Biologic fixation

One of the major problems of implant surgery is the failure of the bone—cement interface. Because of such failures, observed with increasing frequency with the passage of time, biologic fixation of total joint implants by means of bone ingrowth has become the focus of considerable interest among orthopedic surgeons. Actual bone ingrowth has been demonstrated into porous metals, resulting in a strong interface between metal and bone. Many clinical trials of biologic fixation, including endoprostheses and total hip, shoulder, and knee prostheses, are being conducted. The brief experience of such fixation in humans supports the hypothesis that bone ingrowth will provide stable fixation for load-bearing prostheses. Many questions remain to be answered about biologic fixation and the burden that falls upon the clinical scientist to identify the proper niche for this process in the care of the musculoskeletal patient.