Trial radial head implant

Abstract

The present invention provides an orthopedic trial implant having a plurality of bearing component reinforcements of varying heights, wherein each reinforcement is releasably and slidably connected to the trial implant.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This is a continuation-in-part of U.S. patent application serial number 16 / 025,964, filed on July 2, 2018, which in turn claims priority to U.S. patent application serial number 62 / 638,844, filed on March 5, 2018, the disclosures of each of which are hereby incorporated by reference as if set forth in their entirety. Background Art 1. Technical Field

[0004] The present invention relates generally to trial orthopedic implant devices and systems, and more particularly to trial orthopedic implant devices and systems for determining the height of a final radial head implant.

[0005] 2. Description of Related Technology

[0006] Some fractures of the radius occur in the part of the bone near the elbow joint, called the "head" of the radius. A radial head fracture is a common injury that may result from an acute elbow injury. Depending on the severity of the injury, fractures of the radial head are typically treated with a variety of surgical and non-surgical options. For example, surgical options for more severe injuries of the radial head may include open reduction and internal fixation (ORIF), radial head resection, hemiarthroplasty (e.g., radial head arthroplasty), and total arthroplasty (i.e., total elbow replacement).

[0007] Radial head arthroplasty involves resection of the fractured and damaged radial head and replacement of the natural joint surface with an artificial joint surface of an implant that articulates with the natural cartilage surface of the capitellum of the distal humerus.

[0008] In a radial head replacement, a radial head prosthesis is implanted into the medullary canal of the proximal radius. The radial head can be combined with the ulna or an ulnar prosthesis to provide radioulnar joint motion. The radial head can also be combined with the humerus or a humeral prosthesis to provide radiohumeral joint motion.

[0009] Before implanting the radial head implant, the surgeon selects an implant with a size that is appropriately suited to the implant site of a particular patient. Many known systems include trial rods and trial heads that the surgeon can assemble and use before final implantation to assess the fitness of the implant for selecting the most appropriate size. However, known systems do not provide a simple, effective means for trying multiple different humeral head heights to determine the appropriate height of the final radial head implant. Exemplary systems include the following prior art devices:

[0010] U.S. Patent 6,746,487 discloses an intramedullary fixation device for use in securing a trial in the medullary canal of a bone to determine the offset and orientation of a disclosed prosthetic implant for replacing an articular surface of a bone. The fixation device includes 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, the system including a selection of prosthetic implants of various sizes, a selection of trials of various sizes corresponding to the sizes of the implants, a selection of fixation devices of various sizes corresponding to the sizes of the trials, a trial fixation device driver for inserting the fixation device and the attached trial into the bone canal, and a trial device extractor for removing the fixation device from the resected bone. Methods of using the fixation device and system of the present invention are disclosed.

[0011] U.S. Patent 7740661 discloses radial head implant equipment and method. In one embodiment, the radial head implant may include a head portion for articulating with the humerus, a rod portion for engaging with the radius, and a shaft for engaging with the rod portion. The head portion may include an upper surface for engaging the humerus. The rod portion may have an axial opening for receiving at least a portion of the shaft, and a collar may be provided around the rod portion at its proximal end. The upper portion of the shaft may be configured to engage the head portion, and the distal portion of the shaft may be elongated and cylindrical, for axially fitting into the axial opening of the rod portion and moving within the axial opening of the rod portion. Other embodiments for the axial movement of the radial head implant are also disclosed. Various structures for locking the shaft in place in the rod portion are disclosed.

[0012] U.S. Patent 8,535,382 discloses a prosthetic system for replacing the head portion of the proximal radius. The system may include a first polymeric articulation component having a first locking portion and a metal head component having a second locking portion. The second locking portion may cooperate with the first locking portion to form a first locking mechanism to initially couple the first articulation component to the head component. The head component may define a locking channel. The system may also include a rod component having a protrusion that can be received in the locking channel. The protrusion may define a hole, and the rod component may be adapted to couple to the radius. The system may also include a fastener that is received through the locking channel and into the hole to provide a second locking mechanism that couples the head component to the rod component.

[0013] U.S. Patent 8,764,845 discloses a kit for use in implanting an orthopedic joint prosthesis, the kit comprising a head component of an orthopedic joint prosthesis, the head component comprising a body part having a convex bearing surface and a counter surface at which the head component can be connected to a mating component of the joint prosthesis, wherein the head component has a chamfered surface extending around at least a portion of its periphery, and a plurality of markings on the chamfered surface, where the bearing surface and the counter surface meet. The kit also comprises a trial head component comprising a body part having a convex trial bearing surface and a counter surface, wherein the trial head component has a plurality of markings on the trial bearing surface at or toward the interface between the trial bearing surface and the counter surface. The transverse dimension of the head component is substantially the same as the transverse dimension of the trial head component, and wherein 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 bearing surface of the trial head component around its periphery.

[0014] US Patent 8,840,676 discloses a prosthesis testing system comprising at least one head member having an outer surface and a cavity configured to mate with the outer surface of a stem member. The prosthesis testing system further comprises at least one shell member having an inner surface configured to mate with the outer surface of the at least one head member.

[0015] U.S. Patent 8,945,138 discloses a kit for use in performing a trial reduction interarticular joint arthroplasty. The kit includes a trial rod assembly comprising 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 articulation trial component removably and securely secured to the trial rod assembly and a driver for cooperating with the fastener to secure the first component to the second component. The kit also includes a handle. The handle has a first feature for allowing the driver to pass through the handle and a second feature for directionally connecting the handle to the articulation trial component.

[0016] U.S. Patent Application Publication 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 comprising a bone plug and a bone plug insertion instrument. The radial head replacement has a separate adjustable head portion that can be fixed on the rod of the implant so that the implanted radial head replacement and the capitellum of the humerus are smoothly docked. In another form, the radial head replacement uses a crossed bone screw that is used to more firmly anchor the rod of the radial head replacement in the medullary canal of the radius. The resection guide includes a movable cutting guide that ensures the precise resection of the radial head, thereby allowing the radial head replacement implanted to be better positioned. The bone plug limits the advancement of bone cement beyond the region where the rod portion of the radial head replacement is fixed to the radius.

[0017] U.S. 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 and a collar component, the head component having a first connecting portion connected to a second connecting portion, the collar component having a second connecting portion and a third connecting portion. The system also includes a stem component including a fourth connecting portion connected to the third connecting portion, the stem component having a stem anchoring portion connected to the radius. The collar component provides a modular geometry to the prosthesis, eliminating the need for an increased number of head components and stem components with variable lengths and angles.

[0018] U.S. patent application publication 2016005!365 discloses a radial head trial device for replacing a proximal radial head, the radial head trial device comprising a rod component having a central longitudinal axis extending between a proximal end and a distal end, a head component capable of axially and removably attaching to the rod component, wherein the head component is interchangeable with a selection of other head components, each of the other head components being capable of axially and removably attaching to the rod component, an anti-rotation feature and a groove, wherein the anti-rotation feature is configured to be received in the groove to prevent rotation of the head component relative to the rod component.

[0019] What is needed in the art is a trial radial head implant device and system that allows for less joint distraction and a simpler means for confirming the final implant height. Summary of the Invention

[0020] 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 that defines a proximal head body surface and a distal head body surface substantially opposite to 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 rod that extends from the head body along a distal direction substantially defined by the longitudinal direction. At least one spacer may be configured to be removably attached to the radial trial implant along a direction substantially perpendicular to the longitudinal direction so as to define a composite head comprising a spacer head of the head body and the spacer. The composite head defines a proximal composite head surface and a distal composite head surface substantially opposite to the proximal composite head surface along the longitudinal direction, and the composite head defines a composite head height from the proximal composite head surface to the distal composite head surface. One of the proximal composite head surface and the distal composite head surface may be defined by the head body, and the other of the proximal composite head surface and the distal composite head surface 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

[0021] The following detailed description will be better understood when read in conjunction with the accompanying drawings in which exemplary embodiments are shown for purposes of illustration. It should be understood, however, that the disclosure is not limited to the precise arrangements and instrumentalities shown. In the drawings:

[0022] Figure 1 is a perspective exploded view of an orthopedic trial implant assembly including a radial trial implant and a spacer configured to be releasably attached to the radial trial implant;

[0023] Figure 2 for Figure 1 Another perspective exploded view of the orthopedic trial implant assembly shown in ;

[0024] Figure 3 for Figure 1 An exploded front view of the orthopedic trial implant assembly shown in ;

[0025] Figure 4A for Figure 1 A side elevation view of the radial trial implant shown in ;

[0026] Figure 4B for Figure 4A A perspective view of the head body of the radial trial implant shown in , but in one example including cutting teeth;

[0027] Figure 4C for Figure 4AA bottom plan view of the head body of the radial trial implant shown in , showing the cutting teeth having a curved shape;

[0028] Figure 4D For similar Figure 4C a bottom plan view of the head body of the invention, but wherein the cutting teeth are straight and linear;

[0029] Figure 5 is configured to be attached to Figure 4A A side elevation view of a trial spacer of a radial trial implant shown in FIG.

[0030] Figure 6 for Figure 1 a perspective view of the orthopedic trial implant assembly shown in , showing the radial trial implant removably attached to the radial trial implant;

[0031] Figure 7 for Figure 1 Schematic side elevation view of the orthopedic trial implant assembly shown in , showing the radial trial implant attached to the spacer;

[0032] Figure 8 for Figure 1 A schematic plan view of an orthopedic trial implant assembly shown in FIG, showing a radial trial implant attached to a spacer;

[0033] Figure 9A for Figure 1 A side elevation view of the radial trial implant shown in ;

[0034] Figure 9B To include Figure 9A a side elevational view of the orthopedic trial implant assembly of the radial trial implant and the first spacer attached to the radial trial implant shown in FIG;

[0035] Figure 9C To include Figure 9A A side elevation view of an orthopedic trial implant assembly of a radial trial implant and a second spacer attached to the radial trial implant, wherein the second spacer has a Figure 9B The first spacer shown in different heights;

[0036] Figure 9C To include Figure 9A A side elevation view of an orthopedic trial implant assembly of a radial trial implant and a second spacer attached to the radial trial implant, wherein the second spacer has a Figure 9B The first spacer shown in different heights;

[0037] Figure 10A The proximal radius is shown prepared to receive a radial trial implant;

[0038] Figure 10B shows a radius trial implant having been implanted in the proximal radius, further illustrating a first spacer configured to be attached to the implanted radius trial implant;

[0039] Figure 10C An orthopedic trial assembly implanted in the proximal radius is shown showing the first spacer attached to the radius trial implant;

[0040] Figure 10D Shown is an orthopedic trial implant assembly implanted in the proximal radius, as Figure 10C as shown, but whereby the first spacer has been removed and the second spacer has been attached to the radial trial implant;

[0041] Figure 10E The final radius implant is shown implanted in the proximal radius.

[0042] Corresponding reference characters indicate corresponding parts throughout the several views.The exemplary embodiments set forth herein should not be construed as limiting the scope of the present invention in any way. DETAILED DESCRIPTION

[0043] The present invention will be discussed in detail below with reference to the accompanying drawings based on various exemplary embodiments according to the present invention. In the following detailed description, many specific details are set forth in order to provide a comprehensive understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be practiced without these specific details. In other cases, well-known structures are not shown in detail to avoid unnecessarily obscuring the present invention.

[0044] Therefore, all of the implementations described below are exemplary implementations provided to enable those 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 as defined by the claims. As used herein, the word "exemplary" or "illustrative" means "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" or "illustrative" is not necessarily to be construed as preferred or advantageous over other implementations. In addition, in this specification, the terms "upper," "lower," "left," "back," "right," "front," "vertical," "horizontal," and their derivatives shall be used in connection with the present invention, as in Figure 1 oriented in the.

[0045] Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, summary, or the following detailed description. It is also to be understood that the specific devices and methods shown in the drawings and described in the following specification are merely exemplary embodiments of the inventive concepts defined in the appended claims. Therefore, unless the claims expressly indicate otherwise, specific dimensions and other physical characteristics related to the embodiments disclosed herein should not be considered limiting.

[0046] Now refer to Figure 1-Figure 3 , orthopedic trial implant assembly 20 can be configured as a radius trial implant assembly, and this radius trial implant assembly is configured to be implanted in the proximal radius.Orthopedic trial implant assembly 20 comprises radius trial implant 22 and is configured to be removably attached to the radius trial spacer 24 of radius trial implant 22.Radius trial implant 22 and radius trial spacer 24 can be made by any suitable plastics or other suitable materials.

[0047] like Figures 1-4A As shown, the radius 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 integral with the head body 26. Alternatively, the stem 28 can be separate from the head body 26 and can be attached to the head body 26.

[0048] The head body 26 defines a proximal head body surface 30 and a distal head body surface 32 that is substantially opposite the proximal head body surface 30 along the longitudinal direction. For example, the distal head body surface 32 is spaced apart 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 apart from the distal head body surface 32 in a proximal direction that is opposite the distal direction and defined by the longitudinal direction. Therefore, as used herein, the terms "distal," "distalward," and their derivatives refer to a direction from the proximal head body surface 30 to the distal head body surface 32. As used herein, the terms "proximal," "proximal," and their derivatives refer to a direction from the distal head body surface 32 to the proximal head body surface 30.

[0049] As used herein, the terms "substantially" and "approximately" and their derivatives mean that the referenced dimension, size, shape, orientation or other parameter may include the stated dimension, size, shape, orientation or other parameter, and up to ±20%, including ±10%, ±5% and ±2%, of the stated dimension, size, shape, orientation or other parameter.

[0050] In one example, the proximal head body surface 30 can define an articular surface that can be configured to cooperate with the ulna or ulnar prosthesis to provide radioulnar joint motion. The proximal head body surface 30 can cooperate with the humerus or humeral prosthesis to provide radiohumeral joint motion. In this regard, the proximal head body surface 30 can be a concave surface. The distal head body surface 32 can be a substantially flat surface. 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 rod 28 can extend from the distal head body surface 32 in a distal direction.

[0051] In one example, the distal head body surface 32 can be substantially smooth. Alternatively, as Figure 4B-4D As shown, the distal head body surface 32 may define a plurality of cutting teeth 56 configured to flatten the radius when the head body 26 is rotated about its central axis, which is oriented in the longitudinal direction. The cutting teeth 56 may extend distally and may be integral with the distal head body surface 32. Alternatively, the cutting teeth 56 may be separate from the radius trial implant 22 and may be attached to the distal head body surface 32. The cutting teeth 56 may be arranged circumferentially around the distal head body surface 32. Figure 4B-4C In one example shown, the teeth may be shaped as segments of a swept spiral. Thus, the teeth 56 may be referred to as swept spiral teeth. Alternatively, as Figure 4D As shown, the cutting teeth 56 can be oriented to be straight and linear. In addition, the cutting teeth 56 can be oriented radially when they extend around the distal head body surface 32. In one example, the cutting teeth 56 can intersect each other at the center axis of the head body 26.

[0052] Reference again Figures 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 in the longitudinal direction. Alternatively, the at least one sidewall 34 may be defined by a plurality of connected walls that define the outer periphery of the head body 26. In addition, 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 will be described in more detail below, the head body 26 may define a channel 40 extending into the at least one sidewall 34, the at least one sidewall being configured to receive the spacer 24 so as to removably attach the spacer 24 to the radius trial implant 22.

[0053] The head body 26 defines a height H1 that extends substantially in the longitudinal direction from the proximal head body surface 30 to the distal head body surface 32. It is contemplated that the height H1 of the head body 26 may be less than the height of the proximal radius 44 (see FIG. Figure 10A ) and a gap 42 between the complementary articular surfaces 47 that may be defined by one or both of the ulna and humerus. In such cases, it may be desirable to attach the spacer 24 to the radius trial implant 22 in order to increase the height of the head body 26.

[0054] Now refer to Figure 1-Figure 3 and Figure 5 The spacer 24 includes a spacer head 46 having a proximal spacer head surface 48 and a distal spacer head surface 50, which is opposite and distally spaced from the proximal spacer head surface 48. In one example, the proximal spacer head surface 48 can define an articulating surface configured to mate with the ulna or ulnar prosthesis to provide radioulnar joint motion. The proximal spacer head surface 48 can mate with the humerus or humeral prosthesis to provide radiohumeral joint motion. In this regard, the proximal spacer head surface 48 can be concave. The distal spacer head surface 50 can be substantially convex. Thus, when the spacer 24 is attached to the radius trial implant 22, the distal spacer head surface 50 can be configured to nest with the proximal head body surface 30. Of course, it should be understood that the proximal spacer head surface 48 and the distal spacer head surface 50 can be shaped in any suitable manner as desired.

[0055] The spacer 24 can 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 can define an outer periphery of the spacer head 46 in a plane oriented perpendicular to the longitudinal direction. The at least one sidewall 52 can be configured as a single substantially cylindrical sidewall 52. The cylindrical sidewall 52 can extend along a central axis oriented in the longitudinal direction. The central axis of the cylindrical sidewall 52 of the spacer can 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 can be defined by a plurality of connected walls that define the outer periphery of the spacer head 46. Furthermore, the sidewall 52 can be substantially flat along the longitudinal direction from the proximal spacer head surface 48 to the distal spacer head surface 50.

[0056] The spacer head 46 defines a spacer head height H2 that extends substantially in the longitudinal direction from the proximal spacer head surface 48 to the distal spacer head surface 50. It is contemplated 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 height H3 that is greater than the height H1 of the head body 26 (see FIG. Figure 7 For example, the composite head height H3 can be substantially equal to the sum of the height H1 of the head body 26 and the spacer head height H2. Figure 7 shown.

[0057] Continue to refer Figure 1-Figure 3 and Figure 5 , the spacer 24 can include an attachment member 58 configured to attach to a complementary attachment member of the radial trial implant 22. Specifically, the complementary attachment member of the radial trial implant 22 can be configured as a channel 40. The attachment member 58 of the spacer 24 can be received in the channel 40 to attach the spacer 24 to the radial trial implant 22. In other examples, it is contemplated that the attachment member of the radial trial implant 22 can be received in the channel of the spacer 24 to removably attach the spacer 24 to the radial trial implant 22.

[0058] Now, the overall reference Figures 1-8 , the attachment member 58 may include an extension member 60 extending from the spacer head 46. Specifically, the extension member 60 may extend substantially distally from the spacer head 46. In one example, the extension member 60 may extend substantially distally from the distal spacer head surface 50. Thus, the extension member 60 may have a first end extending from the distal spacer head surface 50, and the extension member 60 may extend substantially in a longitudinal direction from the first end to the second end. The extension member 60 is sized to be received in the proximal portion 41 of the channel 40, which may be open to the proximal head body surface 30. Specifically, the channel 40 may extend through the proximal head body surface 30 in a proximal direction.

[0059] The attachment member 58 may further include an attachment tab 62 extending from the extension member 60. Specifically, the attachment tab 62 may extend from the extension member 60 in a first direction substantially perpendicular to the longitudinal direction. For example, the attachment tab 62 may extend from the second end of the extension member. The attachment tab 62 is configured to be slidably inserted into the distal portion 43 of the channel 40 in the first direction substantially perpendicular to the longitudinal direction. When the attachment 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 toward the proximal portion 41 of the channel 40 in the longitudinal direction. The attachment tab 62 may be positioned such that the spacer 24 defines a gap 64 that extends in the longitudinal direction from the attachment tab 62 to the spacer head 46, and specifically to the distal spacer head surface 50. When the attachment member 58 is inserted into the passage 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 defining a proximal end of the distal portion 43 of the passage 40 .

[0060] The attachment member 58 can further include a retaining member 68 that can be releasably secured to the radius trial implant 22. Specifically, the retaining member 68 can be releasably secured to a complementary retaining member of the head body 26 in the channel 40. In one example, the retaining member 68 can be press-fit into the channel 40, and specifically into the distal portion 43 of the channel 43. When sufficient force is applied to the spacer 24 in a second direction opposite to the first direction, the press-fit engagement can be removed, thereby removing the spacer 24 from the radius trial implant 22. The second direction can be referred to as a removal direction. The first direction can be referred to as an attachment direction.

[0061] Now refer to Figure 1 and Figure 7 , when attachment member 58 was inserted into passage 40 in the first direction, spacer head 46 can be facing or adjacent to the head body 26 of trial radius implant 22.Particularly, distal spacer head surface 50 can be facing or adjacent to the proximal head body surface 30.Therefore, orthopedic trial implant assembly 20 can limit the composite head 70 that comprises head body 26 and spacer head 46.Compound head 70 can limit proximal composite head surface 72 and the distal composite head surface 74 relative to proximal composite head surface 72 along the longitudinal direction.Particularly, distal composite head surface 74 is spaced apart from proximal composite head surface 72 substantially in the distal direction.On the contrary, proximal composite head surface 72 is spaced apart from distal composite head surface 74 in the proximal direction.

[0062] The composite head 70 defines a composite head height H3 that extends substantially along the longitudinal direction 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. While in one example, the spacer head 46 is disposed proximally of the head body 26, it is contemplated that the spacer 24 may 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 may face the distal head body surface 32. Furthermore, the proximal head body surface 30 may define the proximal composite head surface 72, and the distal spacer head surface 50 may define the distal composite head surface 74.

[0063] Now refer to Figures 9A-9C , orthopedic trial implant assembly 20 may include multiple spacers 24, such as first spacer 24a and second spacer 24b. Each spacer in multiple spacers 20 can be selectively and removably attached to radius trial implant 22. That is, each spacer in spacer 24 can be attached to radius trial implant 22 in the above-mentioned manner. In addition, each spacer in spacer 24 can be removed from radius trial implant in the above-mentioned manner.

[0064] 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 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. Therefore, when the first spacer 24a is attached to the radial trial implant 22 in the manner described above, the spacer head 46 and head body 26 of the first spacer 24a 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 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 should be understood that the size and shape of the corresponding attachment members 58, including the extension members 60 and attachment tabs 62, of the differently sized spacers 24 can be set to be identical to one another within manufacturing tolerances, such that the attachment members 58 can be removably attached to the same radial trial implant 22.

[0065] Now refer to Figures 10A-10D , the orthopedic trial implant assembly 20 can be configured to identify the size of the permanent implant to be implanted in the proximal radius 44. The term "permanent" implant indicates that the implant is not intended to be removed before the surgical procedure is completed. Specifically, as Figure 10B As shown, the radial trial spacer 22 is coupled to the proximal radius. Specifically, the rod 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 in the gap 42. In some examples, the rod has previously been sized to fit into the medullary canal using a depth gauge of the cortical bone adjacent to the medullary canal to determine the appropriate diameter or alternative cross-sectional size of the rod. In some examples, the rod may be sized to be loosely received in the medullary canal. When the head body 26 includes the above-described Figure 4B-4D When the cutting teeth 56 are depicted, rotation of the radial trial spacer 22 about its central longitudinal axis causes the cutting teeth to remove bone from the proximal radius, thereby flattening the proximal radius. Thus, the head can rest on a flat surface defined by the proximal radius. Figure 10B As shown, the head body 46 does not span the entire gap 42 from the proximal radius 44 to the complementary articular surface 47 .

[0066] Therefore, if Figure 10B As shown, one of the radial trial spacers 24 having a known height may be selected. Because the height of the corresponding spacer head 46 is known, and the height of the head body 26 is known, the resulting height of the resulting composite head may be readily calculated. Figure 10B As shown, the first trial spacer 24a can be aligned with the radial trial implant 22 such that 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. Figure 10C However, in Figure 10C , it is observed that the height of the first composite head 70a is less 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 Figure 10A ).

[0067] Therefore, reference Figure 10C-10D The first trial spacer 24a may be removed from the radial trial implant 22 by moving the first trial spacer 24a in the second direction relative to the radial trial implant 22. Advantageously, the radial trial implant 22 may remain coupled to the proximal radius when the first trial spacer 24a is 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.

[0068] Now refer to Figure 10D , specifically once the first trial spacer 24a has been removed, the second trial spacer 24b can be attached to the radius 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 resulting height of the resulting second composite head 70b can be easily calculated. Figure 10D As shown, the second composite head 70 extends substantially from the proximal radius 74 to the opposing complementary articular surface 47 (see FIG. Figure 10A ). Therefore, the height of the second composite head 70b is substantially equal to the height of the gap 72 along the longitudinal direction. Figure 10E , a permanent radial implant 80 from the permanent implant kit may be selected that has a head height that is substantially equal to or preferably corresponds to the height of the second composite head 70b and, therefore, the height of the gap 72. Referring again to Figure 10D, the second trial spacer 24 can be removed from the radial trial implant 22, and the radial trial implant can be removed from the proximal radius. Next, the selected permanent radial implant 80 can be selected and implanted in the proximal radius 74. Specifically, the shaft of the permanent radial implant 80 can be inserted into the medullary canal, and the head of the permanent radial implant 80 can be articulated around the complementary articular surfaces defined by one or both of the ulna and the distal humerus. The permanent radial implant 80 can be made of titanium, alloys thereof, stainless steel, alloys thereof, or any suitable biocompatible metal or other material.

[0069] It will be appreciated that different patients will have proximal radii of varying sizes. Therefore, a plurality of radial trial implants 22 (see Figure 4A ) kit, the multiple radial trial implants have different sizes and can be selected for implantation into the proximal radius of the appropriate size. In addition, each radial trial implant in the radial trial implant 22 can be configured to be removably attached to the same trial spacer. Therefore, the radial trial implant 22 can have a channel of substantially the same size for receiving the trial spacer. The radial trial implant 22 can have at least one size or shape that is different from at least another of the radial trial implants 22. For example, the size of the rod 28 can be set to be different from each other. In one example, the rod 28 of the radial trial implant 22 can define different cross-sectional dimensions so as to define different sizes. The rod 28 can be cylindrical or conical, and therefore the cross-sectional dimensions can be defined by the corresponding diameters of the rod. The cross-sectional dimensions are measured at a constant distance from the distal head body surface 32 in the distal direction.

[0070] Therefore, at least some of the rods of the radius trial implant of the kit are set to have different cross-sectional sizes along a direction substantially perpendicular to the longitudinal direction relative to the other rods of the radius trial implant of the kit. For example, at least some of the rods of the radius trial implant are set to have different cross-sectional sizes in a plane oriented substantially perpendicular to the longitudinal direction relative to the other rods of the radius trial implant. In addition, at least some of the head bodies of the radius trial implant of the kit can be set to have different cross-sectional sizes along a direction substantially perpendicular to the longitudinal direction relative to the other head bodies of the radius trial implant of the kit.

[0071] It is further contemplated that the kit may include a plurality of spacers 24 having different spacer head heights, as described above. Each of the spacers 24 in the kit may be configured to attach to each of the radial trial implants 22 in the kit. For example, the size and shape of the attachment members 56 of the spacers 24 in the kit may all be set to be substantially the same, and the size and shape of all of the slots 40 in the radial trial implants 22 in the kit may be set to be substantially the same.

[0072] 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. Therefore, this application is intended to cover any variations, uses, or modifications of the present invention using the general principles of the present invention. Furthermore, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which the invention pertains and which fall within the limits of the appended claims.

Claims

1. An orthopedic trial implant assembly comprising: At least one radius trial implant, the at least one radius 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 and having a height extending along the longitudinal direction from the proximal head body surface to the distal head body surface, wherein the proximal head body defines an articular surface; and a rod extending from the head body in a distal direction substantially defined by the longitudinal direction; and at least one spacer configured to be removably attached to the radial trial implant along a direction substantially perpendicular to the longitudinal direction so as to define a composite head comprising the head body and a spacer head of the spacer, wherein the composite head defines a proximal composite head surface and a distal composite head surface opposite the proximal composite head surface along the longitudinal direction, and the composite head defines a composite head height from the proximal composite head surface to the distal composite head surface, wherein 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 head, and wherein the composite head height is greater than a height of the head body; wherein the distal head body surface defines a plurality of cutting teeth configured to flatten the radius when the head body is rotated about a central axis thereof, the central axis being oriented along the longitudinal direction; 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 defines the distal composite head surface, wherein the proximal spacer head surface defines an articular surface; wherein the at least one spacer includes 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; wherein the trial implant body defines a channel extending into the head and configured to receive the attachment member of the at least one spacer to removably attach the at least one spacer to the at least one radial trial implant; wherein the head body includes side walls extending from the proximal head body surface and the distal head body surface, and the channel extends into the side walls along the direction substantially perpendicular to the longitudinal direction; Wherein, the attachment member comprises: an extension member having a first end extending from the distal spacer head surface and extending substantially along the longitudinal direction from the first end to a second end; and an attachment tab extending from the second end of the extension member in 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; Wherein, the attachment member further comprises: A retaining member is releasably secured to a complementary retaining member of the head body in the passageway.

2. The orthopedic trial implant assembly of claim 1, wherein: The at least one spacer defines a spacer height along the longitudinal direction from the proximal spacer head surface to the distal spacer head surface, and the at least one spacer height is less than a height of the head body.

3. The orthopedic trial implant assembly of claim 1 , wherein: The at least one spacer includes a plurality of spacers each having a different respective spacer height, and each of the spacers is configured to be selectively removably attached to the radius trial implant so as to define a corresponding different composite head height.

4. The orthopedic trial implant assembly of claim 3, wherein: Each of the plurality of spacers has an attachment tab configured to be selectively received in a channel of the radius trial implant to attach the spacer to the radius trial implant, and all of the tabs are sized and shaped to be substantially the same.

5. The orthopedic trial implant assembly of claim 1 , wherein: The cutting teeth are arranged circumferentially around the distal head body surface.

6. The orthopedic trial implant assembly of claim 1, wherein: The cutting teeth are oriented to be straight and linear.

7. The orthopedic trial implant assembly of claim 1 , wherein: The cutting teeth define a swept helical shape.

8. The orthopedic trial implant assembly of claim 1, wherein: The at least one radius trial implant includes a plurality of radius trial implants each configured to be selectively removably attached to the at least one spacer, wherein the stems of the radius trial implants are sized differently from one another.

9. The orthopedic trial implant assembly of claim 8, wherein: The rods define different cross-sectional dimensions so as to define correspondingly different sizes.

10. The orthopedic trial implant assembly of claim 9, wherein: The cross-sectional dimensions are defined by the corresponding diameters of the rods.

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