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.

A prosthetic implant is disclosed comprising: a first component comprising a first inner surface and a first outer surface, a second component comprising a second outer surface adapted to contact and engage with the first inner surface, the second component further comprising a second inner surface, a third component comprising a third outer surface adapted to contact and engage with the second inner surface, the third component further comprising a third inner surface, and a fourth component comprising a fourth outer surface adapted to contact and engage with the third inner surface; wherein the second component is rotatable relative to the first component about a first axis, the third component is rotatable relative to the second component about a second axis perpendicular to the first axis, and the fourth component is rotatable relative to the third component about a third axis perpendicular to the first axis and second axis; the first inner surface and the second outer surface are each formed with a first partial cylindrical shape, the first inner surface and the second outer surface each comprise a flat surface normal to the first axis and are engageable with one another such that the second component is rotatable relative to the first component about the first axis only, the second inner surface and the third outer surface are each formed with a second partial cylindrical shape, the second inner surface and the third outer surface each comprise a flat surface normal to the second axis and are engageable with one another such that the third component is rotatable relative to the second component about the second axis only, and the third inner surface and the fourth outer surface are each formed with a third partial cylindrical shape, the third inner surface and the fourth outer surface each comprise a flat surface normal to the third axis and are engageable with one another such that the fourth component is rotatable relative to the third component about the third axis only.

An elbow arthroplasty system having a ball and a socket. The ball is configured for coupling to at least one member of one of the following groups: (i) a humerus, and (ii) a radius, an ulna, or both of the radius and the ulna. The socket is configured for coupling to at least one member of the other of the following groups: (i) the humerus, and (ii) the radius, the ulna, or both of the radius and the ulna. The socket defines a cavity that is configured to receive at least a portion of the ball. The ball may be a spheroid, an ellipsoid, a sphere, or a portion of one of the foregoing with a convex surface. The socket may be configured with a concave surface that is spheroidal, ellipsoidal, or spherical and designed to mate with the ball. An elbow arthroplasty method using a ball and a socket.

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

An implantable medical device for implantation in a mammal joint having at least two contacting surfaces is provided. The medical device comprises; an artificial contacting surface adapted to replace at least the surface of at least one of the mammal's joint contacting surfaces, wherein the artificial contacting surface is adapted to be lubricated, when implanted in said joint. Furthermore the medical device comprises at least one inlet adapted to receive a lubricating fluid from a reservoir, at least one channel at least partly integrated in the artificial contacting surface in connection with the at least one inlet for distributing the lubricating fluid to the surface of the artificial contacting surface. The medical device could be adapted to be operable by an operation device to receive the distributed lubricated fluid from a reservoir.

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.

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.