An experimental study of deformation and squeeze film effect in a synovial joint.

Abstract

Femoral chondrocytes of pigs were pressed against a glass disc to simulate and investigate the lubrication characteristics of a synovial joint under physiological conditions. The surface deflection of articular cartilage was measured by a laser displacement pickup through the glass. The following conclusions were reached through the experimental study : when cartilage is pressed by fluid, no creep deformation is detected; most of the applied load is supported by pressurized synovial fluid entrapped inside a slightly contacting circumferential zone; the external flow from the cartilage to the gap causes creep deformation, a reduction of contact pressure and an increase of fluid pressure in the gap.