Abstract: An acetabular cup has a shell component with an outer surface including a first spherical surface portion and a second spherical surface portion, and an acetabulum is prepared with an inner surface having a spherical configuration complementary to the second spherical surface portion of the shell component, the radius of the first spherical surface portion being slightly greater than the radius of the second spherical surface portion such that upon nesting of the second spherical surface portion of the shell component in contiguous relationship with the inner surface of the acetabulum, the first spherical surface portion engages the inner surface of the acetabulum in an interference fit to secure the shell component within the prepared acetabulum.

Abstract: A method of surgically implanting a human knee prosthesis is provided where (i) the postoperative ratio of the adjusted patellar tendon length to the prosthetic patellar height (APL/PH') is from about 1.2 to about 0.9; and (ii) the tibial component of the knee prosthesis is implanted so that the postoperative anterior/posterior center line of the tibial component is located posterior with respect to the preoperative anterior/posterior center line of the tibial plateau by an amount equal to or greater than about 5% of the anterior/posterior distance of the tibial plateau. An implanted prosthetic human knee joint is also provided having either or both the normalized APL/PH' ratio or the 5% posterior placement.

Abstract: A knee pad comprising an upper resilient pad which may be secured on the leg at a point above the knee and a lower resilient pad which may be secured on the leg at a point below the knee. A cover holds portions of the two pads in overlapping relation at the front of the knee for protecting it. The pads are freely movable with respect to one another inside the cover when the knee is flexed.

Abstract: A knee pad comprising an upper pad which may be secured on the leg at a point above the knee and a lower pad which may be secured on the leg at a point below the knee. A cover holds portions of the two pads in overlapping relation at the front of the knee for protecting it. The pads are freely movable with respect to one another inside the cover when the knee is flexed.