Convertible orthopedic implant system and method

Abstract

The present disclosure relates to orthopedic implant systems and methods for restoring joint function. The implant systems disclosed herein include offset arrangements that can facilitate translation of the implant system during a subsequent surgical procedure.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This disclosure claims the benefit of U.S. Provisional Patent Application No. 63 / 089,878, filed October 9, 2020. [Background technology]

[0002] FIELD OF THE DISCLOSURE The present disclosure relates to orthopedic procedures, and more particularly to orthopedic implant systems and methods for repairing bone defects and restoring joint function.

[0003] Many bones in the human musculoskeletal system contain articular surfaces. The articular surfaces work together to facilitate different types and degrees of joint movement. The articular surfaces can wear down or suffer bone loss over time due to repeated use or wear, or can fracture as a result of traumatic impact. These types of bone defects can cause joint instability and pain.

[0004] Bone defects can occur along the articular surface of the glenoid bone. Some techniques utilize implants to repair the articular surface. The implants may be secured to the glenoid using one or more fasteners. Summary of the Invention [Means for solving the problem]

[0005] The present disclosure relates to orthopedic implant systems and methods for restoring joint function, wherein the implant system may be convertible between a first configuration and a second configuration during different surgical procedures along the same surgical site.

[0006] An implant for an anatomical shoulder replacement of the present disclosure may include a base plate configured to be implanted in or on the glenoid and a pad configured to interface with the humeral or brachial implant, the pad being configured to extend superiorly beyond the base plate relative to the superior-inferior direction of the glenoid.

[0007] The presently disclosed convertible orthopedic implant system for shoulder joint replacement that interfaces with an opposing articular surface associated with the humerus may include: a base plate including a plate body that can be configured to be at least partially implanted in or on the glenoid, the plate body extending in a thickness direction between an anterior surface and a posterior surface; and a pad including a pad body extending in a thickness direction between an articulating surface and a bone-contacting surface, the pad body extending a first length in a longitudinal direction between opposing sides of a peripheral wall that establishes a perimeter of the pad body, the articulating surface being dimensioned to interface with the opposing articular surface associated with the humerus. The base plate may be releasably secured to the pad adjacent the bone-contacting surface. The perimeter of the plate body projected onto a reference plane may define a first plate area associated with a first centroid, and the perimeter of the pad body projected onto the reference plane may define a second plate area associated with a second centroid, the pad body being dimensioned such that the second centroid is offset from the first centroid by a first distance in the longitudinal direction.

[0008] A method of installing a convertible orthopedic implant system of the present disclosure to interface with opposing articular surfaces associated with the humerus may include positioning a base plate against a glenoid face of the glenoid, the base plate including a plate body extending in a thickness direction between an anterior surface and a posterior surface, the base plate including one or more plate openings; positioning at least one fastener in a respective one of the plate openings to secure the base plate to the glenoid; and releasably securing a pad to the base plate, the pad including a pad body extending in a thickness direction between an articulating surface and a bone-contacting surface, the pad body extending a first length between opposing sides of a peripheral wall establishing a perimeter of the pad body, the articulating surface being dimensioned to interface with the opposing articular surface associated with the humerus, and the bone-contacting surface may contact bone along the glenoid. The plate body may define a first center of mass, the pad body may define a second center of mass, and the pad body may be dimensioned such that, in response to securing the pad, the second center of mass is offset upwardly from the first center of mass by a first distance relative to an up-down direction of the glenoid.

[0009] A method of installing a convertible orthopedic implant system for interfacing with an opposing articular surface associated with a humerus of the present disclosure may include removing a pad from a base plate at a first position relative to the glenoid, the base plate including a plate body extending in a thickness direction between an anterior surface and a posterior surface, and the pad including a pad body extending in a thickness direction between an articulating surface and a bone-contacting surface. The plate body may define a first center of mass, and the pad body may define a second center of mass, and the pad body may be dimensioned such that the second center of mass is offset upwardly from the first center of mass by a first distance relative to a vertical direction of the first position. Following the step of removing the pad, the method may include securing a glenosphere to the base plate in situ, the glenosphere including an articulating surface having a generally convex shape dimensioned to interface with the humeral implant. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a perspective view of an exemplary implant system including a base plate and a pad in a first configuration. [Figure 2] FIG. 12 is a perspective view of an implant system including a base plate and glenosphere in a second configuration. [Figure 3] FIG. 2 is a cross-sectional view of the implant of FIG. 1. [Figure 4] FIG. 4 is a plan view of selected portions of the implant system of FIG. 3. [Figure 5] FIG. 4 is a cross-sectional view of the base plate and pad of FIG. 3. [Figure 6] FIG. 10 is a cross-sectional view of a baseplate and pad positioned relative to a surgical site. [Figure 7] FIG. 3 is an exploded view of the implant system of FIG. 2. [Figure 8] 1A-1C illustrate an exemplary method of placing an orthopedic implant system at a surgical site. [Figure 9] 1A-1C illustrate an implant system including a base plate and a pad positioned along a surgical site. [Figure 10] FIG. 10 illustrates an implant system including the base plate of FIG. 9 and a glenosphere positioned along the surgical site. [Figure 11] FIG. 10 illustrates an implant system including the base plate of FIG. 9 and a glenosphere positioned along the surgical site. [Figure 12] FIG. 10 illustrates an implant system including the base plate of FIG. 9 and a glenosphere positioned along the surgical site. [Figure 13] FIG. 1 illustrates an implant system in an anatomical shoulder configuration. [Figure 14] FIG. 14 illustrates the implant system of FIG. 13 in a reverse shoulder configuration. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present disclosure relates to orthopedic implant systems and methods for repairing bone defects and restoring joint function. The implant systems described herein may be utilized during arthroplasty procedures or incorporated into shoulder prostheses to restore function in shoulders with progressive cartilage disease. The disclosed implant systems may be utilized in anatomic and reverse shoulder procedures on the same patient, utilizing one or more common components, potentially leading to improved healing. Various components may be offset from one another, such as relative to the superior / inferior (S / I) direction of the glenoid plane, to facilitate subsequent procedures.

[0012] An implant for an anatomical shoulder replacement according to an exemplary aspect of the present disclosure may include a base plate configured to be implanted in or on the glenoid and a pad configured to interface with the humeral or brachial implant, the center of the pad being configured to extend superiorly beyond the center of the base plate relative to the superior-inferior direction of the glenoid.

[0013] In some embodiments, the base plate is circular.

[0014] In some embodiments, the pad is oblong.

[0015] In some embodiments, at least 25% of the area of ​​the pad and / or the length of the pad extends above the base plate in the vertical direction.

[0016] In some embodiments, the center of mass of the base plate is offset below the center of mass of the pad.

[0017] In some embodiments, the glenosphere is removably secured to the base plate.

[0018] In some embodiments, the spacer is dimensioned to establish a lateral and / or angular offset of the glenosphere relative to the baseplate.

[0019] A convertible orthopedic implant system for shoulder replacement for interfacing with an opposing articular surface associated with the humerus according to an exemplary aspect of the present disclosure may include: a base plate including a plate body that may be configured to be at least partially implanted in or on the glenoid, the plate body extending in a thickness direction between an anterior surface and a posterior surface; and a pad including a pad body extending in a thickness direction between an articulating surface and a bone-contacting surface, the pad body extending a first length longitudinally between opposing sides of a peripheral wall establishing a perimeter of the pad body, the articulating surface being dimensioned to interfacing with the opposing articular surface associated with the humerus. The base plate may be releasably secured to the pad adjacent the bone-contacting surface. The perimeter of the plate body projected onto the reference plane may define a first plate area associated with a first centroid, the perimeter of the pad body projected onto the reference plane may define a second plate area associated with a second centroid, and the pad body may be dimensioned such that the second centroid is offset from the first centroid by a first distance in the longitudinal direction.

[0020] In some embodiments, the perimeter of the plate body may be substantially circular and the perimeter of the pad body may be oblong.

[0021] In some embodiments, the pad may have a monolithic structure and may include a non-metallic material, and the plate body may include a metallic material.

[0022] In some embodiments, the offset ratio of the first distance divided by the first length can be at least 1:4, such that the second centroid is offset upward from the first centroid relative to the superior-subordinate direction of the glenoid. The area ratio of the pad area divided by the plate area can be 1.5:1 or greater. The ratio of the maximum width around the periphery of the plate body to the minimum width around the periphery of the pad body can be 0.5:1 or greater.

[0023] In some embodiments, the plate body can include a plurality of peripheral openings configured to receive respective fasteners to secure the base plate to bone. The base plate can include an anchoring stem extending outwardly from the posterior surface of the plate body along a stem axis, the anchoring stem configured to be at least partially inserted into a bone hole to secure the base plate.

[0024] In some embodiments, the first centroid of the plate body can be substantially aligned with the protrusion of the stem shaft.

[0025] In some embodiments, the peripheral openings can be distributed circumferentially around a central opening in the plate body, and the central opening can extend along a protruding portion of the stem shaft. The pad can include first and second pegs extending outward from the bone-contacting surface, the first peg configured to be received in the central opening and the second peg configured to be received in a respective one of the peripheral openings to limit relative rotation between the plate body and the pad body with respect to the stem shaft.

[0026] In some embodiments, the glenosphere may include an articulating surface having a generally convex shape, and the glenosphere may be releasably secured to the baseplate.

[0027] In some embodiments, the glenosphere may include a recess dimensioned to at least partially receive the plate body.

[0028] In some embodiments, the perimeter of the plate body can be dimensioned to cooperate with the perimeter of the recess to establish a Morse taper connection that limits relative movement between the base plate and the glenosphere.

[0029] In some embodiments, the spacer can be configured to interface with the plate body and the glenosphere such that the glenosphere is spaced a predetermined distance from the plate body.

[0030] In some embodiments, the spacer can be dimensioned so that the posterior surface of the glenosphere is angled laterally relative to the anterior surface of the plate body.

[0031] In some embodiments, the plate body may include a plurality of plate openings. The spacer may include one or more pegs configured for insertion into a respective one of the plate openings. The spacer may include one or more spacer openings that substantially align with a respective one of the plate openings such that a respective fastener is insertable through each respective pair of plate and spacer openings and into the glenoid to secure the base plate.

[0032] A method of installing a convertible orthopedic implant system to interface with opposing articular surfaces associated with a humerus according to an exemplary aspect of the present disclosure may include positioning a base plate against a glenoid face of a glenoid, the base plate including a plate body extending in a thickness direction between an anterior surface and a posterior surface, the base plate including one or more plate openings; positioning at least one fastener in a respective one of the plate openings to secure the base plate to the glenoid; and releasably securing a pad to the base plate, the pad including a pad body extending in a thickness direction between an articulating surface and a bone-contacting surface, the pad body extending at a first length between opposing sides of a peripheral wall establishing a perimeter of the pad body, the articulating surface being dimensioned to interface with the opposing articular surface associated with the humerus, and the bone-contacting surface may contact bone along the glenoid. The plate body may define a first center of mass, the pad body may define a second center of mass, and the pad body may be dimensioned such that, in response to securing the pad, the second center of mass is offset upwardly from the first center of mass by a first distance relative to an up-down direction of the glenoid.

[0033] In some embodiments, the anchoring stem can extend outward from the posterior surface of the plate body along the stem axis. The step of positioning the base plate can include forming a recess in the glenoid, positioning at least a portion of the plate body in the recess, and positioning the anchoring stem at least partially in a bone hole extending inward from the recess. The step of securing the pad can include positioning the pad body such that the bone-contacting surface follows the contour of the glenoid surface.

[0034] In some embodiments, securing the pad may occur such that an offset ratio of the first distance divided by the first length is at least 1: 4. The perimeter of the plate body projected onto the reference plane may define a first plate area, and the perimeter of the pad body projected onto the reference plane may define a second plate area, and the area ratio of the pad area divided by the plate area may be 1.5: 1 or greater.

[0035] In some embodiments, the step of securing the pad may occur such that at least 25% of the pad area and at least 25% of the first length of the pad body are offset upwardly from the first center of mass of the plate body in the vertical direction.

[0036] In some embodiments, the area ratio may be 2:1 to 3:1. The glenoid surface may be divided into three equal regions, including an upper region, a middle region, and a lower region in the up-down direction, with the middle region being between the upper and lower regions. The step of positioning the base plate may occur such that a first center of mass of the plate body is located in the lower region. The step of securing the pad may occur such that a second center of mass of the pad body is located in the middle region.

[0037] In some embodiments, the anchoring stem can extend outward from the posterior surface of the plate body along the stem axis, with a first center of mass of the plate body substantially aligned with the protrusion of the stem axis. The step of positioning the base plate can include forming a recess in the glenoid, positioning at least a portion of the plate body in the recess, and at least partially positioning the anchoring stem in a bone hole extending inward from the recess such that the stem axis is positioned in the inferior region. The step of securing the pad can include positioning the pad body such that the bone-contacting surface follows the contour of the glenoid surface.

[0038] In some embodiments, the method can include removing the pad from the base plate following the step of securing the pad, and securing a glenosphere to the base plate in situ following the step of removing the pad. The glenosphere can include an articulating surface having a generally convex shape dimensioned to interface with the humeral implant.

[0039] In some embodiments, the method may include securing a spacer between the base plate and the glenosphere such that the glenosphere is spaced outward from the plate body by a predetermined distance relative to the lateral-medial direction of the glenoid.

[0040] In some embodiments, the spacer can be dimensioned such that, in response to securing the spacer, the posterior surface of the glenosphere is angled laterally relative to the anterior surface of the plate body.

[0041] A method of installing a convertible orthopedic implant system for interfacing with an opposing articular surface associated with a humerus according to an exemplary aspect of the present disclosure may include removing a pad from a base plate at a first position relative to the glenoid, the base plate including a plate body extending in a thickness direction between an anterior surface and a posterior surface, and the pad including a pad body extending in a thickness direction between an articulating surface and a bone-contacting surface. The plate body may define a first center of mass, and the pad body may define a second center of mass, and the pad body may be dimensioned such that the second center of mass is offset upwardly from the first center of mass by a first distance relative to a vertical direction of the first position. Following the step of removing the pad, the method may include securing a glenosphere to the base plate in situ, the glenosphere including an articulating surface having a generally convex shape dimensioned to interface with the humeral implant.

[0042] In some embodiments, the method may include securing a spacer between the base plate and the glenosphere such that the glenosphere is spaced outward from the plate body by a predetermined distance relative to the lateral-medial direction of the glenoid.

[0043] In some embodiments, the spacer can be dimensioned such that, in response to securing the spacer, the posterior surface of the glenosphere is angled laterally relative to the anterior surface of the plate body.

[0044] 1 and 2 illustrate an exemplary convertible orthopedic implant system 20. The system 20 can be utilized for various surgical procedures, such as arthroplasty procedures, to restore joint function. For example, the system 20 can be incorporated into a shoulder prosthesis and utilized to repair the articular surface along the glenoid in a shoulder replacement procedure. The implant system 20 can be convertible and utilized in both anatomic and reverse shoulder replacement procedures in the same patient. While the systems and methods disclosed herein primarily refer to anatomic and reverse shoulder reconstructions, the disclosed system can also be utilized to restore functionality elsewhere in the patient, such as the knee and hip.

[0045] Implant system 20 is convertible between a first configuration and a second configuration. The first configuration may correspond to an anatomical shoulder replacement procedure or configuration, and the second configuration may correspond to a reverse shoulder replacement procedure or configuration, or vice versa. For example, the configuration of system 20 in FIG. 1 may correspond to the first configuration, and the configuration of system 20 in FIG. 2 may correspond to the second configuration.

[0046] 1 and 2, the system 20 includes a base plate 22, a pad 24 (e.g., a bearing member), and a glenosphere 26. The pad 24 is removably secured to the base plate 22 to establish a first implant, as shown in FIG. 1. The glenosphere 26 is removably secured to the base plate 22 to establish a second, different implant, as shown in FIG. 2. The base plate 22 can be common to both the pad 24 and the glenosphere 26. The common base plate 22 can be positioned along a surgical site during a first surgical procedure and can remain in the same position along the surgical site during a second, subsequent surgical procedure, which can improve healing.

[0047] 1 and with reference to FIG. 3, base plate 22 includes a plate body 28 configured to mount pad 24. Plate body 28 may be configured to be at least partially embedded on or within an articular surface AS (shown with dashed lines in FIG. 3 for illustrative purposes) of a surgical site S, or plate body 28 may be configured to rest on the articular surface AS. In some implementations, surgical site S may be a glenoid or another facet joint of a patient.

[0048] The plate body 28 extends in a thickness direction T between an anterior surface 30 and a posterior surface 32 opposite the anterior surface 30. The posterior surface 32 may be configured to contact bone in an installed position. The posterior surface 32 may generally correspond to the medial side of the patient, and the anterior surface 30 may generally correspond to the lateral side of the patient, for example, when implanted at a surgical site. In some implementations, the plate body 28 has a thickness of about 2.0 millimeters (mm) to about 6.0 mm, e.g., about 4.5 mm.

[0049] A peripheral wall 34 extends in a thickness direction T between the anterior surface 30 and the posterior surface 32 to establish a plate perimeter 36 of the plate body 28. The plate perimeter 36 is dimensioned to surround the anterior surface 30 and the posterior surface 32. The plate perimeter 36 can have a variety of shapes. In some implementations, the plate perimeter 36 has a substantially circular or elliptical shape, as shown in FIG. 4 . For purposes of this disclosure, the terms “about,” “approximately,” and “substantially” mean ±5% of the stated value or relationship, unless otherwise indicated. A generally circular shape may reduce reaming width and the complexity of preparing a surgical site to accept the base plate 22.

[0050] The base plate 22 may include at least one protrusion 38 (e.g., a post or keel) configured to be embedded in bone to secure the base plate 22. The protrusions 38 may be anchoring stems extending outward from the posterior surface 32 of the plate body 28 along respective stem axes SA. The anchoring stems 38 may have a generally cylindrical shape. The anchoring stems 38 may be configured to be at least partially inserted into a bone hole or recess to secure the base plate 22 along the surgical site S. The stem axis SA may establish a central axis of the base plate 22. The anchoring stem 38 may be integrally formed with the plate body 28 or may be a separate, distinct component mechanically attached or otherwise secured to the plate body 28. In some implementations, the anchoring stem 38 has a diameter of about 8 mm to about 10 mm and a length of about 10 mm to about 20 mm, e.g., about 15 mm.

[0051] The plate body 28 may include a plurality of plate openings 40, as shown in FIGS. 3 and 4. The plate openings 40 may be sized to extend from the anterior surface 30 to the posterior surface 32 of the plate body 28 to establish respective passageways. The plate perimeter 36 is sized to surround the plate openings 40. The plate openings 40 may include a central opening 40C and a plurality of peripheral openings 40P. The central opening 40C may extend along the protrusion of the stem axis SA. The peripheral openings 40P may be distributed circumferentially around the central opening 40C and the stem axis SA. The plate body 28 may define four peripheral openings 40P distributed circumferentially around the stem axis SA, as shown in FIG. 4. Of course, fewer or more than four peripheral openings 40P, such as only one peripheral opening 40P, may be utilized.

[0052] Each peripheral opening 40P may be configured to receive a respective fastener F (fasteners F shown in dashed lines in FIGS. 3 and 4 for illustrative purposes) to affix or otherwise secure base plate 22 to bone along surgical site S. Fasteners F may include anchors or compression screws. Openings 40 may be countersunk to allow the heads of fasteners F to be flush with or recessed within base plate 22.

[0053] The pad 24 includes a pad body 42 extending in a thickness direction T between an articulating surface 44 and a bone-contacting surface 46 opposite the articulating surface 44. The base plate 22 may be removably secured to the pad 24 adjacent the bone-contacting surface 46, as shown in FIG. 3. The plate body may be fully or partially embedded within the articular surface AS along the surgical site S. The pad body 42 may be embedded on top of the articular surface AS or may be embedded (partially or fully) within the articular surface AS.

[0054] Articulating surface 44 may have a generally concave shape sized to mate with an opposing articular surface, which may be associated with the humerus, as shown by articular surface AS-1 (FIG. 9). Articular surface AS-1 may be a portion of the humerus or a humeral implant, or an articular surface of another joint.

[0055] The bone-contacting surface 46 may have a generally convex shape sized to substantially follow the contour of the surgical site S, such as the articular surface contour along the glenoid. The bone-contacting surface 46 may have other shapes, such as a substantially planar shape.

[0056] A peripheral wall 48 of the pad 24 extends in a thickness direction T between the articulating surface 44 and the bone-contacting surface 46 to establish a pad perimeter 50 of the pad body 42. The pad perimeter 50 is dimensioned to surround the articulating surface 44 and the bone-contacting surface 46. The pad perimeter 50 can have a variety of shapes. The shape of the pad perimeter 50 can be the same or different from the plate perimeter 36. In some implementations, the pad perimeter 50 and the plate perimeter 36 can both have substantially elliptical shapes. The pad perimeter 50 can be generally rectangular or elliptical, as shown in FIG. 5, such that a maximum distance of the pad body 42 across the pad perimeter 50 is established in the length direction L. The distance of the pad perimeter 50 can be greater than the distance of the plate perimeter 36, as shown in FIG. 5, such that the pad perimeter 50 substantially surrounds the plate perimeter 36.

[0057] The pad 24 may include one or more orientation pegs 52 sized to constrain the orientation of the pad 24 relative to the base plate 22. Each peg 52 may extend outward from the bone-contacting surface 46, as shown in FIG. 3. The pegs 52 may include a central (e.g., first) peg 52C and a peripheral (e.g., second) peg 52P (shown in FIG. 3 and in dashed lines in FIG. 4 for illustrative purposes).

[0058] The central peg 52C may be configured to be at least partially received in the central opening 40C. The peripheral pegs 52P may be configured to be at least partially received in a respective one of the peripheral openings 40P, as shown in FIGS. 3 and 4 . The central peg 52C and the peripheral pegs 52P may be dimensioned to have a shape that substantially complements the respective central opening 40C and peripheral opening 40P. The orientation pegs 52 may be dimensioned to limit relative rotation between the plate body 28 and the pad body 42 about the stem axis SA when in the installed position, which may improve alignment of the articulating surface 44 of the pad 24 to a predetermined position along the surgical site S. In some implementations, the peripheral pegs 52P are omitted or dimensioned so that another fastener F is positioned in each peripheral opening 40P.

[0059] The pad 24 may include at least one protrusion 54 for securing the pad 24 along the surgical site S. The protrusion 54 may be a grooved anchoring peg. The anchoring peg 54 may extend outward from the bone-contacting surface 46 along a peg axis PA. The anchoring peg 54 may include one or more ribs 55 extending outward from the periphery of the anchoring peg 54. The ribs 55 may be at least partially deformable to secure the anchoring peg 54 within a respective bone hole.

[0060] The anchoring pegs 54 may be offset in the longitudinal direction L, as shown in FIG. 3, or may otherwise be spaced apart from the base plate 22 in a mounted position. The offset arrangement of the anchoring stems 38 and anchoring pegs 54 may provide a relatively large fixation area that may improve stability of the pad 24 along the surgical site S.

[0061] Various techniques may be utilized to removably secure or attach the pad 24 to the base plate 22. The pad body 42 may define a recess 56 extending inwardly from the bone-contacting surface 46 (also shown by dashed lines in FIG. 4 for illustrative purposes). The recess 56 may be dimensioned to extend partially through the thickness of the pad body 42 and may be dimensioned to at least partially receive the plate body 28, as shown in FIG. 3. The height of the recess 56 may be from about 0.5 mm to about 2.0 mm, such as, for example, about 1.5 mm.

[0062] The recess perimeter 57 of the recess 56 and the plate perimeter 36 of the plate body 28 may have complementary shapes, as shown in Figures 3-5. The plate perimeter 36 may be dimensioned to cooperate with the recess perimeter 57 to establish a Morse taper connection that limits relative movement between the base plate 22 and the pad 24. The pad 24 may be fitted onto the base plate 22 such that the Morse taper connection establishes an interference fit to secure the pad 24 at the surgical site S.

[0063] Continuing with reference to FIG. 3, and with reference to FIG. 5, the pad body 42 may extend a first length L1 in the longitudinal direction L and a first width W1 in the widthwise direction W between opposing sides of the peripheral wall 48. The first length L1 and first width W1 may respectively establish a maximum length and a maximum width of the pad body 42 between opposing sides of the peripheral wall 48 that establish the perimeter 50, as shown in FIG. 5. In some implementations, the first width W1 is about 24 mm or greater, such as about 33 mm to about 42 mm.

[0064] The plate body 28 may extend a second length L2 in the longitudinal direction L and a second width W2 in the widthwise direction W between opposing sides of the peripheral wall 34. The second length L2 and second width W2 may respectively establish a maximum length and a maximum width of the plate body 28 between opposing sides of the peripheral wall 34 that establish the plate perimeter 36, as shown in FIG. 5 . The plate perimeter 36 may be substantially circular such that the second length L2 and the second width W2 are substantially equal. In some implementations, the second length L2 and / or the second width W2 is greater than or equal to about 20.0 mm, or more narrowly, between about 22.0 mm and about 32.0 mm, e.g., about 24.0 mm.

[0065] The pad 24 may be configured to extend beyond the perimeter 36 of the base plate 22. The base plate 22 and the pad 24 may be dimensioned such that the first width W1 is greater than the second width W2 and / or the first length L1 is greater than the second length L2. The base plate 22 and the pad 24 may be dimensioned such that the ratio of the second width W2 to the first width W1 is about 0.5:1 or greater, or more narrowly, about 0.8:1 or greater.

[0066] The base plate 22 and pad 24 may be positioned in various orientations relative to the patient's anatomy. The longitudinal direction L may correspond to, or have a major component therein, the superior / inferior (S / I) direction in the installed position. The width direction W may correspond to, or have a major component therein, the posterior / inferior (P / I) direction of the patient when the system 20 is in the installed position. The thickness direction T may correspond to, or have a major component therein, the lateral / medial (L / M) direction of the patient when the system 20 is in the installed position.

[0067] The system 20 may be dimensioned such that the base plate 22 and pad 24 establish an offset arrangement, which may facilitate conversion of the system 20 between an anatomical shoulder configuration and a reverse shoulder configuration. The center of the pad 24 may be configured to extend superiorly beyond the center of the base plate 22 relative to the glenoid S / I direction. A portion of the pad body 42 may be configured to extend superiorly beyond the plate body 28 relative to the glenoid S / I direction. Various parameters of the offset arrangements disclosed herein may be selected by the surgeon before and / or during an anatomical shoulder procedure to establish the anatomical shoulder configuration in a manner that facilitates reconfiguration of the system 20 during a subsequent surgical procedure to modify the reverse shoulder configuration. Parameter selection during the initial procedure may reduce surgical site changes in subsequent procedures, which may improve patient healing. The offset arrangement of the base plate 22 and pad 24 in the anatomical shoulder configuration may differ from the reverse shoulder configuration of the system 20, in which the glenosphere 26 may extend relatively more outward from the glenoid G and may be supported more perpendicularly by the base plate 22.

[0068] The plate perimeter 36 may be projected onto a reference plane REF to establish a plate area AP1, and the pad perimeter 50 may be projected onto the reference plane REF to establish a pad area AP2 (REF, AP1, and AP2 shown by dashed lines for illustrative purposes). The reference plane REF may extend in a length direction L and a width direction W. The plate area A1 and the pad area AP2 may be associated with respective maximum lengths L1, L2 and maximum widths W1, W2. The plate body 28 and the pad body 42 may be dimensioned such that the area ratio AP2:AP1 of the pad area AP2 divided by the plate area AP1 is about 1.5:1 or greater. The area ratio AP2:AP1 may be about 4:1 or less, such as between about 2:1 and about 3:1.

[0069] The plate area AP1 of the plate body 28 may define a first centroid C1 along the reference plane REF. The first centroid C1 may be substantially aligned or concentric with the protrusion of the stem axis SA, as shown in FIG. 5 . The pad area AP2 of the pad body 42 may define a second centroid C2 along the reference plane REF. The pad body 42 may be dimensioned such that the second centroid C2 is offset from the first centroid C1 by a first distance D1 in the longitudinal direction L, as shown in FIG. 5 . The first distance D1 may be defined in the S / I direction. The first distance D1 may be approximately 1 mm, 3 mm, or greater. The first distance D1 may be approximately 5 mm, 8 mm, or 10 mm, or greater.

[0070] The base plate 22 and the pad 24 may be configured to establish an offset ratio D1:L1, defined as the first distance D1 divided by the first length L1. The offset ratio D1:L1 may be approximately 1:4 or greater, or more narrowly approximately 1:3 or approximately 1:2 or greater. The offset ratio D1:L1 may be established such that the second centroid C2 is offset upward from the first centroid C1 in the S / I direction, as shown in FIG. 6. The offset ratio D1:L1 may be established such that the second centroid C2 is surrounded by the perimeter 36 of the plate body 28, as shown in FIG. 5. In some implementations, the offset ratio D1:L1 is established such that the second centroid C2 is positioned outside the perimeter 36 of the plate body 28, as shown by the second centroid C2′ in FIG. 5.

[0071] Continuing with reference to FIG. 5 and with reference to FIG. 6, the glenoid surface GF of the glenoid G can be divided into three substantially equal regions R1-R3, including an upper region R1, a middle region R2, and an lower region R3, relative to the S / I direction. The middle region R2 is established between the upper region R1 and the lower region R3. The upper region R1 can extend from the superior glenoid node TS of the glenoid G, and the lower region R3 can extend from the inferior glenoid node TI of the glenoid G.

[0072] The offset configuration of the base plate 22 and the pad 24 may be established relative to the centers of mass of the plate body 28 and the pad body 42. The plate body 28 may define a first center of mass M1. A plate area AP1 may be associated with the first center of mass M1. The pad body 42 may define a second center of mass M2. A pad area AP2 may be associated with the second center of mass M2.

[0073] The pad body 42 may be dimensioned such that the second center of mass M2 is offset upward from the first center of mass M1 by a first distance D1 relative to the S / I direction of the installed position, as shown in FIG. 6 . The first center of mass M1 may substantially coincide with the first centroid C1, and the second center of mass M2 may substantially coincide with the second centroid C2, as shown in FIGS. 5 and 6 . In some implementations, the second center of mass M2 is positioned outside the perimeter 36 of the plate body 28, as shown by the second center of mass M2′ in FIG. 5 . The second center of mass M2′ may substantially coincide with the second centroid C2′, as shown in FIG. 5 . In other implementations, the first and / or second centroids C1, C2, C2′ are offset from their respective centers of mass M1, M2, M2′. The centers of mass M1, M2 exclude protrusions extending outward from the respective plate and pad bodies 42, such as the anchoring stems 38 of the base plate 22 and the pegs 52, 54 of the pad 24.

[0074] With continued reference to FIG. 2 and with reference to FIG. 7, system 20 may include at least one glenosphere 26. Glenosphere 26 includes an articulating surface 58 and a posterior surface 60 opposite articulating surface 58. Articulating surface 58 may have a generally convex shape.

[0075] The glenosphere 26 may be sized to selectively mate with the base plate 22 either directly, as shown in Figure 12, or indirectly via a spacer 66 (e.g., a tapered adapter), as shown in Figure 10. The choice of spacer 66 may provide the surgeon with different options for laterally or otherwise positioning the glenosphere 26 relative to the surgical site.

[0076] Various techniques may be utilized to removably fasten or attach the glenosphere 26 directly or indirectly to the base plate 22. The glenosphere 26 may include a recess 62 extending inwardly from a rear surface 60. The recess 62 may be dimensioned to at least partially receive the plate body 28, as shown in FIG. 12 . The plate perimeter 36 may be dimensioned to cooperate with a perimeter 64 of the recess 62 to establish a Morse taper connection that limits relative movement between the base plate 22 and the glenosphere 26. During assembly, the glenosphere 26 may be impacted onto the plate body 28 to establish the Morse taper connection.

[0077] Each spacer 66 includes a spacer body 68 extending in a thickness direction T between a front surface 70 and a rear surface 72 opposite the front surface 70. The front surface 70 may be sized to abut the glenosphere 26, and the rear surface 72 may be sized to abut the base plate 22. A peripheral wall 73 extends in the thickness direction T between the front surface 70 and the rear surface 72 and establishes a spacer perimeter 75. The spacer perimeter 75 may be sized to surround the front surface 70 and the rear surface 72. The spacer perimeter 75 may have a variety of geometries, such as a substantially circular or elliptical geometry, that complement the geometry of the recess 62. In some implementations, the recess 56 in the pad body 42 and / or the recess 64 in the glenosphere 26 are omitted, and / or an opposite configuration is established in which the respective recesses are established in the plate body 28 to receive a portion of the pad body 28 and / or the respective recesses are established in the spacer body 68 to receive a portion of the glenosphere 26 to secure the respective components.

[0078] Each spacer 66 may be sized to interface with the plate body 28 and the glenosphere 26 such that the glenosphere 26 is offset or spaced from the plate body 28 by a predetermined distance D2 ( FIG. 10 ). The predetermined distance D2 may correspond to the thickness of the spacer 66 and may extend in the L / M direction of the glenoid. The implant system 20 may include multiple spacers 66 having different thicknesses, thereby providing a range of lateral offsets corresponding to different predetermined distances D2. The predetermined distance D2 may be in various increments, such as, for example, approximately 0 mm, 2 mm, 4 mm, and 6 mm.

[0079] The spacer 66 may include one or more spacer pegs 74 extending outward from the spacer body 68. The spacer pegs 74 may be configured for insertion into the respective plate openings 40 of the base plate 22. The spacer pegs 74 may include a central spacer peg 74C that is at least partially insertable into the central opening 40C of the base plate 22. The spacer pegs 74 may include at least one peripheral spacer peg 74P that is at least partially insertable into a respective one of the peripheral openings 40P of the base plate 22. The peripheral spacer pegs 74P may be offset from the central spacer peg 74C such that insertion of the spacer pegs 74C, 74P into their respective openings 40C, 40P limits relative rotation between the base plate 22 and the spacer 66 in the installed position. In some implementations, the peripheral spacer pegs 74P are omitted or are dimensioned so that separate fasteners F are positioned within the respective peripheral openings 40P.

[0080] The spacer 66 may include one or more spacer openings 76, each sized to substantially align with a respective plate opening 40, such that a fastener F can be inserted through a respective pair of plate openings and spacer openings 40, 76 and into the bone B along the glenoid G to secure the base plate 22, as shown in Figure 10. The openings 76 may be countersunk to allow the head of the fastener F to be flush with or recessed within the spacer 66.

[0081] The system 20 may include multiple spacers 66, 166 that establish different orientations between the base plate 22 and the glenosphere 26, as shown in Figures 10 and 11. The system 20 may include at least one spacer 66 having a front surface 70 that is substantially parallel to a rear surface 72, such that the rear surface 60 of the glenosphere 26 is substantially parallel to the front surface 30 of the base plate 22 in the installed position, as shown in Figure 10.

[0082] The system 20 can include at least one spacer 166 having an anterior surface 170 lateral to the posterior surface 172 such that the posterior surface 60 of the glenosphere 26 is lateral to the anterior surface 30 of the base plate 22 in the installed position, as shown in FIG. 11 . The anterior surface 170 is disposed lateral to the posterior surface 172 of the spacer 166, establishing an angle α. The angle α can be, for example, greater than about 5 degrees, or more narrowly, between about 10 degrees and about 45 degrees. The spacers 66, 166 disclosed herein can be utilized to position and / or orient the glenosphere 26 more closely to the articulating surface of the humeral implant in a reverse shoulder procedure, which can improve joint mobility.

[0083] Various materials can be utilized to form the components of the system 20. The materials of the base plate 22, pad 24, spacers 66, 166, and glenospheres 26 can be the same or different and can include metallic materials, such as surgical-grade metals and metal alloys, non-metallic materials, and combinations thereof. One or more coatings or layers 78 can be deposited along the surface of the base plate 22 (shown by dashed lines in FIG. 3 for illustrative purposes). An exemplary coating 78 can include calcium phosphate (CaP) or a biomaterial for promoting bone ingrowth. In some implementations, one or more surfaces of the base plate 22 are textured or have a porous structure to promote bone ingrowth into the base plate 22. The pad 24 can be formed of a non-metallic material, such as polyethylene, nylon, or a ceramic compound. Each of the components of the system 20 can have a monolithic structure or can each include multiple separate and distinct components.

[0084] FIG. 8 illustrates a method for installing a convertible orthopedic implant system in a flowchart 280. Method 280 may be utilized, for example, to perform arthroplasty to restore function in a shoulder with progressive cartilage disease. Method 280 may be utilized with any of the orthopedic implants and implant systems disclosed herein, including implant system 20, 120. Method 280 may include one or more steps for converting implant system 20, 120 between a first configuration and a second configuration. The first configuration may correspond to an anatomical shoulder procedure or placement, and the second configuration may correspond to a reverse shoulder procedure or placement, or vice versa. Steps 280I-280K may be performed in an anatomical shoulder procedure, and steps 280L-280R may be performed in a reverse shoulder procedure, for example. Fewer or additional steps than those listed below may be performed within the scope of this disclosure, and the order of the listed steps is not intended to limit this disclosure.

[0085] The disclosed implant system can be provided to a surgeon as a kit, which can include one or more base plates, pads, glenospheres, and spacers of various shapes and sizes. Specific components can be selected from the kit according to the patient's anatomy.

[0086] With continuing reference to FIG. 8 and with reference to FIG. 9, a surgical site S may be prepared at step 280A. One or more operations may be performed to prepare the surgical site S, such as one or more of reaming, milling, and drilling, to configure a desired shape of the surgical site S. Step 280A may include forming a recess R by removing tissue, such as bone B, along the surgical site S at step 280B.

[0087] The recess R may be formed in an articular surface of the joint, such as the glenoid surface GF. Step 280A may include forming one or more bone holes H in step 280C. Each bone hole H may extend inward from the recess R or the glenoid surface GF. In implementations, step 280A may include provisionally positioning trial base plate 22 and / or pad 24 along surgical site S to select the location and / or orientation of the recess R and bone holes H that will be subsequently formed by removing a portion of bone B in steps 280B, 280C.

[0088] In step 280D, the base plate 22 may be positioned along the surgical site S, such as along the glenoid plane GF. Step 280D may include moving the base plate 22 in direction D3 and positioning the plate body 28 at least partially within the recess R in step 280E. In other implementations, step 280D may include positioning the plate body 28 to sit on its outer surface along the glenoid plane GF. Step 280D may include positioning the anchoring stems 38 of the base plate 22 at least partially in the respective bone holes H in step 280F. Step 280F may occur such that the stem axis SA is positioned in the inferior region R3 of the glenoid G. A lower location of the base plate 22 on the glenoid G and a shape of the pad 24 to extend above the base plate 22 in the S / I direction may provide a more suitable location of the base plate 22 for subsequent attachment of the glenosphere without affecting the positioning of the pad 24 relative to the opposing articular surface AS-1 ( FIG. 9 ). A smaller area of ​​the glenoid G may be used for fixation of the base plate 22, and the bone contact surface 46 of the pad 24 may be configured to abut against the glenoid surface GF or another surface of the glenoid G to maintain security of the pad 24 along the surgical site.

[0089] At step 280G, the base plate 22 may be secured to the surgical site S. Step 280G may include, for example, positioning one or more fasteners F within each plate opening 40 to secure the base plate 22 to the bone along the glenoid G. The fasteners F may be compression screws that may create and maintain compression between the base plate 22 and the bone, reducing relative movement and reducing tissue buildup that may otherwise occur due to spacing between the base plate 22 and the bone contact surface.

[0090] In step 280I, the pad 24 is removably secured or attached to the base plate 22. Step 280I may include positioning the pad 24 relative to the base plate 22 and the glenoid G in response to moving the pad 24 in direction D3 in step 280J. The pad 24 may be impacted onto the base plate 22 to establish an interference fit via a Morse taper connection. Step 280J may occur such that the bone-contacting surface 46 of the pad 24 contacts bone along the glenoid G adjacent the glenoid face GF, such that the bone-contacting surface 46 substantially follows the contour of the glenoid face GF. Step 280I may occur such that relative movement between the plate body 28 and the pad body 42 is limited in at least the S / I direction of the glenoid G.

[0091] The pad body 42 can be positioned at different depths relative to the articular surface, such as the glenoid surface GF. In some implementations, the pad 24 is positioned in an overlay position such that the pad body 42 rests on the glenoid surface GF and the bone-contacting surface 46 follows the contours of the glenoid surface GF, as shown in FIG. 9 . In other implementations, positioning the pad 24 in step 280J includes at least partially or completely fitting the pad body 42 into the recess R′ along the glenoid surface GF, as indicated by the glenoid surfaces GF′ and GF″, respectively.

[0092] Step 280I may include positioning one or more orientation pegs 52 of pad 24, such as central peg 52C and peripheral pegs 52P, within respective plate openings 40 of base plate 22. Positioning pegs 52 in step 280I may limit relative rotation between base plate 22 and pad 24.

[0093] Positioning the base plate 22 in step 280D can occur such that the anchoring stem 38 is located in the inferior region R3 and the first centroid C1 and / or first center of mass M1 of the plate body 28 is located in the inferior region R3 and / or substantially aligned with the protrusion of the stem axis SA, as shown in Figures 6 and 9. Securing the pad 24 in step 280I can occur such that the second centroid C2 and / or second center of mass M2 of the pad body 42 is located in the intermediate region R2, as shown in Figures 6 and 9. The centers of mass M1, M2, and / or the anchoring stem 38 can be located below the superior glenoid node TS and above the inferior glenoid node TI of the glenoid G, as shown in Figure 6.

[0094] The pad 24 may be secured to the base plate 22 in step 280I such that, when in the first position, the anchoring peg 54 and / or the second center of mass M2 of the pad 24 are offset upward from the first center of mass M1 of the base plate 22 by a first distance D1 relative to the S / I direction of the glenoid G, as shown in FIG. 9 . The first center of mass M1 may be offset downward from the second center of mass M2 relative to the S / I direction in the first position. The pad 24 may be secured to the base plate 22 in step 280I such that the first and second centers of mass M1, M2 are located in different regions R1-R3. For example, the first center of mass M1 may be located along the lower region R3, and the second center of mass M2 may be located along the middle region R2, as shown in FIG. 9 .

[0095] Base plate 22 and pad 24 may be arranged to establish a first distance D1 according to any of the offset ratios disclosed herein. Securing pad 24 in step 280I may occur such that at least 25% of pad area AP2 and / or at least 25% of first length L1 (FIG. 5) of pad body 42 is offset upwardly in the S / I direction from the first center of mass M1, as shown in FIG.

[0096] At step 280L, pad 24 may be removed from base plate 22 at a first position relative to surgical site S, such as glenoid G, which may occur after securing the pad at step 280I. One or more of fasteners F may be removed from base plate 22 at step 280M. One or more portions of base plate 22 may include a porous structure and / or coating 78 ( FIG. 3 ) to promote bone ingrowth. Bone ingrowth may facilitate base plate 22 remaining attached to bone B along recesses R after fasteners F are removed.

[0097] With continuing reference to FIG. 8 and with reference to FIG. 10 , the spacer 66 may be positioned relative to the base plate 22 in step 280N. The spacer 66 may be selected to provide a predetermined lateral orientation and / or angular offset from the base plate 22. Spacer pegs 74C, 74P may be positioned within respective ones of the central and peripheral openings 40C, 40P to limit relative rotation between the base plate 22 and the spacer 66. Step 280N may include positioning the spacer 166 relative to the base plate 22 so that the front surface 170 of the spacer 166 is disposed laterally relative to the rear surface 172 of the spacer 166 to establish an angle α, as shown in FIG. 11 . The angle α may include any of the values ​​disclosed herein. The selected spacer 66, 166 may be impacted onto the base plate 22 to establish an interference fit via a Morse taper connection.

[0098] At step 280P, spacer 66 may be secured to base plate 22 with one or more fasteners F (shown for illustrative purposes). At step 280Q, one or more fasteners F may be positioned in each pair of plate openings 40 and spacer openings 76 to secure spacer 66 and base plate 22 to surgical site S.

[0099] In step 280R, the glenosphere 26 is secured to the base plate 22, which may occur after removing the pad 24 in step 280L. The articulating surface 58 of the glenosphere 26 may have a generally convex shape sized to interface with an opposing articular surface. The opposing articular surface may be associated with the humerus, as illustrated by articular surface AS-2 (shown in dashed lines in FIGS. 10-12 for illustrative purposes). Articular surface AS-2 may have a generally concave shape that complements the shape of the articulating surface 58 of the glenosphere 26. Articular surface AS-2 may be a portion of the humerus or a humeral implant, or an articular surface of another joint. The articular surfaces AS-1 and AS-2 in FIGS. 3 and 10-12 may be the same or different.

[0100] The selected spacer 66 may be secured between the base plate 22 and the glenosphere 26 such that the glenosphere 26 is laterally spaced from the base plate 22 by a predetermined distance D2 relative to the L / M direction of the glenosphere G, as shown in FIG. 10. The selected spacer 166 may be positioned on the step 280N and secured to the step 280R such that the rear surface 60 of the glenosphere 26 is oriented laterally relative to the front surface 30 of the base plate 22, as shown in FIG. 11. The spacer 166 may be dimensioned such that the portion of the glenosphere 126 defining the recess 62 is spaced from the base plate 22 by at least the minimum thickness of the spacer body 168. The glenosphere 26 may be impacted onto the selected spacer 66, 166 to establish an interference fit via a Morse taper connection.

[0101] Step 280R may include preparing the surgical site S before positioning the glenosphere 26. In some implementations in which the pad 24 is at least partially or completely inlaid into the glenoid surface GF' / GF" a material M may be placed in each recess R' after removing the pad 24 in step 280L (for illustrative purposes, M is shown with a dashed line in FIG. 10). The material M may be, for example, bone graft or bone slurry. The material M may be substantially flush with the adjacent glenoid surface GF' / GF".

[0102] 13 shows a system 220 including a base plate 222 and a pad 224 positioned relative to a surgical site S. The surgical site S may be a shoulder joint, including a glenoid G and a humerus H. The pad 224 may cooperate with an articular surface AS of the humeral head HH of the humerus H.

[0103] 14 illustrates a system 220 including a glenosphere 226 and a spacer 366 secured to a base plate 222 adjacent a surgical site S. The glenosphere 226 cooperates with a humeral implant HI located adjacent the humeral head HH. A portion HP of the humeral head HH can be resected by performing an osteotomy (HP is shown by a dashed line in FIG. 14 for illustrative purposes).

[0104] The novel implant systems and methods disclosed herein may provide versatility in restoring function to the joint. Various components of the implant system disclosed herein, such as a common base plate utilized in both anatomical and reverse shoulder procedures for the same patient, may remain in place during subsequent arthroplasty procedures, improving healing and reducing the number of parts. Utilizing the techniques disclosed herein, offsetting the pad relative to the base plate may facilitate later surgical revision from an anatomical shoulder configuration to a reverse shoulder configuration, which may become more appropriate as the patient's glenohumeral joint disease progresses. The disclosed offset technique may provide a more appropriate position for the common base plate reused in the reverse shoulder configuration. While a smaller area of ​​the glenoid may be used for base plate fixation, abutting the bone-contacting surface of the pad outward of the base plate may improve stabilization of the pad along the glenoid. The attached glenosphere may be better positioned to avoid scapular notching during glenoid preparation.

[0105] Although different non-limiting embodiments are illustrated as having particular components or steps, embodiments of the present disclosure are not limited to those particular combinations. Some of the components or features from any of the non-limiting embodiments can be used in combination with features or components from any of the other non-limiting embodiments.

[0106] It should be understood that like reference numerals identify corresponding or similar elements throughout the several views. While particular component arrangements are disclosed and illustrated in these exemplary embodiments, it should be further understood that other arrangements can also benefit from the teachings of the present disclosure.

[0107] The foregoing description is illustrative and is not to be construed in any limiting sense. Those skilled in the art will recognize that certain modifications would be possible within the scope of the present disclosure. [Explanation of symbols]

[0108] 20 Implant System 22 Base Plate 24 pads 26 Glenosphere 28 Plate body 30 front 32 Rear 34 Perimeter Wall 36 Perimeter 38 Protrusion 40 aperture 42 Pad body 44 Articulating Surfaces 46 Bone contact surface 48 Perimeter Wall 50 perimeter 52 Orientation Pegs 54 Protrusion 55 Ribs 56 Recess 57 Around the recess 58 Articulating Surfaces 60 Rear 62 recess 64 Perimeter 64 recess 66 Spacer 68 Spacer body 70 front 72 Rear 73 Perimeter Wall 74 spacer peg 75 Spacer circumference 76 Spacer opening 78 layers, coating 120 Implant System 126 Glenosphere 166 Spacer 168 Spacer body 170 Front 172 Rear 220 System 222 base plate 224 Pad 226 Glenosphere 366 Spacer

Claims

1. 1. An implant for an anatomical shoulder replacement, said implant comprising: a base plate configured to be implanted in or on the glenoid; a pad configured to interface with a humerus or humeral implant, the pad being configured such that the center of the pad extends upward beyond the center of the base plate relative to the superior-inferior direction of the glenoid; Equipped with An implant wherein the base plate is circular, the pad is oblong, and at least 25% of the area and / or length of the pad extends above the base plate in the vertical direction.

2. The implant of claim 1 , wherein the center of mass of the base plate is offset below the center of mass of the pad.

3. The implant of claim 1 further comprising a glenosphere removably secured to the base plate.

4. The implant of claim 3 , further comprising a spacer dimensioned to establish a lateral and / or angular offset of the glenosphere relative to the base plate.

5. 1. A convertible orthopaedic implant system for shoulder joint replacement that interfaces with an opposing articular surface associated with a humerus, comprising: a base plate including a plate body configured to be at least partially embedded in or on the glenoid, the plate body extending in a thickness direction between an anterior surface and a posterior surface; a pad including a pad body extending in the thickness direction between an articulating surface and a bone-contacting surface, the pad body extending a first length in the longitudinal direction between opposing sides of a peripheral wall establishing a perimeter of the pad body, the articulating surface being dimensioned to interface with the opposing articular surface associated with the humerus; Equipped with the base plate is releasably secured to the pad adjacent the bone-contacting surface; a perimeter of the plate body projected onto a reference plane defines a plate area associated with a first centroid, the perimeter of the pad body projected onto the reference plane defines a pad area associated with a second centroid, the pad body being dimensioned such that the second centroid is offset from the first centroid by a first distance relative to the longitudinal direction; The perimeter of the plate body is circular and the perimeter of the pad body is oblong; an offset ratio of the first distance divided by the first length is at least 1:4, such that the second centroid is offset upward from the first centroid relative to an up-down direction of the glenoid; the ratio of the pad area to the plate area is 1.5:1 or greater; and / or A convertible orthopedic implant system, wherein a ratio of a maximum width around the perimeter of the plate body to a minimum width around the perimeter of the pad body is 0.5:1 or greater.

6. The system of claim 5 , wherein the pad comprises a metallic material.

7. The system of claim 5 , wherein the pad has a monolithic structure and comprises a non-metallic material, and the plate body comprises a metallic material.

8. the plate body including a plurality of peripheral openings configured to receive respective fasteners for securing the base plate to bone; 6. The system of claim 5, wherein the base plate includes an anchoring stem extending outward from the posterior surface of the plate body along a stem axis, the anchoring stem configured to be inserted at least partially into a bone hole to secure the base plate.

9. The system of claim 8 , wherein the first centroid of the plate body is aligned with a protrusion of the stem shaft.

10. the peripheral openings are circumferentially distributed around a central opening of the plate body, the central opening extending along a protruding portion of the stem shaft; and 9. The system of claim 8, wherein the pad includes first and second pegs extending outward from the bone-contacting surface, the first peg configured to be received within the central opening and the second peg configured to be received within a respective one of the peripheral openings to limit relative rotation between the plate body and the pad body with respect to the stem axis.

11. 6. The system of claim 5, further comprising a glenosphere including an articulating surface having a generally convex shape, said glenosphere being releasably secured to said baseplate.

12. The system of claim 11 , wherein one of the pad and the glenosphere comprises a metallic material and another of the pad and the glenosphere comprises a non-metallic material.

13. The system of claim 12 , wherein the pad comprises a metallic material.

14. The system of claim 12 , wherein the pad comprises a non-metallic material.

15. The system of claim 11 , wherein the glenosphere includes a recess dimensioned to at least partially receive the plate body.

16. 16. The system of claim 15, wherein the perimeter of the plate body is dimensioned to cooperate with the perimeter of the recess to establish a Morse taper connection that limits relative movement between the base plate and the glenosphere.

17. 12. The system of claim 11, further comprising a spacer configured to interface with the plate body and the glenosphere such that the glenosphere is spaced a predetermined distance from the plate body.

18. 18. The system of claim 17, wherein the spacer is dimensioned such that a posterior surface of the glenosphere is angled laterally relative to the anterior surface of the plate body.

19. the plate body includes a plurality of plate openings; the spacer including one or more pegs configured for insertion into respective ones of the plate openings; 18. The system of claim 17, wherein the spacer includes one or more spacer openings that align with a respective one of the plate openings such that a respective fastener is insertable through each respective pair of the base plate and spacer openings and into the glenoid to secure the base plate.

Images