlay compression slot of the second inlay body 301 and the corresponding compression slot of the intramedullary nail 101. The inlay compression slot may be released to align with the compression slot of the intramedullary nail 101. In one aspect, the inlay compression slot of the second inlay body 301 may have a shape that substantially matches the shape of the corresponding compression slot of the intramedullary nail 101. The inlay compression slot of the second inlay body 301 may have cross-sectional dimensions (e.g., diameter and / or width) that are substantially the same as the cross-sectional dimensions (e.g., diameter and / or width) of the corresponding compression slot of the intramedullary nail 101. In an alternative embodiment, the cross-sectional dimensions (e.g., diameter and / or width) of the inlay compression slots of the second inlay body 301 may be smaller than the cross-sectional dimensions (e.g., diameter and / or width) of the corresponding compression slots of the intramedullary nail 101. The alignment of the inlay compression slots of the second inlay body 301 with the compression slots of the intramedullary nail 101 provides positional flexibility when the intramedullary nail assembly 100 is inserted into the medullary canal of the fractured long bone 20.

[0057] The second inlay 300 includes at least one engagement feature configured to engage with the intramedullary nail 101 to limit one or both of (1) translation of the second inlay 300 relative to the intramedullary nail 101 along the central axis C′ and (2) rotation of the second inlay 300 relative to the intramedullary nail 101 about the central axis C′. The at least one engagement feature may include one or more, and up to all, of the protrusion 309, the engagement member 350, the protrusion 360, and the alignment member 311. Each engagement feature may extend from the outer surface 314 of the first inlay 300, for example, outwardly from the outer surface 314. However, it will be understood that each engagement feature may alternatively extend inwardly from the outer surface 314.

[0058] The second inlay body 301 can include an engagement member 350. In one embodiment, the engagement member 350 is positioned adjacent one of the bone anchor fixation holes 324. In alternative embodiments, the engagement member 350 can be positioned adjacent the compression slot or another location on the outer surface 314 of the second inlay body 301. The engagement member 350 is configured to be received in the engagement or receiving slot 352 to limit one or both of translation of the second inlay 300 relative to the intramedullary nail 101 along the anterior direction L and rotation of the second inlay 200 about the central axis C. The engagement member 350 extends radially outward from the outer surface 314. The engagement member 350 can be flexible such that when the second inlay body 301 is inserted into the cannulated portion 120 of the intramedullary nail 101, the engagement member 350 flexes radially inward toward the central axis C''.

[0059] The second inlay body 301 can define a receiving slot 352. The receiving slot 352 can extend from at least one of the bone anchor fixation holes 324 or the inlay compression slots. For example, an edge 332 of the tubular wall 322 of the second inlay body 301, which defines an opening to one of the bone anchor fixation holes 324, can extend around the tubular wall 322 to further define the receiving slot 352. The receiving slot 352 extends into and through the second inlay body 301 in a direction substantially perpendicular to the central axis C". The engaging member 350 can extend from the edge 332 into the receiving slot 352. In one aspect, the engaging member 350 extends from the edge 332 into the receiving slot 352 in a posterior direction T". The posterior direction T" is opposite the anterior direction L".

[0060] The second inlay body 301 can further include one or more radial protrusions 360 (see FIG. 18 ). The radial protrusions 360 extend radially around the outer surface 314 of the second inlay body 301. In one aspect, each radial protrusion 360 can extend around the outer surface 314 at a location where a bone anchor fixation hole 324 is located. For example, each radial protrusion 360 can be aligned with a bone anchor fixation hole 424 around the circumference of the outer surface 314. The radial protrusions 360 have a cross-sectional dimension (e.g., diameter) that is larger than the cross-sectional dimension (e.g., diameter) of the outer surface 314. The radial protrusions 360 are configured to provide stability between the second inlay 300 and the intramedullary nail 101.

[0061] 21 shows a perspective view of an inlay 400 according to one embodiment of the present disclosure. The inlay 400 is configured to be inserted through the cannulated portion 120 of the intramedullary nail 101. The inlay 400 may also be referred to as an "eyelet." The inlay 400 has a body 401 extending from a first end 402 to a second end 404 along an eyelet direction E. The eyelet body 401 extends along a central axis C''' that extends from the first end 402 to the second end 404 in the eyelet direction E. The eyelet body 401 may be inserted into one of the bone anchor fixation holes 124 of the intramedullary nail 101 such that the central axis C''' of the eyelet body 401 is substantially aligned with and / or coaxial with the axis A of the respective bone anchor fixation hole 124.

[0062] The inlay body 401 has an inner surface 418 opposite the outer surface 414. The inlay body 401 includes a tubular wall 422 between the inner surface 418 and the outer surface 414. The inner surface 418 defines a cannulation portion 420 that extends through the eyelet body 401 in a direction that is angularly offset from the eyelet direction E, e.g., substantially perpendicular to the eyelet direction E. The cannulation portion 420 is configured to align with the cannulation portion 120 of the intramedullary nail 101 when the inlay body 401 is received in the respective bone anchor fixation hole 124.

[0063] The eyelet body 401 defines bone anchor fixation holes 424 extending through the eyelet body 401 from the first end 402 to the second end 404 along the central axis C'''. Each bone anchor fixation hole 424 is configured to receive a bone anchor for attaching the intramedullary nail 101 to bone when the inlay 400 is positioned within the intramedullary nail 101. The bone anchor fixation holes 424 intersect the cannulated portion 420 of the inlay body 401. In one aspect, the cross-sectional dimension of the holes 424 is smaller than the diameter of the holes 124 in the intramedullary nail 101 so that a bone anchor positioned within the holes 124 can bite into the inlay 400.

[0064] The inlay 400 includes at least one engagement feature configured to engage with the intramedullary nail 101 to limit one or both of (1) translation of the inlay 400 relative to the intramedullary nail 101 along the central axis C′, and (2) rotation of the inlay 400 relative to the intramedullary nail 101 about the central axis C′. The at least one engagement feature may include one or more, and up to all, of the engagement members 450 and the protrusions 460. Each engagement feature may extend from the outer surface 414 of the inlay 400, for example, outwardly from the outer surface 414. However, it will be understood that each engagement feature may alternatively extend inwardly from the outer surface 414.

[0065] The inlay body 401 can include at least one engagement member 450. The engagement member 450 is configured to engage the intramedullary nail 101 to limit translation along the axis A of the respective bone anchor fixation hole 124 in which the inlay 400 is attached. In one embodiment, the engagement member 450 is disposed at the second end 404 of the eyelet body 401. In alternative embodiments, the engagement member 450 can be disposed at another location on the outer surface 414 of the eyelet body 401. The engagement member 450 extends radially outward from the outer surface 414. The engagement member 450 can be resilient such that when the eyelet body 401 is inserted into the bone anchor fixation hole of the intramedullary nail 101, the engagement member 450 flexes radially inward toward the central axis C'''.

[0066] In one aspect, the at least one engaging member 450 can include a pair of opposing engaging members 450 a, 450 b. When the inlay 400 is inserted into the nail 101, the engaging members 450 a, 450 b flex inward toward the central axis C′″ and then flex outward after the elements 450 a, 450 b are inserted to engage with the nail 101. The engaging members 450 a, 450 b can be biased radially outward to automatically recoil.

[0067] The inlay body 401 can further include at least one radial protrusion 460. The radial protrusion 460 is configured to engage the intramedullary nail 101 to limit translation along the axis A of the respective bone anchor fixation hole 124 to which the inlay 400 is attached. The radial protrusion 460 is configured to limit translation along the axis A in a direction opposite to the direction in which the at least one engagement member 450 limits translation. The radial protrusion 460 is also configured to align the inlay 400 within the respective bone anchor fixation hole 124 such that the cannulated portion 420 of the inlay body 401 is aligned with the cannulated portion of the intramedullary nail 101. The radial protrusion 460 extends radially outward from the outer surface 414. In one aspect, the radial protrusion 460 is located at or toward the first end 402 of the eyelet body 401. The radial protrusion 460 has a cross-sectional dimension (eg, diameter) that is greater than the cross-sectional dimension (eg, diameter) of the outer surface 414 of the eyelet body 401 .

[0068] FIG. 22 shows a perspective view of the inlay 400 positioned within the bone anchor fixation hole 124 of the intramedullary nail 101 (Note: The intramedullary nail 101 is shown transparent to show the position of the inlay 400). The engagement member 450 can be removably connected to edges or chamfers defining the openings 124a, b of the bone anchor fixation hole 124. In one aspect, the removably connected can be a snap-fit ​​connection that clicks when locked into place. When the inlay 400 is positioned within the intramedullary nail 101, contact between the radial projections 460 of the eyelet 400 and the tubular wall 122 of the intramedullary nail 101 provides stability between the eyelet 400 and the intramedullary nail 101, thereby reducing circumferential movement of the eyelet 400 relative to the intramedullary nail 101. In one aspect, the tubular wall 122 defines at least one recess that corresponds to the at least one radial protrusion 460, such that the radial protrusion 460 can be disposed within the recess.

[0069] FIG. 23 shows a perspective view of an alternative eyelet 500 according to one embodiment of the present disclosure. Portions of the embodiment of the eyelet 500 disclosed in FIG. 23 are similar to the embodiments described above in FIGS. 22 and 23 and function similarly. The eyelet 500 has a body 501 extending from a first end 502 to a second end 504 along an eyelet direction E′. The eyelet body 501 extends along a central axis C″″ that extends from the first end 502 to the second end 504 in the eyelet direction E′. The eyelet body 501 can be inserted into one of the bone anchor fixation holes 124 of the intramedullary nail 101 such that the central axis C″″ of the eyelet body 501 is substantially aligned with and / or coaxial with the axis A of the respective bone anchor fixation hole 124.

[0070] The eyelet body 501 can further include at least one radial protrusion 560. The radial protrusion 560 extends radially around the outer surface 514. In one embodiment, the radial protrusion 560 is disposed between the first end 502 and the second end 504 of the eyelet body 501. In one embodiment, the radial protrusion 560 is disposed around the cannulated portion 520 defined by the outer surface 514. For example, the radial protrusion 560 can be aligned with the bone anchor fixation holes around the circumference of the outer surface 514. The radial protrusion 560 has a cross-sectional dimension (e.g., diameter) that is larger than the cross-sectional dimension (e.g., diameter) of the outer surface 514 of the eyelet body 501. The at least one radial protrusion 560 can include a pair of radial protrusions 560 extending in opposite directions from the outer surface 514.

[0071] 24 and 25 show side and top views, respectively, of the eyelet 500 positioned within the bone anchor fixation hole 124 of the intramedullary nail 101 (note: the intramedullary nail 101 is shown transparent to show the position of the eyelet 500). FIG. 26 shows a cross-sectional view of the eyelet 500 positioned within the bone anchor fixation hole 124 of the intramedullary nail 101 taken along line 25-25 shown in FIG. 25. The radial protrusions 560 can contact the inner surface 118 of the intramedullary nail 101 to removably secure the eyelet 500 within the bone anchor fixation hole 124 of the intramedullary nail 101. In one aspect, the radial protrusions 560 may be received within recesses 561 defined by a surface (not labeled) of the bone anchor fixation hole 124. When the eyelet 500 is positioned within the intramedullary nail 101, contact between the radial protrusion 560 of the eyelet 500 and the surface of the bone anchor fixation hole 124 provides stability between the eyelet 500 and the intramedullary nail 101, thereby reducing linear movement of the eyelet 500 along the axis A of the bone anchor fixation hole 124.

[0072] FIG. 27 shows a perspective view of an alternative inlay 600 according to one embodiment of the present disclosure. Portions of the embodiment disclosed in FIG. 27 for the inlay 600 are similar to and function similarly to the embodiments described above in FIGS. 8 and 20 for the first inlay 200 and the second inlay 300. The inlay 600 has a body 601 extending from a posterior end 604 to an anterior end 602 along an anterior direction L'". The inlay body 601 extends along a central axis C'"" that extends from the posterior end 604 to the anterior end 602 in the anterior direction L'". The inlay 600 is configured to be inserted into the cannulated portion 120 of the intramedullary nail 101 such that the central axis C'"" of the inlay body 601 is substantially aligned with and / or coaxial with the central axis C of the intramedullary nail 101.

[0073] The inlay body 601 can further include at least one radial protrusion 660. The radial protrusion 660 is configured to contact the inner surface 118 of the intramedullary nail 101 to further limit one or both of translation of the inlay 600 along the posterior direction T and the anterior direction L and / or rotation of the inlay 600 about the central axis C. The radial protrusion 660 extends radially outward from the outer surface 614 on the body 601. The radial protrusion 660 has a cross-sectional dimension (e.g., diameter) that is larger than the cross-sectional dimension (e.g., diameter) of the outer surface 614 of the body 601. The radial protrusion 660 can be positioned closer to the posterior end 604 than the anterior end 602. For example, the radial protrusion 660 can be positioned between the most rearmost bone anchor fixation hole 624a and a bone anchor fixation hole 624 located distally along the body 601 from the bone anchor fixation hole 624a. In one example, the radial protrusion 660 can be positioned between the most rearmost bone anchor fixation hole 624 a and the immediately adjacent bone anchor fixation hole 624 .

[0074] The inlay body 601 can further include an alignment element 662 (e.g., a keying feature). The alignment element 662 is configured to be received within a recess defined by the inner surface 118 of the intramedullary nail 101 to rotationally align the inlay body 601 with the intramedullary nail 101. The alignment element 662 extends radially outward from the outer surface 614 of the body 601. The alignment element 662 has a cross-sectional dimension (e.g., diameter) that is greater than the cross-sectional dimension (e.g., diameter) of the outer surface 614 of the body 601.

[0075] 3, 9, and 15, the intramedullary nail assembly 100 can be assembled by inserting one or both of the first inlay 200 and the second inlay 300 into the intramedullary nail 101. The first inlay 200 is inserted in an anterior direction L through the second end 104 and through the cannulated portion 120 of the intramedullary nail 101 into the posterior body portion 108. The first inlay 200 is moved into the cannulated portion 120 until the shoulder surface 211 of the first inlay body 201 abuts the shoulder surface 111 of the intramedullary nail 101. Contact between the shoulder surfaces 111 and 211 substantially prevents the first inlay 200 from further axial movement in the anterior direction L through the cannulated portion 120. After the first inlay 200 is inserted into the cannulated portion 120, at least one of the bone anchor fixation holes 224 and compression slots 230 of the first inlay 200 aligns with at least one of the posterior bone anchor fixation holes 126 and compression slots 130 of the intramedullary nail 101, respectively.

[0076] In one aspect, after the first inlay 200 is positioned within the intramedullary nail 101, contact between the radial projections 260 of the first inlay 200 and the inner surface 118 of the intramedullary nail 101 provides stability between the first inlay 200 and the intramedullary nail 101, thereby limiting or preventing any radial movement of the anterior body portion 206 of the first inlay 200 relative to the intramedullary nail 101. The alignment member 262 of the first inlay 200 is configured to be received within the recess 140 (see FIG. 8 ) defined by the inner surface 118 of the intramedullary nail 101 to circumferentially align the first inlay 200 with the intramedullary nail 101.

[0077] During insertion of the first inlay 200 into the nail 101, the engaging member 250 flexes radially inward. After the first inlay 200 is inserted, the engaging member 250 engages with the receiving slot or element 131. In one aspect, the engaging member 250 moves radially outward into the receiving slot 131 of the nail 101. The engagement between the engaging member 250 and the receiving slot 131 releasably locks the first inlay 200 within the cannulated portion 120 of the nail 101. In one aspect, the releasable lock between the engaging member 250 and the nail 101 substantially prevents linear and rotational movement between the first inlay 200 and the nail 101. In one aspect, the engaging member 250 and the receiving slot 131 form a snap-fit ​​connection such that the engaging member 250 snaps into the receiving slot 131 after the engaging member 250 is aligned with the receiving slot 131. The engaging member 250 can be disengaged from the receiving slot 131 by applying a force to the engaging member 250 radially inward toward the central channel C of the nail 101 until the engaging member 250 moves away from the receiving slot 131. In one aspect, the engagement between the engaging member 250 and the receiving slot 131 locks or securely locks the first inlay 200 within the cannulated portion 120 of the intramedullary nail 101, thereby substantially preventing removal of the first inlay 200 from the cannulated portion 120.

[0078] The second inlay 300 is inserted through the first end 102 in the posterior direction T through the cannulation portion 120 of the intramedullary nail 101 and into the anterior body portion 106. The second inlay 300 is moved into the cannulation portion 120 until the protrusion 309 abuts the first end 102 of the intramedullary nail 101. Contact between the protrusion 309 and the first end 102 of the intramedullary nail 101 substantially prevents the second inlay 300 from further axial movement in the posterior direction T through the cannulation portion 120. After the second inlay 300 is inserted into the cannulation portion 120, at least one of the bone anchor fixation holes 324 and compression slots of the second inlay 300 aligns with at least one of the anterior bone anchor fixation holes 128 and compression slots 130 of the intramedullary nail 101, respectively.

[0079] In one aspect, after the second inlay 300 is positioned within the intramedullary nail 101, contact between the radial protrusions 360 of the second inlay 300 and the inner surface 118 of the intramedullary nail 101 provides stability between the second inlay 300 and the intramedullary nail 101, thereby reducing circumferential movement of the second inlay 300 relative to the intramedullary nail 101. The alignment member 311 of the second inlay 300 is configured to be received within a recess defined by the inner surface 118 of the intramedullary nail 101 to circumferentially align the second inlay 300 with the intramedullary nail 101.

[0080] During insertion of the second inlay 300 into the nail 101, the engaging member 350 flexes radially inward. After the second inlay 300 is inserted, the engaging member 350 engages with the anterior receiving slot or element 121. In one aspect, the engaging member 350 moves radially outward into the receiving slot 121 of the nail 101. The engagement between the engaging member 350 and the receiving slot 121 releasably locks the second inlay 300 within the cannulated portion 120 of the nail 101. In one aspect, the releasable lock between the engaging member 350 and the nail 101 substantially prevents linear and rotational movement between the second inlay 300 and the nail 101. In one aspect, the engaging member 350 and the receiving slot 121 form a snap-fit ​​connection whereby the engaging member 350 snaps into the receiving slot 121 after the engaging member 350 is aligned with the receiving slot 121. The engaging member 350 can be disengaged from the receiving slot 121 by applying a force to the engaging member 350 radially inward toward the central channel C of the nail 101 until the engaging member 350 moves away from the receiving slot 121. In one aspect, the engagement between the engaging member 350 and the receiving slot 121 locks or securely locks the second inlay 300 within the cannulated portion 120 of the intramedullary nail 101, thereby substantially preventing removal of the second inlay 300 from the cannulated portion 120.

[0081] After the first inlay 200 and the second inlay 300 are inserted into the intramedullary nail 100, the cannulation portion 120 of the intramedullary nail 101, the cannulation portion 220 of the first inlay 200, and the cannulation portion 320 of the second inlay 300 form a cannulation portion (not labeled) that extends through the intramedullary nail assembly 100 from the posterior end 104 to the anterior end 102.

[0082] The intramedullary nail assembly 100 is implanted by driving the assembly 100 into the medullary canal of a long bone, such as the tibia, fibula, humerus, or femur. Prior to inserting the assembly 100, a medical professional may enlarge the medullary canal to create space for the assembly 100. For example, the medullary canal may be enlarged by inserting a reaming rod along the canal and guiding a reamer head (not shown) having at least one cutting edge along the reaming rod so that the at least one cutting edge penetrates the canal. The reaming rod may be flexible so that it can bend to fit the contours of the canal. After enlarging the canal, the intramedullary nail assembly 100 is driven into the enlarged canal. Optionally, the reamer head may be removed, leaving the reaming rod in place, and the intramedullary nail assembly 100 may then be guided along the reaming rod into the canal. In this manner, when the nail assembly 100 is driven into the medullary canal along the reaming rod, the reaming rod can be received in the cannulated portion 120 of the intramedullary nail 101, the cannulated portion 220 of the first inlay 200, and / or the cannulated portion 320 of the second inlay 300.

[0083] The intramedullary nail assembly 100 can be secured to the bone by (1) drilling a hole in the bone that aligns with each bone anchor fixation hole 124 of the intramedullary nail, which is aligned with the corresponding bone anchor fixation hole 224 of the first inlay 200 and bone anchor fixation hole 324 of the second inlay 300, and (2) inserting a bone anchor through the bone into each bone anchor fixation hole, such that the bone anchor engages the bone on at least one side, e.g., both sides, of the intramedullary nail assembly 100. The first inlay 200 and the second inlay 300 provide angular stability and screw pull-out safety to the intramedullary nail assembly 100.

[0084] The intramedullary nail assembly 100 can be used with a variety of tools for inserting, positioning, and aligning the assembly 100 within bone. For example, targeting instruments, probes, locators, sensors, magnetic field generators, guide wires, hook removal instruments, or other tools / components can be used with the intramedullary nail assembly 100 to perform a medical procedure.

[0085] It will be understood that the foregoing description provides examples of the disclosed systems and methods. However, it is contemplated that other implementations of the present disclosure may differ in detail from the foregoing embodiments. All references to the present disclosure or its embodiments are intended to refer to the particular embodiment being discussed at the time, and are not intended to suggest any limitation on the scope of the disclosure more generally. All discriminatory and negative language regarding particular features is intended to indicate a lack of preference for those features, but is not intended to completely exclude such from the scope of the disclosure unless otherwise indicated.

[0086] [Embodiment] (1) An intramedullary nail assembly, an intramedullary nail having an outer surface and an opposite inner surface, the outer surface extending from a leading end of the body to a trailing end of the nail, the inner surface defining a cannulated portion extending toward the leading end and into the trailing end, the nail defining at least one nail hole extending in and through the outer surface; an inlay positionable within the cannulated portion, the inlay having an outer surface and an opposing inner surface, the inlay defining at least one inlay hole extending within the outer surface and through the inner surface of the inlay, the at least one nail hole aligning with a respective at least one inlay hole when the inlay is positioned within the cannulated portion, the at least one nail hole having a cross-sectional dimension greater than a cross-sectional dimension of a respective at least one inlay hole; the inlay includes at least one engagement feature extending from the outer surface and configured to engage the nail to limit one or both of (1) translation of the inlay relative to the nail along a central axis of the nail, and (2) rotation of the inlay relative to the nail about the central axis. Intramedullary nail assembly. (2) The intramedullary nail assembly of claim 1, wherein the at least one engagement feature includes an engagement member configured to engage with the intramedullary nail to releasably lock the inlay within the cannulated portion of the intramedullary nail. (3) An intramedullary nail assembly as described in embodiment 2, wherein the removable lock between the engaging member and the intramedullary nail substantially limits the translation and rotation of the inlay relative to the intramedullary nail. (4) The intramedullary nail assembly of embodiment 2, wherein the intramedullary nail includes a receiving element configured to engage with the engaging member of the inlay to releasably lock the inlay within the cannulated portion of the body. (5) An intramedullary nail assembly as described in embodiment 2, wherein the engaging member is configured to bend inward toward the central axis of the intramedullary nail during insertion of the inlay into the cannulated portion.

[0087] (6) An intramedullary nail assembly according to embodiment 2, wherein the engagement member is positioned adjacent to one of the at least one inlay hole. (7) The inlay is a first inlay, and the first inlay is positionable within the cannulated portion of the posterior body portion, and the intramedullary nail is a second inlay having an outer surface and an opposite inner surface positionable within the anterior body portion of the cannulated portion, the second inlay defining at least one second inlay hole extending within the outer surface of the second inlay and through the inner surface of the second inlay, the at least one nail hole aligning with a respective second at least one inlay hole when the second inlay is positioned within the cannulated portion, the alignment of the nail hole and the second inlay hole defining another assembly hole extending through the intramedullary nail assembly; 3. The intramedullary nail assembly of claim 2, further comprising: (8) The intramedullary nail assembly of embodiment 7, wherein the engagement member is a first engagement member and the second inlay includes a second engagement member configured to engage with the intramedullary nail to releasably lock the second inlay within the cannulated portion of the intramedullary nail. (9) The intramedullary nail assembly of embodiment 1, wherein the nail hole and the inlay hole include fastener holes, and the nail hole substantially coincides with the inlay hole. (10) The intramedullary nail assembly of embodiment 1, wherein the nail hole and the inlay hole include compression slots, and the nail hole substantially coincides with the inlay hole.

[0088] (11) The intramedullary nail assembly of claim 1, wherein the inner surface of the intramedullary nail defines a nail shoulder, the inner surface of the inlay defines an inlay shoulder, and when the inlay is positioned within the cannulated portion of the intramedullary nail, contact between the nail shoulder and the inlay shoulder substantially prevents axial movement of the inlay relative to the intramedullary nail. (12) An inlay for an intramedullary nail assembly, the intramedullary nail assembly including an intramedullary nail having an outer surface and an opposite inner surface, the outer surface extending from a leading end of the nail body to a trailing end of the nail body, the inner surface defining a cannulated portion extending toward the leading end and into the trailing end, the intramedullary nail defining at least one nail hole extending into the outer surface and to the inner surface, the inlay comprising: an outer surface and an opposite inner surface positionable within the cannulated portion, the inlay defining at least one inlay hole extending within the outer surface of the inlay and through the inner surface of the inlay, the at least one inlay hole aligning with a respective at least one nail hole when the inlay is positioned within the cannulated portion, the at least one inlay hole having a cross-sectional dimension smaller than a cross-sectional dimension of the respective at least one nail hole; at least one engagement feature extending from the outer surface and configured to engage the nail to limit one or both of (1) translation of the inlay relative to the nail along a central axis of the nail, and (2) rotation of the inlay relative to the nail about the central axis. Inlay for intramedullary nail assembly. (13) The inlay of embodiment 12, wherein the at least one engagement feature includes an engagement member configured to engage with the intramedullary nail to releasably lock the inlay within the cannulated portion of the intramedullary nail. (14) The inlay of embodiment 12, wherein the inlay body includes an anterior body portion defining the anterior end of the inlay body and a posterior body portion defining the posterior end of the inlay body, the posterior body portion being offset from the anterior body portion along a posterior direction, and the posterior body portion having a cross-sectional dimension different from the cross-sectional dimension of the anterior body portion, such that the interface between the anterior body portion and the posterior body portion defines an inlay shoulder. (15) An inlay as described in embodiment 13, wherein the removable lock between the engaging member and the nail body substantially prevents linear and rotational movement between the inlay and the nail body.

[0089] (16) The inlay of embodiment 12, wherein the inlay body has an outer surface and an opposite inner surface, the inner surface of the inlay body defining a cannulation portion, and when the inlay is placed within the cannulation portion of the nail body, a central axis of the cannulation portion of the inlay body is substantially aligned with a central axis of the cannulation portion of the nail body. (17) The inlay of embodiment 16, wherein the inlay body defines a hole extending in the outer surface of the inlay body and through the inner surface of the inlay body, the inlay hole being positioned to align with a hole defined by the nail body extending in the outer surface of the nail body and through the inner surface of the nail body. (18) A method of assembling an intramedullary nail assembly, comprising: aligning an inlay with an intramedullary nail, the intramedullary nail including a body having an outer surface and an opposing inner surface, the outer surface extending from a leading end of the body to a trailing end of the body, the inner surface defining a cannulated portion extending toward the leading end and into the trailing end, the intramedullary nail defining at least one nail hole extending in and through the outer surface; inserting the inlay into the cannulated portion of the body, the inlay having an outer surface and an opposing inner surface, the inlay defining at least one inlay hole extending into and through the outer surface of the inlay, after the inserting step, the at least one nail hole aligns with a respective at least one inlay hole, and at least one engagement feature extending from the outer surface of the inlay engages with the intramedullary nail to limit one or both of (1) translation of the inlay relative to the intramedullary nail along a central axis of the intramedullary nail, and (2) rotation of the inlay relative to the intramedullary nail about the central axis; A method comprising: (19) The method of embodiment 18, wherein the inserting step includes releasably locking the inlay within the cannulated portion of the body after the inlay is inserted to limit linear and rotational movement between the inlay and the body. (20) The method of embodiment 18, wherein the inserting step includes bending the engaging member inward toward a central axis of the intramedullary nail while inserting the inlay into the cannulated portion.

[0090] (21) The inlay and the engaging member are a first inlay and a first engaging member, respectively, and the first inlay is disposed within the cannulated portion of the rear body portion, and the method includes: and further including inserting a second inlay into the cannulated portion of the body within the anterior body portion, the second inlay including a second engaging member configured to engage the body to releasably lock the second inlay within the cannulated portion of the body after the second inlay is inserted. The method of embodiment 18.

Claims

1. 1. An intramedullary nail assembly comprising: an intramedullary nail having an outer surface and an opposite inner surface, the outer surface extending from a leading end of the nail to a trailing end of the nail, the inner surface defining a cannulated portion extending toward the leading end and into the trailing end, the nail defining at least one nail hole extending into and through the outer surface; an inlay positionable within the cannulation portion, the inlay having an outer surface and an opposing inner surface, the inlay defining at least one inlay hole extending within the outer surface and through the inner surface of the inlay, the at least one nail hole aligning with a respective at least one inlay hole when the inlay is positioned within the cannulation portion, the at least one nail hole having a cross-sectional dimension greater than a cross-sectional dimension of the respective at least one inlay hole; the inlay includes at least one engagement feature extending from the outer surface and configured to engage the nail to limit one or both of (1) translation of the inlay relative to the nail along a central axis of the nail, and (2) rotation of the inlay relative to the nail about the central axis; the at least one engagement feature includes an engagement member configured to engage the nail to releasably lock the inlay within the cannulated portion of the nail to limit the translation and rotation of the inlay relative to the nail; the engaging member is configured to flex inwardly toward the central axis of the intramedullary nail during insertion of the inlay into the cannulated portion; the intramedullary nail includes a receiving element; when the inlay is inserted into the cannulated portion in a direction from the posterior end of the nail toward the anterior end of the nail and the at least one nail hole is aligned with the respective at least one inlay hole, the engaging member is configured to return outward from the central axis of the intramedullary nail into and engage with the receiving element of the intramedullary nail. Intramedullary nail assembly.

2. the at least one engagement feature further includes a protrusion configured to contact the inner surface of the nail to limit the translation and rotation of the inlay relative to the nail; The intramedullary nail assembly of claim 1 , wherein the protrusions are disposed around the outer surface of the inlay.

3. The intramedullary nail assembly of claim 1 , wherein the engagement member is positioned adjacent one of the at least one inlay hole.

4. the inlay is a first inlay, the at least one inlay hole is a first at least one inlay hole, the cannulation is a first cannulation, the first inlay is positionable within the first cannulation, the inner surface of the intramedullary nail defines a second cannulation extending into the anterior end toward the posterior end, and the intramedullary nail assembly comprises: a second inlay having an outer surface and an opposite inner surface positionable within the second cannulated portion of the intramedullary nail, the second inlay defining at least one second inlay hole extending within the outer surface of the second inlay and through the inner surface of the second inlay, the at least one nail hole aligning with a respective second at least one inlay hole when the second inlay is positioned within the second cannulated portion, the alignment of the at least one nail hole with the respective second at least one inlay hole defining another assembly hole extending through the intramedullary nail assembly; The intramedullary nail assembly of claim 1 further comprising:

5. 5. The intramedullary nail assembly of claim 4, wherein the engaging member is a first engaging member and the second inlay includes a second engaging member configured to engage the intramedullary nail to releasably lock the second inlay within the second cannulated portion of the intramedullary nail.

6. 2. The intramedullary nail assembly of claim 1, wherein the at least one nail hole and the at least one inlay hole comprise fastener holes, and the shape of the at least one nail hole substantially matches the shape of the at least one inlay hole.

7. 2. The intramedullary nail assembly of claim 1, wherein the inner surface of the intramedullary nail defines a nail shoulder and the outer surface of the inlay defines an inlay shoulder, and when the inlay is positioned within the cannulated portion of the intramedullary nail, contact between the nail shoulder and the inlay shoulder substantially prevents axial movement of the inlay relative to the intramedullary nail.

8. 1. An inlay for an intramedullary nail assembly, the intramedullary nail assembly including an intramedullary nail having an outer surface and an opposite inner surface, the outer surface extending from a leading end of the nail to a trailing end of the nail, the inner surface defining a cannulated portion extending toward the leading end and into the trailing end, the intramedullary nail defining at least one nail hole extending in the outer surface and to the inner surface, the inlay comprising: an outer surface and an opposite inner surface positionable within the cannulation portion, the inlay defining at least one inlay hole extending within the outer surface of the inlay and through the inner surface of the inlay, the at least one inlay hole aligning with a respective at least one nail hole when the inlay is positioned within the cannulation portion, the at least one inlay hole having a cross-sectional dimension smaller than a cross-sectional dimension of the respective at least one nail hole; at least one engagement feature extending from the outer surface and configured to engage the nail to limit one or both of (1) translation of the inlay relative to the nail along a central axis of the nail, and (2) rotation of the inlay relative to the nail about the central axis; the at least one engagement feature includes an engagement member configured to engage the nail to releasably lock the inlay within the cannulated portion of the nail to limit the translation and rotation of the inlay relative to the nail; the engaging member is configured to flex inwardly toward the central axis of the intramedullary nail during insertion of the inlay into the cannulated portion; the intramedullary nail includes a receiving element; when the inlay is inserted into the cannulated portion in a direction from the posterior end of the nail toward the anterior end of the nail and the at least one nail hole is aligned with the respective at least one inlay hole, the engaging member is configured to return outward from the central axis of the intramedullary nail into and engage with the receiving element of the intramedullary nail. Inlay.

9. the at least one engagement feature further includes a protrusion configured to contact the inner surface of the nail to limit the translation and rotation of the inlay relative to the nail; The inlay of claim 8 , wherein the protrusions are disposed around the outer surface of the inlay.

10. 9. The inlay of claim 8, wherein the inlay includes an anterior body portion defining a front end of the inlay and a posterior body portion defining a rear end of the inlay, the posterior body portion being adjacent to the anterior body portion along a posterior direction, the posterior body portion having a cross-sectional dimension that is different from the cross-sectional dimension of the anterior body portion, such that an interface between the anterior body portion and the posterior body portion defines an inlay shoulder.

11. 9. The inlay of claim 8, wherein the inner surface of the inlay defines a cannulation, and when the inlay is placed within the cannulation of the intramedullary nail, a central axis of the cannulation of the inlay is substantially aligned with a central axis of the cannulation of the intramedullary nail.

12. 1. A method of assembling an intramedullary nail assembly, comprising: aligning an inlay with an intramedullary nail, the intramedullary nail including a body having an outer surface and an opposing inner surface, the outer surface extending from a leading end of the body to a trailing end of the body, the inner surface defining a cannulated portion extending toward the leading end and into the trailing end, the intramedullary nail defining at least one nail hole extending in and through the outer surface; inserting the inlay into the cannulated portion of the body, the inlay having an outer surface and an opposing inner surface, the inlay defining at least one inlay hole extending into and through the outer surface of the inlay, after the inserting step, the at least one nail hole aligns with a respective at least one inlay hole, and at least one engagement feature extending from the outer surface of the inlay engages with the intramedullary nail to limit one or both of (1) translation of the inlay relative to the intramedullary nail along a central axis of the intramedullary nail, and (2) rotation of the inlay relative to the intramedullary nail about the central axis; Including, the at least one engagement feature includes an engagement member configured to engage the body to releasably lock the inlay within the cannulated portion of the body to limit the translation and rotation of the inlay relative to the nail; the engaging member is configured to flex inwardly toward the central axis of the intramedullary nail during insertion of the inlay into the cannulated portion; the intramedullary nail includes a receiving element; wherein the engaging member is configured to extend outward from the central axis of the intramedullary nail back into and engage with the receiving element of the intramedullary nail when the inlay is inserted into the cannulated portion in a direction from the posterior end of the body toward the anterior end of the body and the at least one nail hole is aligned with the respective at least one inlay hole.

13. the at least one engagement feature further includes a protrusion configured to contact the inner surface of the body to limit the translation and rotation of the inlay relative to the nail; The method of claim 12 , wherein the protrusions are disposed around the outer surface of the inlay.

14. the inlay and the engaging member are a first inlay and a first engaging member, respectively; the cannulation portion is a first cannulation portion, the first inlay is disposed within the first cannulation portion of the body, and the inner surface of the body defines a second cannulation portion extending toward the rear end and into the front end; and the method includes:

13. The method of claim 12, further comprising inserting a second inlay into the second cannulation portion of the body, the second inlay including a second engagement member configured to engage the body to releasably lock the second inlay within the second cannulation portion of the body after the second inlay is inserted.

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