The invention reduces wear in total joint articulations by modifications of the shape of either component of the kinematic pair, so as to result in an annular surface contact between the two components. Fluid trapped between the two components within the inner contour of the annular contact area is pressurized under load due to elastic deformation of the components and exuded out through inter-articular gap over the surface of contact, aiding in lubrication and reducing the wear. Reduced to practice for a total hip joint with UHMWPE-metal pair, the wear rate tested in a hip joint simulator up to five million cycles was reduced by factor seven to fifteen compared to conventionally shaped components.

In one embodiment a method of implanting a prosthetic includes implanting a first member including a concave articulation surface portion defined by a first radius of curvature in a first bone, implanting in a second bone a second member including a first convex articulation surface portion defined by a second radius of curvature and a second convex articulation surface defined by a third radius of curvature, wherein the second convex articulation surface is defined by the lemon portion of a spindle torus and each of the second radius of curvature and the third radius of curvature has a length that is different from the length of the first radius of curvature by less than 0.05 millimeters and wherein the origin of the second radius of curvature is not coincident with the origin of the third radius of curvature, and bringing the first member into slidable contact with the second member

A prosthetic ball for use in a ball and cup joint system includes a spherical cap articulation portion defined by a first radius of curvature, and a toroidal articulation portion defined by a second radius of curvature having a circular origin such that the toroidal articulation portion is defined by a portion of the inner surface of a spindle torus.

Femoral heads, mobile inserts, acetabular components, and modular junctions for orthopedic implants, e.g., hip replacement implants, and methods of using femoral heads, mobile inserts, acetabular components, and modular junctions for orthopedic implants are provided. Prosthetic femoral heads, mobile inserts, and acetabular components are provided that can alleviate soft tissue impingement, reduce implant wear, and/or reduce frictional torque. Modular junctions are provided that can minimize the incidence of loosening and micromotion that can occur at modular junctions of orthopedic implants.

The present invention relates to an artificial hip joint replacement system. The system includes an acetabulum portion having a cup suitable to be received by a subject's acetabular bone. The cup includes a rigid portion and an elastic portion attached to the rigid portion. Also included in the system is a ball received within the cup and in contact with the elastic portion and a femoral stem attached to the ball. The elastic portion is positioned to cause expansion and allow contraction of a space between the ball and the rigid portion of the cup so they are further apart from one another during periods of low mechanical loads.

A partial hip prosthesis for reducing friction and wear in partial hip prosthesis by combining optimized geometry of the articulation and surface treatment of the prosthetic component. In the prosthesis, one of the articulating surfaceseither that of the reamed acetabulum, or that of the femoral head prosthesis is a-spherical so that a fluid-filled gap is formed at the area of major load transfer. The fluid-filled gap is sealed by an annular area of contact, over which the concave and the convex components are congruent. A prosthetic head is fixed to the femur by either a conventional stem, a perforated shell, or a femoral neck prosthesis screwed onto the femur so that it is partially covered by bone and partially exposed on the medial-inferior aspect, where it abuts the reamed cortex of the calcar region.

A method of assembling a mobile bearing acetabular component of a prosthetic hip joint is disclosed. The method includes mounting an acetabular cup insert to an acetabular cup. The method includes concurrently repositioning the acetabular cup insert deeper into an interior of the acetabular cup and repositioning the acetabular cup insert outside of an outline of the acetabular cup.

De-escalation revision systems and methods for total hip arthroplasty (THA), or total hip replacement, according to which a hip cone is installed in a femur, and a femoral stem is installed through the hip cone via bone cement, unitizing the femoral stem to the hip cone. The hip cone experiences mechanical fixation due to the bone cement, as well as long-term biologic fixation due to, for example, bony ingrowth into the hip cone. The systems and methods are suitable for complex primary, conversion, or revision total hip replacement, and are suitable from any approach such as, for example, direct anterior (DA), posterior, or lateral approaches.