Resorption of bone and the formation of a membrane at the interface
between acrylic cement and bone were induced by particles of high-density
polyethylene that were similar in size to those that are present in the
tissues surrounding a human joint prosthesis. A non-weight-bearing plug of
methylmethacrylate was inserted through the knee joint into the distal part
of the femur of the rat. The plug rapidly became surrounded by a shell of
bone. After repeated injections of particles of high-density polyethylene
into the knee joint, resorption of bone occurred at this stable interface.
No resorption of bone occurred after the opposite knee was injected with a
control preparation that did not contain particles. The resorption of bone
that occurred around the plug after the injection of particles of
polyethylene took place in the absence of mechanical causes for loosening
and in the absence of infection.