Constraint type prosthetic knee

Abstract

A system includes a prosthetic assembly for a constraining knee, the system including a tibial substrate, a movable support, and a fixed support. The tibial substrate may include a distal surface and a proximal surface, and the proximal surface may be configured to receive the hinge post. The movable support may be configured to couple with the tibial substrate and rotate about at least a first axis that approximates a centerline of the hinge post. Rotation about the at least first axis may be restricted by the at least first engagement feature. The fixation support may be configured to be coupled to a tibial substrate. Rotation of the fixation support about the first axis may be limited by at least a first engagement feature of the tibial substrate. The tibial substrate may be configured to be assembled with either a movable support or a fixed support.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 434,590 filed on December 22, 2022 and U.S. Patent Application No. 18 / 526,737 filed on December 1, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates generally to orthopedic prostheses. More particularly, the present disclosure relates to orthopedic prostheses for constrained knee replacement. Background Art

[0004] Orthopedic surgery and prostheses are commonly used to repair or replace damaged bones and tissues in the human body. In general, the knee consists of a pair of condyles at the distal portion of the femur, whose lower surfaces bear on a correspondingly shaped proximal surface platform of the tibia. The femur and tibia are connected by means of ligaments, such as the posterior cruciate ligament, lateral collateral ligament, medial collateral ligament and anterior cruciate ligament. These ligaments provide stability to the knee joint.

[0005] Prosthetic knee joints can be divided into constrained (restrictive) and unconstrained (non-restrictive). A constrained prosthetic knee system may include a femoral prosthesis and a tibial prosthesis that are mechanically connected or constrained to each other to limit the relative movement between the femoral prosthesis and the tibial prosthesis. Common mechanisms for such mechanical connection include hinges, straps or other connecting structures. An unconstrained prosthetic knee system includes a femoral prosthesis and a tibial prosthesis that are not mechanically connected. An unconstrained knee utilizes the patient's existing ligaments and other soft tissues to provide joint stability. A constrained prosthetic knee is particularly suitable for situations where the patient's ligaments are missing or the existing ligaments are unable to provide adequate support and stability to the knee. Summary of the invention

[0006] The present disclosure relates generally to improved constrained knee prostheses, particularly those that utilize hinge posts. Some constrained knee prostheses with hinge posts are designed so that the femoral component (and hinge post) is free to move generally proximally / distally relative to the tibial baseplate and tibial bearing component. The inventors of the present disclosure have recognized that there is a need for a system that provides a prosthesis that can be reconfigured for use in either a mobile bearing system or a fixed bearing system. Such a system may include components that can be assembled to form a mobile bearing constrained knee prosthesis and a fixed constrained knee prosthesis. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The accompanying drawings illustrate various embodiments by way of example. These embodiments are exemplary and are not intended to be exhaustive or exclusive embodiments of the subject matter of the present invention.

[0008] Figure 1 and Figure 2 A knee joint structure is shown that provides a suitable environment in which a constrained prosthetic assembly according to one example of the present application may be utilized.

[0009] Figure 3 is a perspective view of a constrained knee prosthesis assembly according to one example of the present application.

[0010] Figure 4 yes Figure 3 A cross-sectional view of a constrained knee prosthesis assembly according to an example of the present application.

[0011] Figure 5 is a top view of a constrained knee prosthesis according to an example of the present application.

[0012] Figure 6 is along Figure 5 A partial cross-sectional view of a constrained knee prosthesis assembly according to an example of the present application, taken along the indicator line 6-6.

[0013] Figure 7 1 is a top view of an example of a constrained knee prosthesis including a mobile bearing rotated to a first set limit according to an example of the present application.

[0014] Figure 8 1 is a top view of an example of a constrained knee prosthesis including a mobile bearing rotated to a second set limit according to an example of the present application.

[0015] Fig. 9 is a top view of an example of a constrained knee prosthesis including a fixed bearing according to an example of the present application.

[0016] Fig.10 is a top view of an example of a constrained knee prosthesis assembly including a mobile bearing with a press-fit insert according to an example of the present application. DETAILED DESCRIPTION

[0017] The present application relates to a system including a constrained (restrictive) knee prosthesis. The system may include a set of components, such as a tibial tray or base plate, an interlocking member, a femoral component, a hinge post, a polymer box, a sleeve or the like. This set of components can be configured for use with a tibial bearing component. For example, the system may include a mobile tibial bearing component or a fixed tibial bearing component, which can be replaced at the surgeon's discretion. The mobile tibial bearing component can be configured to limit rotation (or movement) around at least one axis compared to the mobile tibial bearing component by engaging with one or more engagement features of the tibial tray. The fixed bearing component can prevent or completely strictly limit rotation (or movement) around at least one axis by contacting one or more engagement features of the tibial tray.

[0018] In another example, the system may include a set of components, a mobile tibial bearing component and a press-fit insert. In such examples, the press-fit insert may be configured to fill a space between the mobile tibial bearing component and one or more engagement features of the tibial tray to further limit or prevent / block rotation or movement of the tibial bearing component relative to the tibial tray about one or more axes.

[0019] To better understand knee replacement surgery, it may be helpful to understand the relationship between the bones and the bone cuts that can be made toward the various temporary and permanent prosthetic components within the knee joint. Figure 1 and Figure 2 Several features of the knee joint structure and orientation are shown. Figure 1 , a front view of a lower limb 102 including a femur 104 and a tibia 106 shows various lower limb axes. The femur 104 has an anatomical axis 108 that roughly coincides with its intramedullary canal. The femur 104 also has a mechanical axis 110, or load axis, from the center of the femoral head 112 to the center of the knee joint 114. The angle 116 extending between these two axes varies from patient to patient, but is roughly between 5-7 degrees (including 5 degrees and 7 degrees). Like the femur 104, the tibia 106 also has an anatomical axis that roughly coincides with its intramedullary canal. The mechanical axis 118 of the tibia 106 extends from the center of the knee joint 114 to the center of the ankle region 120 and is roughly colinear with the anatomical axis of the tibia 106.

[0020] The joint line 122 about which the knee joint 114 flexes is approximately parallel to a line passing through the medial and lateral femoral condyles 124 and to the tibial plateau 126. Figure 1104 and 106, respectively, the joint line 122 may extend at a varus or valgus angle relative to the mechanical axes 110 and 118 of the femur 104 and tibia 106, respectively. Typically, during a partial or total knee replacement surgery, a portion of the distal side of the femur 104 or a portion of the proximal side of the tibia 106 will be resected parallel or approximately parallel to the joint line 122, and thus perpendicular to the mechanical axes 110 and 118, as shown at 128 and 130, respectively.

[0021] A typical knee can move between an extended state, in which the longitudinal axis of the femur 104 is substantially parallel to the longitudinal axis of the tibia 106, and a flexed state, in which the longitudinal axis of the femur 104 and the longitudinal axis of the tibia 106 are at an angle of approximately 140 degrees relative to each other. In various embodiments, the extended state can be limited to + / - 10 degrees, while the flexed state can be much less than 140 degrees. For example, the flexed state can include a limitation that the longitudinal axis of the femur 104 and the longitudinal axis of the tibia 106 are at an angle of approximately 90 to 140 degrees relative to each other.

[0022] Figure 2 A close-up view of the knee joint 114 and its coordinate system is shown, wherein the medial / lateral axis 202 corresponds approximately to the joint line 122 ( Figure 1 ), the proximal / distal axis 204 corresponds approximately to the mechanical axes 110 and 118 ( Figure 1 ), and the anterior / posterior axis 206 is approximately normal to the other two axes. Arrows can depict the position along each of these axes to represent the positioning of the inserted prosthetic component on the medial / lateral 208, anterior / posterior 210, and proximal / distal 212. Rotation about each axis can also be represented by arrows. Rotation about the proximal / distal axis 204 anatomically corresponds to external rotation of the femoral component, while rotation about the anterior / posterior axis 206 and the medial / lateral axis 202 corresponds to the extension plane inclination and varus / valgus angle of the component, respectively. Based on the proximal tibial notch 130 ( Figure 1 ) can affect the varus / valgus angle 214, the extension plane angle 216, the external rotation 218, or the joint extension gap. Similarly, the distal femoral notch 128 ( Figure 1 ) may also affect the position of the joint line 122, the extension gap, the varus / valgus angle 214, or the extension plane angle 216.

[0023] The terms "proximal" and "distal" used in this article should be defined according to the generally understood anatomical interpretation. The term "proximal" refers to the direction generally toward the patient's trunk, while "distal" refers to the direction opposite to the proximal, that is, the direction away from the patient's trunk. It should be understood that the terms "proximal" and "distal" should be interpreted with reference to the patient's knee joint being in an extended state when standing. The purpose is to distinguish "proximal" and "distal" from "front" and "back". The terms "front" and "back" used in this article should be interpreted according to the generally understood anatomical interpretation. Therefore, "back" refers to the back of the patient, for example, behind the knee. Similarly, "front" refers to the front of the patient, for example, in front of the knee. Therefore, "back" refers to the direction opposite to the "front". Similarly, the term "outside" refers to the direction opposite to the "inside". The term "inside / outside" refers to the inside to the outside or the outside to the inside. The term "proximal / distal" refers to the proximal to the distal or the distal to the proximal. The term "front / rear" means front to rear or rear to front.

[0024] As described herein, the "perimeter" of the tibial baseplate refers to any perimeter as viewed from a top plan view (e.g., on a generally transverse anatomical plane). Alternatively, the perimeter of the tibial baseplate may also be any perimeter as viewed from a bottom plan view (e.g., on a generally transverse anatomical plane), with the distal surface of the tibial baseplate adapted to contact the resected proximal surface of the tibia.

[0025] The term "micromotion" refers to the small movements that may exist between prosthetic components, such as between the tibial baseplate and the capture element, respectively, when forces are applied. These small movements may be caused by material deformation of one or both of the interacting components, or by the presence of small spaces or gaps between them. Micromotion is distinguished from larger movements of the components, such as proximal / distal movement of the femoral component relative to the tibial baseplate and tibial bearing component.

[0026] Figure 3 A prosthetic assembly 300 for a constrained knee is shown. Prosthetic assembly 300 may include a tibial baseplate 302, a tibial bearing component 304 (also sometimes referred to as a meniscal component, polymer component, articular component, or bearing), a femoral component 306, and a hinge post 308.

[0027] The tibial bearing component 304 can be coupled to the proximal surface 310 of the tibial baseplate 302 and is located on top of the proximal surface 310 of the tibial baseplate 302. The tibial bearing component 304 can be formed of a polymer material, such as ultra-high molecular weight polyethylene (UHMWPE) or the like. The tibial bearing component 304 can be configured to articulate with the femoral component 306 in a manner known in the art for use in knee flexion and extension. The femoral component 306 and the tibial baseplate 302 of the prosthetic assembly 300 are mechanically connected to each other. This is achieved by the hinge post 308 and Figure 4 Hinge post 308 is coupled to femoral component 306 and is received within recess 309 of tibial bearing component 304 and recess 322 of tibial baseplate 302 ( Figure 4 )Inside.

[0028] Figure 4 An exploded view of prosthetic assembly 300, tibial baseplate 302, tibial bearing component 304, femoral component 306, hinge post 308 is shown, and further illustrating hinge shaft 312, polymer cartridge 314, sleeve 316, shackle 318, and bushing.

[0029] Hinge post 308 is connected to femoral component 306 via interlock 318, sleeve 316 and hinge shaft 312. The distal portion of interlock 318 is received in recess 309 in tibial bearing component 304, and the distal portion is connected to hinge post 308 by threads or other means. Hinge post 308 extends distally, passes through recess 309 of tibial bearing component 304, and is received in recess 322 of tibial baseplate 302. Recess 322 of tibial baseplate 302 receiving hinge post 308 can be at least partially formed by keel 324 of tibial baseplate 302. Hinge post 308 is movable relative to tibial bearing component 304 or tibial baseplate 302, for example, rotatable or capable of distraction. Hinge post 308 can be rotatably connected to femoral component 306 via hinge shaft 312. Thus, when the femoral component 306 and the tibial baseplate 302 are mechanically coupled, the longitudinal axis LA defining the centerline of the hinge post 308 can define the rotation / articular axis ARA for the knee joint.

[0030] When assembly is complete, the interlocking piece 318 can be placed between the opposing side walls of the polymer box 314. When assembled to the hinge shaft 312, the sleeve 316 is additionally retained in the aperture on the proximal portion of the interlocking piece 318. The interlocking piece 318 and the hinge post 308 can be formed of suitable materials such as titanium alloy, cobalt chromium alloy or the like, while the sleeve 316 and the polymer box 314 can be formed of different materials such as plastic (e.g., UHMWPE). The sleeve 316 can serve as a support between the interlocking piece 318 and the hinge shaft 312. The polymer box 314 can serve as a support between the femoral component 306 and the interlocking piece 318.

[0031] Figure 4 The prosthesis assembly 300 of FIG. 300 illustrates the components of a system 326 in which the distraction of the knee is not limited by the capture element or other features of the prosthesis assembly 300. Thus, the components provided by the system 326 are configured for full distraction when assembled. Thus, as previously described, the soft tissue of the knee is relied upon to limit the distraction between the femoral component 306 and the tibial baseplate 302 and the tibial bearing component 304. The bushing 320 can be configured to be inserted into the groove 322 of at least the tibial baseplate 302. In some examples, the bushing 320 can also be inserted into or through the groove 309 of the tibial bearing component 304 ( Figure 3 ). Bushing 320 can be configured to receive at least a portion of hinge post 308. Bushing 320 can serve as a bearing between hinge post 308 and tibial baseplate 302. Hinge post 308 can move generally proximally / distally relative to bushing 320.

[0032] Figure 5 5 is a top view of an example of an active bearing prosthesis (e.g., prosthesis assembly 500) according to an example of the present application. Prosthesis assembly 500 can be configured to be implanted in a patient with a constrained knee. In an example, prosthesis assembly 500 can include a tibial baseplate 502, a tibial insert or tibial bearing component (tibial bearing component 504), and a hinge post 508.

[0033] Tibial baseplate 502 and Figure 3 Similar to the tibial baseplate 302 in FIG. 1 , the tibial baseplate 302 may be configured to be inserted into the tibia of a patient, for example, Figure 1 The tibia 106 in the tibial baseplate 502 may include a distal surface 530 (e.g. Figure 6 530) and a proximal surface 532. The proximal surface 532 can be opposite the distal surface 530, and a perimeter 534 of the tibial baseplate 502 can extend between the distal surface 530 and the proximal surface 532. The proximal surface 532 can include a recess configured to receive the hinge post 508. The proximal surface 532 can also include a first engagement feature 540 and a second engagement feature 550.

[0034] The tibial bearing component 504 is similar to Figure 3 The tibial bearing component 304 in the embodiment of the present invention can be configured to be coupled to the tibial baseplate 502 and rotate about at least the first axis 542, for example, about Figure 2 The distal axis 204 in the external rotation 218. In an example, the first axis 542 can extend through the centerline of the hinge post 508. The tibial bearing component 504 can include a third engagement feature 560 and a fourth engagement feature 570.

[0035] The first engagement feature 540 can be configured to limit rotation or movement of the tibial bearing component 504 relative to the tibial baseplate 502 about at least a first axis 542. The first engagement feature 540 can include a protrusion 541. The protrusion 541 can extend from the proximal surface 532 of the tibial baseplate 502. Alternatively, other examples of the present application also contemplate that the first engagement feature 540 can be a notch, an aperture, or other recess. Figure 5 In the example shown, protrusion 541 can extend from an anterior portion of proximal surface 532 adjacent perimeter 534 and can extend away from distal surface 530. In another example, protrusion 541 can extend from a posterior portion, a medial portion, a lateral portion, or any other portion of proximal surface 532 to limit rotation or movement of tibial bearing component 504 relative to tibial baseplate 502 about at least first axis 542 or the like. First engagement feature 540 can include first edge 544, second edge 546, and third edge 548.

[0036] The first edge 544 can extend posteriorly from the periphery of the tibial baseplate 502. The second edge 546 can also extend posteriorly from the periphery of the tibial baseplate 502. The third edge 548 can extend from the first edge 544 to the second edge 546. The third edge 548 can also include a concave profile 549 so that the thickness of the first engagement feature 540 is reduced in the middle portion compared to the first edge 544 or the second edge 546. In an example, the first edge 544 or the second edge 546 can engage the tibial bearing component 504 to limit further rotation of the tibial bearing component 504 relative to the tibial baseplate 502 about the first axis 542. The interaction between the tibial bearing component 504 and the first edge 544, the second edge 546, and the third edge 548 of the first engagement feature 540 will be described below with reference to Figure 7 and Figure 8 Discuss in more detail.

[0037] Third engagement feature 560 can be configured to engage first engagement feature 540 of tibial bearing component 504 to limit rotation of tibial bearing component 504 relative to tibial baseplate 502 about at least first axis 542. Third engagement feature 560 can be an anterior recess that can include first inner wall 562 and second inner wall 564. For example, third engagement feature 560 can be configured to contact third edge 548 of first engagement feature 540 when tibial bearing component 504 is coupled to tibial baseplate 502. The contact between third engagement feature 560 and third edge 548 can help retain tibial bearing component 504 on tibial baseplate 502.

[0038] Second inner wall 564 of third engagement feature 560 may engage first edge 544. First inner wall 562 of third engagement feature 560 may engage second edge 546. Thus, first inner wall 562 and second inner wall 564 of third engagement feature 560 may engage second edge 546 and first edge 544, respectively, to limit rotation of tibial bearing component 504 relative to tibial baseplate 502 about first axis 542 in a clockwise or counterclockwise direction. Figure 5 As shown, third engagement feature 560 can be formed on the anterior portion of tibial bearing component 504, adjacent to periphery 534 of tibial baseplate 502. In another example, third engagement feature 560 can be formed in any other portion of tibial bearing component 504, such that third engagement feature 560 can limit rotation of tibial bearing component 504 relative to tibial baseplate 502 about first axis 542. Figure 7 and Figure 8 The interaction between the third engagement feature 560 and the first engagement feature 540 is discussed in greater detail.

[0039] Second engagement feature 550 can be configured to limit movement of tibial bearing component 504 relative to tibial baseplate 502 in at least second direction 552. Movement of tibial bearing component 504 in second direction 552 can be limited by engagement of second engagement feature 550 with tibial bearing component 504. Figure 5 As shown, the second engagement feature 550 may include a protrusion 551 extending from a central portion of the proximal surface 532, for example, proximal to but spaced from the rear side of the recess receiving the hinge post 508. In another example, the second engagement feature 550 may extend from the rear portion, the medial portion, the lateral portion, or any other portion of the proximal surface 532 so that the second engagement feature 550 can limit the movement of the tibial bearing component 504 relative to the tibial baseplate 502 in the second direction 552 or the like. Fig.10 and Figure 8 The interaction between tibial bearing component 504 and second engagement feature 550 is discussed in greater detail.

[0040] Fourth engagement feature 570 can be configured to engage second engagement feature 550 of tibial bearing component 504 to limit movement of tibial bearing component 504 relative to tibial baseplate 502 in at least second direction 552. Fourth engagement feature 570 can be a wall of a recess formed in tibial bearing component 504. The recess can be centralized / centered and can receive hinge post 508 in addition to second engagement feature 550. Fig.10 and Figure 8 The interaction between the fourth engagement feature 570 and the second engagement feature 550 is discussed in greater detail.

[0041] like Figure 5 As shown, first engagement feature 540 and second engagement feature 550 of tibial baseplate 502 may be protrusions, while third engagement feature 560 and fourth engagement feature 570 of tibial bearing component 504 may be walls of a groove. In another example, first engagement feature 540 and second engagement feature 550 of tibial baseplate 502 may be grooves, ridges, depressions, or any other formations, or the like, formed in the surface of tibial baseplate 502, while third engagement feature 560 and fourth engagement feature 570 may be protrusions, ridges, extensions, or any other formations, or the like, extending from the surface of tibial bearing component 504.

[0042] Figure 6 is along Figure 5 A partial cross-sectional view of a constrained knee prosthesis assembly, such as prosthesis assembly 500, according to an example of the present application, taken along the line 6-6. Figure 6 As shown, tibial bearing component 504 can be configured to couple to tibial baseplate 502. When tibial bearing component 504 is coupled to tibial baseplate 502, third engagement feature 560 and fourth engagement feature 570 of tibial bearing component 504 can engage with first engagement feature 540 and second engagement feature 550, respectively.

[0043] like Figure 6As shown, third engagement feature 560 may include a ridge that can slide under a surface of protrusion 541, the surface of protrusion 541 facing distal surface 530 of tibial baseplate 502. Fourth engagement feature 570 may also include a ridge that can slide under a surface of protrusion 551, the surface of protrusion 551 facing distal surface 530 of tibial baseplate 502. Therefore, during coupling of tibial bearing component 504 to tibial baseplate 502, the ridge of third engagement feature 560 may slide under protrusion 541, and then the ridge of fourth engagement feature 570 may slide under protrusion 551. During coupling, first engagement feature 540 and second engagement feature 550 may be configured to flex away from and toward hinge post 508, respectively, to facilitate coupling of tibial bearing component 504 to tibial baseplate 502. Once coupled, protrusions 541 and 551 can engage the ridges of third engagement feature 560 and fourth engagement feature 570 , respectively, to prevent movement of tibial bearing component 504 relative to tibial baseplate 502 in second direction 552 .

[0044] Figure 7 is a top view of an example of a constrained knee prosthesis (e.g., prosthesis assembly 500) according to an example of the present application including a mobile bearing 704 rotated to a first set limit. The mobile bearing 704 is similar to the tibial bearing component 504 ( Figure 5 ), which can be configured to couple with the tibial baseplate 502. As discussed above, the movable bearing 704 can rotate about at least the first axis 542, which can be along the centerline of the hinge post 508. Figure 7 As shown, movable support 704 can be rotated into orientation 772.

[0045] In orientation 772, movable bearing 704 can be rotated counterclockwise about first axis 542 relative to tibial baseplate 502. For example, movable bearing 704 can be rotated counterclockwise about first axis 542 relative to tibial baseplate 502 until second inner wall 564 of third engagement feature 560 contacts first edge 544 of first engagement feature 540. In such an example, the contact between second inner wall 564 and first edge 544 can prevent movable bearing 704 from further rotating about first axis 542 relative to tibial baseplate 502. Figure 7 As shown, second engagement feature 550 can engage fourth engagement feature 570 to prevent mobile bearing 704 from further rotating about first axis 542 relative to tibial baseplate 502 .

[0046] Figure 87 is a top view of an example of a constrained knee prosthesis (e.g., prosthesis assembly 500) including a mobile bearing 704 rotated clockwise to a second set limit according to an example of the present application. The mobile bearing 704 can be rotated clockwise about the first axis 542 relative to the tibial baseplate 502 to any degree between the orientation 772 and the orientation 774. The prosthesis assembly 500 with the mobile bearing 704 is generally more biased to a neutral position between the orientation 772 and the orientation 774.

[0047] exist Figure 7 In the orientation 774 of FIG. 7 , the movable bearing 704 can rotate relative to the tibial baseplate 502 about the first axis 542. For example, the movable bearing 704 can rotate relative to the tibial baseplate 502 about the first axis 542 until the first inner wall 562 of the third engagement feature 560 contacts the second edge 546 of the first engagement feature 540. In such an example, the contact between the first inner wall 562 and the second edge 546 can prevent the movable bearing 704 from further rotating relative to the tibial baseplate 502 about the first axis 542.

[0048] Fig. 9 is a top view of an example of a constrained knee prosthesis (e.g., prosthesis assembly 500) including a fixed bearing 904 according to an example of the present application. The fixed bearing 904, for example, the tibial bearing component 504 ( Figure 5 ), can be configured to couple with tibial baseplate 502. As discussed above, fixed bearing 904 can prevent fixed bearing 904 from rotating or moving relative to tibial baseplate 502 about first axis 542 and second direction 552.

[0049] The third engagement feature 560 of the fixed bearing 904 is configured to surround and contact the first engagement feature 540 of the tibial baseplate 502 to prevent the fixed bearing 904 from moving relative to the tibial baseplate 502 about the first axis 542. For example, the recess of the third engagement feature 560 includes a first inner wall 562 and a second inner wall 564 along the anterior portion of the fixed bearing 904, and is smaller than the recess of the third engagement feature 560 on the movable bearing 704. Therefore, when the fixed bearing 904 is coupled to the tibial baseplate 502, the first inner wall 562 and the second inner wall 564 of the third engagement feature 560 of the fixed bearing 904 are configured to contact the second edge 546 and the first edge 544, respectively. Therefore, the first inner wall 562 and the second inner wall 564 of the fixed bearing 904 prevent the fixed bearing 904 from rotating relative to the tibial baseplate 502 about the first axis 542.

[0050] Fourth engagement feature 570 of fixed bearing 904 is configured to surround and contact second engagement feature 550 of tibial baseplate 502 to prevent fixed bearing 904 from moving relative to tibial baseplate 502 about second axis 551. Fourth engagement feature 570 may include a flange, a protrusion, a tang, or a rib (rib 972). Rib 972 is configured to surround the opposite side of second engagement feature 550 and protrusion 551 to help prevent fixed bearing 904 from rotating relative to tibial baseplate 502 about first axis 542.

[0051] Fig.10 is a top view of an example of a constrained knee prosthesis assembly (eg, prosthesis assembly 500 ) including a mobile bearing (eg, mobile bearing 704 ) with a press fitting 1070 according to an example of the present application.

[0052] As discussed above, the prosthesis assembly 500 can be used as a mobile bearing prosthesis by coupling the mobile bearing 704 to the tibial baseplate 502. The prosthesis assembly 500 can be used as a fixed bearing prosthesis by coupling the fixed bearing 904 to the tibial baseplate 502. In another example, the prosthesis assembly 500 can be made into a fixed prosthesis by using a press fitting 1070. In an example, the press fitting 1070 can be configured to be inserted into the third engagement feature 560 of the mobile bearing 704. In such an example, the press fitting can be configured to fill the space between the first inner wall 562 of the third engagement feature 560 and the second edge 546 of the first engagement feature 540, and to fill the gap between the second inner wall 564 of the third engagement feature 560 and the first edge 544 of the first engagement feature 540. Therefore, the press fitting 1070 can effectively turn the mobile bearing 704 into a fixed bearing. Thus, mobile bearing 704 may be coupled to tibial baseplate 502 and then press fitting 1070 may be installed onto mobile bearing 704 such that the press fitting engages third engagement feature 560 .

[0053] like Fig.10 As shown, the first engagement feature 540 may include a slot extending from the periphery of the movable support 704. The slot may receive the press fitting 1070 so that the press fitting 1070 slides within the slot and surrounds the first engagement feature 540. Fig.10In the example of the present invention, the press fitting 1070 is configured to fill the entire space between the first edge 544 of the first engagement feature 540 and the second inner wall 564 of the third engagement feature 560, and to fill the entire space between the second edge 546 of the first engagement feature 540 and the first inner wall 562 of the third engagement feature 560. In another example, the press fitting 1070 may be configured to fill any portion of the space between the first edge 544 of the first engagement feature 540 and the second inner wall 564 of the third engagement feature 560, and to fill the space between the second edge 546 of the first engagement feature 540 and the first inner wall 562 of the third engagement feature 560.

[0054] Additional Notes and Examples

[0055] The following non-limiting examples detail certain aspects of the subject matter to address the challenges discussed herein and provide benefits, among other things.

[0056] Example 1 is a system including a prosthetic assembly for a constrained knee, the system comprising: a set of components. The set of components includes: a femoral component, an interlocking component extending between a first end portion and a second end portion; a hinge shaft configured to secure the femoral component to the first end portion of the interlocking component; a tibial baseplate having a distal surface, a proximal surface opposite the distal surface, and a perimeter extending between the proximal surfaces, the tibial baseplate including a first engagement feature; and a hinge post extending between a first end segment and a second end segment, the first end segment being configured to be attached to the second end portion of the interlocking component, the second end segment being configured to be at least partially received by a recess in the tibial baseplate. The system also includes: a movable support, which is configured to be connected to the tibial baseplate and rotate around at least a first axis, the first axis is approximately the centerline of the hinge post, and the rotation around at least the first axis is limited by at least a first engagement feature of the tibial baseplate; and a fixed support, which is configured to be connected to the tibial baseplate, and the fixed support is limited by at least the first engagement feature of the tibial baseplate and cannot rotate around the first axis; wherein the group of components is configured to be assembled with the movable support or the fixed support.

[0057] In Example 2, the subject matter of Example 1 includes wherein the first engagement feature of the tibial baseplate includes a first protrusion extending from an anterior portion of the proximal surface away from the distal surface.

[0058] In Example 3, the protection subject of Example 2 includes, wherein the first protrusion includes: a first edge extending posteriorly from the periphery of the tibial baseplate; a second edge extending posteriorly from the periphery of the tibial baseplate; and a third edge extending from the first edge to the second edge, the third edge including a concave profile.

[0059] In Example 4, the protected subject matter of Example 3 includes wherein the tibial baseplate further includes a second engagement feature.

[0060] In Example 5, the protected subject matter of Example 4 includes, wherein the second engagement feature includes a second protrusion extending from a central portion of the proximal surface away from the distal surface.

[0061] In Example 6, the protected subject matter of Example 5 includes, wherein the movable support includes a third engagement feature, the third engagement feature is configured to contact a third edge of the first engagement feature when the movable support is connected to the tibial baseplate, and the third engagement feature is also configured to engage with the first edge or the second edge of the first engagement feature when the movable support is rotated about at least the first axis.

[0062] In Example 7, the subject matter of Example 6 includes, wherein engagement of the third engagement feature with the first edge and the second edge of the first engagement feature limits rotation of the movable support.

[0063] In Example 8, the protected subject matter of Examples 6-7 includes, wherein the third engagement feature is formed in a front portion of the movable support.

[0064] In Example 9, the protected subject matter of Examples 5-8 includes, wherein the movable support includes a fourth engagement feature, the fourth engagement feature is configured to engage with the second engagement feature of the tibial baseplate when the movable support is rotated about the second axis relative to the tibial baseplate, and wherein engagement of the fourth engagement feature with the second engagement feature limits rotation of the movable support about the second axis.

[0065] In Example 10, the subject matter of Example 9 includes, wherein the fourth engagement feature is formed in the movable support adjacent to the recess configured to receive the hinge post.

[0066] In Example 11, the protected subject matter of Example 10 includes, wherein the fourth engagement feature is located at a rear side of a recess configured to receive the hinge pillar.

[0067] In Example 12, the subject matter of Examples 9-11 includes wherein rotation of the mobile support about the second axis includes adduction and abduction of the prosthetic component.

[0068] In Example 13, the subject matter of Examples 4-12 includes wherein the fixation bearing is configured to engage with the first engagement feature of the tibial baseplate when the fixation bearing is coupled to the tibial baseplate.

[0069] In Example 14, the subject matter of Example 13 includes wherein the fixed support includes a third engagement feature that contacts the first edge, the second edge, and the third edge of the first engagement feature to prevent the movable support from rotating about at least the first axis.

[0070] In Example 15, the subject matter of Examples 13-14 includes wherein the fixed bearing includes a fourth engagement feature formed in a central portion of the fixed bearing, the fourth engagement feature contacting the second engagement feature of the tibial baseplate when the fixed bearing is coupled to the tibial baseplate.

[0071] In Example 16, the subject matter of Example 15 includes, wherein the fourth engagement feature includes a pair of ribs that engage the second engagement feature on opposite sides of the second engagement feature.

[0072] Example 17 is a system comprising a prosthetic component for a constrained knee, wherein the system comprises: a tibial base having a distal surface and a proximal surface opposite the distal surface, the proximal surface being configured to receive a hinge post, the tibial base comprising a first engagement feature; a movable bearing configured to be connected to the tibial base and to rotate about at least a first axis, the first axis being approximately the centerline of the hinge post, the rotation about at least the first axis being limited by at least the first engagement feature; a fixed bearing configured to be connected to the tibial base, the fixed bearing being limited by at least the first engagement feature of the tibial base so as not to rotate about the first axis; wherein the tibial base is configured to be assembled with the movable bearing or the fixed bearing.

[0073] In Example 18, the subject matter of Example 17 includes wherein the first engagement feature of the tibial baseplate includes a first protrusion extending from an anterior portion of the proximal surface away from the distal surface.

[0074] In Example 19, the protected subject matter of Example 18 includes, wherein the first protrusion includes: a first edge extending posteriorly from a periphery of the tibial baseplate, the periphery of the tibial baseplate being defined by a distal surface and a proximal surface of the tibial baseplate; a second edge extending posteriorly from the periphery of the tibial baseplate; and a third edge extending from the first edge to the second edge, the third edge including a concave profile.

[0075] In Example 20, the protected subject matter of Example 19 includes wherein the tibial baseplate further includes a second engagement feature.

[0076] In Example 21, the protected subject matter of Example 20 includes, wherein the second engagement feature includes a second protrusion extending from a central portion of the proximal surface away from the distal surface.

[0077] In Example 22, the protected subject matter of Example 21 includes, wherein the movable support includes a third engagement feature, the third engagement feature is configured to contact a third edge of the first engagement feature when the movable support is connected to the tibial baseplate, and the third engagement feature is also configured to engage with the first edge or the second edge of the first engagement feature when the movable support is rotated about at least the first axis.

[0078] In Example 23, the subject matter of Example 22 includes, wherein engagement of the third engagement feature with the first edge and the second edge of the first engagement feature limits rotation of the movable support.

[0079] In Example 24, the protected subject matter of Examples 22-23 includes, wherein the third engagement feature is formed in a front portion of the movable support.

[0080] In Example 25, the protected subject matter of Examples 21-24 includes, wherein the movable support includes a fourth engagement feature, the fourth engagement feature is configured to engage with the second engagement feature of the tibial baseplate when the movable support is rotated about the second axis relative to the tibial baseplate, and wherein engagement of the fourth engagement feature and the second engagement feature limits rotation of the movable support about the second axis.

[0081] In Example 26, the subject matter of Example 25 includes, wherein the fourth engagement feature is formed in the movable support adjacent to the recess configured to receive the hinge post.

[0082] In Example 27, the protected subject matter of Example 26 includes, wherein the fourth engagement feature is located at a rear side of a recess configured to receive the hinge pillar.

[0083] In Example 28, the subject matter of Examples 25-27 includes wherein rotation of the mobile support about the second axis includes adduction and abduction of the prosthetic component.

[0084] In Example 29, the subject matter of Examples 20-28 includes wherein the fixation bearing is configured to engage with the first engagement feature of the tibial baseplate when the fixation bearing is coupled to the tibial baseplate.

[0085] In Example 30, the subject matter of Example 29 includes wherein the fixed support includes a third engagement feature that contacts the first edge, the second edge, and the third edge of the first engagement feature to prevent the movable support from rotating about at least the first axis.

[0086] In Example 31, the protected subject matter of Examples 29-30 includes wherein the fixed bearing includes a fourth engagement feature formed in a central portion of the fixed bearing, the fourth engagement feature contacting the second engagement feature of the tibial baseplate when the fixed bearing is coupled to the tibial baseplate.

[0087] In Example 32, the subject matter of Example 31 includes, wherein the fourth engagement feature includes a pair of ribs that engage the second engagement feature on opposite sides of the second engagement feature.

[0088] Example 33 is an apparatus comprising the device of any one of Examples 1-32.

[0089] Example 34 is a system implementing any one of Examples 1-32.

[0090] Example 35 is a method of implementing any one of Examples 1-32.

[0091] Example 36 is a system, method, or apparatus comprising any element of any of Examples 1-32.

[0092] The above detailed description refers to the accompanying drawings, which form a part of the detailed description. The accompanying drawings illustrate specific embodiments that can be implemented in a diagrammatic manner. These embodiments are also referred to as "examples" in this article. In addition to the content shown or described, these examples may also include other content. However, the inventors of the present application also consider examples that only provide those elements shown or described. In addition, the inventors of the present application also consider examples using any combination or arrangement of those elements shown or described (or one or more aspects thereof), whether for a specific example (or one or more aspects thereof), or for other examples shown or described herein (or one or more aspects thereof).

[0093] All publications, patents, and patent documents mentioned in this application are incorporated herein by reference in their entirety, as if individually incorporated herein by reference. If there is any inconsistency between the usage in this application and the documents incorporated by reference, the usage in the incorporated referenced documents shall be deemed to supplement the usage in this document; for irreconcilable inconsistencies, the usage in this application shall prevail.

[0094] In this document, the use of the terms "a" or "an" is the same as common usage in patent documents, including one or more, and is independent of any other instances or uses of "at least one" or "one or more". In this document, the term "or" is used to refer to non-exclusivity, thus, "A or B" includes "A but not B", "B but not A", and "A and B", unless otherwise stated. In the appended claims, the terms "including" and "in..." are used as the plain English / Chinese equivalents of the corresponding terms "comprising" and "wherein". In addition, in the following claims, the terms "including" and "comprising" are open-ended, that is, a system, device, article, or method is deemed to fall within the scope of a claim if it includes elements other than the elements listed after the term in the claim. In addition, in the following claims, the terms "first", "second", and "third", etc. are used merely as labels and are not intended to impose numerical requirements on their objects.

[0095] The term "approximately" as used herein means approximately, within the range of, roughly or about. When the term "approximately" is used in conjunction with a numerical range, it modifies the range by extending the upper and lower boundaries of the specified numerical value. In general, the term "approximately" is used here to modify a numerical value with an upper and lower deviation of 10% of the numerical value. In one aspect, the term "approximately" refers to plus or minus 10% of the numerical value used. Therefore, "about 50%" refers to 45%-55%. The numerical ranges described herein by endpoints include all numbers and fractions within the range, for example, 1 to 5 include 1, 1.5, 2, 2.75, 3, 3.90, 4, 4.24 and 5. Similarly, the numerical ranges described herein by endpoints also include subranges contained within the range, for example, 1 to 5 include 1-1.5, 1.5-2, 2-2.75, 2.75-3, 3-3.90, 3.90-4, 4-4.24, 4.24-5, 2-5, 3-5, 1-4 and 2-4. It should also be understood that all numbers and fractions thereof are assumed to be modified by the word "about".

[0096] The above description is intended to illustrate the problem and is not restrictive. For example, the above examples (or one or more aspects thereof) may be used in combination with each other. After reading the above description, a person of ordinary skill in the art may also use other embodiments. The abstract is intended to allow readers to quickly determine the nature of the technical disclosure. When submitting the abstract, it should be understood that the abstract will not be used to interpret or limit the scope or meaning of the claims. In addition, in the above detailed description, various features may be combined together to simplify the disclosure. This should not be interpreted as not requiring the disclosed features to be essential to any claim. On the contrary, the subject matter of creative protection may not lie in all the features of a particular disclosed embodiment. Therefore, the following claims are hereby incorporated into the detailed description, and each claim exists independently as a separate embodiment. The scope of the specific embodiment should be determined by reference to the attached claims and all equivalent scopes enjoyed by these claims.

Claims

1. A system comprising a prosthetic assembly for a constrained knee, the system comprising: A set of components comprising: Femoral component; an interlocking member extending between the first end portion and the second end portion; a hinge axis configured to secure the femoral component to the first end portion of the interlocking component; a tibial baseplate having a distal surface, a proximal surface opposite the distal surface, and a perimeter extending between the proximal surfaces, the tibial baseplate including a first engagement feature; and a hinge post extending between a first end segment configured to be attached to the second end portion of the interlocking component and a second end segment configured to be at least partially received by the recess in the tibial baseplate; a mobile bearing configured to couple with the tibial baseplate and to rotate about at least a first axis, the first axis being approximately the centerline of the hinge post, the rotation about at least the first axis being limited by at least a first engagement feature of the tibial baseplate; and a fixed bearing configured to be coupled to the tibial baseplate, the fixed bearing being restrained from rotating about a first axis by at least a first engagement feature of the tibial baseplate; Wherein, the group of components is configured to be assembled together with a movable support or a fixed support.

2. The system according to claim 1, wherein: The first engagement feature of the tibial baseplate includes a first protrusion extending from an anterior portion of the proximal surface away from the distal surface.

3. The system according to claim 2, wherein: The first protrusion includes: a first edge extending posteriorly from a perimeter of the tibial baseplate; a second edge extending posteriorly from the perimeter of the tibial baseplate; and A third edge extends from the first edge to the second edge, the third edge comprising a concave profile.

4. The system according to claim 3, wherein: The tibial baseplate further includes a second engagement feature.

5. The system according to claim 4, wherein: The second engagement feature includes a second protrusion extending from a central portion of the proximal surface away from the distal surface.

6. The system according to claim 5, wherein: The mobile bearing includes a third engagement feature configured to contact a third edge of the first engagement feature when the mobile bearing is coupled to the tibial baseplate and further configured to engage with the first edge or the second edge of the first engagement feature when the mobile bearing is rotated about at least the first axis.

7. The system according to claim 6, wherein: Engagement of the third engagement feature with the first and second edges of the first engagement feature limits rotation of the movable support.

8. The system according to claim 6, wherein: A third engagement feature is formed in the front portion of the movable support.

9. The system according to claim 5, wherein: The mobile bearing includes a fourth engagement feature configured to engage the second engagement feature of the tibial baseplate when the mobile bearing is rotated about the second axis with respect to the tibial baseplate, and wherein engagement of the fourth engagement feature with the second engagement feature limits rotation of the mobile bearing about the second axis.

10. The system according to claim 9, wherein: A fourth engagement feature is formed in the movable support adjacent to the recess configured to receive the hinge post.

11. The system according to claim 10, wherein: The fourth engagement feature is located on a rear side of the recess configured to receive the hinge pillar.

12. The system according to claim 9, wherein: Rotation of the mobile bearing about the second axis includes adduction and abduction of the prosthetic component.

13. The system according to claim 4, wherein: The fixation bearing is configured to engage the first engagement feature of the tibial baseplate when the fixation bearing is coupled to the tibial baseplate.

14. The system according to claim 13, wherein: The fixed support includes a third engagement feature that contacts the first edge, the second edge, and the third edge of the first engagement feature to prevent the movable support from rotating about at least the first axis.

15. The system of claim 13, wherein: The fixation bearing includes a fourth engagement feature formed in a central portion of the fixation bearing that contacts the second engagement feature of the tibial baseplate when the fixation bearing is coupled to the tibial baseplate.

16. The system of claim 15, wherein: The fourth engagement feature includes a pair of ribs that engage the second engagement feature on opposite sides of the second engagement feature.

17. A system comprising a prosthetic assembly for a constrained knee, the system comprising: a tibial baseplate having a distal surface and a proximal surface opposite the distal surface, the proximal surface being configured to receive the hinge post, the tibial baseplate including a first engagement feature; a mobile bearing configured to couple with the tibial baseplate and to rotate about at least a first axis, the first axis being approximately the centerline of the hinge post, the rotation about at least the first axis being limited by at least a first engagement feature; as well as a fixed bearing configured to be coupled to the tibial baseplate, the fixed bearing being restrained from rotating about a first axis by at least a first engagement feature of the tibial baseplate; Therein, the tibial baseplate is configured to be assembled with a movable bearing or a fixed bearing.

18. The system of claim 17, wherein: The first engagement feature of the tibial baseplate includes a first protrusion extending from an anterior portion of the proximal surface away from the distal surface, and wherein the first protrusion includes: a first edge extending posteriorly from a perimeter of the tibial baseplate, the perimeter of the tibial baseplate being defined by a distal surface and a proximal surface of the tibial baseplate; a second edge extending posteriorly from the perimeter of the tibial baseplate; and A third edge extends from the first edge to the second edge, the third edge comprising a concave profile.

19. The system of claim 18, wherein: The tibial baseplate further includes a second engagement feature, the second engagement feature including a second protrusion extending from a central portion of the proximal surface away from the distal surface, wherein the movable bearing includes a third engagement feature, the third engagement feature is configured to contact a third edge of the first engagement feature when the movable bearing is coupled to the tibial baseplate, the third engagement feature is further configured to engage with a first edge or a second edge of the first engagement feature when the movable bearing rotates about at least the first axis, wherein engagement of the third engagement feature with the first edge and the second edge of the first engagement feature limits rotation of the movable bearing.

20. The system of claim 19, wherein: The mobile bearing includes a fourth engagement feature configured to engage with a second engagement feature of the tibial baseplate when the mobile bearing rotates about a second axis relative to the tibial baseplate, wherein engagement of the fourth engagement feature with the second engagement feature limits rotation of the mobile bearing about the second axis, wherein the fourth engagement feature is formed in the mobile bearing adjacent to a recess configured to receive a hinge post, wherein the fourth engagement feature is located posterior to the recess configured to receive the hinge post, and wherein rotation of the mobile bearing about the second axis includes adduction and abduction of the prosthetic component.

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