WO2018106633A1

WO2018106633A1 - Shoulder prosthesis with variable inclination, offset, and version of humeral component

Info

Publication number: WO2018106633A1
Application number: PCT/US2017/064613
Authority: WO
Inventors: John W. Sperling; Kendall Dennis; Michael B. Larson
Original assignee: Mayo Foundation For Medical Education And Research
Priority date: 2016-12-06
Filing date: 2017-12-05
Publication date: 2018-06-14
Also published as: CA3046366A1; AU2017372734A1; JP2020500683A; EP3551134A1; EP3551134A4

Abstract

Methods and devices are disclosed for joint (e.g., shoulder) arthroplasty, including for reverse joint arthroplasty. In one aspect, there is provided a trial device for determining inclination, offset, and/or version of a prosthetic tray with respect to a prosthetic stem or stemless implant. In another aspect, there is provided a joint (e.g., shoulder) prosthesis, which allows for variable offset, inclination or version or any combination thereof. In another aspect, there is provided a method for setting an offset or inclination angle or a version angle or any combination thereof of a prosthetic tray with respect to a stem or stemless device implanted or to be implanted in a bone of a joint (e.g., shoulder) by matching the corresponding offset or version or inclination or any combination thereof to a trial device.

Description

Shoulder Prosthesis with Variable Inclination, Offset, and

Version of Humeral Component

CROSS-REFERENCES TO RELATED APPLICATIONS

[0001] This application claims priority to U .S. Patent Application No. 62/430,443 filed December 6, 2016, which is incorporated herein by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

[0002] Not Applicable.

BACKGROUND OF THE INVENTION

1 . Field of the Invention

[0003] The invention relates to a prosthesis and method for variable inclination, and/or offset, and/or version of the humeral tray, head, or glenosphere for shoulder arthroplasty, or radial head, ulna, or humerus for the elbow, or femoral head or acetabular component for hip arthroplasty, or tibial or femoral component for knee arthroplasty, or tibial or talar component for ankle arthroplasty, or radius or ulna for wrist arthroplasty, or phalanges or metacarpals for hand arthroplasty, or vertebral bodies for spine arthroplasty, or tarsals, metatarsals and phalanges for foot arthroplasty.

2. Description of the Related Art

[0004] Various prostheses for the replacement of the shoulder joint are known. In one example shoulder prosthesis, the upper portion of the humerus is replaced by a humeral component including (i) a stem, meaning an implant that extends into a bore formed within the humerus and (ii) a generally hemispherical head portion that is connected to the implant. Alternatively, stem less implants have been proposed. The hemispherical head of the humeral component articulates with a complementary concave section of a glenoid component mounted within the glenoid cavity of the scapula. This type of shoulder prosthesis may be called an anatomic total shoulder prosthesis. In another example shoulder prosthesis, often called a hemiarthroplasty, a hemispherical head of the humeral component articulates with the native glenoid. In another example shoulder prosthesis, often called a "reverse" or "inverted" prosthesis, the glenoid component includes a convex section that articulates with a complementary concave section of the humeral component. [0005] There has been demonstrated to be a significant theoretical as well as practical need to have variable inclination of the humeral component in shoulder arthroplasty. This has been demonstrated in strong marketplace acceptance as well as a clear demand for this feature in shoulder arthroplasty. Elbow, wrist, hand, knee, ankle, foot, spine and hip arthroplasty share a similar need for variable adjustments. In addition, there is a future trend toward patient specific instrumentation in joint arthroplasty. Variable inclination would be a very desirable, if not necessary, component of any shoulder arthroplasty system to allow the surgeon to exactly match the inclination chosen for the humeral component on the pre-operative plan and to match the instrumentation for that individual patient.

[0006] However, a review of competitive systems in the marketplace reveals that the range of inclination provided by these systems does not properly address the range of component inclination required at the time of shoulder arthroplasty. In addition, many of the ranges provided by shoulder arthroplasty systems are not physiologic and may result in significant component malposition. The range of inclination in currently available systems appears randomly chosen without a true anatomic basis.

[0007] In addition to a lack of understanding of the proper range of inclination necessary for a humeral component, the method to achieve this inclination has associated challenges. There are several potential strategies to change the inclination of the humerus available in the marketplace. Each of these methods has disadvantages.

[0008] One can manufacture a variety of humeral stems that have a fixed amount of inclination. However, this can result in a significant increase in inventory requiring multiple stem inclinations for a wide breadth of stem diameters.

[0009] In one alternative method, a set screw can be used within the stem to lock in the inclination angle of the humeral component. This can make the set screw the "weak link" in the design and could be problematic during attempted removal.

[0010] In another alternative method, one can use a screw through a lateral opening in the humeral implant and into the proximal humeral component to fix the amount of inclination. This can result in making proximal humeral component removal impossible without removing the distal humeral implant. This system may be used without the set screw; however, the manufacturer recommends impacting the proximal humeral component and distal implant together prior to insertion in the humerus. However, the lateral opening in the humeral implant remains, making removal of the humeral implant much more difficult if used with cement.

[001 1] In yet another alternative method, complex assembly can be performed with a locking mechanism connecting the distal humeral implant and proximal humeral component requiring more than ten steps. This method also does not allow one to place the distal humeral implant in the humeral canal independent of the proximal humeral component.

[0012] Thus, there exists a need for an improved prosthesis and method that provide for variable inclination, offset and/or version of the proximal humeral component in reverse or total shoulder arthroplasty, as well as a need for variability in elbow, wrist, hand, knee, ankle, foot, spine and hip arthroplasty.

SUMMARY OF THE INVENTION

[0013] The present disclosure addresses the foregoing needs by providing improved methods and devices for reverse joint (e.g., shoulder) arthroplasty. There is provided a joint (e.g., shoulder) prosthesis. There is also provided a device for determining inclination, offset and/or version of a prosthetic tray with respect to a prosthetic stem. Inclination, offset or version can be adjusted individually, or can be adjusted in some combination. Here, a prosthetic tray means either a tray alone, or a tray construct with a bearing surface this is inserted into a subject. There is also provided a method for setting an inclination angle, offset and version of a prosthetic head with respect to a stem or stemless implant implanted or to be implanted in a bone of a joint (e.g., shoulder).

[0014] In one aspect, a joint prosthesis is provided. The joint prostheses may include a stem or stemless device, dimensioned to be implanted in a first bone of a joint of a subject and a prosthetic tray having an outer surface dimensioned for articulation with an articular surface of an artificial joint surface of a second bone of the joint. A stem may refer to an implant inserted into a humerus and may have varying lengths, including no extension in the distal humerus, which would be considered a stemless implant. The joint prosthesis may further include an adapter dimensioned to be impacted into a depression in an end surface of the prosthetic tray opposite the outer surface of the prosthetic tray thereby forming an interference fit between the adapter and the depression and a mounting stud having a first end and a second end. The first end of the mounting stud may be dimensioned for impaction into a socket in the adapter that forms an interference fit between the first end and the socket. The second end may be dimensioned for insertion into an opening in the stem.

[0015] In some aspects, the second end of the mounting stud may be

dimensioned for impaction into the opening in the implant thereby forming an interference fit between the second end and the implant. The first end of the mounting stud may include a semi-spherical surface. The semi-spherical surface of the first end of the mounting stud may be rotated in the socket to set at least one of inclination or version of the prosthetic tray with respect to the implant before forming the interference fit between the first end of the mounting stud and the socket. The semi-spherical surface of the first end of the mounting stud may be contained within the depression in the end surface of the prosthetic tray. The second end of the mounting stud may include an outer surface that tapers inward from an intermediate section to an outermost section of the second end of the mounting stud. The mounting stud may include circumferential reference indicia at or adjacent a junction of the semi-spherical surface of the first end of the mounting stud and the outer surface of the second end of the mounting stud.

[0016] In some aspects, a longitudinal axis of the second end of the mounting stud may form an angle with respect to an axis of the prosthetic tray when the interference fit is formed between the first end and the socket. The socket of the adapter may be offset with respect to a central longitudinal axis of the adapter. The adapter may have a circular outer surface and the depression has a circular inner surface such that the adapter is rotated in the depression to set radial offset of the prosthetic tray with respect to the implant before forming the interference fit between the adapter and the depression.

[0017] In some aspects, the prosthetic tray may include at least one first reference marking for alignment with a second reference mark on the adapter. A surface of at least one of the first end of the mounting stud or the socket may be modified by at least one of abrasive blasting, roughening, cutting machining lines, adding sharp blade-like structures, or modifying the shape.

[0018] In some aspects, the first bone is the humerus and the second bone is the scapula. In other aspects, the first bone is the scapula and the second bone is the humerus. In other aspects, the first bone is the femur and the second bone is the pelvis. In other aspects, the first bone is the humerus and the second bone is the radius. In other aspects, the first bone is the femur and the second bone is the tibia. In other aspects, the first bone is the tibia and the second bone is the femur. In other aspects, the first bone is the tibia and the second bone is the talus. In other aspects, the first bone is the vertebral body and the second bone is an adjacent vertebral body in the spine. In other aspects, the first bone is the pelvis and the second bone is the femur. In still other aspects, the first bone is the humerus and the second bone is the ulna. In still other aspects, the first bone is the talus and the second bone is the tibia.

[0019] In another aspect, a device for determining an inclination, offset and version of a prosthetic tray with respect to a stem is provided. The inclination, offset and/or the version may be determined when the prosthetic tray is coupled to the stem. The prosthetic tray may have an outer surface for articulation with an articular surface of an artificial joint surface of a bone of a joint of a subject. The device may include a body with a well and a joint element. The joint element may have a first end and a second end; the first end may be positioned in the well, and the second end may be movable between positions where a longitudinal axis of the second end is angled with respect to an axis of the body.

[0020] In some aspects, the device may have a retainer having an opening extending between a first side and an opposed second side of the retainer, the retainer being arranged in the well, the retainer being dimensioned for translation in the well. The first end of the joint element is dimensioned to be positioned between the body and the first side of the retainer such that the second end of the joint element extends through and outwardly of the opening of the retainer. The second end of the joint element is dimensioned to be movable between positions where the longitudinal axis of the second end is angled with respect to an axis of the opening of the retainer. The device may further have a fastener movable between a first position in which the fastener allows the retainer to translate in the well and a second position in which the fastener prevents translation of the retainer in a well. The fastener may be a screw that when in the second position causes the first end of the joint element to be immobilized between the body and the retainer. The retainer may have an oblong shape with a pair of parallel sides. The first end of the joint element may include a semi-spherical bearing surface. The second end of the joint element may include an outer diameter that decreases from an intermediate section to an outermost section of the second end of the joint element. The second end of the joint element may be dimensioned to contact an inner surface of an opening in the implant. The body and the retainer may include reference markings for determining a positional relationship of the retainer with respect to the body. The first end of the joint element contains a semi-spherical body that receives a fastener, the semi- spherical bearing surface being movable around the semi-spherical body providing the movement to a plurality of angles of the second end of the joint element.

[0021] In some aspects, the first end of the joint element may contain a hinge assembly, the hinge assembly comprising a hinge pin and a hinge body, the hinge body configured to receive a fastener, the hinge pin extending through an end of the hinge body, the hinge assembly providing hinged movement to a plurality of angles of the second end of the joint element with respect to an axis of the hinge assembly. The first end of the joint element may be contacted by a locking member configured to surround an outer surface of the first end of the joint element, the locking member is contacted by at least one fastener that selectively presses the locking member into engagement with the first end of the joint element.

[0022] In some aspects, the bone is the scapula, and the joint is the shoulder. In other aspects, the bone is the humerus, and the joint is the shoulder. In other aspects, the bone is the pelvis, and the joint is the hip. In other aspects, the bone is the femur, and the joint is the hip. In some aspects, the bone is the radius, and the joint is the elbow. In some aspects, the bone is the femur, and the joint is the knee. In some aspects, the bone is the tibia, and the joint is the knee. In some aspects, the bone is the tibia, and the joint is the ankle. In some aspects, the bone is the vertebral body, and the joint is a vertebral articulation in the spine. In some aspects, the bone is the humerus, and the joint is the elbow.

[0023] In another aspect, a method for setting an inclination, offset angle and/or a version angle of a prosthetic tray with respect to an implant implanted or to be implanted in a bone of a joint of a subject is provided. The method comprises at least the steps of: (a) providing a trial device that includes a body that has a well, and a joint element that has a first end and a second end. The first end can be positioned in the well, and the second end can be movable between positions where a longitudinal axis of the second end is angled with respect to an axis of the body; (b) inserting the second end of the joint element in an opening in the stem; (c) immobilizing the joint element with respect to the body; and (d) securing a mounting stud to the prosthetic tray in a fixed position with respect to the prosthetic tray so as to match an orientation of the immobilized joint element with respect to the body. This method also facilitates adjustment of the proximal humeral component after it has been inserted in the stem allowing fine-tune adjustment in real-time.

[0024] In some aspects, the method may further comprise: (e) securing an end of the mounting stud in the opening in the implant. The trial device may further include a retainer arranged in the well, and step (c) comprises causing the first end of the joint element to be immobilized between the body and the retainer. The retainer may be dimensioned for translation in the well, and step (c) may further comprise preventing translation of the retainer in the well. Step (c) may further comprise moving a fastener movable into a position in which the fastener prevents translation of the retainer in the well.

[0025] In some aspects, step (d) comprises (i) placing an orientation template over the immobilized joint element, (ii) noting a position of a reference line on the template with respect to a first reference point on the body, (iii) placing an impact template over the mounting stud, (iv) aligning a reference line with a second reference point on the prosthetic tray, and (v) securing the mounting stud to the prosthetic tray in the fixed position with respect to the prosthetic tray.

[0026] In some aspects, the orientation template may include an opening, and the opening is placed over the immobilized joint element before noting the position of the reference line on the orientation template with respect to the first reference point on the body, and the implant template includes an opening, and is placed over the mounting stud before aligning the reference line with the second reference point on the prosthetic tray.

[0027] In some aspects, step (d) comprises moving the mounting stud to a first angle with respect to the prosthetic tray, the first angle being about the same as a second angle of the immobilized joint element with respect to the body. The first angle may be determined using a first reference circle surrounding the mounting stud, and the second angle may be determined using a second reference circle surrounding the joint element. The first angle may be determined by using a first reference circle surrounding the mounting stud and a reference line on the impact template, and the second angle may be determined using a second reference circle surrounding the joint element and the reference line on the orientation template.

[0028] In some aspects, the method may further comprise step (e) adjusting the prosthetic after it has been placed in the implant. A surface of the mounting stud may be modified by at least one of abrasive blasting, roughening, cutting machining lines, adding sharp blade-like structures, or modifying the shape.

[0029] In some aspects, the bone is the scapula, and the joint is the shoulder. In other aspects, the bone is the humerus, and the joint is the shoulder. In other aspects, the bone is the femur, and the joint is the hip. In some aspects, the bone is the radius, and the joint is the elbow. In some aspects, the bone is the femur, and the joint is the knee. In some aspects, the bone is the tibia, and the joint is the knee. In some aspects, the bone is the tibia, and the joint is the ankle. In some aspects, the bone is the vertebral body, and the joint is a vertebral articulation in the spine. In some aspects, the bone is the humerus, and the joint is the elbow.

[0030] In another aspect, the invention provides a joint prosthesis including a stem dimensioned to be implanted in a first bone of a joint of a subject; a prosthetic head having an outer surface dimensioned for articulation with an articular surface of a natural or artificial joint surface of a second bone of the joint; an adapter dimensioned to be impacted into a depression in an end surface of the prosthetic head opposite the outer surface of the prosthetic head thereby forming an interference fit between the adapter and the depression; and a mounting stud having a first end and a second end wherein the first end is dimensioned for impaction into a socket in the adapter thereby forming an interference fit between the first end and the socket, and the second end is dimensioned for insertion into an opening in the stem.

[0031] In one version of the joint prosthesis, the second end of the mounting stud is dimensioned for impaction into the opening in the stem thereby forming an interference fit between the second end and the stem.

[0032] In another version of the joint prosthesis, the first end of the mounting stud includes a spherical surface. The spherical surface of the first end of the mounting stud can be rotated in the socket to set inclination and/or version of the head with respect to the stem before forming the interference fit between the first end of the mounting stud and the socket.

[0033] In another version of the joint prosthesis, the second end of the mounting stud includes an outer surface that tapers inward from an intermediate section to an outermost section of the second end of the mounting stud.

[0034] In another version of the joint prosthesis, the mounting stud includes circumferential reference indicia at or adjacent a junction of the spherical surface of the first end of the mounting stud and the outer surface of the second end of the mounting stud.

[0035] In another version of the joint prosthesis, a longitudinal axis of the second end of the mounting stud forms an oblique angle with respect to an axis of the prosthetic head when the interference fit is formed between the first end and the socket.

[0036] In another version of the joint prosthesis, the socket of the adapter is offset with respect to a central longitudinal axis of the adapter.

[0037] In another version of the joint prosthesis, the adapter has a circular outer surface and the depression has a circular inner surface such that the adapter can be rotated in the depression to set radial offset of the head with respect to the stem before forming the interference fit between the adapter and the depression.

[0038] In another version of the joint prosthesis, the head includes at least one first reference marking for alignment with a second reference mark on the adapter.

[0039] The joint prosthesis is suitable for use in different joints. For example, the first bone may be the humerus, and the second bone may be the scapula. The first bone may be the scapula, and the second bone may be the humerus. The first bone may be the femur, and the second bone may be the pelvis. The first bone may be the humerus, and the second bone may be the radius.

[0040] In another aspect, the invention provides a device for determining an inclination and/or a version of a prosthetic head with respect to a stem wherein the inclination and/or the version are used when the prosthetic head is coupled to the stem. The prosthetic head has an outer surface for articulation with an articular surface of a natural or artificial joint surface of a bone of a joint of a subject. The device can include a body having a well; and a joint element having a first end and a second end wherein the first end is positioned in the well, and the second end is movable between positions wherein a longitudinal axis of the second end is angled with respect to an axis of the body.

[0041] One version of the device includes a retainer having an opening extending between a first side and an opposed second side of the retainer wherein the retainer is arranged in the well, and the retainer is dimensioned for translation in the well. The first end of the joint element is dimensioned to be positioned between the body and the first side of the retainer such that the second end of the joint element extends through and outwardly of the opening of the retainer, and the second end of the joint element is dimensioned to be movable between positions where the longitudinal axis of the second end is angled with respect to an axis of the opening of the retainer. The retainer can have an oblong shape with a pair of parallel sides.

[0042] Another version of the device includes a fastener movable between a first position in which the fastener allows the retainer to translate in the well and a second position in which the fastener prevents translation of the retainer in the well. The fastener may be a screw that when in the second position causes the first end of the joint element to be immobilized between the body and the retainer.

[0043] In one version of the device, the first end of the joint element includes a spherical bearing surface, and the second end of the joint element includes an outer diameter that decreases from an intermediate section to an outermost section of the second end of the joint element. The second end of the joint element may be dimensioned to contact an inner surface of an opening in the stem.

[0044] In one version of the device, the body and the retainer include reference markings for determining a positional relationship of the retainer with respect to the body.

[0045] The device is suitable for determining an inclination and/or a version of a prosthetic head with respect to a stem of a prosthesis for different joints. For example, the prosthetic head may articulate with the scapula when the joint is the shoulder. The prosthetic head may articulate with the humerus when the joint is the shoulder. The prosthetic head may articulate with the pelvis when the joint is the hip. The prosthetic head may articulate with the radius when the joint is the elbow.

[0046] In another aspect, the invention provides a method for setting an inclination angle and/or a version angle of a prosthetic head with respect to a stem implanted or to be implanted in a bone of a joint of a subject. The method uses a trial device including (i) a body having a well, and (ii) a joint element having a first end and a second end wherein the first end is positioned in the well, and the second end is movable between positions wherein a longitudinal axis of the second end is angled with respect to an axis of the body. The second end of the joint element is inserted in an opening in the stem, and the joint element is immobilized with respect to the body. A mounting stud is secured to the prosthetic head in a fixed position with respect to the prosthetic head so as to match an orientation of the immobilized joint element with respect to the body. An end of the mounting stud may be secured in the opening in the stem.

[0047] In one version of the method, the trial device further includes a retainer arranged in the well, and the first end of the joint element may be immobilized between the body and the retainer. The retainer may be dimensioned for translation in the well, and the method may comprise preventing translation of the retainer in the well. A fastener may be movable into a position in which the fastener prevents translation of the retainer in the well.

[0048] In another version of the method, a template is placed over the immobilized joint element, and a position of a reference line on the template with respect to a first reference point on the body is noted. The template is then placed over the mounting stud, and the reference line is aligned with a second reference point on the prosthetic head. The mounting stud is then secured to the prosthetic head in the fixed position with respect to the prosthetic head. The template may include an opening, and the opening may be placed over the immobilized joint element before noting the position of the reference line on the template with respect to the first reference point on the body. The opening may be placed over the mounting stud before aligning the reference line with the second reference point on the prosthetic head.

[0049] In another version of the method, the mounting stud can be moved to a first angle with respect of the prosthetic head before the mounting stud is secured to the prosthetic head in the fixed position. The first angle is about the same (e.g., ± 20°, or ± 10°, or ± 5°) as a second angle of the immobilized joint element with respect to the body. The first angle can be determined using a first reference circle surrounding the mounting stud, and the second angle can be determined using a second reference circle surrounding the joint element. The first angle can be determined using a first reference circle surrounding the mounting stud and a reference line on the template, and the second angle can be determined using a second reference circle

surrounding the joint element and the reference line on the template.

[0050] The method is suitable for setting an inclination angle and/or a version angle of a prosthetic head with respect to a stem implanted or to be implanted in a bone of various joints of a subject. The bone can be the scapula, and the joint can be the shoulder. The bone can be the humerus, and the joint can be the shoulder. The bone can be the femur, and the joint can be the hip. The bone can be the humerus, and the joint can be the elbow.

[0051] In one non-limiting embodiment, it is an advantage of the invention to use a humeral head assembly with a taper to set the inclination/version of a shoulder prosthesis. This construct allows for the use of a pre-existing stem design. The variable inclination is a part of the humeral head assembly. The use of a taper within the humeral head assembly provides the ability to not only change humeral inclination but also humeral version. This eliminates the need to create a separate humeral stem to allow adjustment for inclination and version. A taper of the humeral head assembly has the ability to rotate and then lock in place at the desired inclination/version in the humeral head. This allows the surgeon to maximize intraoperative flexibility by using one stem design to achieve the desired amount of inclination and version. This has the benefit of decreasing humeral component inventory and allows changing humeral inclination/version without removing the stem.

[0052] The proper range of inclination can be established with patient studies in order to properly define the range of inclination that will accommodate patients. This can facilitate the accurate and efficient design of a variable inclination system to determine the exact range of inclination that is necessary for the system.

[0053] Adjustment of humeral inclination has become a clear need in the shoulder arthroplasty marketplace. Significant deficiencies have become recognized in the currently available systems including a range of inclinations that are not based on the anatomic distribution. Moreover, the currently available systems used to create variable inclination have significant technical drawbacks. Therefore, the method of the invention has been designed to address these significant market needs. In addition, applications that may benefit from similar adjustability include the

glenosphere of the shoulder, radial head of the elbow, femoral head of the hip, and the like.

[0054] These and other features, aspects, and advantages of the present invention will become better understood upon consideration of the following detailed description, drawings, and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 is an anterior view, partially in cross section, of one embodiment of the shoulder prosthesis.

[0056] Figure 2 is a cross-sectional view of the shoulder prosthesis of Figure 1 , in a direction of line 2-2 of Figure 1 .

[0057] Figure 3 is a cross-sectional view of a humeral tray assembly of one embodiment of the shoulder prosthesis.

[0058] Figure 4 is a perspective view of the humeral tray assembly of Figure 3.

[0059] Figure 5 is a front distal view of the humeral tray assembly of Figure 3 with an impact ring on the surface.

[0060] Figure 6 is an exploded perspective view of the humeral tray assembly of Figure 3.

[0061] Figure 7 is a perspective view of an impactor according to one embodiment of the shoulder prosthesis.

[0062] Figure 8 is a front view of a template used in determining an offset of a prosthesis.

[0063] Figure 9 is a proximal perspective view of one embodiment of a trial tray assembly used in implanting a shoulder prosthesis.

[0064] Figure 10 is a distal perspective view of the trial tray assembly of Figure 9.

[0065] Figure 1 1 is a perspective cross-sectional view of the trial tray assembly of Figure 9.

[0066] Figure 12 is a perspective view of another embodiment of a trial tray assembly used in implanting a shoulder prosthesis.

[0067] Figure 13 is a distal perspective view of the trial tray assembly of Figure 12.

[0068] Figure 14 is a distal perspective view, partially in cross-section, of the trial tray assembly of Figure 12.

[0069] Figure 15 is a proximal perspective view, partially in cross-section, of the trial tray assembly of Figure 12.

[0070] Figure 16 is a cross sectional view of yet another embodiment of a trial tray assembly used in implanting a shoulder prosthesis.

[0071] Figure 17 is an exploded view of the embodiment of a trial tray assembly of Figure 16.

[0072] Figure 18 is a perspective view of the embodiment of a trial tray assembly of Figure 16 additionally showing an orientation ring.

[0073] Figure 19 shows a distal view of the trial tray assembly of Figure 16 with inclination adjusted.

[0074] Figure 20 shows a distal view of the trial tray assembly of Figure 16 with version adjusted.

[0075] Like reference numerals will be used to refer to like parts from Figure to Figure in the following description of the drawings.

DETAILED DESCRIPTION OF THE INVENTION

[0076] Figure 1 shows an example embodiment of a shoulder prosthesis 40. The humeral component 44 may include a stem 48 that extends into a bore formed within the humerus 52, or may include a stemless component. The stem 48 has a longitudinal stem axis S. A humeral tray assembly 56 has an insert 60 that has a generally concave bearing surface 140. The humeral tray assembly 56 is connected to the stem 48. The insert 60 articulates with a complementary convex hemispherical glenosphere 64 of a glenoid component 68 that is fixed within the glenoid cavity of the scapula 72 as shown in Figure 1. In the humeral tray assembly 56, the insert 60 includes an extension 76 that can be received by a tray 80 having a body 84 with a well 88 configured to receive an adapter 92 with a socket that is eccentric, i.e., the central axis of the socket 96 is offset from the central axis of the body 84. The humeral tray assembly 56 also includes a mounting stud 100 having a first end 104 with a semi-spherical bearing surface 108 and a second end 1 12 comprising a tapered shaft 1 16. The first end 104 of the mounting stud 100 is secured in the socket 96 of the adapter 92 by way of an interference fit formed by impacting the mounting stud 100 in the socket 96. The second end 1 12 of the mounting stud 100 is secured in a stem opening 120 of the stem 48 by way of a taper lock formed by impacting the mounting stud 100 in the stem opening 120. The mounting stud 100 may be impacted into the socket 96 of the adapter 92 using an impact ring 124 that has one or more proximal extensions 128 and one or more distal extensions 132. The one or more proximal extensions 128 may extend into the adapter 92 when the tray assembly 56 is being assembled, and the one or more distal extensions 132 guide the impactor 160.

[0077] The parts of the humeral component 44 may be formed from, for example: (i) a metal or metal alloy such as a titanium alloy (e.g., titanium-6-aluminum-4- vanadium), a cobalt alloy, a stainless steel alloy, or tantalum; (ii) a nonresorbable ceramic such as aluminum oxide or zirconia; (iii) a nonresorbable polymeric material such as polyethylene; or (iv) a nonresorbable composite material such as a carbon fiber-reinforced polymers (e.g., polysulfone). The prosthetic component can be manufactured by machining an article formed from these materials, or by molding these materials in a suitable mold.

[0078] In Figure 1 , taking the included angle in an anterior view between stem axis S and tray assembly axis C in degrees is one way to define the inclination angle Ainciination of the tray assembly 56 in degrees. The inclination angle of the tray assembly 56 can be adjusted to have a selected angle between the longitudinal tray axis C and the longitudinal stem axis S by assembling the tray 80 with adapter 92 in a selected position with respect to the tray 80 and where the mounting stud 100 may be in a selected orientation in the socket 96 of the adapter 92.

[0079] In Figure 2, taking the included angle in a medial view between stem axis S and tray axis C in degrees is one way to define the version angle Aversion of the tray assembly 56 in degrees. The version angle of the tray assembly 56 can be expressed as a positive or negative angle with respect to the stem axis S. The version angle of the tray assembly 56 can be adjusted to have a selected positive or negative angle between the longitudinal tray axis C and the longitudinal stem axis S by assembling the tray 80 with adapter 92 in a selected position with respect to the tray 80 and where the mounting stud 100 may be in a selected orientation in the socket 96 of the adapter 92.

[0080] Figures 3-8 show an example embodiment of the shoulder prosthesis 40. The insert 60 may have an angled proximal surface 136 such that a superior thickness of the insert 60 may be smaller than an inferior surface of the insert 60. The angled proximal surface 136 of the insert 60 causes the insert 60 to have a semi- spherical concave bearing surface 140. The angled proximal surface 136 may cause an inferior portion of the insert 60 to extend outward further than a superior portion of the insert 60. The extension 76 of the insert 60 extends from a proximal surface of the insert 60 and is received in a cylindrical recess 144 in a distal surface of the tray 80.

[0081 ] The tray 80 may have a cylindrical outer shape containing the well 88 that may be a cylindrical recess positioned in the proximal surface of the tray 80. In some embodiments, the well 88 may be non-centrally positioned in the tray 80. Offset may be adjusted by movement of the adapter 92 within the well 88. The adapter 92 can be shifted in any direction to adjust offset. A bottom surface of the well 88 may be defined by the tray body 84, where the proximal surface of tray body 84 may interface with a distal surface of the extension 76 of the insert 60. The well 88 may receive the adapter 92 and the impact ring 124 such that the adapter 92 is contained within a skirt 148 of the well 88. The skirt 148 of the well 88 may be defined as the remaining depth of the well 88 after the adapter 92 is positioned within the well 88. The well 88 may have a depth that contains the first end 104 of the mounting stud 100 such that the first end 104 of the mounting stud 100 does not extend past a distal surface of the tray 80 in order to decrease the gap between the tray 80 and the cut humeral bone surface. Skirt 148 may have varying depths in order to accommodate varying sized mounting studs 100 with larger or smaller first end 104. The size of the skirt 148 may be selected to decrease the appearance of a gap between the tray 80 and the cut humeral surface. The tray 80 may extend proximally around the recess 144 to circumferentially surround the extension 76 of the insert 60. The distal surface of the tray 80 may feature alignment markings 82 (A, B, C, D, E) positioned around the well 88.

[0082] The adapter 92 may be cylindrical in shape and positioned in the well 88 such that a proximal surface of the adapter 92 contacts the bottom surface of the well 88. The adapter 92 may further include a reference marking 94. Reference marking 94 may be used to determine the amount of offset when comparing reference marking 94 with alignment markings 82. The socket 96 in the adapter 92 may be semi-spherically tapered such that the diameter of the socket 96 at a proximal surface of the adapter 92 may be greater than the diameter of the socket 96 at a distal surface of the adapter 92. The socket 96 may be non-centrally positioned in the adapter 92, for example, the socket 96 may be positioned inferiorly off-center. In other embodiments, the socket 96 may be centrally positioned, superiorly positioned, or positioned in any desirable location of the tray. The socket 96 may extend from a proximal surface of the adapter 92 to a distal surface of the adapter 92 thereby creating an opening in the adapter 92. The distal surface of the adapter 92 may include one or more openings 152 positioned around the socket 96 to receive the one or more proximal extensions 128 of the impact ring 124. [0083] The mounting stud 100 is placed into the socket 96 in the adapter 92. The first end 104 of the mounting stud 100 may be on the proximal side of the mounting stud 100 that has the semi-spherical bearing surface 108 on the outer surface. The semi-spherical bearing surface 108 can be received by the socket 96 which can be tapered such that the first end 104 of the mounting stud 100 can be secured within the socket 96. The socket 96 or the semi-spherical bearing surface 108, or both, may be textured or otherwise have their surfaces modified to facilitate frictional engagement of the surfaces. This can be done by sand or bead blasting the surfaces, or otherwise roughening the surfaces in some way. The surfaces may also be modified by shaping the surfaces, such as by using blades, pointed structures, machining lines or a geometric feature on the surface such as pyramidal shapes, a geodesic dome shape, and the like. The first end 104 of the mounting stud 100 can be semi-spherical in shape with a flat proximal surface 154 that may or may not be wholly contained within the socket 96. The second end 1 12 of the mounting stud 100 distally extends out of the socket 96 from the first end 104 via the tapered shaft 1 16 which tapers to a diameter of the second end 1 12 that is smaller than the diameter of the first end 104.

[0084] For assembly, a proximal surface of the impact ring 124 interfaces with a distal surface of the adapter 92 and the proximal extensions 128 extend into the adapter 92. The impact ring 124 may have a cylindrical outer shape configured to fit within the well 88 of the tray 80 distal to the adapter 92. A distal surface of the impact ring 124 may include distal extensions 132 that guide the impactor 160 during assembly. In some embodiments, the proximal extensions 128 may be cylindrical in shape and the distal extensions 132 may be oblong in shape with an inward curvature configured to receive an impactor 160 between them. The impact ring 124 may have an opening 156 that may be positioned off-center such that the opening 156 in the impact ring 124 aligns with the socket 96 in order to allow the second end 1 12 of the mounting stud 100 to extend through the impact ring 124. The distal surface of the impact ring 124 includes alignment markings 158 that provide an indication of the angled position of the mounting stud 100. Mounting stud 100 may also include concentric reference circles which surround the mounting stud 100 near the junction of the semi-spherical bearing surface 108 and the tapered shaft 1 16 of the mounting stud 100. The concentric reference circles may be placed on the mounting stud 100 in such a way as to indicate discrete angular increments. These concentric reference circles may be used in combination with the alignment markings 158 to align the mounting stud 100 at the desired angle.

[0085] The impactor 160 has a round flat end surface 164, a first side wall 168 with an end surface 170, and a second side wall 172 with an end surface 174. The end surfaces 170, 174 of the impactor 160 are placed in contact with the distal surface of the impact ring 124. The end surfaces 170, 174 connect to form a horseshoe-shaped end surface that interfaces with the distal surface of the impact ring 124 between the distal extensions 132.

[0086] Figure 8 shows a transparent implant template 180 that can be used to match the orientation of the components of the humeral tray assembly 56 with a trial tray assembly. The implant template 180 has an opening or a protrusion 182 and reference lines 184. The template 180 may take other forms, such as a platform with a non-marring, low-friction surface for the tray 80 to rest upon while it is being rotated to its maximum offset, while still retaining a protrusion 182, and reference lines 184.

[0087] A surgeon can implant the humeral component 44 and the stem 48 in the humerus of a subject and the hemispherical glenosphere 64 in the glenoid cavity of the scapula 72 of a subject such that the humeral component 44 would include tray assembly 56. The insert 60 of tray assembly 56 articulates with a complementary convex hemispherical glenosphere 64 of a glenoid component 68 that is fixed within the glenoid cavity of the scapula 72. The fixing of the glenoid component 68 within the glenoid cavity of the scapula 72 can be done in a conventional manner.

[0088] Figures 9-1 1 show one embodiment of a trial tray assembly 190. The trial tray assembly 190 includes a body 198. One side of the body 198 has a generally round-corned rectangular shaped well 202 with offset markings 204 (A,B,C,D,E) on parallel side sections of the well 202. Opposite the side of the body 198 having the well 202, there is a side of the body 198 that has a generally semi-spherical insert surface 196 identical or substantially similar to the concave bearing surface 140 of the insert 60 of the humeral tray assembly 56. A retainer 206 can slide in the well In the trial tray assembly 190, an orientation ring 392 from Figure 18 with one or more extensions to facilitate placement may be received in the well 202 or in one or more openings 220 in the retainer 206 and can provide an indication of the angle of joint element 210. The round-corned rectangular shape of the well 202 may prevent the retainer 206 from rotating within the well 202 while one or more fasteners are tightened. Non-limiting examples of fasteners that may be used include set screws, pins, and the like, and may be used to slide along tightly-clearanced slots to prevent rotation of the retainer 206. The retainer 206 has an opening 224 and alignment markings 228. The ball joint element 210 of the trial tray assembly 190 has a first end 212 with a spherical bearing surface 214 and a second end 216 in the shape of a tapered shaft 218. The second end 216 of the ball joint element 210 protrudes outwardly through the retainer opening 224, and the first end 212 of the ball joint element 210 is positioned between the retainer 206 and the surface of the well 202. The first end 212 of the ball joint element 210 contains a hinge assembly 232 having a hinge pin 234 and a hinge body 236. The hinge pin 234 is cylindrical in shape and is received through an end of the hinge body 236. The hinge body 236 is also configured to receive a fastener 240 through an opening 244 in the trial tray 194 of the trial tray assembly 190, which can lock the position of the retainer 206 in the well 202.

[0089] The trial tray assembly 190 is configured to provide adjustable offset, inclination, and version of the ball joint element 210. Offset can be adjusted by altering the position of the retainer 206 within the well 202. The retainer 206 can translate within the well prior to the one or more fasteners being tightened.

Translation of retainer 206 within the well 202 adjusts the offset position of the ball joint element 210 as indicated by the offset markings 204. Inclination and version can be adjusted via the hinge assembly 232 and the spherical bearing surface 214 of the first end 212 of the ball joint element 210. The spherical bearing surface 214 can rotate within the retainer opening 224 perpendicular to a hinge axis 248 which extends through the center along a longitudinal axis of the hinge pin 234. Rotation of the spherical bearing surface 214 alters the position of the hinge assembly 232 and, consequently, the hinge axis 248. The second end 216 of the ball joint element 210 pivots about the hinge axis 248 thereby allowing the ball joint element 210 to be angularly positionable with respect to the trial tray assembly 190. Once the desired angular position of the ball joint element 210 is achieved, the fastener 240 and the one or more fasteners can be tightened in order to retain the position of the ball joint element 210. The offset position of the ball joint element 210 can be determined using the retainer alignment markings 228 and the body offset markings 204.

[0090] Preparing the trial tray assembly 190 begins with ensuring that the fastener 240 on the trial tray assembly 190 is loose. One verifies that the ball joint element 210 rotates freely in all directions and the retainer 206 slides freely in the well 202. The stem 48 is fixed within a bore formed within the humerus 52 (see Fig. 1 ). The second end 216 of the ball joint element 210 is then seated in an opening in the stem 48 which has been implanted in the humerus 52 of a subject. The body 198 of the trial tray assembly 190 is adjusted to the desired radial offset, inclination and/or version in the patient, and the fastener 240 is tightened to lock the offset and the angle of the ball joint element 210 of the trial tray assembly 190. The trial tray assembly 190 is then removed from the stem 48.

[0091] Figures 12-15 show another embodiment of a trial tray assembly 260. The trial tray assembly 260 includes a body 264 with a trial tray 266. One side of the body 264 has a generally round-corned rectangular shaped well 272 with offset markings 274 (A,B,C,D,E) on parallel side sections of the well 272. Opposite the side of the body 264 having the well 272, there is a side of the body 264 that has a generally semi-spherical insert surface 268 identical or substantially similar to the concave bearing surface 140 of the insert 60 of the humeral tray assembly 56. A retainer 276 can slide in the well 272 of the body 264. In the trial tray assembly 260, an orientation ring 392 from Figure 18 with one or more extensions to facilitate placement may be received in the well 272 or in one or more openings 292 in the retainer 276 and can provide an indication of the angle of joint element 280. The round-corned rectangular shape of the well 272 may prevent the retainer 276 from rotating within the well 272 while one or more fasteners are tightened. Non-limiting examples of fasteners that may be used include set screws, pins, and the like, and may be used to slide along tightly-clearanced slots to prevent rotation of the retainer 276. The retainer 276 has an opening 296 and alignment markings 300. The ball joint element 280 of the trial tray assembly 260 has a first end 282 with a spherical bearing surface 284 and a second end 286 in the shape of a tapered shaft 288. The second end 286 of the ball joint element 280 protrudes outwardly through the retainer opening 296, and the first end 282 of the ball joint element 280 is positioned between the retainer 276 and the surface of the well 272. The first end 282 of the ball joint element 280 may be selectively contacted by a locking member 304 that surrounds the spherical bearing surface 284 of the ball joint element 280. The locking member 304 may be positioned within the retainer 276 and may be rounded in shape such that it can receive the spherical bearing surface 284 of the ball joint element 280.

[0092] The trial tray assembly 260 is configured to provide adjustable offset, inclination, and version of the ball joint element 280. Offset can be adjusted by altering the position of the retainer 276 within the well 272. The retainer 276 can translate within the well prior to the one or more fasteners being tightened.

Translation of retainer 276 within the well 272 adjusts the offset position of the ball joint element 280 as indicated by the offset markings 274. Inclination and version can be adjusted using the spherical bearing surface 284 of the first end 282 of the ball joint element 280. The spherical bearing surface 284 can rotate within the retainer opening 296 thereby allowing the ball joint element 280 to be angularly positionable with respect to the trial tray 260. Once the desired angular position of the ball joint element 280 is achieved, the one or more fasteners can be tightened in order to retain the position of the ball joint element 280. The one or more fasteners may hold the locking member 304 in place via at least one of one or more body openings 306 or one or more trial tray assembly openings 308. The body openings 306 and trial tray assembly openings 308 allow fasteners to tighten and lock the locking member 304, and consequently the ball joint element 280, in place. The offset position of the ball joint element 280 can be determined using the retainer alignment markings 300 and the body alignment markings 274.

[0093] Preparing the trial tray assembly 260 begins with ensuring that the one or more fasteners on the trial tray assembly 260 are loose. One verifies that the ball joint element 280 rotates freely in all directions and the retainer 276 slides freely in the well 272. The stem 48 is fixed within a bore formed within the humerus 52 (see Fig. 1 ). The second end 286 of the ball joint element 280 is then seated in an opening in the stem 48 which has been implanted in the humerus 52 of a subject. The body 264 of the trial tray assembly 260 is adjusted to the desired radial offset, inclination and/or version in the patient, and the one or more fasteners are tightened to lock the offset and the angle of the ball joint element 280 of the trial tray assembly 260. The trial tray assembly 260 is then removed from the stem 48.

[0094] Figures 16-20 show yet another embodiment of a trial tray assembly 330. The trial tray assembly 330 includes a body 334. One side of the body 334 has a generally round-corned rectangular shaped well 342 with offset markings 344

(A,B,C,D,E) on parallel side sections of the well 342. Opposite the side of the body 334 having the well 342, there is a side of the body 334 that has a generally semi- spherical insert surface 338 identical or substantially similar to the concave bearing surface 140 of the insert 60 of the humeral tray assembly 56. A retainer 346 can slide in the well 342 of the body 334. The round-corned rectangular shape of the well 342 may prevent the retainer 346 from rotating within the well 342. The retainer 346 has an opening 368 and alignment markings 372. A ball joint element 350 of the trial tray assembly 330 has a first end 352 with a spherical bearing surface 354 and a second end 356 in the shape of a tapered shaft 358. The second end 356 of the ball joint element 350 protrudes outwardly through the retainer opening 368, and the first end 352 of the ball joint element 350 is positioned between the retainer 346 and the surface of the well 342. The first end 352 of the ball joint element 350 may receive an interior ball element 376. The interior ball element 376 may be disposed inside of the spherical bearing surface 354 of the first end 352 of the ball joint element 350. The interior ball joint element 350 may be semi-spherical in shape and may receive a fastener 380. The fastener 380 may extend into the interior ball joint element 350 via an opening 384 in the trial tray 336, an opening 388 in a proximal surface of the body 334 and a proximal side of the retainer opening 368. The trial tray assembly 330 may further include an orientation ring 392 having an opening 394, a first portion 396, a second portion 398, and alignment markings 400. The opening 394 may be circular and centrally positioned and may be configured to receive the second end 356 of the ball joint element 350. The first portion 396 may extend circumferentially outward further than the second portion 398. The second portion 398 being configured to interface with a top surface of the retainer 346 or the sides of the well 342. The alignment markings 400 may surround the opening 368 thereby indicating a plurality of angles around the circumference of the opening 368.

[0095] The trial tray assembly 330 is configured to provide adjustable offset, inclination, and version of the ball joint element 350. Offset can be adjusted by altering the position of the retainer 346 within the well 342. The retainer 346 can translate within the well 342 prior to the fastener 380 being tightened. Translation of retainer 346 within the well 342 adjusts the offset position of the ball joint element 350 as indicated by the offset markings 344. Inclination and version can be adjusted using the spherical bearing surface 354 of the first end 352 of the ball joint element 350. The spherical bearing surface 354 can rotate with respect to the interior ball element 376 within the retainer opening 368 thereby allowing the ball joint element 350 to be angularly positionable with respect to the trial tray 330. The spherical bearing surface 354 can rotate along an outer surface of the interior ball element 376 while the interior ball element 376 remains fixed due to the connection to the fastener 380. Once the desired angular position of the ball joint element 350 is achieved, the fastener 380 can be tightened in order to retain the position of the ball joint element 350 via a frictional fit. The offset or angular position of the ball joint element 350 can be determined using the retainer alignment markings 372 and/or the alignment markings 400 on the orientation ring 392 respectively.

[0096] Preparing the trial tray assembly 330 begins with ensuring that the fastener 380 on the trial tray assembly 330 is loose. One verifies that the ball joint element 350 rotates freely in all directions and the retainer 346 slides freely in the well 342. The stem 48 is fixed within a bore formed within the humerus 52 (see Fig. 1 ). The second end 356 of the ball joint element 350 is then seated in an opening in the stem 48 which has been implanted in the humerus 52 of a subject. The body 334 of the trial tray assembly 330 is adjusted to the desired radial offset, inclination and/or version in the patient, and the fastener 380 is tightened to lock the offset and the angle of the ball joint element 350 of the trial tray assembly 330. The trial tray assembly 330 is then removed from the stem 48.

[0097] Figure 19 shows the trial tray assembly 330 with offset and inclination adjusted.

[0098] Figure 20 shows the trial tray assembly 330 with offset and version adjusted.

[0099] Now that the structure and functionality of each trial tray assembly 190, 260, 330 have been described in detail, the preparation method of a shoulder prosthesis such as the shoulder prosthesis 40 based on the preparation of any of the trial tray assemblies 190, 260, or 330 can be appreciated.

[00100] The trial tray assembly 190, 260, or 330 is then turned upside-down such that the retainer 206, 276, or 346 and the ball joint element 210, 280, or 350 are visible to the surgeon. The surgeon notes the alignment markings 228, 300, or 372 on the surface of the retainer 206, 276, or 346. The offset is indicated by the position of the alignment markings 228, 300, or 372 of the retainer 206, 276, or 346 relative to the offset markings 204, 274, or 344 (A, B, C, D, E) on the body 198, 264, or 334. The surgeon also notes a reference angle indicated by concentric reference circles on the ball joint element 210, 280, or 350. In a non-limiting example configuration shown, there are three concentric reference circles present on the ball joint element 210, 280, or 350, which can be of different colors such as black, red, and blue. One method for determining the reference angle is by noting the position of the concentric reference circles at the location where one of the retainer alignment markings 228, 300, or 372 would intersect the retainer's 206, 276, or 346 inner opening 224, 296, or 368 circumference. By noting the position of the concentric reference circles at two of these orthogonal locations (i.e., two adjacent alignment markings 228, 300, or

372), the reference angle is fully characterized. Another method for determining the orientation angle of the trial joint element 210, 280 or 350 is to observe the relative position of the joint element 210, 280 or 350 with respect to the orientation ring 392 and the concentric reference circles which surround the joint element 210, 280 or 350.

[00101] The trial tray assembly 190, 260, or 330 can be located adjacent the humeral tray assembly 56 during assembly for reference with the maximum offset oriented in the same direction. The humeral tray assembly 56 is assembled to match the orientation of the ball joint element 210, 280, or 350 in the trial tray assembly 190, 260, or 330. The adapter 92 is inserted into the tray 80, and the adapter 92 is rotated so that the offset reference marking 94 on the adapter 92 align with the appropriate alignment marking 82 on the adapter 92.

[00102] An impactor 160 is then used in the method. The impactor 160 has a round flat end surface 164, a first side wall 168 with an end surface 170, and a second side wall 172 with an end surface 174. The end surfaces 170, 174 of the impactor 160 are placed on top of adapter 92, and a mallet is used to strike the flat end surface 164 of the impactor 160 to impact the adapter 92 into the well 88 of the tray 80 at the corresponding offset of the trial.

[00103] The protrusion 182 of the implant template 180 is placed over the socket 96 of the adapter 92, and the reference lines 184 of the implant template 180 are used to align the maximum offset direction of the tray 80 with the maximum offset direction of the body 198, 264, 334 of the trial tray assembly 190, 260, 330. The orientation of the maximum offset is marked on the tray assembly 56. The implant template 180 is removed, noting its position relative to the tray 80. The first end 104 of the mounting stud 100 is placed vertically onto the socket 96 of the adapter 92, and the mounting stud 100 is pressed down using just enough force to barely seat it. The socket 96 may also be lined with a material, such as rubber, that may act to hold the mounting stud 100 in place. Surface texturing may also be performed as indicated previously to facilitate engagement between the socket 96 and the mounting stud 100.

[00104] An impact ring 124 having an opening 156 is placed over the mounting stud 100, and rotated so the impact ring 124 aligns such that the proximal extensions 128 align with the openings 152 of the adapter 92. As noted above, the mounting stud 100 should not change orientation after the desired angle has been matched to the trial, and the impact ring 124 may be lined with a material, such as rubber, or otherwise have surface texturing to prevent motion. The proximal extensions 128 of the impact ring 124 are pushed into openings 152 of the adapter 92. In one method, the implant template 180 is re-placed over the mounting stud 100 in the same position as when the implant template 180 was removed. The reference lines 184 on the implant template 180 are referenced to confirm offset, and the mounting stud 100 is moved to the same angle of the ball joint element 210, 280, 350 of the trial tray assembly 190, 260, 330 using concentric reference circles which surround the mounting stud 100 near the junction of the semi-spherical bearing surface 108 and the tapered shaft 1 16 of the mounting stud 100. The implant template 180 is then removed. In another method, the orientation ring 392 and the concentric reference circles which surround the joint element 210, 280 or 350 are used to determine the orientation angle of the trial joint element 210, 280 or 350. The impact ring 124 and the concentric reference circles which surround the mounting stud 100 are used to match the position of mounting stud 100 on the implant to the observed orientation angle of the trial.

[00105] The angle of the mounting stud 100 of the tray 80 and the ball joint element 210, 280, 350 of the trial tray assembly 190, 260, 330 are visually compared by looking at them horizontally from two orthogonal directions. If the angles match acceptably, one gently pushes down on the impact ring 124, applying even pressure around the mounting stud 100. The impact ring 124 guides the mounting stud 100 at the correct angle during the subsequent steps. One then visually re-confirms that the angle of the mounting stud 100 of the humeral tray assembly 56 is still acceptable.

[00106] The impactor 160 is positioned concentric with the impact ring 124 with the end surfaces 170, 174 of the impactor 160 contacting the impact ring 124. One uses downward pressure to hold the impactor 160 in place with one hand, and then one strikes the end surface 164 of the impactor 160 with a mallet. This pushes down the impact ring 124, which in turn drives the mounting stud 100 into an interference fit with the socket 96 of the adapter 92. The interference fit may be enhanced by modifying the surfaces of either the mounting stud 100, or the socket 96, by abrasive blasting, roughening the surfaces, cutting rough machining lines, or adding sharp blade-like structures to engage the opposing surface, and the like, or otherwise modifying the shape of either the mounting stud 100 or the socket 96. The mounting stud 100 is fully seated when the desired interference fit strength is achieved, such that the mounting stud 100 cannot be moved. One then visually re-confirms that the angle of the mounting stud 100 of the humeral tray assembly 56 is still acceptable.

[00107] The impact ring 124 can be removed by pinching the distal extensions 132 with the thumb and index finger and pulling upward. The impact ring may then be discarded. Alternatively, the impact ring 124 may remain in place and become a component of the tray assembly 56. Insert 60 is now attached to the tray 80. Insert 60 can be attached to tray 80 with a conventional lock ring, or an adhesive, and the like. Different size trial inserts may be used to adjust and determine the desired thickness of the implant prior to implantation. The insert 60 may provide for further adjustment of the tray assembly 56 by allowing for rotation to a desired angle before being locked in place. The humeral tray assembly 56 is now ready for implantation. The second end 1 12 of the mounting stud 100 of the humeral tray assembly 56 is secured in an opening of the stem 48. Seating the humeral tray assembly 56 in the humeral stem 48 using a mallet may further seat the assembled components together. The method may facilitate fine-tune adjustments once the tray assembly 56 is seated due to adjusting the interference fit.

[00108] Thus, the invention provides an improved prosthesis and method that provide for variable inclination and/or version and/or offset of the humeral tray component in arthroplasty. While methods and devices for shoulder arthroplasty have been described herein, the method and devices could be used for other joints (e.g., hip, knee, elbow, foot, ankle, spine, wrist, hand, etc.).

[00109] Although the present invention has been described in detail with reference to certain embodiments, one skilled in the art will appreciate that the present invention can be practiced by other than the described embodiments, which have been presented for purposes of illustration and not of limitation. Therefore, the scope of the appended claims should not be limited to the description of the embodiments contained herein.

Claims

CLAIMS What is claimed is:

1 . A joint prosthesis comprising:

an implant dimensioned to be implanted in a first bone of a joint of a subject; a prosthetic tray having an outer surface dimensioned for articulation with an articular surface of an artificial joint surface of a second bone of the joint;

an adapter dimensioned to be impacted into a depression in an end surface of the prosthetic tray opposite the outer surface of the prosthetic tray thereby forming an interference fit between the adapter and the depression; and

a mounting stud having a first end and a second end, the first end being dimensioned for impaction into a socket in the adapter thereby forming an

interference fit between the first end and the socket, the second end being

dimensioned for insertion into an opening in the implant.

2. The joint prosthesis of claim 1 wherein:

the second end of the mounting stud is dimensioned for impaction into the opening in the implant thereby forming an interference fit between the second end and the implant.

3. The joint prosthesis of claim 1 wherein:

the first end of the mounting stud includes a semi-spherical surface.

4. The joint prosthesis of claim 3 wherein:

the semi-spherical surface of the first end of the mounting stud is rotated in the socket to set at least one of inclination or version of the prosthetic tray with respect to the implant before forming the interference fit between the first end of the mounting stud and the socket.

5. The joint prosthesis of claim 3 wherein:

the semi-spherical surface of the first end of the mounting stud is contained within the depression in the end surface of the prosthetic tray.

6. The joint prosthesis of claim 1 wherein:

the second end of the mounting stud includes an outer surface that tapers inward from an intermediate section to an outermost section of the second end of the mounting stud.

7. The joint prosthesis of claim 5 wherein:

the mounting stud includes circumferential reference indicia at or adjacent a junction of the semi-spherical surface of the first end of the mounting stud and the outer surface of the second end of the mounting stud.

8. The joint prosthesis of claim 1 wherein:

a longitudinal axis of the second end of the mounting stud forms an angle with respect to an axis of the prosthetic tray when the interference fit is formed between the first end and the socket.

9. The joint prosthesis of claim 1 wherein:

the socket of the adapter is offset with respect to a central longitudinal axis of the adapter.

10. The joint prosthesis of claim 9 wherein:

the adapter has a circular outer surface and the depression has a circular inner surface such that the adapter is rotated in the depression to set radial offset of the prosthetic tray with respect to the implant before forming the interference fit between the adapter and the depression.

1 1 . The joint prosthesis of claim 10 wherein:

the prosthetic tray includes at least one first reference marking for alignment with a second reference mark on the adapter.

12. The joint prosthesis of claim 1 wherein:

a surface of at least one of the first end of the mounting stud or the socket has been modified by at least one of abrasive blasting, roughening, cutting machining lines, adding sharp blade-like structures, or modifying the shape.

13. The joint prosthesis of claim 1 wherein:

the first bone is the humerus, and

the second bone is the scapula.

14. The joint prosthesis of claim 1 wherein:

the first bone is the scapula, and

the second bone is the humerus.

15. The joint prosthesis of claim 1 wherein:

the first bone is the femur, and

the second bone is the pelvis.

16. The joint prosthesis of claim 1 wherein:

the first bone is the humerus, and

the second bone is the radius.

17. The joint prosthesis of claim 1 wherein:

the first bone is the femur, and

the second bone is the tibia.

18. The joint prosthesis of claim 1 wherein:

the first bone is the tibia, and

the second bone is the femur.

19. The joint prosthesis of claim 1 wherein:

the first bone is the tibia, and

the second bone is the talus.

20. The joint prosthesis of claim 1 wherein:

the first bone is the vertebral body, and

the second bone is an adjacent vertebral body in the spine.

21 . The joint prosthesis of claim 1 wherein:

the first bone is the pelvis, and

the second bone is the femur.

22. The joint prosthesis of claim 1 wherein:

the first bone is the humerus, and

the second bone is the ulna.

23. The joint prosthesis of claim 1 wherein:

the first bone is the talus, and

the second bone is the tibia.

24. A device for determining at least one of inclination, offset, or version of a prosthetic tray with respect to an implant wherein the inclination and/or the version and/or the offset are used when the prosthetic tray is coupled to the implant, the prosthetic tray having an outer surface for articulation with an articular surface of an artificial joint surface of a bone of a joint of a subject, the device comprising:

a body having a well; and

a joint element having a first end and a second end, the first end being positioned in the well, the second end being movable between positions wherein a longitudinal axis of the second end is angled with respect to an axis of the body.

25. The device of claim 24 further comprising:

a retainer having an opening extending between a first side and an opposed second side of the retainer, the retainer being arranged in the well, the retainer being dimensioned for translation in the well,

wherein the first end of the joint element is dimensioned to be positioned between the body and the first side of the retainer such that the second end of the joint element extends through and outwardly of the opening of the retainer, and

wherein the second end of the joint element is dimensioned to be movable between positions where the longitudinal axis of the second end is angled with respect to an axis of the opening of the retainer.

26. The device of claim 25 further comprising:

a fastener movable between a first position in which the fastener allows the retainer to translate in the well and a second position in which the fastener prevents translation of the retainer in a well.

27. The device of claim 26 wherein:

the fastener is a screw that when in the second position causes the first end of the joint element to be immobilized between the body and the retainer.

28. The device of claim 25 wherein:

the retainer has an oblong shape with a pair of parallel sides.

29. The device of claim 24 wherein:

the first end of the joint element includes a semi-spherical bearing surface.

30. The device of claim 24 wherein:

the second end of the joint element includes an outer diameter that decreases from an intermediate section to an outermost section of the second end of the joint element.

31 . The device of claim 24 wherein:

the second end of the joint element is dimensioned to contact an inner surface of an opening in the implant.

32. The device of claim 25 wherein:

the body and the retainer include reference markings for determining a positional relationship of the retainer with respect to the body.

33. The device of claim 29 wherein:

the first end of the joint element contains a semi-spherical body that receives a fastener, the semi-spherical bearing surface being movable around the semi- spherical body providing the movement to a plurality of angles of the second end of the joint element.

34. The device of claim 29 wherein:

the first end of the joint element contains a hinge assembly, the hinge assembly comprising a hinge pin and a hinge body, the hinge body configured to receive a fastener, the hinge pin extending through an end of the hinge body, the hinge assembly providing hinged movement to a plurality of angles of the second end of the joint element with respect to an axis of the hinge assembly.

35. The device of claim 29 wherein:

the first end of the joint element is contacted by a locking member configured to surround an outer surface of the first end of the joint element, the locking member is contacted by at least one fastener that selectively presses the locking member into engagement with the first end of the joint element.

36. The device of claim 24 wherein:

the bone is the scapula, and

the joint is the shoulder.

37. The device of claim 24 wherein:

the bone is the humerus, and

the joint is the shoulder.

38. The device of claim 24 wherein:

the bone is the pelvis, and

the joint is the hip.

39. The device of claim 24 wherein

the bone is the femur, and

the joint is the hip.

40. The device of claim 24 wherein: the bone is the radius, and

the joint is the elbow.

41 . The device of claim 24 wherein: the bone is the femur, and

the joint is the knee.

42. The device of claim 24 wherein: the bone is the tibia, and

the joint is the knee.

43. The device of claim 24 wherein: the bone is the tibia, and

the joint is the ankle.

44. The device of claim 24 wherein: the bone is the vertebral body, and the joint is a vertebral articulation in the spi

45. The device of claim 24 wherein: the bone is the humerus, and

the joint is the elbow.

46. A method for setting at least one of offset, inclination angle or a version angle of a prosthetic tray with respect to an implant implanted or to be implanted in a bone of a joint of a subject, the method comprising:

(a) providing a trial device including (i) a body having a well, and (ii) a joint element having a first end and a second end, the first end being positioned in the well, the second end being movable between positions wherein a longitudinal axis of the second end is angled with respect to an axis of the body;

(b) inserting the second end of the joint element in an opening in the implant;

(c) immobilizing the joint element with respect to the body; and

(d) securing a mounting stud to the prosthetic tray in a fixed position with respect to the prosthetic tray so as to match an orientation of the immobilized joint element with respect to the body.

47. The method of claim 46 further comprising:

(e) securing an end of the mounting stud in the opening in the implant.

48. The method of claim 46 wherein:

the trial device further includes a retainer arranged in the well, and step (c) comprises causing the first end of the joint element to be immobilized between the body and the retainer.

49. The method of claim 48 wherein:

the retainer is dimensioned for translation in the well, and

step (c) further comprises preventing translation of the retainer in the well.

50. The method of claim 48 wherein:

step (c) further comprises moving a fastener movable into a position in which the fastener prevents translation of the retainer in the well.

51 . The method of claim 46 wherein:

step (d) comprises

(i) placing an orientation template over the immobilized joint element,

(ii) noting a position of a reference line on the template with respect to a first reference point on the body,

(iii) placing an impact template over the mounting stud,

(iv) aligning a reference line with a second reference point on the prosthetic tray, and

(v) securing the mounting stud to the prosthetic tray in the fixed position with respect to the prosthetic tray.

52. The method of claim 51 wherein:

the orientation template includes an opening,

the opening is placed over the immobilized joint element before noting the position of the reference line on the orientation template with respect to the first reference point on the body, and

the implant template includes an opening, and is placed over the mounting stud before aligning the reference line with the second reference point on the prosthetic tray.

53. The method of claim 51 wherein:

step (d) comprises

moving the mounting stud to a first angle with respect to the prosthetic tray, the first angle being about the same as a second angle of the immobilized joint element with respect to the body.

54. The method of claim 53 wherein:

the first angle is determined using a first reference circle surrounding the mounting stud, and

the second angle is determined using a second reference circle surrounding the joint element.

55. The method of claim 53 wherein:

the first angle is determined by using a first reference circle surrounding the mounting stud and a reference line on the impact template, and

the second angle is determined using a second reference circle surrounding the joint element and the reference line on the orientation template.

56. The method of claim 46 further comprising:

(e) adjusting the prosthetic after it has been placed in the implant.

57. The method of claim 46 wherein:

a surface of the mounting stud has been modified by at least one of abrasive blasting, roughening, cutting machining lines, adding sharp blade-like structures, or modifying the shape.

58. The method of claim 46 wherein:

the bone is the scapula, and

the joint is the shoulder.

59. The method of claim 46 wherein:

the bone is the humerus, and

the joint is the shoulder.

60. The method of claim 46 wherein: the bone is the femur, and

the joint is the hip.

61 . The method of claim 46 wherein: the bone is the humerus, and

the joint is the elbow.

62. The device of claim 46 wherein: the bone is the femur, and

the joint is the knee.

63. The device of claim 46 wherein: the bone is the tibia, and

the joint is the knee.

64. The device of claim 46 wherein: the bone is the tibia, and

the joint is the ankle.

65. The device of claim 46 wherein: the bone is the vertebral body, and the joint is a vertebral articulation in the spi

66. The device of claim 46 wherein: the bone is the pelvis, and

the joint is the hip.

67. The device of claim 46 wherein: the bone is the radius, and

the joint is the elbow.