RETRIEVAL ANALYSIS OF TOTAL JOINT REPLACEMENT COMPONENTS: A SIX-YEAR EXPERIENCE.
Quality of Health Care
Total joint replacement components have been examined as part of an ongoing implant retrieval analysis program. Examination of 65 fractured metal femoral components from total hip replacements revealed that all were caused by a fatigue mechanism and that factors such as stem position, material defects, cement technique, patient weight and activity, and stem design played an important role. Metal components from total knee replacements faired better, except those from metal-on-metal constrained designs, which were subject to fracture and considerable wear. Ultrahigh molecular weight polyethylene components showed several modes of damage, including surface wear, permanent deformation, and fracture. Subjective damage grading of 75 acetabular and 57 tibial components revealed significant correlations with patient weight and implantation time.