Trial Radial Head Implant

Abstract

An orthopedic trial implant having a plurality of support component augments of different heights, each augment releasably and slidably connected to the trial implant.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application is a continuation-in-part of U.S. application Ser. No. 16 / 025,964, filed July 2, 2018, which claims priority to U.S. application Ser. No. 62 / 638,844, filed March 5, 2018, the disclosures of each of which are incorporated by reference in their entireties.

[0002] FIELD OF THEINVENTION The present invention relates generally to orthopedic implant trial devices and systems, and more particularly to orthopedic implant trial devices and systems for determining the height of a final radial head implant. [Background technology]

[0003] Fractures of the radius occur in the part of the bone closest to the elbow called the radial "head." Radial head fractures are a common injury that can result from acute elbow injuries. Radial head fractures are typically treated with a variety of surgical and non-surgical options, depending on the severity of the injury. For example, surgical options for more severe injuries to the radial head may include open reduction with internal fixation (ORIF), radial head resection, hemiarthroplasty (e.g., radial head arthroplasty), and total arthroplasty (i.e., total elbow replacement).

[0004] Radial head arthroplasty involves resection of the fractured and damaged radial head and replacing the natural articular surface with an artificial articular surface of an implant that articulates with the natural cartilage surface of the capitellum of the distal humerus.

[0005] In a radial head replacement procedure, a radial head prosthesis is implanted in the medullary canal of the proximal radius. The radial head may cooperate with an ulna or ulnar prosthesis to provide a radioulnar joint. The radial head may cooperate with a humerus or humerus prosthesis to provide a radiohumeral joint.

[0006] Prior to implantation of a radial head implant, a surgeon selects an implant having a size that properly fits the implant site of a particular patient. Many known systems include trial stems and trial heads that the surgeon can assemble and use prior to final implantation to evaluate the fit to select the most appropriately sized implant. However, known systems do not provide a simple and effective means to try multiple different humeral head heights to determine the appropriate height of the final radial head implant. Exemplary systems include the following prior art devices:

[0007] US6746487 discloses an intramedullary fixation device for fixing a trial in the medullary canal of a bone to determine the offset and orientation of an artificial implant for replacing the articular surface of the bone. The fixation device comprises a body for receiving the trial and a fixation portion for engaging the trial. A system for use in surgical repair of a joint is disclosed, comprising a selection of different sizes of artificial implants, a selection of different sizes of trials corresponding to the implant sizes, a selection of different sizes of fixation devices corresponding to the trial sizes, a trial fixation device driver for inserting the fixation device and attached trial into the bone canal, and a trial device remover for removing the fixation device from the resected bone. A method of using the fixation device and system of the present invention is disclosed.

[0008] US Patent No. 7,740,661 discloses a radial head implant device and method. In one embodiment, the radial head implant can include a head portion for articulating engagement with the humerus, a stem portion for engaging the radius, and a shaft for engaging the stem portion. The head portion can include an upper surface for engaging the humerus. The stem portion can have an axial opening for receiving at least a portion of the shaft, and a collar can be disposed around the stem portion at its proximal end. An upper portion of the shaft can be configured to engage the head portion, while a distal portion of the shaft can be elongated and cylindrical for axially fitting and moving within the axial opening of the stem portion. Other embodiments are also disclosed for axial movement of the radial head implant. Various structures are disclosed for locking the shaft in position within the stem portion.

[0009] US Patent No. 8,535,382 discloses a prosthetic system for replacing a head portion of a proximal radius. The system can include a first polymeric joint component having a first locking portion and a metal head component having a second locking portion. The second locking portion can mate with the first locking portion to form a first locking mechanism to initially couple the first joint component to the head component. The head component can define a locking channel. The system can also include a stem component having a protrusion receivable within the locking channel. The protrusion can define a bore, and the stem component can be adapted to be coupled to the radius. The system can also include a fastener received through the locking channel and within the bore to provide a second locking mechanism to couple the head component to the stem component.

[0010] No. 8,764,845 discloses a kit for use in a procedure for implanting an orthopedic joint prosthesis, comprising a head component of an orthopedic joint prosthesis with a body portion having a convex support surface and a back surface by which the head component can be connected to a mating component of the joint prosthesis, the head component having a chamfered surface extending around at least a portion of its circumference where the support surface and the back surface are united, and a plurality of markings on the chamfered surface. The kit includes a trial head component with a body portion having a convex trial support surface and a back surface, the trial head component having a plurality of markings on the trial support surface at or towards the interface between the trial support surface and the back surface. The lateral dimensions of the head component are approximately the same as the lateral dimensions of the trial head component, and the positions of the markings on the chamfered surface around the periphery of the head component correspond to the positions of the markings on the trial support surface around the periphery of the trial head component.

[0011] No. 8,840,676 discloses a prosthesis trial system including at least one head member having an outer surface and a cavity configured to mate with an outer surface of a stem member. The prosthesis trial system further includes at least one shell member having an inner surface configured to mate with the outer surface of the at least one head member.

[0012] No. 8,945,138 discloses a kit for use in performing a trial reduction arthroplasty. The kit includes a trial stem assembly including a first component, a second component selectively movable relative to the first component, and a fastener for securing the first component to the second component. The kit also includes an articulating trial component removably secured to the trial stem assembly, and a driver for cooperating with the fastener for securing the first component to the second component. The kit also includes a handle. The handle has a first feature for allowing a driver to pass through the handle and a second feature for orientably connecting the handle to the articulating trial component.

[0013] US Patent Application Publication No. 20040186.580 discloses a radial head replacement system, which includes a radial head replacement, a device for guiding the resection of the radial head, and a kit including a bone plug and a bone plug insertion instrument. The radial head replacement has a separate adjustable head portion that can be fixed onto the implanted stem so that the implanted radial head replacement smoothly contacts the capitellum of the humerus. In another form, the radial head replacement uses cross bone screws that help to more securely fix the stem of the radial head replacement within the medullary canal of the radius. The resection guide includes a movable cutting guide that ensures accurate resection of the radial head, thereby allowing for better positioning of the implanted radial head replacement. The bone plug limits migration of bone cement beyond the fixation area of ​​the stem of the radial head replacement to the radius.

[0014] US Patent Application Publication No. 20050075735 discloses a modular prosthesis system for replacing the head portion of the radius. The prosthesis system includes a head component having a first connecting portion that connects to a second connecting portion, and a collar component having a second connecting portion and a third connecting portion. The system also includes a stem component including a fourth connecting portion that connects to the third connecting portion, the stem component having a stem fixation portion that connects to the radius. The collar component provides a modular geometry to the prosthesis without the need for a multiplicity of head and stem components with different lengths and angles.

[0015] U.S. Patent Application Publication No. 20160051365 discloses a radial head trial device for replacing a proximal radial head, the radial head trial device including a stem component having a central longitudinal axis extending between a proximal end and a distal end, a head component axially removably attachable to the stem component, the head component being interchangeable with a selection of other head components each axially removably attachable to the stem component, an anti-rotation feature, and a recess, the anti-rotation feature structured to be received in the recess to inhibit rotation of the head component relative to the stem component. Summary of the Invention [Problem to be solved by the invention]

[0016] What is needed in the art is a trial radial head implant device and system that allows for less joint distraction and a simpler device for confirming the final implant height. [Means for solving the problem]

[0017] According to one example of the present disclosure, an orthopedic trial implant assembly may include at least one radial trial implant and at least one spacer. The radial trial implant may include a head body defining a proximal head body surface and a distal head body surface substantially opposite the proximal head body surface along a longitudinal direction. The head body may have a height extending from the proximal head body surface to the distal head body surface along the longitudinal direction. The radial trial implant may further include a stem extending from the head body along a distal direction substantially defined by the longitudinal direction. The at least one spacer may be configured to removably attach to the radial trial implant along a direction substantially perpendicular to the longitudinal direction to define a composite head including the head body and a spacer head of the spacer. The composite head defines a proximal composite head surface and a distal composite head surface opposite the proximal composite head surface along a longitudinal direction, the composite head defining a composite head height from the proximal composite head surface to the distal composite head surface. One of the proximal and distal composite head surfaces may be defined by the head body, and the other of the proximal and distal composite head surfaces may be defined by the spacer head. In one example, the composite head height is greater than the head body height. [Brief description of the drawings]

[0018] The following detailed description will be better understood when read in conjunction with the accompanying drawings, in which there is shown, for purposes of illustration, exemplary embodiments, it being understood, however, that the disclosure is not limited to the precise arrangements and instrumentalities shown. [Figure 1] FIG. 1 is an exploded perspective view of an orthopaedic trial implant assembly including a radial trial implant and a spacer configured to be releasably attached to the radial trial implant. [Diagram 2] 2 is another perspective exploded view of the orthopedic trial implant assembly shown in FIG. 1. [Diagram 3] FIG. 2 is an exploded elevational view of the orthopedic trial implant assembly shown in FIG. 1. [Figure 4A]FIG. 2 is a side elevational view of the radial trial implant shown in FIG. 1. [Figure 4B] FIG. 4B is a perspective view of the head body of the radial trial implant shown in FIG. 4A, but including cutting teeth in one example. [Figure 4C] FIG. 4B is a bottom view of the head body of the radial trial implant shown in FIG. 4A, showing cutting teeth having a curved shape. [Figure 4D] 4D is a bottom view of the head body similar to FIG. 4C, but with straight, linear cutting teeth. [Diagram 5] FIG. 4B is a side view of a trial spacer configured to be attached to the radial trial implant shown in FIG. 4A. [Figure 6] FIG. 2 is a perspective view of the orthopedic trial implant assembly shown in FIG. 1 showing the radial trial implant removably attached to the radial trial implant. [Figure 7] 2 is a schematic side view of the orthopedic trial implant assembly shown in FIG. 1, showing the radial trial implant attached to the spacer. [Figure 8] 2 is a schematic top view of the orthopedic trial implant assembly shown in FIG. 1, showing the radial trial implant attached to the spacer. [Figure 9A] FIG. 2 is a side elevational view of the radial trial implant shown in FIG. 1. [Figure 9B] 9B is a side view of an orthopaedic trial implant assembly including the radial trial implant shown in FIG. 9A and a first spacer attached to the radial trial implant. [Figure 9C] FIG. 9B is a side view of an orthopedic trial implant assembly including the radial trial implant shown in FIG. 9A and a second spacer attached to the radial trial implant, the second spacer having a different height than the first spacer shown in FIG. [Figure 10A] FIG. 1 illustrates a proximal radius prepared to receive a radial trial implant. [Figure 10B]FIG. 1 illustrates a radial trial implant implanted in the proximal radius, further illustrating a first spacer configured to attach to the implanted radial trial implant. [Figure 10C] 1A-1D show an orthopedic trial assembly implanted in the proximal radius, showing a first spacer attached to a radial trial implant. [Figure 10D] FIG. 10C illustrates the orthopedic trial implant assembly implanted in the proximal radius whereby the first spacer has been removed and a second spacer has been attached to the radial trial implant. [Figure 10E] The final radial implant is shown implanted in the proximal radius.

[0019] Corresponding reference characters indicate corresponding parts throughout the several views.The exemplary embodiments described herein should not be construed in any way as limiting the scope of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The present invention will be described in detail below with reference to the accompanying drawings, using various exemplary embodiments according to the present invention. In the following detailed description, many specific details are described in order to fully understand the present invention. However, it will be obvious to those skilled in the art that the present invention can be practiced without these specific details. In other instances, well-known structures are not shown in detail to avoid unnecessarily obscuring the present invention.

[0021] Thus, all of the embodiments described below are exemplary embodiments provided to enable a person skilled in the art to make or use the embodiments of the present disclosure, and are not intended to limit the scope of the present disclosure, which is defined by the claims. As used herein, the word "exemplary" means "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" should not necessarily be construed as preferred or advantageous over other embodiments. Also, as used herein, "upper," "lower," "left," "rear," "right," "front," "vertical," "horizontal," and their derivatives refer to the present invention as oriented in FIG. 1.

[0022] Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description. It is also to be understood that the specific devices and processes illustrated in the accompanying drawings and described in the following specification are merely exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.

[0023] 1-3, the orthopaedic trial implant assembly 20 may be configured as a radial trial implant assembly configured to be implanted in the proximal radius. The orthopaedic trial implant assembly 20 includes a radial trial implant 22 and a radial trial spacer 24 configured to be releasably attached to the radial trial implant 22. The radial trial implant 22 and the radial trial spacer 24 may be made of any suitable plastic or other suitable material.

[0024] 1-4A, the radial trial implant 22 includes a head body 26 and a stem 28 extending from the head body 26. In one example, the stem 28 can be unitary with the head body 26. Alternatively, the stem 28 can be separate from and attached to the head body 26.

[0025] The head body 26 defines a proximal head body surface 30 and a distal head body surface 32 substantially opposite the proximal head body surface 30 along a longitudinal direction. For example, the distal head body surface 32 is spaced from the proximal head body surface 30 in a distal direction defined by the longitudinal direction. Conversely, the proximal head body surface 30 is spaced from the distal head body surface 32 in a proximal direction opposite the distal direction, also defined by the longitudinal direction. Thus, as used herein, the terms "distal," "distally," and their derivatives refer to a direction from the proximal head body surface 30 toward the distal head body surface 32. Also, as used herein, the term "proximal," and its derivatives refer to a direction from the distal head body surface 32 toward the proximal head body surface 30.

[0026] As used herein, the terms "substantially" and "about," and their derivatives, acknowledge that a referenced dimension, size, shape, orientation, or other parameter may include up to ±20%, i.e., ±10%, ±5%, and ±2%, of the stated dimension, size, shape, orientation, or other parameter, as well as the exact dimension, size, shape, orientation, or other parameter as stated.

[0027] In one example, the proximal head body surface 30 can define an articulation surface that can be configured to cooperate with an ulna or ulnar prosthesis to provide a radio-ulnar joint. The proximal head body surface 30 can cooperate with a humerus or humerus prosthesis to provide a radio-humeral joint. In this regard, the proximal head body surface 30 can be concave. The distal head body surface 32 can be substantially planar. Of course, it should be understood that the proximal head body surface 30 and the distal head body surface 32 can be shaped in any suitable manner as desired. The stem 28 can extend distally from the distal head body surface 32.

[0028] In one example, the distal head body surface 32 may be substantially smooth. Alternatively, as shown in FIGS. 4B-4D, the distal head body surface 32 may define a plurality of cutting teeth 56 configured to flatten the radius as the head body 26 rotates about its longitudinally oriented central axis. The cutting teeth 56 may extend distally and may be unitary with the distal head body surface 32. Alternatively, the cutting teeth 56 may be separate from the radial trial implant 22 and attached to the distal head body surface 32. The cutting teeth 56 may be circumferentially disposed about the distal head body surface 32. In one example shown in FIGS. 4B-4C, the teeth may be shaped as curved spiral shaped segments. Thus, the teeth 56 may be referred to as curved spiral shaped teeth. Alternatively, as shown in FIG. 4D, the cutting teeth 56 may be oriented in a straight line. Additionally, the cutting teeth 56 may be oriented radially to extend about the distal head body surface 32. In one example, the cutting teeth 56 can intersect one another at a central axis of the head body 26 .

[0029] 1-4A, the head body 26 may further include at least one sidewall 34 extending from the proximal head body surface 30 to the distal head body surface 32. The at least one sidewall may define an outer periphery of the head body 26 in a plane oriented perpendicular to the longitudinal direction. The at least one sidewall 34 may be configured as a single substantially cylindrical sidewall 34. The cylindrical sidewall 34 may extend along a central axis oriented along the longitudinal direction. Alternatively, the at least one sidewall 34 may be defined by a plurality of connected walls that define an outer periphery of the head body 26. Additionally, the sidewall 34 may be substantially flat along the longitudinal direction from the proximal head body surface 30 to the distal head body surface 32. As described in more detail below, the head body 26 may define a channel 40 extending in the at least one sidewall 34 configured to receive the spacer 24 to removably attach the spacer 24 to the radial trial implant 22.

[0030] The head body 26 defines a height H1 that extends substantially longitudinally from the proximal head body surface 30 to the distal head body surface 32. It is envisioned that the height H1 of the head body 26 may be less than the gap 42 between the proximal radius 44 (see FIG. 10A ) and a complementary articular surface 47 that may be defined by one or both of the ulna and humerus. In such cases, it may be desirable to attach a spacer 24 to the radial trial implant 22 to increase the height of the head body 26.

[0031] 1-3 and 5, the spacer 24 includes a spacer head 46 including a proximal spacer head surface 48 and a distal spacer head surface 50 opposite the proximal spacer head surface 48 and spaced apart from the proximal spacer head surface 48 along a distal direction. In one example, the proximal spacer head surface 48 can define an articulating surface that can be configured to cooperate with an ulna or ulna prosthesis to provide a radioulnar joint. The proximal spacer head surface 48 can cooperate with a humerus or humerus prosthesis to provide a radiohumeral joint. In this regard, the proximal spacer head surface 48 can be concave. The distal spacer head surface 50 can be substantially convex. Thus, the distal spacer head surface 50 can be configured to nest with the proximal head body surface 30 when the spacer 24 is attached to the radial trial implant 22. Of course, it should be understood that the proximal spacer head surface 48 and the distal spacer head surface 50 may be shaped in any suitable manner as desired.

[0032] The spacer 24 may further include at least one sidewall 52 extending from the proximal spacer head surface 48 to the distal spacer head surface 50. The at least one sidewall 52 may define an outer periphery of the spacer head 46 in a plane oriented perpendicular to the longitudinal direction. The at least one sidewall 52 may be configured as a single substantially cylindrical sidewall 52. The cylindrical sidewall 52 may extend along a central axis oriented along the longitudinal direction. The central axis of the cylindrical sidewall 52 of the spacer may be parallel to or coincident with the central axis of the cylindrical sidewall 34 of the trial radial prosthesis 22. Alternatively, the at least one sidewall 52 may be defined by a plurality of connected walls that define an outer periphery of the spacer head 46. Additionally, the sidewall 52 may be substantially flat along the longitudinal direction from the proximal spacer head surface 48 to the distal spacer head surface 50.

[0033] The spacer head 46 defines a spacer head height H2 that extends substantially longitudinally from a proximal spacer head surface 48 to a distal spacer head surface 50. It is envisioned that the spacer head height H2 may be less than the height H1 of the head body 26. The spacer 24 is configured to be removably attached to the radial trial implant 22 such that the spacer head 46 and the head body 26 define a composite head 54 having a composite head height H3 that is greater than the height H1 of the head body 26 (see FIG. 7). For example, the composite head height H3 may be substantially equal to the sum of the height H1 of the head body 26 and the spacer head height H2, as shown in FIG. 7.

[0034] 1-3 and 5 , the spacer 24 may include an attachment member 58 configured to attach to a complementary attachment member of the radial trial implant 22. In particular, the complementary attachment member of the radial trial implant 22 may be configured as a channel 40. The attachment member 58 of the spacer 24 may be received within the channel 40 to attach the spacer 24 to the radial trial implant 22. In other examples, it is envisioned that the attachment member of the radial trial implant 22 may be received within the channel of the spacer 24 to removably attach the spacer 24 to the radial trial implant 22.

[0035] 1-8, generally, the attachment member 58 can include an extension member 60 extending from the spacer head 46. In particular, the extension member 60 can extend substantially distally from the spacer head 46. In one example, the extension member 60 can extend substantially distally from the distal spacer head surface 50. Thus, the extension member 60 can have a first end extending from the distal spacer head surface 50, and the extension member 60 can extend substantially along a longitudinal direction from the first end to a second end. The extension member 60 is sized to be received in a proximal portion 41 of a channel 40 that can open to the proximal head body surface 30. In particular, the channel 40 can extend through the proximal head body surface 30 along a proximal direction.

[0036] The mounting member 58 may further include a mounting tab 62 extending from the extension member 60. In particular, the mounting tab 62 may extend from the extension member 60 along a first direction substantially perpendicular to the longitudinal direction. For example, the mounting tab 62 may extend from a second end of the extension member. The mounting tab 62 is configured to be slidably inserted into the distal portion 43 of the channel 40 along the first direction substantially perpendicular to the longitudinal direction. When the mounting tab 62 is inserted into the channel 40, the distal spacer head surface 50 may face or abut the proximal head body surface 30. The distal portion 43 of the channel 40 may open to the proximal portion 41 of the channel 40 along the longitudinal direction. The mounting tab 62 may be arranged such that the spacer 24 defines a gap 64 extending along the longitudinal direction from the mounting tab 62 to the spacer head 46, in particular to the distal spacer head surface 50. When the mounting member 58 is inserted into the channel 40 , the gap 64 can receive a portion of the head body 26 , including the proximal head body surface 30 and an opposing inner surface 66 that defines the proximal end of the distal portion 43 of the channel 40 .

[0037] The attachment member 58 may further include a retention member 68 that may be releasably secured to the radial trial implant 22. In particular, the retention member 68 may be releasably secured to a complementary retention member of the head body 26 within the channel 40. In one example, the retention member 68 may be press-fit into the channel 40, and in particular the distal portion 43 of the channel 43. The press-fit engagement may be released when a sufficient force is applied to the spacer 24 along a second direction opposite the first direction, thereby allowing the spacer 24 to be removed from the radial trial implant 22. The second direction may be referred to as a removal direction. The first direction may be referred to as an attachment direction.

[0038] 1 and 7, when the attachment member 58 is inserted into the channel 40 in a first direction, the spacer head 46 may face or abut the head body 26 of the trial radial implant 22. In particular, the distal spacer head surface 50 may face or abut the proximal head body surface 30. The orthopaedic trial implant assembly 20 may thus define a composite head 70 including the head body 26 and the spacer head 46. The composite head 70 may define a proximal composite head surface 72 and a distal composite head surface 74 longitudinally opposite the proximal composite head surface 72. In particular, the distal composite head surface 74 is substantially spaced distally from the proximal composite head surface 72. Conversely, the proximal composite head surface 72 is spaced proximally from the distal composite head surface 74.

[0039] The composite head 70 defines a composite head height H3 extending substantially longitudinally from a proximal composite head surface 72 to a distal composite head surface 74. One of the proximal composite head surface 72 and the distal composite head surface 74 is defined by the head body 26, and the other of the proximal composite head surface 72 and the distal composite head surface 74 is defined by the spacer head 46. In one example, the proximal spacer head surface 48 defines the proximal composite head surface 72, and the distal head body surface 32 defines the distal composite head surface 74. Although the spacer head 46 is disposed proximally of the head body 26 in one example, it is envisioned that the spacer 24 can alternatively be attached to the head body 26 such that the spacer head 46 is disposed distally of the head body 26. In this regard, the proximal spacer head surface 48 can face the distal head body surface 32. Additionally, the proximal head body surface 30 may define a proximal composite head surface 72 and the distal spacer head surface 50 may define a distal composite head surface 74 .

[0040] 9A-9C, an orthopaedic trial implant assembly 20 can include a plurality of spacers 24, such as a first spacer 24a and a second spacer 24b. Each of the plurality of spacers 20 can be selectively and removably attached to a radial trial implant 22. That is, each spacer 24 can be attached to the radial trial implant 22 in the manner described above. Additionally, each of the spacers 24 can be removed from the radial trial implant in the manner described above.

[0041] The first spacer 24a can be attached to the radial trial implant 22 in the manner described above to define a first composite head 70a. The second spacer 24b can be attached to the radial trial implant 22 in the manner described above to define a second composite head 70b. Each of the spacers 24 of the plurality of spacers 24 can have a different spacer height substantially along the longitudinal direction, as described above. For example, the first spacer 24a can define a first spacer height HS1. Thus, when the first spacer 24a is attached to the radial trial implant 22 in the manner described above, the first spacer 24a and the spacer head 46 of the head body 26 can combine to define a first composite head 70a having a first composite head height. The first spacer 24a can be removed from the radial trial implant 22 and the second spacer 24b can be attached to the radial trial implant 22 such that the spacer head 46 and the head body 26 of the second spacer 24b can combine to define a second composite head 70b having a second composite head height. The second spacer 24b can define a second spacer height HS2 that is different from HS1. For example, the second spacer height HS2 can be greater than the first spacer height HS1. Thus, the height of the resulting first composite head 70a can be different from the height of the resulting second composite head 70b. For example, the height of the second composite head 70b can be greater than the height of the first composite head 70a. It is understood that each of the mounting members 58, including the extension members 60 and mounting tabs 62, of the different sized spacers 24 can be identical in size and shape to one another within manufacturing tolerances so that the mounting members 58 can be removably attached to the same radial trial implant 22.

[0042] 10A-10D, the orthopaedic trial implant assembly 20 may be configured to identify the size of a permanent implant to be implanted in the proximal radius 44. The term "permanent" implant indicates that the implant is not intended to be removed prior to the completion of the surgical procedure. In particular, as shown in FIG. 10B, the radial trial spacer 22 is coupled to the proximal radius. In particular, the stem 28 of the radial trial spacer 22 is inserted into the medullary canal of the proximal radius 44 such that the head body 26 is disposed within the gap 42. In some instances, the stem is pre-sized to fit within the medullary canal using a sounder that abuts against cortical bone within the medullary canal to determine the appropriate diameter or alternative cross-sectional dimension. In some instances, the stem may be sized to be loosely received within the medullary canal. 4B-4D, the cutting teeth 56 can remove bone from the proximal radius when the radial trial spacer 22 is rotated about its central longitudinal axis, thereby flattening the proximal radius. Thus, the head can rest on a plane defined by the proximal radius. As shown in FIG. 10B, the head body 46 does not span the entire gap 42 from the proximal radius 44 to the complementary articular surface 47.

[0043] Therefore, one of the radial trial spacers 24 having a known height can be selected, as shown in FIG. 10B. Since the height of the corresponding spacer head 46 is known and the height of the head body 26 is known, the resulting composite head height can be easily calculated. As shown in FIG. 10B, the first trial spacer 24a can be aligned with the radial trial implant 22, so that a sliding movement of the first trial spacer 24a in a first direction attaches the first trial spacer 24a to the radial trial implant 22, as shown in FIG. 10C. However, in FIG. 10C, it is observed that the height of the first composite head 70a is smaller than the height of the gap 42 along the longitudinal direction. Therefore, the first composite head 70a cannot extend from the proximal radius 44 to the complementary articular surface 47 (see FIG. 10A).

[0044] 10C-10D , the first trial spacer 24a may be removed from the radial trial implant 22 by moving the first trial spacer 24a in a second direction relative to the radial trial implant 22. Advantageously, the radial trial implant 22 may remain coupled to the proximal radius while the first trial spacer 24a is being removed. Otherwise, the first trial spacer 24a may be removed from the radial trial implant 22 without removing the radial trial implant 22 from the proximal radius 44.

[0045] 10D, once the first trial spacer 24a has been removed, the second trial spacer 24b may be attached to the radial trial implant 22 in the manner described above. Because the height of the corresponding spacer head 46 of the second trial spacer 24b is known and the height of the head body 26 is known, the height of the resulting second composite head 70b may be readily calculated. As shown in FIG. 10D, the second composite head 70 is substantially aligned with the proximal radial bone. 4 4 to the opposing complementary articular surface 47 (see FIG. 10A). Thus, the height of the second composite head 70b is substantially equal to the height of the gap 72 along the longitudinal direction. Thus, referring now to FIG. 10E, a permanent radial implant 80 in the kit of permanent implants may be selected to have a head height that is substantially equal to or best corresponds to the height of the second composite head 70b and thus the height of the gap 72. Referring again to FIG. 10D, the second trial spacer 24 may be removed from the radial trial implant 22 and the radial trial implant may be removed from the proximal radius. The selected permanent radial implant 80 may then be selected and attached to the proximal radius. 4 4. In particular, the stem of the permanent radial implant 80 can be inserted into the medullary canal and the head of the permanent radial implant 80 can articulate about complementary articular surfaces defined by one or both of the ulna and the distal humerus. The permanent radial implant 80 can be made from titanium, alloys thereof, stainless steel, alloys thereof, or any suitable biocompatible metal or other material.

[0046] It is recognized that different patients have proximal radii of different sizes. Thus, a kit can be provided that includes a plurality of radial trial implants 22 (see FIG. 4A ) having different sizes and that can be selected for implantation into an appropriately sized proximal radius. Additionally, each of the radial trial implants 22 can be configured to be removably attached to the same trial spacer. Thus, the radial trial implants 22 can have substantially identically sized channels that receive the trial spacers. The radial trial implants 22 can have at least one size or shape that is different from at least one other of the radial trial implants 22. For example, the stems 28 can be sized differently from one another. In one example, the stems 28 of the radial trial implants 22 can define different cross-sectional dimensions to define the different sizes. The stems 28 can be cylindrical or tapered, and thus the cross-sectional dimensions can be defined by the respective diameters of the stems. The cross-sectional dimension is measured at a fixed distance distally from the distal head body surface 32 .

[0047] Thus, at least some of the stems of the radial trial implants of the kit are sized differently in cross-section relative to the other stems of the radial trial implants of the kit along a direction substantially perpendicular to the longitudinal direction. For example, at least some of the stems of the radial trial implants are sized differently in cross-section relative to the other stems of the radial trial implants of the kit in a plane oriented substantially perpendicular to the longitudinal direction. Further, at least some of the head bodies of the radial trial implants of the kit may be sized differently in cross-section relative to the other head bodies of the radial trial implants of the kit along a direction substantially perpendicular to the longitudinal direction.

[0048] It is further envisioned that the kit may include a plurality of spacers 24 having different spacer head heights, as described above. Each of the spacers 24 of the kit may be configured to attach to each of the radial trial implants 22 of the kit. For example, all of the mounting members 56 of the spacers 24 of the kit may be substantially equal in size and shape, and all of the slots 40 of the radial trial implants 22 of the kit may be substantially equal in size and shape.

[0049] Although the present invention has been described with respect to at least one embodiment, the present invention may be further modified within the spirit and scope of the present disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or conventional practice in the art to which this invention pertains and which fall within the scope of the appended claims.

[0050] [Embodiment] (1) An orthopedic trial implant assembly, comprising: at least one radial trial implant, a head body defining a proximal head body surface and a distal head body surface substantially opposite the proximal head body surface along a longitudinal direction, the head body having a height extending from the proximal head body surface to the distal head body surface along the longitudinal direction; at least one radial trial implant including: a stem extending from the head body along a distal direction substantially defined by the longitudinal direction; at least one spacer configured for removably mounting to the radial trial implant along a direction substantially perpendicular to the longitudinal direction to define a composite head including the head body and a spacer head of the spacer, the composite head defining a proximal composite head surface and a distal composite head surface opposite the proximal composite head surface along the longitudinal direction, the composite head defining a composite head height from the proximal composite head surface to the distal composite head surface; Equipped with one of the proximal and distal composite head surfaces is defined by the head body, and the other of the proximal and distal composite head surfaces is defined by the spacer head; An orthopaedic trial implant assembly, wherein the combined head height is greater than the head body height. (2) An orthopedic trial implant assembly as described in embodiment 1, wherein the spacer head defines a proximal spacer head surface and a distal spacer head surface opposite the proximal spacer head surface along the longitudinal direction, the proximal spacer head surface defining the proximal composite head surface, and the head body defining the distal composite head surface. (3) The orthopedic trial implant assembly of claim 2, wherein the at least one spacer comprises an attachment member extending from the spacer head and configured to be received by the head body to removably attach the at least one spacer to the at least one radial trial implant. (4) The orthopedic trial implant assembly of embodiment 3, wherein the trial implant body defines a channel extending into the head and is configured to receive the mounting member of the at least one spacer to removably mount the at least one spacer to the at least one radial trial implant. (5) An orthopedic trial implant assembly as described in embodiment 4, wherein the head body has a sidewall extending from the proximal head body surface and the distal head body surface, and the channel extends within the sidewall along a direction substantially perpendicular to the longitudinal direction.

[0051] (6) The mounting member is an extension member having a first end extending from the distal spacer head surface, the extension member extending from the first end substantially along the longitudinal direction to a second end; a mounting tab extending from the second end of the extension member along a direction substantially perpendicular to the longitudinal direction and configured to be inserted into the channel such that the distal spacer head surface faces the proximal head body surface; 5. An orthopedic trial implant assembly as described in embodiment 4, comprising: (7) The orthopedic trial implant assembly of claim 2, wherein the at least one spacer defines a spacer height from the proximal spacer head surface along the longitudinal direction to the distal spacer head surface, the at least one spacer height being less than the height of the head body. (8) The orthopedic trial implant assembly of claim 2, wherein the at least one spacer comprises a plurality of spacers, each spacer having a different respective spacer height, each spacer being configured for selectively removably attachment to the radial trial implant to define a corresponding different composite head height. (9) The orthopedic trial implant assembly of claim 8, wherein each spacer of the plurality of spacers comprises an attachment tab configured to be selectively received within a channel of the radial trial implant to attach the spacer to the radial trial implant, and all of the tabs are substantially the same size and shape. (10) An orthopedic trial implant assembly as described in embodiment 1, wherein the distal head body surface defines a plurality of cutting teeth configured to flatten the radius when the head body rotates about its central axis oriented along the longitudinal direction.

[0052] (11) The orthopedic trial implant assembly of claim 10, wherein the cutting teeth are circumferentially disposed about the distal head body surface. (12) The orthopedic trial implant assembly of claim 10, wherein the cutting teeth are oriented in a straight line. (13) The orthopedic trial implant assembly of claim 10, wherein the cutting teeth define a swept spiral shape. (14) The orthopedic trial implant assembly of claim 1, wherein the at least one radial trial implant comprises a plurality of radial trial implants, each configured for selectively removably attachment to the at least one spacer, and the stems of the radial trial implants are different sizes from one another. (15) The orthopedic trial implant assembly of claim 14, wherein the stems define different cross-sectional dimensions to define respective different sizes.

[0053] (16) The orthopedic trial implant assembly of claim 15, wherein the cross-sectional dimension is defined by a diameter of each of the stems. (17) A kit comprising: A plurality of radial trial implants, each radial trial implant comprising: a head body defining a proximal head body surface and a distal head body surface substantially opposite the proximal head body surface along a longitudinal direction, the head body having a height extending from the proximal head body surface to the distal head body surface along the longitudinal direction; a stem extending from the head body along a distal direction substantially defined by the longitudinal direction; Including, a plurality of radial trial implants, the trial implants being different sizes from one another; at least one spacer configured for removably mounting to the radial trial implant along a direction substantially perpendicular to the longitudinal direction to define a composite head including the head body and the spacer, the composite head defining a proximal composite head surface and a distal composite head surface opposite the proximal composite head surface along the longitudinal direction, the composite head defining a composite head height from the proximal composite head surface to the distal composite head surface; Including, one of the proximal composite head surface and the distal composite head surface is defined by the head body, and the other of the proximal composite head surface and the distal composite head surface is defined by the spacer; The composite head height is greater than the head body height. kit. (18) The kit of embodiment 17, wherein the at least one spacer comprises a plurality of spacers, each spacer having a different respective spacer height, each spacer being configured to be selectively removably attached to the radial trial implant to define a corresponding different composite head height. (19) The kit of embodiment 17, wherein at least some of the stems of the radial trial implants are sized differently in cross section relative to other stems of the radial trial implants along a direction substantially perpendicular to the longitudinal direction. (20) The kit of embodiment 17, wherein at least some of the head bodies of the radial trial implant are sized differently in cross section relative to other head bodies of the radial trial implant along a direction substantially perpendicular to the longitudinal direction.

Claims

1. An orthopaedic trial implant assembly for measuring the longitudinal height of a gap between a proximal cut end surface of a proximal radius and a complementary articular surface to identify the longitudinal size of a permanent implant to be implanted in the proximal radius, comprising: At least one radial trial implant, a head body defining a proximal head body surface and a distal head body surface substantially opposite the proximal head body surface along a longitudinal direction, the head body having a height extending from the proximal head body surface to the distal head body surface along the longitudinal direction; at least one radial trial implant including: a stem extending from the head body along a distal direction substantially defined by the longitudinal direction; at least one spacer configured for removably attaching to the radial trial implant by movement along a direction substantially perpendicular to the longitudinal direction relative to the head body to define a composite head including the head body and a spacer head of the spacer, the composite head defining a proximal composite head surface and a distal composite head surface opposite the proximal composite head surface along the longitudinal direction, the composite head defining a composite head height from the proximal composite head surface to the distal composite head surface, the proximal composite head surface being a plane substantially perpendicular to the longitudinal direction; Equipped with one of the proximal and distal composite head surfaces is defined by the head body, and the other of the proximal and distal composite head surfaces is defined by the spacer head; An orthopaedic trial implant assembly, wherein the combined head height is greater than the height of the head body.

2. 2. The orthopaedic trial implant assembly of claim 1, wherein the spacer head defines a proximal spacer head surface and a distal spacer head surface opposite the proximal spacer head surface along the longitudinal direction, the proximal spacer head surface defining the proximal composite head surface, and the head body defining the distal composite head surface.

3. 3. The orthopaedic trial implant assembly of claim 2, wherein the at least one spacer comprises an attachment member extending from the spacer head and configured to be received by the head body to removably attach the at least one spacer to the at least one radial trial implant.

4. 4. The orthopaedic trial implant assembly of claim 3, wherein the at least one radial trial implant defines a channel extending into the head and configured to receive the mounting member of the at least one spacer to removably mount the at least one spacer to the at least one radial trial implant.

5. 5. The orthopaedic trial implant assembly of claim 4, wherein the head body includes a sidewall extending from the proximal head body surface and the distal head body surface, the channel extending within the sidewall along the direction substantially perpendicular to the longitudinal direction.

6. The mounting member is an extension member having a first end extending from the distal spacer head surface, the extension member extending from the first end substantially along the longitudinal direction to a second end; a mounting tab extending from the second end of the extension member along a direction substantially perpendicular to the longitudinal direction and configured to be inserted into the channel such that the distal spacer head surface faces the proximal head body surface; The orthopaedic trial implant assembly of claim 4 comprising:

7. 3. The orthopaedic trial implant assembly of claim 2, wherein the at least one spacer defines a spacer height from the proximal spacer head surface along the longitudinal direction to the distal spacer head surface, the at least one spacer height being less than the height of the head body.

8. 3. The orthopaedic trial implant assembly of claim 2, wherein the at least one spacer comprises a plurality of spacers each having a different respective spacer height, each of the spacers configured for selectively removably attachment to the radial trial implant to define a corresponding different composite head height.

9. 9. The orthopaedic trial implant assembly of claim 8, wherein each spacer of the plurality of spacers comprises an attachment tab configured to be selectively received within a channel of the radial trial implant to attach the spacer to the radial trial implant, all of the tabs being substantially the same size and shape.

10. 2. The orthopaedic trial implant assembly of claim 1, wherein the distal head body surface defines a plurality of cutting teeth configured to flatten the proximal radius as the head body rotates about its central axis oriented along the longitudinal direction, and the orthopaedic trial implant assembly is configured to measure the height of the gap after cutting of the proximal cut end surface of the proximal radius.

11. The orthopaedic trial implant assembly of claim 10 , wherein the cutting teeth are circumferentially disposed about the distal head body surface.

12. The orthopaedic trial implant assembly of claim 10 , wherein the cutting teeth are oriented in a straight line.

13. The orthopaedic trial implant assembly of claim 10 , wherein the cutting teeth define a curvilinear spiral shape.

14. 2. The orthopaedic trial implant assembly of claim 1, wherein the at least one radial trial implant comprises a plurality of radial trial implants each configured for selectively removably attachment to the at least one spacer, the stems of the radial trial implants being different sizes from one another.

15. The orthopaedic trial implant assembly of claim 14 , wherein the stems define different cross-sectional dimensions to define respective different sizes.

16. The orthopaedic trial implant assembly of claim 15 , wherein the cross-sectional dimension is defined by a diameter of each of the stems.

17. A kit for measuring the longitudinal height of a gap between a proximal cut end surface of a proximal radius and a complementary articular surface to identify the longitudinal size of a permanent implant to be implanted in the proximal radius, comprising: A plurality of radial trial implants, each radial trial implant comprising: a head body defining a proximal head body surface and a distal head body surface substantially opposite the proximal head body surface along a longitudinal direction, the head body having a height extending from the proximal head body surface to the distal head body surface along the longitudinal direction; a stem extending from the head body along a distal direction substantially defined by the longitudinal direction; Including, a plurality of radial trial implants, the trial implants being different sizes from one another; at least one spacer configured for removably attaching to the radial trial implant by movement along a direction substantially perpendicular to the longitudinal direction relative to the head body to define a composite head including the head body and the spacer, the composite head defining a proximal composite head surface and a distal composite head surface opposite the proximal composite head surface along the longitudinal direction, the composite head defining a composite head height from the proximal composite head surface to the distal composite head surface, the proximal composite head surface being a plane substantially perpendicular to the longitudinal direction; Including, one of the proximal composite head surface and the distal composite head surface is defined by the head body, and the other of the proximal composite head surface and the distal composite head surface is defined by the spacer; The composite head height is greater than the height of the head body; kit.

18. 18. The kit of claim 17, wherein the at least one spacer comprises a plurality of spacers each having a different respective spacer height, each of the spacers configured for selectively removably attachment to the radial trial implant to define a corresponding different composite head height.

19. 20. The kit of claim 17, wherein at least some of the stems of the radial trial implant are sized differently in cross section relative to other stems of the radial trial implant along a direction substantially perpendicular to the longitudinal direction.

20. 20. The kit of claim 17, wherein at least some of the head bodies of the radial trial implant are sized differently in cross section relative to other head bodies of the radial trial implant along a direction substantially perpendicular to the longitudinal direction.

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