An artificial knee that has first and second knee components connected together for rotation between a first, upright position and a second position where one knee component is positioned at an angle to the other, an alignment mechanism associated with the first and second knee components to assure rotation in a vertical plane from the first position to the second position, and a biasing member. One knee component includes an extension member located in a central location, while the other includes a centrally located slot that receives the extension member and allows rotation only in a vertical plane. The biasing member normally holds the knee components in the first position, such that rotation of the first knee component away from the second knee component stretches or elongates the biasing member to provide a force that urges the knee components to move back to the first position.

A modular knee joint prosthesis is configured to move between an extended position and a flexion position. The modular knee joint prosthesis includes a femoral component that is configured to be mounted to a femur. The femoral component has a first cutout or opening in a central region thereof for receiving a femoral insert. The modular knee joint prosthesis also includes a tibial component that is configured to (i) be mounted either directly or indirectly to a tibia, and (ii) engage the femoral component. The tibial component has a second cutout or opening in a central region thereof for receiving a tibial insert. A kit includes the modular knee joint prosthesis, at least two of the femoral inserts having different geometries, and at least two of the tibial inserts having different geometries.

A prosthetic assembly is provided. The prosthetic assembly comprises: a tibial tray having a medial retaining bracket, a lateral retaining bracket and a substantially centrally disposed boss, a medial bearing, a lateral bearing and a retention clip having a pair or arms which engage opposite sides of the boss and trap the medial lateral bearings, against the medial and lateral retaining brackets, respectively. A method of securing bearing components to a prosthetic assembly is also provided.

A system and method for sharing and absorbing energy between body parts. In one particular aspect, the system facilitates absorbing energy between members forming a joint such as between articulating bones. In one embodiment, there is provided a system for manipulating energy transferred by members defining a joint, the members collectively defining a path of motion and having a cartilage having an energy absorption component configured therebetween.

A modular knee joint prosthesis is configured to move between an extended position and a flexion position. The modular knee joint prosthesis includes a femoral component that is configured to be mounted to a femur. The femoral component has a first cutout or opening in a central region thereof for receiving a femoral insert. The modular knee joint prosthesis also includes a tibial component that is configured to (i) be mounted either directly or indirectly to a tibia, and (ii) engage the femoral component. The tibial component has a second cutout or opening in a central region thereof for receiving a tibial insert. A kit includes the modular knee joint prosthesis, at least two of the femoral inserts having different geometries, and at least two of the tibial inserts having different geometries.

A total knee prosthesis includes a femoral component and a tibial component. The femoral component includes medial and lateral condyles defining an intercondylar notch therebetween. The femoral component further includes a spherical member and a cam member disposed within the intercondylar notch. The tibial component includes a post defining a recess thereon sized to fit the spherical member of the femoral component. At some positions of flexion of the knee prosthesis, the spherical member may rotate with respect to the post recess, allowing the femoral component to articulate with respect to the tibial component. At some positions of flexion of the knee prosthesis, the cam member may contact the post of the tibial member, causing a translation of the spherical member within the post recess and allowing articulation of the femoral component with respect to the tibial component.

A tibial implant includes one or more stiffness-modifying features to reduce the stiffness of one or more sections of the tibial implant. The stiffness-modifying features may include slots, recesses, or passageways defined in various locations of the tibial implant to selectively reduce the stiffness of a tibial insert and/or tibial base of the tibial implant.

A modular spacer device for a knee joint includes a tibial element adapted to be constrained to an end of the tibial bone and a femoral element adapted to be constrained to an end of the femoral bone and to be articulated on the tibial element. The tibial element has first and second surfaces opposite to each other, and the femoral element has first surface and second surfaces opposite to each other. The first surface of the femoral element is convex and laterally has a curved, ammonite-shaped contour with a curvature radius that increases starting from a rear section with a curvature radius R1, a first central section having a curvature radius R2, a second central section having a curvature radius R3, and a front section having a curvature radius R4, with R1≤R2≤R3≤R4.

A system for replacing a portion of an articular surface including providing an implant site and installing an implant into the implant site. The implant site includes a first and a second excision site which at least partially intersect with one another. Each of the first and second excision sites are formed by providing a respective axis and excising a portion of the articular surface relative to the respective axes.

An orthopaedic surgical system for a total knee implant includes a plurality of commonly-sized femoral trial components. Each commonly-sized femoral trial component includes a first femoral condyle having a first articulation surface configured to engage a tibial component, and a second femoral condyle may be spaced apart from the first femoral condyle. The second femoral condyle has a second articulation surface configured to engage the tibial component. An anterior cam is positioned between the first femoral condyle and the second femoral condyle. A method of using such a system is also disclosed.