Prevention of wear and osteolysis - Alumina-on-alumina bearing

Alumina-on-alumina bearings in total hip replacement have been used for 30 years. Excellent tribologic properties and extra low debris generation coul d, in theory, provide an answer to osteolysis. A review of the authors' exp erience with alumina-on-alumina bearings showed that, except in a few beari ngs that had been loose for a long time, osteolysis was not a problem. Alth ough the cemented titanium stem and the alumina-on-alumina couple were not a problem, fixation of the socket had to be im proved. To improve the socke t fixation system and to avoid the use of a cemented titanium stem that may have created problems in the long-term, a new design was introduced in 199 7. The current authors present the preliminary results of the first 96 hips with cementless fully-coated hydroxyapatite titanium alloy stems and socke ts, 32-mm alumina femoral head, and alumina liner, both held with a Morse t aper. Ninety-six consecutive hips in 89 patients (57 males, 32 females) wit h a median age of 46 years (range, 14-72 years) were analyzed. One socket w as revised at 4 months because of poor primary stability in a patient with a severe acetabular fracture. One patient experienced a traumatic fracture of the implanted femur 3 weeks after surgery. The mean followup was 16 mont hs (range, 4-38 months). One patient died from rupture of an aneurysm. Nine ty-three hips in 86 patients were assessed regarding the clinical and radio logic ratings. Two patients (two hips) were interviewed by telephone. The M erle d'Aubigne rating system was 18 in 65 hips (59 patients), 17 in 25 hips (25 patients), and 16 in three hips (three patients) mainly related to a p revious disability including limp, sciatic palsy, or stiffness. Examination of 93 available radiographs revealed no ostelolysis, no radiolucent lines at the last examination, and no subsidence. The level of excellent results, even in this young population, and lack of osteolysis and wear are encoura ging, even if the followup is too short to allow any conclusions to be made .