Implant apparatus and methods directed toward treating conditions involving the knee joint and the patella specifically are disclosed. Full range of motion of the knee joint and tissue integrity are maintained in treatment approaches involving implanting a joint surface load reducing implant proximate the joint to change the direction of the tendons or muscles exerting forces on the joints.

The disclosure is directed to a resilient implant for implantation into human or animal joints to act as a cushion allowing for renewed joint motion. The implant endures variable joint forces and cyclic loads while reducing pain and improving function after injury or disease to repair, reconstruct, and regenerate joint integrity. The implant is deployed in a prepared debrided joint space, secured to at least one of the joint bones and expanded in the space, molding to surrounding structures with sufficient stability to avoid extrusion or dislocation. The implant has opposing walls that move in varied directions, and an inner space filled with suitable filler to accommodate motions which mimic or approximate normal joint motion. The implant pads the damaged joint surfaces, restores cushioning immediately and may be employed to restore cartilage to normal by delivering regenerative cells.

A knee joint prosthesis which comprises a tibial component (4, 6) and a femoral component (2). The femoral component has condyles (14, 16) which act against the tibial component, directly or indirectly, during flexing of the knee. A cam (20) on the femoral component acts against a post (26) on the tibial component at high flex angles. The surface of the post which is contacted by the cam at high flex angles is convex when the post viewed generally perpendicular to the tibial bone contact and bearing surfaces, and the femoral bearing surface which is provided by the cam, where it contacts the convex surface of the post at high flex angles, is locally concave (32) when viewed along the surface of the post which contacts the cam so that the area of contact between the post and the cam is greater at high flex angles than at lower flex angles.

Certain embodiments generally provide an improved tibial base member comprising keel portions that allow one or both cruciate ligaments to be preserved. Other embodiments provide improved lateral and/or medial inserts having a mesial lip that helps relieve and or prevent impingement between the femoral component and the tibial eminence. Other embodiments provide improved femoral components having various chamfers to provide additional clearance with respect to the tibial eminence and posterior cruciate ligament without decreasing bone coverage.

This disclosure is directed to restoring joints by deploying a resilient interpositional arthroplasty implant. Such implants function to pad cartilage defects, cushion, and replace or restore the articular surface, which may preserve joint integrity, reduce pain and improve function. The implant may endure variable joint compressive and shear forces and cyclic loads. The implant may repair, reconstruct, and regenerate joint anatomy, and thereby improve upon joint replacement alternatives. The walls of this invention may capture, distribute and hold living cells until aggregation and hyaline cartilage regrowth occurs. The implant may be deployed into debrided joint spaces, molding and conforming to surrounding structures with sufficient stability so as to enable immediate limb use after outpatient surgery. Appendages of the implant may repair or reconstruct tendons or ligaments, and menisci by interpositional inflatable or compliant polymer arthroplasties that promote anatomic joint motion.

Methods and devices are provided for knee joint replacement with anterior cruciate ligament (ACL) substitution. Generally, the methods and devices can allow a knee joint to be partially or totally replaced in conjunction with substitution of the knee joint's ACL. In one embodiment, a knee replacement prosthesis can include a medial or lateral femoral implant, a femoral intercondylar notch structure, a medial or lateral tibial insert, and an ACL-substitution member. The ACL-substitution member can be configured to engage with the femoral intercondylar notch structure during a full range of knee motion and/or during only early knee flexion.

Custom moldable cushions for covering medical implants fastened to a bone are provided. Such cushions inhibit irritation of the surrounding soft tissue by covering the bone-implant interface and by reducing friction caused by movement of soft tissue adjacent the implant. Such cushions may also be employed to spread and absorb forces reducing patient discomfort and risk of injury and infection associated with such implants.

Methods and devices are provided for knee joint replacement with anterior cruciate ligament (ACL) substitution. Generally, the methods and devices can allow a knee joint to be partially or totally replaced in conjunction with substitution of the knee joint's ACL. In one embodiment, a knee replacement prosthesis can include a medial or lateral femoral implant, a femoral intercondylar notch structure, a medial or lateral tibial insert, and an ACL-substitution member. The ACL-substitution member can be configured to engage with the femoral intercondylar notch structure during a full range of knee motion and/or during only early knee flexion.

The present invention provides an artificial knee joint that can reconstruct an anterior cruciate ligament in a state close to an original function. An artificial knee joint (1) that is used in a total knee replacement includes a femur member (10) and a tibia member (20). The tibia member (20) has a ligament insertion hole (20h) which pierces the tibia member (20) and which is formed at a position where once an anterior cruciate ligament (ACL) exists in a knee replaced for the artificial knee joint (1). Therefore, a ligament can be provided such that a distal end (DT) of a femur (F) and a proximal end (PE) of a tibia (T) are joined to each other by passing the ligament through the ligament insertion hole (20h), which allows the anterior cruciate ligament (ACL) to be reconstructed so as to be in the substantially same state as a knee replaced for the artificial knee joint (1).

A tibial prosthesis comprises a medial base portion configured to engage a medial surface of a tibia and a lateral base portion configured to engage a lateral surface of the tibia. At least a portion of the medial and lateral base portions are separated by a passage interposed therebetween. The tibial prosthesis also comprises a bridge coupling the medial base portion and the lateral base portion, wherein at least a portion of the bridge is elevated above a portion of the passage between the medial base portion and the lateral base portion. The bridge may define an underlying area that receives at least a portion of a tibial eminence when the tibial prosthesis is engaged with the tibia, wherein the height of the bridge varies in a superior direction across the passage.