Acetabular cup bearing liner

A bearing component for a ball-and-socket joint prosthesis, the bearing component comprising

• a bearing liner formed with a rim defining an opening, the rim connected to a concave bearing surface defining a bearing liner cavity that describes more than a hemisphere, a lip extending around the bearing liner rim, a channel formed in the lip defining a first radial inner and a second radial outward outer surface to permit outward elastic deformation of the bearing liner out radially the rim sufficient to allow a ball prosthesis with generally the same diameter as the bearing liner cavity to enter the bearing liner cavity, and
• a securing ring formed to fit in the channel to inhibit the radial outward elastic deformation of the bearing liner around the rim after insertion of the securing ring into the channel.

A bearing liner assembly for a hip joint prosthesis having a femoral ball, the bearing liner assembly comprising:

• a bearing liner having an inner articular surface forming a greater than hemispherical cavity for receiving the femoral ball, an outer face formed to include a channel defining first radially inner and second radially outer concentric extensions, the first extension forming an integral portion of the inner articular surface and being outwardly flexible into the channel and toward the second extension upon introduction of the femoral ball into the cavity, and
• means for securing the ball within the bearing liner cavity by restricting the first extension against radially outward movement.

The bearing liner assembly of claim, 20, wherein the distance from the inner articular surface to an outer surface of the securing ring is greater than the width of the channel.

A bearing liner assembly for a hip joint prosthesis having a femoral ball, the bearing liner assembly comprising

• a bearing liner having an inner articular surface forming a greater than hemispherical cavity for receiving the femoral ball, an outer face formed to include a concentric channel having a radial inner and a radial outer wall, the radially inner wall of the bearing liner, adjacent the face being flexible radially outwardly into the channel to permit the femoral ball to be inserted into the cavity, and
• a securing ring formed for insertion into the channel to restrict the radially outward movement of the radially inner wall of the channel.

A bearing component for a ball-and-socket joint prosthesis, the bearing component comprising:

• a one-piece bearing liner defined by an outer surface and an inner concave spherical bearing surface describing a spherical cavity of more than 180 degrees and with a rim surface extending between the outer and inner surfaces to define an end surface of the bearing liner and an opening into the inner spherical concave bearing surface;
• a channel extending into the bearing liner from the rim surface between the inner and outer surfaces, for providing a space for outward deformation of an end portion of the inner concave surface, located adjacent the opening, toward an area of the outer surface adjacent the rim end surface.