The absence of a metal-on-metal bearing does not preclude the formation of a destructive pseudotumor in the hip - A case report

摘要

In 2009, a 62-year-old woman with rheumatoid arthritis and a total hip arthroplasty (THA) on the right (uncemented Ti-6 AL-7Nb stem combined with a Ti threaded cup, polyethylene inlay, and a 28-mm ceramic head; Zweymuller Alloclassic; Zimmer Orthopaedics, Warsaw, IN) implanted in 2006 presented with a left femoral neck fracture. A THA with a double-mobility acetabular system (Avantage Double-Mobility Acetabular System; Biomet, Warsaw, IN) was implanted. An uncemented titanium-niobium (Ti-6Al-7Nb) stem was used (Zweymuller Alloclassic; Zimmer) with a 12/14 mm trunnion combined with an XXL (+10.5 mm) 28-mm cobalt-chromium head with a 12/14 mm tapered bore (Biomet). The femoral head was introduced into the highly cross-linked, vitamin E-stabilized polyethylene bearing using a bearing press. An uncemented Ti HA-coated 52-mm acetabular shell was press-fitted in the socket and the large polyethylene femoral head was reduced into the metal articular surface. Postoperative recovery was uneventful, with normal wound hearing.