Tissue response to titanium implants in experimental antigen-induced arthritis.

The healing of threaded, non-alloyed titanium implants in bone was studied in an experimental model of monoarticular arthritis in New Zealand white rabbits. Immunization with bovine serum albumin (BSA) and repeated intra-articular injections with BSA elicited an immune response and clinical signs of inflammation. Implants were inserted and 6 wk after surgery, with full weight-bearing, the rabbits were killed by perfusion fixation. Light microscopic morphometry showed that the cartilage was thinner and the subchondral bone had a lower density in the arthritic joints compared to the control side. The titanium implants in the arthritic joints had a lesser degree of mineralized bone-implant contact and surrounding bone than the implants inserted in control joints. The present study shows that the healing of titanium implants in the rabbit knee joint is impaired in experimental immunologic arthritis. This model may be useful for the study of biomaterial-tissue interactions under pathological conditions.