Hip arthroplasty trial systems, and associated medical devices, methods and kits

Abstract

To provide hip arthroplasty trial systems that enable easy determination of a desired offset amount between a femoral head implant and a femoral stem when the femoral head is implanted in a hip arthroplasty procedure.SOLUTION: Hip arthroplasty trial systems and associated medical devices, methods and kits are described that can be utilized in situ to complete a femoral head trial. A hip arthroplasty trial system 1 comprises: a head member 12; a femoral stem 20; a spacer 14 disposed between the head member 12 and the femoral stem 20; and a shaft 16 with a cam that is rotatable relative to the head member 12 and the femoral stem 20. The rotation of the cam moves the spacer 14 to change a relative distance between the femoral stem 20 and the head member 12.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to the field of medical devices. More specifically, the present disclosure relates to hip arthroplasty trial systems and related medical devices, methods, and kits.

Background Art

[0002] When implanting the femoral head in hip arthroplasty, surgeons currently utilize multiple options regarding the bone length that need to be individually tried to determine the desired offset between the femoral head and the femoral stem. In each trial, it is necessary to assemble or disassemble various bone lengths to determine whether the desired offset has been achieved, whereby the hip joint is detached and reattached multiple times during the trial procedure. This multiple trial approach for determining the desired offset between the femoral head implant and the femoral stem has significant drawbacks such as the need to attach the hip joint multiple times, being complex and time-consuming, and causing tissue damage.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Accordingly, there is a need for an improved and new hip arthroplasty trial system and related medical devices, kits, and methods.

Means for Solving the Problems

[0004] Various hip arthroplasty trial systems, medical devices, methods, and kits are described herein.

[0005] An exemplary hip arthroplasty trial system includes a femoral head member, a spacer, a shaft, and a femoral stem. The femoral head member has a femoral head member first end, a femoral head member second end, a femoral head member first longitudinal axis, and a femoral head member body defining a femoral head member articular surface and a femoral head member first recess. The femoral head member first recess extends into the femoral head member body along the femoral head member first longitudinal axis from the femoral head member first end toward the femoral head member second end. The spacer is disposed within the femoral head member first recess and is movable between a spacer first position and a spacer second position. The shaft is movable between a shaft first position and a shaft second position. Movement of the shaft from the shaft first position to the shaft second position causes the spacer to move from the spacer first position to the spacer second position. The femoral stem has a femoral stem first end and a femoral stem second end. The femoral stem second end is disposed at a position a first distance from the femoral head member first end when the shaft is at the shaft first position and at a position a second distance from the femoral head member first end when the shaft is at the shaft second position. The second distance is a distance different from the first distance.

[0006] An exemplary medical device has a bone member, a spacer, a shaft, and a lock member. The bone member has a first bone member end, a second bone member end, a first longitudinal axis of the bone member, a second longitudinal axis of the bone member, a bone member joint surface, and a bone member body defining a first recess of the bone member, a second recess of the bone member, and a third recess of the bone member. The first recess of the bone member extends into the bone member body from the first end of the bone member toward the second end of the bone member along the first longitudinal axis of the bone member. The second longitudinal axis of the bone member extends through the second recess of the bone member and intersects the first longitudinal axis of the bone member. The second recess of the bone member extends into the bone member body along the second longitudinal axis of the bone member and communicates with the first recess of the bone member. The third recess of the bone member extends into the bone member body and communicates with the second recess of the bone member. The spacer is disposed within the first recess of the bone member and is movable between a first spacer position and a second spacer position. The spacer has a first spacer end, a second spacer end, and a spacer length extending from the first spacer end to the second spacer end. When the spacer is in the first spacer position, a first portion of the spacer length is disposed within the first recess of the bone member. When the spacer is in the second spacer position, a second portion of the spacer length is disposed within the first recess of the bone member. The first portion of the spacer length is longer than the second portion of the spacer length. The shaft is movably disposed within the second recess of the bone member and is movable between a first shaft position and a second shaft position. Movement of the shaft from the first shaft position to the second shaft position causes the spacer to move from the first spacer position to the second spacer position. The lock member is disposed within the third recess of the bone member and contacts the shaft. The lock member is adapted to removably fix the shaft in its first shaft position and its second shaft position.

[0007] Exemplary methods of performing a femoral hip arthroplasty trial include obtaining a medical device for use in the hip arthroplasty trial and including a head member, a shaft, and a locking member; implanting a femoral stem into the femur; placing the head member on the femoral stem; moving the shaft in a first direction in-situ so that the head member moves away from the femoral stem until a desired offset amount between the head member and the femoral stem is achieved; moving the shaft in a second direction in-situ so that the head member moves toward the femoral stem; obtaining a femoral head implant corresponding to the desired offset amount between the head member and the femoral stem; removing the head member from the femoral stem; and placing the femoral head implant on the femoral stem.

[0008] Additional understanding of exemplary hip arthroplasty trial systems, medical devices, methods, and kits can be obtained by considering the following detailed description and the accompanying drawings.

Brief Description of the Drawings

[0009]

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DETAILED DESCRIPTION OF THE INVENTION

[0010] The following detailed description and the accompanying drawings describe and illustrate various embodiments of a hip arthroplasty trial system, a medical instrument for hip arthroplasty, a method of using a hip arthroplasty trial system, and a kit. The description and illustration of these examples are provided to enable those skilled in the art to make and use a hip arthroplasty trial system, a medical instrument, a kit including the hip arthroplasty trial system, and to practice a method of using the hip arthroplasty trial system and / or the medical instrument. They are not intended to limit the scope of the claims in any way.

[0011] Figures 2-38 show a first example of a hip arthroplasty trial system 1 including a medical instrument 10 and a femoral stem 20. The medical instrument 10 has a head member 12, a spacer 14, a shaft 16, and a locking member 18. Some of the drawings show the medical instrument 10 detachably attached to the femoral stem 20, as in Figure 2.

[0012] As shown in FIGS. 4 to 10, FIG. 36, and FIG. 37, the bone member 12 (e.g., a trial bone member) has a bone member first end portion 24, a bone member second end portion 26, a bone member first longitudinal axis 25, a bone member second longitudinal axis 27, a bone member joint surface 30, a bone member first recess 32, a bone member second recess 34, a bone member third recess 36, a bone member first passage 38, a bone member second passage 40, and a bone member third passage 42, and a bone member main body 28 that defines them. The bone member first longitudinal axis 25 extends through the bone member first recess 32 and the bone member second end portion 26. The bone member second longitudinal axis 27 extends through the bone member second recess 34 and intersects the bone member first longitudinal axis 25 at an angle 29. The bone member first recess 32 extends into the bone member main body 28 along the bone member first longitudinal axis 25 from the bone member first end portion 24 toward the bone member second end portion 26. The bone member second recess 34 extends into the bone member main body 28 along the bone member second longitudinal axis 27 and communicates with the bone member first recess 32. As described in more detail herein, the bone member second recess 34 is disposed at a position of a first distance 35 from the bone member first end portion 24 and a second distance 37 from the bone member second end portion 26 in order to match the shape of the shaft 16, and the second distance 37 is shorter than the first distance 35. The bone member third recess 36 extends into the bone member main body 28 along the second longitudinal axis 27 and communicates with the bone member second passage 40. However, in another embodiment, the bone member third recess may also extend into the bone member main body along an axis that is parallel to the axis defining the bone member second recess or along an axis disposed at a specific angle. The bone member first passage 38 and the bone member second passage 40 each extend from the bone member second recess 34 to the bone member third recess 36. The bone member third passage 42 extends from the bone member second recess 34 to the bone member joint surface 30.

[0013] In the illustrated embodiment, the first bone member recess 32 has an inner diameter 33 that tapers from the first end 24 of the bone member toward the second end 26 of the bone member, and the second bone member recess 34 has a first second recess portion 44 and a second second recess portion 46. However, in another embodiment, a first bone member recess having a constant inner diameter can be defined. The first second recess portion 44 is adapted to receive a cam projection 72 and a portion of a first cam boss 70, as will be described in more detail herein, and has a first cross-sectional shape at the bone member articular surface 30. The second second recess portion 46 is adapted to receive the cam projection 72, and the cam projection 72 is rotatable about a second longitudinal axis 27 within the second second recess portion 46. The second second recess portion 46 has a second different cross-sectional shape at the intersection of the first longitudinal axis 25 of the bone member and the second longitudinal axis 27 of the bone member. The first cross-sectional shape is the shape along a first virtual plane 45 that is orthogonal to the second longitudinal axis 27, and the second cross-sectional shape is the shape along a second virtual plane 47 that is orthogonal to the second longitudinal axis 27.

[0014] The second longitudinal axis of the bone member can be arranged at any suitable angle with respect to the first longitudinal axis of the bone member, and the suitable arrangement angle of the second longitudinal axis of the bone member with respect to the first longitudinal axis of the bone member can be selected based on various considerations, such as the structural arrangement of the shaft planned to be used in the medical device. Examples of angles considered suitable as the arrangement angle of the second longitudinal axis of the bone member with respect to the first longitudinal axis of the bone member include equal to 45 degrees, greater than 45 degrees, less than 45 degrees, or about 45 degrees, or equal to 90 degrees, greater than 90 degrees, less than 90 degrees, or about 90 degrees, or equal to 135 degrees, greater than 135 degrees, less than 135 degrees, or about 135 degrees, an angle of about 10 degrees to about 170 degrees, an angle of about 45 degrees to about 135 degrees, and any other arbitrary angle considered suitable for a particular embodiment. In the illustrated embodiment, angle 29 is equal to about 90 degrees. The bone member may have any suitable outer diameter extending from the first end of the bone member to the second end of the bone member. Examples of outer diameters considered suitable for the bone member include equal to 28 mm, longer than 28 mm, shorter than 28 mm, or about 28 mm, or equal to 32 mm, longer than 32 mm, shorter than 32 mm, or about 32 mm, or equal to 36 mm, longer than 36 mm, shorter than 36 mm, or about 36 mm outer diameter, an outer diameter of about 20 mm to about 45 mm, and any other arbitrary outer diameter considered suitable for a particular embodiment.

[0015] In the illustrated embodiment, as shown in FIGS. 23 and 27, when the bone member 12 is in the first position, the first end 24 of the bone member is disposed at a position that is a first distance from the second end of the femoral stem 20. As shown in FIGS. 24 and 28, when the bone member 12 is in the second position, the first end 24 of the bone member is disposed at a position that is a second distance from the second end of the femoral stem 20. As shown in FIGS. 25 and 29, when the bone member 12 is in the third position, the first end 24 of the bone member is disposed at a position that is a third distance from the second end of the femoral stem 20. As shown in FIGS. 26 and 30, when the bone member 12 is in the fourth position, the first end 24 of the bone member is disposed at a position that is a fourth distance from the second end of the femoral stem 20. The first distance is longer than the second distance, the second distance is longer than the third distance, and the third distance is longer than the fourth distance.

[0016] In the illustrated embodiment, the spacer 14 is disposed within the first recess 32 of the bone member and is movable relative to the bone member 12 between a first spacer position, a second spacer position, a third spacer position, and a fourth spacer position. As shown in FIGS. 12 and 13, the spacer 14 includes a first spacer end 50, a second spacer end 52, a spacer longitudinal axis 51, a spacer length 53 extending from the first spacer end 50 to the second spacer end 52, and a spacer body 54 defining a spacer passage 56 and a plurality of spacer grooves 57. The spacer passage 56 extends from the first spacer end 50 to the second spacer end 52 of the spacer and tapers from the second spacer end 52 towards the first spacer end 50. Each of the plurality of spacer grooves 57 extends into the spacer body 54 and is disposed at a certain distance from the first spacer end 50. The first spacer groove 59 is disposed at a position of a first distance 61 from the first spacer end 50. The second spacer groove 63 is disposed at a position of a second distance 65 from the first spacer groove 59. The third spacer groove 67 is disposed at a position of a third distance 69 from the second spacer groove 63. The plurality of spacer grooves 57 are believed to be advantageous as they provide at least a mechanism for measuring the distance the spacer 14 has moved relative to the bone member 12. Although a plurality of spacer grooves 57 are illustrated, in another embodiment, any suitable marker or other structure that aids in measuring the distance of movement of the spacer relative to the bone member may be included.

[0017] As shown in FIGS. 23 and 27, when the spacer 14 is in the first spacer position, the first portion 58 of the spacer length 53 is disposed within the first recess 32 of the bone member. As shown in FIGS. 24 and 28, when the spacer 14 is in the second spacer position, the second portion 60 of the spacer length 53 is disposed within the first recess 32 of the bone member. As shown in FIGS. 25 and 29, when the spacer 14 is in the third spacer position, the third portion 62 of the spacer length 53 is disposed within the first recess 32 of the bone member. As shown in FIGS. 26 and 30, when the spacer 14 is in the fourth spacer position, the fourth portion 64 of the spacer length 53 is disposed within the first recess 32 of the bone member. The first portion 58 of the spacer length 53 is longer than the second portion 60 of the spacer length 53, the second portion 60 of the spacer length 53 is longer than the third portion 62 of the spacer length 53, and the third portion 62 of the spacer length 53 is longer than the fourth portion 64 of the spacer length 53. The positions of the conventional modular neck trial system are shown by dashed lines in FIGS. 23-30 for purposes of illustration.

[0018] The spacer 14 is shown as being separate from the bone member 12, but the spacer may be integrated with the bone member such that each of the spacer and the bone member forms a single unitary component of the medical device. According to this alternative configuration of the bone member and the spacer, as described in more detail herein, the spacer can be movably disposed within the femoral stem such that the spacer can move to the first spacer position, the second spacer position, the third spacer position, and / or the fourth spacer position relative to the femoral stem. This alternative configuration reduces the number of components included in the medical device and / or the hip arthroplasty trial system.

[0019] Although the spacer 14 is shown as being separate from the femoral stem 20, the spacer may be integrated with the femoral stem such that each of the spacer and the femoral stem forms a single unitary component of the medical device. According to this alternative configuration of the spacer and the femoral stem, the spacer can be disposed movably within the bone member such that the spacer can move to the spacer first position, the spacer second position, the spacer third position, and / or the spacer fourth position relative to the bone member. This alternative configuration reduces the number of components included in the medical device and / or the hip arthroplasty trial system.

[0020] The shaft is disposed movably within the second recess 34 of the bone member and contacts the second end of the femoral head when the head is removably attached to the femoral stem. Alternatively, depending on the structural arrangement of the components, the spacer may contact both the second end of the femoral stem and the spacer, or the spacer only. Any suitable shaft can be included in the medical device, and the suitable shaft may be selected based on various considerations such as the structural arrangement of the bone member and / or the spacer. For example, the shaft 16 included in the illustrated medical device 10 is a cam 68 that is rotatably disposed within the second recess 34 of the bone member. However, in another embodiment, any suitable shaft and / or spacer that translates the spacer and / or the femoral stem as described herein may be included. For example, the shaft may include a threaded member that interacts with a threaded spacer and / or femoral stem to translate the spacer as described herein. Alternatively, the spacer may be a telescoping member that interacts with the shaft to translate the spacer as described herein.

[0021] As shown in FIGS. 17 to 19 and FIGS. 23 to 30, the cam 68 is rotatable about the second longitudinal axis 27 of the bone member, and includes a cam first boss 70, a cam protrusion 72 attached to the cam first boss 70, a cam body 76, a cam second boss 74 that defines a cam groove 78, a plurality of cam detents 80, a cam recess 82, a cam indicator 84, and a cam protrusion first end 88. The cam protrusion 72 is disposed between the cam first boss 70 and the cam second boss 74, and contacts the second end of the femoral stem 20 and / or, when a spacer is removably attached to the femoral stem, contacts the second end of the spacer, as shown in FIGS. 27, 28, 29, and 30. The cam groove 78 is defined on the cam second boss 74 and extends to a cam groove base 86. The cam groove 78 is adapted to receive a lock member first protrusion 96 and a lock member second protrusion 98, as will be described in more detail herein. Each of the plurality of cam detents 80 extends from the cam groove base 86 into the cam groove 78 within the cam body 76 and is adapted to receive the lock member first protrusion 96 or the lock member second protrusion 98, as will be described in more detail herein. The cam recess 82 extends into the cam first boss 70 and has a hexagonal cross-sectional shape along a virtual plane perpendicular to the second longitudinal axis 27. However, in another embodiment, the cam recess may include any suitable cross-sectional shape that can receive a tool for moving the cam at various positions. The cam indicator 84 is disposed on the cam first boss 70 and has a longitudinal axis 85 that is perpendicular to a plane 87 that includes the cam protrusion first end 88. The cam indicator 84 provides a mechanism for indicating to the user of the medical device 10 the position of the cam protrusion first end 88 relative to the spacer 14.

[0022] The cam 68 is movable between a first cam position as shown in FIGS. 23 and 27, a second cam position as shown in FIGS. 24 and 28, a third cam position as shown in FIGS. 25 and 29, and a fourth cam position as shown in FIGS. 26 and 30. As shown in FIGS. 23, 24, 27, and 28, when the cam 68 is moved from the first cam position to the second cam position, the spacer 14 moves from the first spacer position to the second spacer position, the femoral stem 20 moves from its first position to its second position, and vice versa. As shown in FIGS. 24, 25, 28, and 29, when the cam 68 is moved from the second cam position to the third cam position, the spacer 14 moves from the second spacer position to the third spacer position, the femoral stem 20 moves from its second position to its third position, and vice versa. As shown in FIGS. 25, 26, 29, and 30, when the cam 68 is moved from the third cam position to the fourth cam position, the spacer 14 moves from the third spacer position to the fourth spacer position, the femoral stem 20 moves from its third position to its fourth position, and vice versa.

[0023] In the illustrated embodiment, the locking member 18 is disposed within the third recess 36 of the bone member and contacts the shaft 16 as shown in FIGS. 32, 33, 36, and 37. The locking member 18 is adapted to removably attach the shaft 16 to the bone member 12 and removably fix the shaft 16 in its first shaft position, second shaft position, third shaft position, and fourth shaft position. As shown in FIGS. 20-22, the locking member 118 has a first end 90, a second end 92, and a body 94 that defines a first locking member protrusion 96 and a second locking member protrusion 98. As shown in FIGS. 36 and 37, the first locking member protrusion 96 extends through the first passage 38 of the bone member, and the second locking member protrusion 98 extends through the second passage 40 of the bone member.

[0024] The locking member 18 moves between a first locking member position as shown in FIGS. 21 and 36 and a second locking member position as shown in FIGS. 22 and 37. The locking member 18 is biased to the first locking member position. When the locking member 18 is in the first position, the first locking member projection 96 is disposed within the first detent of the plurality of cam detents 80, the second locking member projection 98 is disposed within the second detent of the plurality of cam detents 80, and the first locking member projection 96 and the second locking member projection 98 are separated by a first length 97. When the locking member 18 is in the second position, the first locking member projection 96 is disposed within the cam groove 78, the second locking member projection 98 is disposed within the cam groove 78, and the first locking member projection 96 and the second locking member projection 98 are separated by a second length 99. The second length 99 is longer than the first length 97.

[0025] In use, due to the interaction between the shaft 16 and the locking member 18, a user such as a surgeon can move the shaft 16 in-situ such that the spacer 14 and / or the femoral stem 20 are disposed at predetermined first, second, third, and / or fourth positions relative to the bone member 12. For example, due to the interaction between the first and second locking member projections 96, 98 and the plurality of cam detents 80, the user can removably fix the spacer 14 in a predetermined position. Since the user moves the shaft 16 in-situ, the movement of the shaft 16 to the first, second, third, and fourth positions does not require the user to remove the bone member 12 or the spacer 14 when determining the desired offset of the femoral head implant of the patient. Rather, since the bone member 12 and the spacer 14 remain within the patient throughout the hip joint trial process, the user can more efficiently determine the desired offset of the femoral head implant during the hip arthroplasty trial.

[0026] During use, the femoral stem 20 is removably attached to the medical instrument 10 (e.g., the head member 12, the spacer 14) during hip arthroplasty trials and is used with a selected femoral head implant. The compatibility between the femoral stem 20 and the medical instrument 10 is advantageous in that, at least during the hip arthroplasty trial procedure, the user does not need to remove the medical instrument 10 or the femoral stem 20, and the femoral stem 20 is ultimately used with and interacts with both the trial head member 12 and the final femoral head implant. The compatibility between the femoral stem 20 and the medical instrument 10 eliminates the need to move the hip joint to the first, second, third, and fourth positions and back each time the shaft is adjusted, enabling the user to perform the trial process and the implantation process more quickly and efficiently compared to conventional instruments used in hip arthroplasty trials. For example, the user can perform the initial trial by adjusting the medical instrument 10 (e.g., the shaft, the spacer) in-situ by applying a rotational force to the shaft 16 (e.g., the cam 68) to push the spacer 14 out of the head member as described herein. Subsequently, the user can implant the femoral stem (e.g., the femoral stem 20), attach the head member 12 to the femoral stem, and adjust the medical instrument 10 (e.g., the shaft, the spacer) in-situ by applying a rotational force to the shaft 16 (e.g., the cam 68) to move the spacer 14 and the femoral stem 20 in and out of the head member 12 to perform the final trial as described herein. Thereby, the user can start from the shortest length of the trial system (e.g., the shaft 16 is in the first position), adjust upward (e.g., move the shaft 16 to the second position) to set the tension appropriately, then adjust downward (e.g., move the shaft 16 to the first position) to remove the medical instrument 10, and implant the final head implant. Thus, the user can perform both the initial trial and the final trial using the head member 12.

[0027] Figures 40 - 76 show a second exemplary hip arthroplasty trial system 100 including a medical instrument 110 and a femoral stem 120. The medical instrument 110 is similar to the medical instrument 10 shown in FIGS. 2 - 38 and is as described above, except as detailed below. The medical instrument 110 has a bone member 112, a spacer 114, a shaft 116, and a locking member 118. Some of the drawings show the medical instrument 110 detachably attached to the femoral stem 120.

[0028] In the illustrated embodiment, the bone member first passage 138 has a first inner diameter 139 and a bone member second inner diameter 141, and the bone member body 128 defines a bone member fourth recess 143 that extends from the bone member third recess 136 toward the bone member second longitudinal axis 127. However, in another embodiment, the bone member fourth recess can extend from the bone member third recess toward any configuration of the bone member. The bone member first inner diameter 139 is defined at the bone member first end 124, and the bone member second inner diameter 141 is defined between the bone member first end 124 and the bone member second passage 140. The bone member second inner diameter 141 is shorter than the bone member first inner diameter 139. The locking member 118 defines a locking member third protrusion 195 disposed within the bone member fourth recess 143.

[0029] In the illustrated embodiment, the spacer 114 has a spacer first outer diameter 171 at the spacer first end 150 and a spacer second outer diameter 173 at the spacer second end 152, and the spacer second outer diameter 173 is shorter than the spacer first outer diameter 171. The cam body 176 defines a cam recess 175 that extends into the cam protrusion 172.

[0030] In the illustrated embodiment, the medical instrument includes an O - ring 191 disposed within one of the plurality of spacer grooves 157, groove 179. The O - ring 191 is considered advantageous as it provides at least a mechanism for maintaining the position of the spacer 114 relative to the bone member 112 during use.

[0031] The femoral head member, spacer, shaft, cam, locking mechanism, and femoral stem are shown as having a particular structural arrangement, but the femoral head member, spacer, shaft, cam, locking mechanism, and femoral stem may have any suitable structural arrangement. The suitable structural arrangement of the femoral head member, spacer, shaft, cam, locking mechanism, and femoral stem can be selected based on various considerations, such as the materials forming the femoral head member, spacer, shaft, cam, locking mechanism, and / or femoral stem.

[0032] The femoral head member, spacer, shaft, cam, locking mechanism, O-ring, and femoral stem may be formed of any suitable material, and the suitable material can be selected based on various considerations, such as the materials to be used in hip arthroplasty trial systems and / or the hip joints to be formed in medical devices. Examples of materials considered suitable for forming the femoral head member, spacer, shaft, cam, locking mechanism, and / or femoral stem include biocompatible materials, bioadaptable materials, ceramics, polymers, polyethylene, ultra-high molecular weight polyethylene (UHMWPE), metals, tantalum, titanium (Ti), cobalt alloys (e.g., cobalt chrome (CoCr), cobalt chrome molybdenum (CoCrMo)), combinations of the materials described herein, and any other materials considered suitable for particular embodiments. Examples of materials considered suitable for forming the O-ring include silicone, the materials described herein, and any other materials considered suitable for particular embodiments.

[0033] Various methods for performing hip arthroplasty trials (e.g., using medical devices for hip arthroplasty trials) are described herein. The methods described herein are shown and described as a series of acts, but some acts may be performed in a different order than shown and described, in accordance with the method, and / or simultaneously with other acts described herein, so the method should be understood not to be limited by the order of the acts.

[0034] FIG. 77 is a schematic diagram of an exemplary method 200 for performing a hip arthroplasty trial using a medical device.

[0035] Step 202 includes obtaining a medical device for use in the hip arthroplasty trial. Another step 204 includes disposing the shaft into the second recess of the bone member. Another step 206 includes disposing a locking member into the third recess of the bone member such that the shaft is removably attached to the bone member. Another step 208 includes disposing the shaft into the first position. Another step 210 includes disposing a spacer onto the end of the femoral stem. Another step 212 includes disposing the spacer into the first recess of the bone member. Another step 214 includes determining whether the offset between the bone member and the femoral stem is a desired amount. Another step 216 includes moving the shaft such that the spacer translates parallel to the bone member. Another step 218 includes determining whether the offset between the bone member and the femoral stem is a desired amount. Another step 220 includes documenting the desired offset amount. Another step 222 includes removing the bone member from the femoral stem. Another step 224 includes obtaining a femoral head implant corresponding to the desired offset amount between the bone member and the femoral stem. Another step 226 includes implanting the femoral head implant.

[0036] Step 202 can be accomplished using any medical device that is considered suitable for a particular embodiment. Examples of medical devices considered suitable for performing step 202 include medical device 10, medical device 110, medical device 310, medical device 510, medical device 710, variations of the medical devices described herein, and any other medical device considered suitable for a particular embodiment.

[0037] Step 204 can be accomplished by applying a force to the shaft toward the second recess of the bone member until the shaft is disposed within the second recess of the bone member.

[0038] Step 206 can be achieved by applying a force to the locking member toward the third recess of the bone member until the locking member is disposed within the third recess of the bone member and the shaft is removably attached to the bone member. This can be achieved, for example, by disposing the first protrusion and the second protrusion within a groove defined by the shaft or within a detent defined by the shaft.

[0039] Step 208 can be achieved by applying a rotational force to the shaft about the second longitudinal axis of the bone member (e.g., using a hex driver) until the shaft is disposed in its first position, as shown in FIGS. 23, 27, 60, and 64. In embodiments where the shaft is pre-positioned in the first position, step 208 can be omitted if desired.

[0040] Step 210 can be achieved by applying a force to the spacer toward the femoral stem until the femoral stem is disposed within the spacer passageway and the second end of the femoral stem is adjacent to or planar with the second end of the spacer, as shown in FIGS. 27, 28, 29, 30, 31, 64, 65, 66, 67, 71, and 72. In embodiments where the spacer is pre-assembled with the femoral stem, step 210 can be omitted if desired.

[0041] Procedure 212 can be accomplished by applying a force to the bone member toward the spacer until the spacer and a portion of the femoral stem are disposed within the first recess of the bone member and the spacer and / or the femoral stem contact the shaft, as shown in FIGS. 27 and 64. Alternatively, procedure 212 may be performed prior to procedure 210 such that the spacer is disposed within the first recess of the bone member. Any procedure can be performed after procedure 212 and prior to procedure 210 to perform an initial trial. For example, any procedure that may be performed after procedure 212 includes positioning the bone member adjacent to the acetabular component. Another optional procedure includes determining whether an initial offset between the bone member and the femur is desirable. Another optional procedure includes moving the shaft such that the spacer translates parallel to the bone member. Another procedure includes determining whether the bone member and the femur are at a desirable offset. Another optional procedure includes documenting the desirable offset. Another optional procedure includes removing the bone member from the adjacent acetabular component. Subsequently, procedure 210 and the remainder of method 200 can be performed to complete the final trial and implantation of the femoral head implant.

[0042] In embodiments where the medical device utilized in method 200 is pre-assembled, procedure 204, procedure 206, procedure 208, and / or procedure 212 may be omitted from method 200.

[0043] Procedure 214 can be accomplished by considering the position of the bone member relative to the femoral stem and determining whether the bone member and the femoral stem are at a desirable offset. If it is determined that the bone member and the femoral stem are at a desirable offset when the shaft is in the first position, then procedure 216 and procedure 218 may be omitted from method 200.

[0044] When it is determined that the desired offset between the bone member and the femoral stem is not achieved when the shaft is in the first position, step 216 can be achieved by applying a rotational force to the shaft about the second longitudinal axis of the bone member (e.g., using a hex driver) until the shaft is disposed in its second position and the spacer translates parallel to the bone member, as shown in FIGS. 24, 28, 61, and 65. The movement of the shaft is performed in-situ, and a hip arthroplasty trial can be performed without the need to move the hip joint during the trial procedure.

[0045] Step 218 can be achieved in the manner described with respect to step 214. When it is determined that the desired offset between the bone member and the femoral stem is achieved when the shaft is in the second position, the method proceeds to step 220. When it is determined that the desired offset between the bone member and the femoral stem is not achieved when the shaft is in the second position, step 216 is repeated such that the shaft is disposed in its third position and the spacer translates parallel to the bone member, as shown in FIGS. 25, 29, 62, and 66, and then step 218 is repeated. When it is determined that the desired offset between the bone member and the femoral stem is achieved when the shaft is in the third position, the method proceeds to step 220. When it is determined that the desired offset between the bone member and the femoral stem is not achieved when the shaft is in the third position, step 216 is repeated such that the shaft is disposed in its fourth position and the spacer translates parallel to the bone member, as shown in FIGS. 26, 30, 63, and 67, and then step 218 is repeated. When it is determined that the desired offset between the bone member and the femoral stem is achieved when the shaft is in the fourth position, the method proceeds to step 220.

[0046] Step 220 can be achieved by using any suitable technique for documenting the desired offset between the medical device and the femoral stem after the desired offset has been achieved.

[0047] Procedure 222 can be achieved by applying a force to the bone member in a direction away from the femoral stem until the bone member and the spacer disengage from the femoral stem. In a method where the bone member has been removed from the femoral stem but the spacer remains disposed on the femoral stem, any procedure includes removing the spacer from the femoral stem and can be achieved by applying a force to the spacer in a direction away from the femoral stem until the spacer disengages from the femoral stem. Alternatively, the spacer may be left on the femoral stem and utilized with the femoral head implant.

[0048] Procedure 224 can be achieved using any femoral head implant that is considered suitable for a particular embodiment.

[0049] Procedure 226 can be achieved using any suitable technique or method for implanting the femoral head implant within the patient's body. For example, Procedure 226 can be achieved by applying a force to the bone member implant toward the femoral stem until the femoral stem is disposed within a recess defined by the bone member implant.

[0050] Figures 78 - 100 show a third exemplary hip arthroplasty trial system 300 including a medical instrument 310 and a femoral stem 320. The hip arthroplasty trial system 300 is similar to the hip arthroplasty trial system 1 shown in FIGS. 2 - 38 and is as described above, except as detailed below.

[0051] 80 and 81 , the head member 312 has a head member first end 324, a head member second end 326, a head member first longitudinal axis 325, a head member second longitudinal axis 327, and a head member body 328 that defines a head member articular surface 330 and a head member first recess 332. The head member first longitudinal axis 325 extends through the head member first recess 332 and the head member second end 326. The head member second longitudinal axis 327 extends through the head member 312 and intersects the head member first longitudinal axis 325 at an angle 329 (e.g., 90 degrees). The head member first recess 332 extends into the head member body 328 along the head member first longitudinal axis 325 from the head member first end 324 toward the head member second end 326. As shown in FIG. 81 , the entire head member first recess 332 has a constant inner diameter 333 that extends from the head member first end 324 toward the head member second end 326.

[0052] In the illustrated embodiment, as shown in Figures 93 and 94, when the head member 312 is in the head member first position, the head member first end 324 is positioned a first distance from the femoral stem second end 392. As shown in Figures 95 and 96, when the head member 312 is in the head member second position, the head member first end 324 is positioned a second distance from the femoral stem second end 392. As shown in Figures 97 and 98, when the head member 312 is in the head member third position, the head member first end 324 is positioned a third distance from the femoral stem second end 392. As shown in Figures 99 and 100, when the head member 312 is in the head member fourth position, the head member first end 324 is positioned a fourth distance from the femoral stem second end 392. The first distance is greater than the second distance, the second distance is greater than the third distance, and the third distance is greater than the fourth distance.

[0053] As shown in FIGS. 91 to 98, the spacer 314 is disposed within the first bone member recess 332 and moves between a first spacer position, a second spacer position, a third spacer position, and a fourth spacer position. As shown in FIGS. 82 and 83, the spacer 314 includes a first spacer end 350, a second spacer end 352, a spacer longitudinal axis 351, a spacer length 353 extending from the first spacer end 350 to the second spacer end 352, and a spacer body 354 defining a spacer recess 356, a spacer recess base 358, and a peg 360. The spacer recess 356 extends from the first spacer end 350 to the spacer recess base 358 and has a spacer recess length 359. The peg 360 extends along the spacer longitudinal axis 351 from the spacer recess base 358 beyond the first spacer end 350, as will be described in more detail below, and has a peg length 361 and a peg diameter 363 and is adapted to be received by the fourth femoral stem passage 406. The peg length 361 is longer than the spacer length 353, and the spacer length 353 is longer than the spacer recess length 359. The peg diameter 363 is constant between the spacer recess base 358 and the spacer tip 362. However, in another embodiment, the peg diameter may vary along the length of the peg.

[0054] As shown in FIGS. 84, 85, and 91 - 98, in the illustrated embodiment, the shaft 316 is a cam 368 that is rotatable within the femur stem first, second, and third passages 400, 402, 404, as will be described in more detail below. The cam 368 has a cam first boss 370, a cam protrusion 372 attached to the cam first boss 370, a cam second boss 374 attached to the cam protrusion 372, and a cam body 376 that defines a cam recess 382, a cam indicator 384, and a first end portion 388 of the cam protrusion. The cam protrusion 372 is disposed between the cam first boss 370 and the cam second boss 374 and contacts the second end portion 392 of the femur stem 320, as shown in FIGS. 91 - 98. The cam recess 382 extends into the cam first boss 370 and has a hexagonal cross - sectional shape. The cam indicator 384 is disposed on the cam first boss 370 and has a longitudinal axis 385 that is orthogonal to a plane 387 that includes the first end portion 388 of the cam protrusion. The cam indicator 384 provides a mechanism for indicating to the user of the hip arthroplasty trial system 300 that the position of the first end portion 388 of the cam protrusion corresponds to the spacer 314.

[0055] The cam 368 is movable between a cam first position as shown in FIGS. 93 and 94, a cam second position as shown in FIGS. 95 and 96, a cam third position as shown in FIGS. 97 and 98, and a cam fourth position as shown in FIGS. 99 and 100. As shown in FIGS. 93 - 96, when the cam 368 is moved from the cam first position to the cam second position, the spacer 314 moves from the spacer first position to the spacer second position. As shown in FIGS. 95 - 98, when the cam 368 is moved from the cam second position to the cam third position, the spacer 314 moves from the spacer second position to the spacer third position. As shown in FIGS. 97 - 100, when the cam 368 is moved from the cam third position to the cam fourth position, the spacer 314 moves from the spacer third position to the spacer fourth position.

[0056] In the illustrated embodiment, the femoral stem 320 has a femoral stem body 394 that includes a first femoral stem end 390, a second femoral stem end 392, a first femoral stem longitudinal axis 391, a second femoral stem longitudinal axis 393, a first femoral stem portion 396, a second femoral stem portion 398, a first femoral stem passage 400, a second femoral stem passage 402, a third femoral stem passage 404, and a fourth femoral stem passage 406. As best shown in FIG. 86, the first femoral stem longitudinal axis 391 extends from the first femoral stem end 390 toward the curve defined by the femoral stem 320, and the second femoral stem longitudinal axis 393 extends from the second femoral stem end 392 toward the curve defined by the femoral stem 320. The first femoral stem portion 396 extends along the first femoral stem longitudinal axis 391 from the first femoral stem end 390 toward the curve defined by the femoral stem 320. The second femoral stem portion 398 extends along the second femoral stem longitudinal axis 393 from the second femoral stem end 392 toward the curve defined by the femoral stem 320. Each of the first, second, third, and fourth passages 400, 402, 404, 406 is defined in the second femoral stem portion 398.

[0057] Each of the femur stem first, second, third, and fourth passages is best shown in FIGS. 86-90. The femur stem first and second passages 400, 402 are coaxial with each other and extend into the femur stem body 394 along an axis perpendicular to the femur stem second longitudinal axis 393. The femur stem first passage 400 has a constant femur stem first diameter 401, and the femur stem second passage 402 has a constant femur stem second diameter 403. As best shown in FIGS. 91 and 92, each of the femur stem first and second diameters 401, 403 is sized and configured to receive a portion of the shaft 316, so that the femur stem first passage 400 receives the cam first boss 370 and the femur stem second passage 402 receives the cam second boss 374. The femur stem first and second passages 400, 402 provide a mechanism for rotatably positioning the shaft 316 within the femur stem 320 to change the positions of the spacer 314 and the bone member 312.

[0058] Each of the femur stem first and second passages 400, 402 can have any suitable size, shape, and configuration, and the appropriate size, shape, and configuration of the femur stem passage can be selected based on various considerations such as the size of the shaft to be disposed within the passage. In the illustrated embodiment, each of the femur stem first and second passages has a circular cross-sectional shape. Further, each of the femur stem first and second passages 400, 402 can be disposed at any angle with respect to the femur stem second longitudinal axis 393 along the femur stem second portion 398. Examples of angles that are considered suitable for disposing the femur stem passage with respect to the femur stem longitudinal axis include equal to 45 degrees, greater than 45 degrees, less than 45 degrees, or about 45 degrees, or equal to 90 degrees, greater than 90 degrees, less than 90 degrees, or about 90 degrees, or equal to 135 degrees, greater than 135 degrees, less than 135 degrees, or about 135 degrees, angles from about 10 degrees to about 170 degrees, angles from about 45 degrees to about 135 degrees, and any other arbitrary angles that are considered suitable for a particular embodiment.

[0059] The femur stem third passage 404 extends through the femur stem body 394 along the femur stem second longitudinal axis 393 and communicates with each of the femur stem first and second passages 400, 402. As shown in FIG. 88, the femur stem third passage 404 has a femur stem third passage length 405 that extends between the femur stem second end 392 and the curve defined by the femur stem 320 along the femur stem second longitudinal axis 393. The femur stem third passage 404 is sized and configured to receive a portion of the shaft 316 (e.g., cam projection 372) such that the shaft 316 (e.g., cam projection 372) can rotate within the femur stem third passage 404 during use. As best shown in FIGS. 89 and 90, the femur stem fourth passage 406 extends along the femur stem second longitudinal axis 393 from the femur stem second end 392 to the femur stem third passage 404 and has a femur stem fourth passage length 409. The femur stem fourth passage 406 communicates with the femur stem third passage 404 as shown in FIGS. 93 - 100 and has a femur stem fourth passage diameter 408 sized and configured to receive the peg 360 such that the peg 360 is movable within the femur stem fourth passage 406. The communication between the femur stem third and fourth passages 404, 406 provides a mechanism for contacting the cam projection 372 with the peg 360 such that when the cam 368 is moved from the first cam position to the second cam position, the spacer 314 moves from the first spacer position to the second spacer position, adjusting the bone member 312 to a desired length relative to the femur stem 320.

[0060] FIGS. 93 and 94 show the hip arthroplasty trial system 300 in a first position where the bone member 312, spacer 314, and shaft 316 are each in a first position. Further, a first portion of the peg first length 364 is disposed within the femur stem third and fourth passages 404, 406. In the first position of the hip arthroplasty trial system, each of the bone member 312 and spacer 314 is disposed at a first distance 335 from the end of the femur stem third passage 404.

[0061] Figures 95 and 96 show the hip arthroplasty trial system 300 in the second position. The movement from the first position to the second position can be achieved by a user, such as a surgeon, applying a force to the shaft 316 (e.g., by placing the tool inside the cam recess 382) and rotating the shaft 316 clockwise 90 degrees about an axis perpendicular to the second longitudinal axis 393 of the femoral stem. As best shown in FIG. 96, when the shaft 316 rotates from the shaft first position to the shaft second position, the cam projection 372 contacts the peg 360 and the spacer 314 moves from the spacer first position to the spacer second position. When the spacer 314 is disposed in the spacer second position, the second portion of the peg length 365 is disposed in the third and fourth passages 404, 406 of the femoral stem. The second portion of the peg length 365 is shorter than the first portion of the peg length 364. In the second position of the hip arthroplasty trial system, each of the head member 312 and the spacer 314 is disposed at a position of a second distance 337 from the end of the third passage 404 of the femoral stem toward the femoral stem 320, and the second distance 337 is shorter than the first distance 335.

[0062] Figures 97 and 98 show the hip arthroplasty trial system 300 in the third position. The movement from the third position to the fourth position can be achieved by a user such as a surgeon applying a force to the shaft 316 (e.g., by placing a tool inside the cam recess 382) and rotating the shaft 316 clockwise 90 degrees about an axis perpendicular to the second longitudinal axis 393 of the femoral stem. As best shown in FIG. 98, when the shaft 316 rotates from the shaft third position to the shaft fourth position, the cam projection 372 contacts the peg 360 and the spacer 314 moves from the spacer third position to the spacer fourth position. When the spacer 314 is disposed in the spacer third position, the third portion of the peg length 367 is disposed in the femoral stem third and fourth passages 404, 406. The fourth portion of the peg length 367 is shorter than the third portion of the peg length 364. In the third position of the hip arthroplasty trial system, each of the head member 312 and the spacer 314 is disposed at a position of a third distance 339 from the end of the femoral stem third passage 404, and the third distance 339 is longer than the second distance 337.

[0063] Figures 99 and 100 show the hip arthroplasty trial system 300 in the fourth position. The movement from the second position to the third position can be achieved by a user such as a surgeon applying a force to the shaft 316 (e.g., by placing a tool inside the cam recess 382) and rotating the shaft 316 clockwise 90 degrees about an axis perpendicular to the second longitudinal axis 393 of the femoral stem. As best shown in FIG. 100, when the shaft 316 rotates from the shaft third position to the shaft fourth position, the cam projection 372 contacts the peg 360 and the spacer 314 moves from the spacer third position to the spacer fourth position. When the spacer 314 is disposed in the spacer fourth position, the fourth portion of the peg length 367 is disposed in the femoral stem fourth passage 406. The fourth portion of the peg length 367 is shorter than the third portion of the peg length 364. In the fourth position of the hip arthroplasty trial system, each of the head member 312 and the spacer 314 is disposed at a position of a fourth distance 341 from the end of the femoral stem third passage 404, and the fourth distance 341 is longer than the third distance 339.

[0064] Figures 101 - 115 show a fourth exemplary hip arthroplasty trial system 500 including a medical device 510 and a femoral stem 520. The hip arthroplasty trial system 500 is similar to the hip arthroplasty trial system 310 shown in FIGS. 78 - 100 and is as described above, except as detailed below.

[0065] As shown in FIGS. 103 - 105, the femoral stem 520 has a femoral stem body 594 including a first femoral stem end 590, a second femoral stem end 592, a first femoral stem longitudinal axis 591, a second femoral stem longitudinal axis 593, a first femoral stem portion 596, a second femoral stem portion 598, a first femoral stem passage 600, a second femoral stem passage 602, a third femoral stem passage 604, and a fourth femoral stem passage 606. In the illustrated embodiment, the first, second, third, and fourth passages 600, 602, 604, 606 are defined on the second femoral stem portion 598. In the illustrated embodiment, the first, second, and third femoral stem passages 600, 602, 604 are disposed at a position offset by 90 degrees relative to the position shown in the hip arthroplasty trial system 300.

[0066] FIGS. 108 and 109 show the hip arthroplasty trial system 500 in a first position where the bone member 512, spacer 514, and shaft 516 are each in a first position. Further, a first portion of the peg length 564 is disposed in the third and fourth femoral stem passages 604, 606. In the first position of the hip arthroplasty trial system, each of the bone member 512 and spacer 514 is disposed at a position a first distance 535 from the end of the third femoral stem passage 604.

[0067] Figures 110 and 111 show the hip arthroplasty trial system 500 in the second position. The movement from the first position to the second position can be achieved by a user, such as a surgeon, applying a force to the shaft 516 (e.g., by placing a tool inside the cam recess 582) and rotating the shaft 516 clockwise 90 degrees about an axis perpendicular to the second longitudinal axis 593 of the femoral stem. As best shown in FIG. 111, when the shaft 516 rotates from the shaft first position to the shaft second position, the cam protrusion 572 contacts the peg 560 and the spacer 514 moves from the spacer first position to the spacer second position. When the spacer 514 is disposed in the spacer second position, the second portion of the peg length 565 is disposed in the third and fourth passages 604, 606 of the femoral stem. The second portion of the peg length 565 is shorter than the first portion of the peg length 564. In the second position of the hip arthroplasty trial system, each of the head member 512 and the spacer 514 is disposed at a position of a second distance 537 from the end of the third passage 604 of the femoral stem, and the second distance 537 is longer than the first distance 535.

[0068] Figures 112 and 113 show the hip arthroplasty trial system 500 in the third position. The movement from the second position to the third position can be achieved by a user, such as a surgeon, applying a force to the shaft 516 (e.g., by placing a tool inside the cam recess 582) and rotating the shaft 516 clockwise 90 degrees about an axis perpendicular to the second longitudinal axis 593 of the femoral stem. As best shown in FIG. 113, when the shaft 516 rotates from the shaft second position to the shaft third position, the cam protrusion 572 contacts the peg 560 and the spacer 514 moves from the spacer second position to the spacer third position. When the spacer 514 is disposed in the spacer third position, the third portion of the peg length 566 is disposed in the third and fourth passages 604, 606 of the femoral stem. The third portion of the peg length 566 is shorter than the second portion of the peg length 565. In the third position of the hip arthroplasty trial system, each of the head member 512 and the spacer 514 is disposed at a position of a third distance 539 from the end of the third passage 604 of the femoral stem, and the third distance 539 is longer than the second distance 537.

[0069] Figures 114 and 115 show a hip arthroplasty trial system 500 in a fourth position. The movement from the third position to the fourth position can be achieved by a user, such as a surgeon, applying a force to the shaft 516 (e.g., by placing a tool inside the cam recess 582) and rotating the shaft 516 clockwise 90 degrees about an axis perpendicular to the second longitudinal axis 593 of the femoral stem. As best shown in FIG. 115, when the shaft 516 rotates from the shaft third position to the shaft fourth position, the cam projection 572 contacts the peg 560 and the spacer 514 moves from the spacer third position to the spacer fourth position. When the spacer 514 is disposed in the spacer fourth position, a fourth portion of the peg length 567 is disposed in the fourth passage 606 of the femoral stem. The fourth portion of the peg length 567 is shorter than the third portion of the peg length 566. In the fourth position of the hip arthroplasty trial system, each of the head member 512 and the spacer 514 is disposed at a position of a fourth distance 541 from the end of the third passage 604 of the femoral stem, and the fourth distance 541 is longer than the third distance 539.

[0070] Figures 116, 117, and 119 - 128 show a fifth exemplary hip arthroplasty trial system 700 that includes a medical instrument 710 and a femoral stem 720. The hip arthroplasty trial system 700 is similar to the hip arthroplasty trial system 310 shown in FIGS. 78 - 100 and is as described above, except as detailed below.

[0071] In the illustrated embodiment, the femoral component 712 has a first femoral component end 724, a second femoral component end 726, a first femoral component longitudinal axis 725, a second femoral component longitudinal axis 727, and a femoral component body 728 that defines a femoral component articular surface 730 and a femoral component recess 732. The first femoral component longitudinal axis 725 extends through the femoral component recess 732 and the second femoral component end 726. The femoral component recess 732 extends into the femoral component body 728 along the first femoral component longitudinal axis 725 from the first femoral component end 724 toward the second femoral component end 726 and has a first recess length 731. The femoral component recess 732 has a constant inner diameter 733 that extends from the first femoral component end 724 toward the second femoral component end 726. As shown in FIGS. 119 and 120, the femoral component 712 and the spacer 314 are a single unitary part such that the femoral component body 728 defines a peg 760 that is disposed within the femoral component recess 732. The peg 760 extends along the first femoral component longitudinal axis 725 from a femoral component recess base 734 beyond the first femoral component end 724 and has a peg length 761 and a peg diameter 763. The hip arthroplasty trial system 700 is shown as including a medical instrument 710 and a femoral stem 720, but the hip arthroplasty trial system can include a femoral stem having a suitable structural arrangement. For example, FIG. 118 shows another hip arthroplasty trial system 700' that is similar to the hip arthroplasty trial system 700 but includes a femoral stem 720' having a different structural arrangement than the femoral stem 720.

[0072] FIGS. 121 and 122 show the hip arthroplasty trial system 700 in a first position where each of the femoral component 712 and the shaft 716 is in a first position. Further, a first portion of the peg length 764 is disposed within the third and fourth femoral stem passages 804, 806. In the first position of the hip arthroplasty trial system, the femoral component 712 is disposed at a first distance 735 from an end of the third femoral stem passage 804.

[0073] Figures 123 and 124 show the hip arthroplasty trial system 700 in the second position. The movement from the first position to the second position can be achieved by a user, such as a surgeon, applying a force to the shaft 716 (e.g., by placing a tool inside the cam recess 782) and rotating the shaft 716 clockwise by 90 degrees about an axis perpendicular to the second longitudinal direction 793 of the femoral stem. As best shown in FIG. 124, when the shaft 716 rotates from the shaft first position to the shaft second position, the cam protrusion 772 contacts the peg 760 and the femoral head member 712 moves from the femoral head member first position to the femoral head member second position. When the femoral head member 714 is disposed in the femoral head member second position, the second portion of the peg length 765 is disposed in the third and fourth passages 804, 806 of the femoral stem. The second portion of the peg length 765 is shorter than the first portion of the peg length 764. In the second position of the hip arthroplasty trial system, the femoral head member 512 is disposed at a position of a second distance 737 from the end of the third passage 804 of the femoral stem, and the second distance 737 is shorter than the first distance 735.

[0074] Figures 125 and 126 show the hip arthroplasty trial system 700 in the third position. The movement from the second position to the third position can be achieved by a user, such as a surgeon, applying a force to the shaft 716 (e.g., by placing a tool inside the cam recess 782) and rotating the shaft 716 clockwise by 90 degrees about an axis perpendicular to the second longitudinal direction 793 of the femoral stem. As best shown in FIG. 126, when the shaft 716 rotates from the shaft second position to the shaft third position, the cam protrusion 772 contacts the peg 760 and the femoral head member 712 moves from the femoral head member second position to the femoral head member third position. When the femoral head member 712 is disposed in the femoral head member third position, the third portion of the peg length 766 is disposed in the third and fourth passages 804, 806 of the femoral stem. The third portion of the peg length 766 is shorter than the second portion of the peg length 765. In the third position of the hip arthroplasty trial system, the femoral head member 512 is disposed at a position of a third distance 739 from the end of the third passage 804 of the femoral stem, and the third distance 739 is longer than the second distance 737.

[0075] Figures 127 and 128 show a hip arthroplasty trial system 700 in a fourth position. The movement from the third position to the fourth position can be achieved by a user, such as a surgeon, applying a force to the shaft 716 (e.g., by placing a tool inside the cam recess 782) and rotating the shaft 716 clockwise 90 degrees about an axis perpendicular to the second longitudinal direction 793 of the femoral stem. As best shown in FIG. 127, when the shaft 716 rotates from the shaft third position to the shaft fourth position, the cam projection 772 contacts the peg 760 and the femoral head member 712 moves from the femoral head member third position to the femoral head member fourth position. When the femoral head member 712 is disposed in the femoral head member fourth position, a fourth portion of the peg length 767 is disposed in the fourth passage 806 of the femoral stem. The fourth portion of the peg length 767 is shorter than the third portion of the peg length 766. In the fourth position of the hip arthroplasty trial system, the femoral head member 712 is disposed at a position of a fourth distance 741 from the end of the third passage 804 of the femoral stem, and the fourth distance 741 is longer than the third distance.

[0076] FIG. 129 is a schematic diagram of an exemplary method 900 for performing a hip arthroplasty trial of the femur.

[0077] Procedure 902 includes obtaining medical devices for use in a hip arthroplasty trial. The medical devices include a femoral head member, a shaft, and a locking member. Another procedure 904 includes implanting a femoral stem into a patient's femur. Another procedure 906 includes positioning the femoral head member on the femoral stem. Another procedure 908 includes moving the shaft in a first direction in-situ such that the shaft moves to a second position and the femoral head member moves away from the femoral stem. Another procedure 910 includes moving the shaft in a second direction in-situ such that the shaft moves to a first position and the femoral head member moves towards the femoral stem. Another procedure 912 includes obtaining a femoral head implant corresponding to a desired offset amount between the femoral head member and the femoral stem. Another procedure 914 includes removing the femoral head member from the femoral stem. Another procedure 916 includes placing the femoral head implant on the femoral stem.

[0078] Procedure 902 can be accomplished using any medical device that is considered suitable for a particular embodiment. Examples of medical devices considered suitable for performing procedure 902 include medical device 10, medical device 110, medical device 310, medical device 510, medical device 710, variations of the medical devices described herein, and any other medical device considered suitable for a particular embodiment. Alternatively, procedure 902 may include obtaining a hip arthroplasty trial system for use in a hip arthroplasty trial. The hip arthroplasty trial system includes a medical device and a femoral stem. In this alternative embodiment, procedure 904 includes implanting the femoral stem into a patient's femur.

[0079] Step 904 can be achieved by using any suitable technique or method for implanting the femoral stem into the patient's body and applying a force to the femoral stem toward the patient's femur such that the femoral stem fits within a defined bore in the patient's femur. Examples of femoral stems that are considered suitable for performing Step 904 include femoral stem 20, femoral stem 120, femoral stem 320, femoral stem 520, femoral stem 720, variations of the femoral stems described herein, and other femoral stems that are considered suitable for a particular embodiment.

[0080] Step 906 can be achieved by applying a force to the bone head member toward the second end of the femoral stem until the bone head member is disposed at the second end of the femoral stem. Examples of bone head members that can be used to achieve Step 906 include bone head member 12, bone head member 112, bone head member 312, bone head member 512, bone head member 712, variations of the bone head members described herein, and other bone head members that are considered suitable for a particular embodiment. Optionally, as described herein, a spacer can be disposed within the bone head member or on the femoral stem prior to Step 906. Any steps can be performed prior to Steps 904 and 906 and an initial trial may be conducted. For example, any steps that can be performed prior to Steps 904 and 906 include disposing the bone head member adjacent to the acetabular component. Another optional step includes determining whether an initial offset amount between the bone head member and the femur is desirable. Another optional step includes moving the shaft such that the spacer translates parallel to the bone head member. Another step includes determining whether the amount of offset between the bone head member and the femur is at a desirable amount. Another optional step includes documenting the desirable offset amount. Another optional step includes removing the bone head member from the adjacent acetabular component. Subsequently, Steps 904 and 906 and the remainder of Method 900 can be performed to complete the final trial and implantation of the femoral head implant.

[0081] Step 908 can be achieved by applying a rotational force to the shaft (e.g., using a hex driver) until each of the shaft and the bone member moves from the first position to the second position. Before performing Step 908, if it is determined that the desired offset amount exists between the bone member and the femoral stem, Step 908 can be omitted from Method 900. After performing Step 908, if it is determined that the desired offset amount exists between the bone member and the femoral stem when the shaft is in the second position, the method continues to Step 910. If it is determined that the desired offset amount does not exist between the bone member and the femoral stem when the shaft is in the second position, Step 908 is repeated so that the shaft is disposed in its third position. If it is determined that the desired offset amount exists between the bone member and the femoral stem when the shaft is in the third position, the method continues to Step 910. If it is determined that the desired offset amount does not exist between the bone member and the femoral stem when the shaft is in the third position, Step 908 is repeated so that the shaft is disposed in its fourth position. If it is determined that the desired offset amount exists between the bone member and the femoral stem when the shaft is in the fourth position, the method continues to Step 910.

[0082] Step 910 can be achieved by applying a rotational force to the shaft (e.g., using a hex driver) until each of the shaft and the bone member moves from the second position to the first position. Before performing Step 908, if it is determined that the desired offset amount exists between the bone member and the femoral stem, Step 910 can be omitted from Method 900. If necessary, Step 910 may be repeated multiple times until each of the shaft and the bone member reaches the first position.

[0083] Step 912 can be achieved by using any femoral head implant that is considered suitable for a particular embodiment. For example, step 912 can be achieved by selecting a femoral head implant that is related to the desired amount of offset between the bone member and the femoral stem.

[0084] Step 914 can be achieved by applying a force to the bone member in a direction away from the femoral stem until the bone member disengages from the femoral stem. In a method where the bone member is removed from the femoral stem while the spacer remains disposed on the femoral stem, any step that includes removing the spacer from the femoral stem can be achieved by applying a force to the spacer in a direction away from the femoral stem until the spacer disengages from the femoral stem.

[0085] Step 916 can be achieved by using any suitable technique or method for implanting the femoral head implant into the patient's body. For example, step 916 can be achieved by applying a force to the femoral head implant in a direction towards the second end of the femoral stem until the femoral head implant is disposed at the second end of the femoral stem.

[0086] FIG. 130 is a schematic diagram of an exemplary method 1000 for performing a hip arthroplasty trial of the femur.

[0087] Procedure 1002 includes obtaining medical devices for use in hip arthroplasty trials. Another procedure 1004 includes implanting the first portion of the femoral stem into the femur. In another procedure 1006, a spacer is placed within the femoral head member. Another procedure 1008 includes placing the femoral head member and the spacer onto the second portion of the femoral stem. Another procedure 1010 includes moving the shaft in-situ in a first direction such that the spacer and the femoral head member move in the first direction. Another procedure 1012 includes determining whether the offset between the femoral head member and the femoral stem is at a desired amount. Another procedure 1014 includes documenting the desired offset amount. Another procedure 1016 includes moving the shaft in-situ in a second direction such that the spacer and the femoral head member move in the second direction. Another procedure 1018 includes obtaining a femoral head implant corresponding to the desired offset amount between the femoral head member and the femoral stem. Another procedure 2020 includes removing the femoral head member and the spacer from the femoral stem. Another procedure 1022 includes placing the femoral head implant onto the second portion of the femoral stem.

[0088] Procedure 1002 can be accomplished as described herein with respect to Procedures 202 and 902.

[0089] Procedure 1004 can be accomplished as described with respect to Procedure 904.

[0090] Procedure 1006 can be accomplished as described with respect to Procedure 212. Optionally, if the femoral head member and the spacer are pre-assembled as a medical device, Procedure 1006 can be omitted. Optionally, if the user utilizes medical device 710, Procedure 1006 can be omitted.

[0091] Procedure 1008 can be accomplished as described with respect to Procedures 906, 210, and 212.

[0092] Step 1010 can be achieved as described with respect to step 908.

[0093] Step 1012 can be achieved by considering the position of the bone member relative to the femoral stem and determining whether the offset between the bone member and the femoral stem is the desired amount. If it is determined that the offset between the bone member and the femoral stem is the desired amount when the shaft is in the first position, the method proceeds to step 1014. If it is determined that the offset between the bone member and the femoral stem is not the desired amount when the shaft is in the first position, step 1010 is repeated.

[0094] Step 1014 can be achieved by using any suitable technique for documenting the desired offset between the medical device and the femoral stem.

[0095] Step 1016 can be achieved as described with respect to step 910.

[0096] Step 1018 can be achieved as described with respect to step 912.

[0097] Step 1020 can be achieved as described with respect to steps 222 and 914.

[0098] Step 1022 can be achieved as described with respect to step 916.

[0099] FIG. 131 shows a sample kit including a first femoral head member 1112 according to one embodiment; a second femoral head member 1212 according to one embodiment; a third femoral head member 1312 according to one embodiment; a first spacer 1114 according to one embodiment; a second spacer 1214 according to one embodiment; a first shaft 1116 according to one embodiment; a second shaft 1216 according to one embodiment; a locking member 1118 according to one embodiment; an O-ring 1191 according to one embodiment; a first femoral stem 1120 according to one embodiment; a second femoral stem 1220 according to one embodiment; and a third femoral stem 1320 according to one embodiment. Although not shown, the kit may include instructions for use as needed.

[0100] Any suitable bone member, spacer, shaft, lock member, O-ring, and femoral stem can be included in the kit, and the suitable bone member, spacer, shaft, lock member, O-ring, and femoral stem to be included in the kit can be selected based on various considerations, such as any desirable amount of offset aimed to be achieved during the trial procedure. Examples of bone members considered suitable for inclusion in the kit include bone member 12, bone member 112, bone member 312, bone member 512, bone member 712, bone member 712', variations of the bone members described herein, and any other bone member according to one embodiment. Examples of spacers considered suitable for inclusion in the kit include spacer 14, spacer 114, spacer 314, spacer 514, variations of the spacers described herein, and any other spacer according to one embodiment. Examples of shafts considered suitable for inclusion in the kit include shaft 16, shaft 116, shaft 316, shaft 516, shaft 716, shaft 716', variations of the shafts described herein, and any other shaft according to one embodiment. Examples of lock members considered suitable for inclusion in the kit include lock member 18, lock member 118, variations of the lock members described herein, and any other lock member according to one embodiment. Examples of O-rings considered suitable for inclusion in the kit include O-ring 191, variations of the O-rings described herein, and any other O-ring according to one embodiment. Examples of femoral stems considered suitable for inclusion in the kit include femoral stem 20, femoral stem 120, femoral stem 320, femoral stem 520, femoral stem 720, femoral stem 720', variations of the femoral stems described herein, and any other femoral stem according to one embodiment.In the illustrated embodiment, kit 1100 includes a bone member 12 as shown in FIG. 2, a bone member 312 as shown in FIG. 78, a bone member 712 as shown in FIG. 119, a spacer 114 as shown in FIG. 51, a spacer 314 as shown in FIG. 82, a shaft 116 as shown in FIG. 55, a shaft 716 as shown in FIG. 84, a lock member 118 as shown in FIG. 57, an O-ring 191 as shown in FIG. 53, a femoral stem 20 as shown in FIG. 2, a femoral stem 320 as shown in FIG. 78, and a femoral stem 520 as shown in FIG. 101.

[0101] Kit 1100 is shown as including bone members 1112, 1212, 1312, spacers 1114, 1214, shafts 1116, 1216, lock member 1118, O-ring 1191, and femoral stems 1120, 1220, 1320, but an appropriate number and type of bone members, spacers, shafts, lock members, O-rings, and / or femoral stems (e.g., those described herein) may be included in the kit. The number of bone members, spacers, shafts, lock members, O-rings, and / or femoral stems appropriate to include in a kit according to a particular embodiment can be selected based on various considerations such as the procedure planned to be performed using the components included in the kit. Examples of the number of bone members, spacers, shafts, lock members, O-rings, and / or femoral stems appropriate to include in a kit include one, at least one, two, a plurality, three, four, and any other number considered suitable for a particular embodiment.

[0102] Kit 1100 including bone members 1112, 1212, 1312, spacers 1114, 1214, shafts 1116, 1216, lock members 1118, O-rings 1191, and femoral stems 1120, 1220, 1320 is illustrated, although the kit may include any suitable number of optional components. Examples of the number of optional components (e.g., bone member implants) considered suitable for inclusion in the kit include one, at least one, two, a plurality, three, four, five, more than five, and any other number considered suitable for a particular embodiment. Examples of optional components and / or devices considered suitable for inclusion in the kit include containers of various sizes, boring devices, hex drivers, bone member implants, and / or any other components and / or devices considered suitable for a particular embodiment.

[0103] The hip arthroplasty trial system, medical device, method, and kit described herein are described with respect to use in hip arthroplasty trials, although the hip arthroplasty trial system, medical device, method, and / or kit described herein can be utilized in any suitable procedure, and the suitable procedure for utilizing the hip arthroplasty trial system, medical device, method, or kit described herein can be selected based on various considerations such as the treatment being planned.

[0104] Furthermore, the hip arthroplasty trial systems, medical devices, methods, and kits described herein are believed to be advantageous in that they provide at least a mechanism for performing the femoral head trial in-situ (e.g., adjusting the bone length in-situ). This reduces the impact on surrounding tissue, the time required to perform the procedure, and the overall complexity of the procedure. This is different from the current practice as shown in FIGS. 1 and 1A (i.e., the way of trying multiple options regarding the length of the modular femoral neck or femoral head to determine the desired offset between the head and the femoral stem). In the current practice, to determine the desired offset, the components have to be assembled and disassembled multiple times and the hip joint has to be removed and attached multiple times, which is tissue-destructive, time-consuming, and complex. This applies to both the initial trial using the trial components and the final trial using the implanted femoral stem.

[0105] One of ordinary skill in the art will appreciate that, in light of the overall disclosed teachings, various modifications and alternative embodiments of the described and illustrated embodiments may be developed. Accordingly, the specific configurations disclosed are for illustrative purposes only and do not limit the scope of the invention, which is applicable to the appended claims in their entirety and equivalents thereof.

Claims

1. A bone member having a first end portion of the bone member, a second end portion of the bone member, a first longitudinal axis, and a bone member body defining a joint surface of the bone member and a first recess of the bone member, wherein the first recess of the bone member extends into the bone member body from the first end portion of the bone member toward the second end portion of the bone member along the first longitudinal axis. A femoral stem having a first end portion of the femoral stem and a second end portion of the femoral stem, and being movable relative to the bone member along the first longitudinal axis. A spacer disposed between the bone member and the femoral stem and being movable between a first spacer position and a second spacer position relative to one of the bone member and the femoral stem together with one of the bone member and the femoral stem with respect to the other of the bone member and the femoral stem. A cam rotatable between a first cam position and a second cam position about a second longitudinal axis extending in a direction different from the first longitudinal axis with respect to the bone member and the femoral stem, and when rotating from the first cam position to the second cam position, moving the spacer from the first spacer position to the second spacer position together with one of the members. Comprising When the cam is in the first cam position, the second end portion of the femoral stem is at a position of a first distance from the first end portion of the bone member, and when the cam is in the second cam position, the second end portion of the femoral stem is at a position of a second distance from the first end portion of the bone member, and the second distance is different from the first distance. A hip arthroplasty trial system.

2. The system according to claim 1, wherein one of the bone member and the femoral stem is the femoral stem, the other of the bone member and the femoral stem is the bone member, and the cam is rotatably attached to the bone member.

3. The bone member defines the second longitudinal axis. The bone member body defines a second recess of the bone member and a third recess of the bone member. The second longitudinal axis extends through the second recess of the bone member and intersects the first longitudinal axis. The second recess of the bone member extends into the bone member body along the second longitudinal axis and communicates with the first recess of the bone member. The system according to claim 2, wherein the third recess of the bone member extends into the bone member body and communicates with the second recess of the bone member.

4. The cam has a first cam boss located within the second recess of the bone member, a second cam boss located within the third recess of the bone member, and a cam protrusion disposed between the first cam boss and the second cam boss. The second cam boss defines a cam groove and a plurality of cam detents. The cam groove extends to a cam groove base. The system according to claim 3, wherein each of the plurality of cam detents extends from the cam groove base into the cam groove.

5. The system according to claim 4, further comprising a locking member disposed within the third recess of the bone member and configured to removably secure the cam in the first cam position and the second cam position.

6. The locking member has a body that defines a first locking member protrusion and a second locking member protrusion, and is movable between a first locking member position and a second locking member position. In the first locking member position, the first locking member protrusion and the second locking member protrusion are separated by a first length. In the second locking member position, the first locking member protrusion and the second locking member protrusion are separated by a second length. The second length is longer than the first length. The system according to claim 5, wherein the first locking member protrusion and the second locking member protrusion are each received by one of the cam groove and the plurality of cam detents.

7. The bone member body defines a first bone member passage and a second bone member passage. The first bone member passage and the second bone member passage each extend from the second recess of the bone member to the third recess of the bone member. The first locking member protrusion extends through the first bone member passage. The system according to claim 6, wherein the second locking member protrusion extends through the second bone member passage.

8. The spacer has a first spacer end, a second spacer end, a spacer length extending from the first spacer end to the second spacer end, a spacer body, a first spacer outer diameter at the first spacer end, and a second spacer outer diameter at the second spacer end. The system according to claim 1, wherein the second spacer outer diameter is shorter than the first spacer outer diameter.

9. The spacer body defines a plurality of grooves extending into the spacer body, and further includes an O-ring disposed within one of the plurality of grooves, the system of claim 8.

10. One of the bone member and the femoral stem is the bone member, the other of the bone member and the femoral stem is the femoral stem, and the cam is rotatably attached to the femoral stem, the system of claim 1.

11. The femoral stem has a femoral stem first passage, a femoral stem second passage, a femoral stem third passage, and a femoral stem fourth passage, the femoral stem first passage is coaxial with the femoral stem second passage, the femoral stem third passage communicates with each of the femoral stem first passage, the femoral stem second passage, and the femoral stem fourth passage, and each of the femoral stem first passage and the femoral stem second passage is in contact with a part of the cam, the system of claim 10.

12. The spacer has a spacer first end, a spacer second end, a spacer recess, a spacer recess base, and a spacer peg, the spacer recess extends from the spacer first end to the spacer recess base, the spacer peg is disposed within the spacer recess and extends beyond the spacer first end from the spacer recess base and is movably disposed within the femoral stem fourth passage, the system of claim 11.

13. The bone member and the spacer are a single unitary component, the system of claim 1.

14. The femoral stem is formed of a first material and the bone member is formed of a second material different from the first material, the system of claim 1.

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