Thin cement mantle and osteolysis with a precoated stem

The radiographic and clinical results of 55 hips (52 patients) implanted wi th the Harris precoat hip prosthesis using second generation cementing tech nique were investigated in this study. All metal backed sockets were fixed with cement, The preoperative diagnoses were osteoarthritis secondary to dy splastic hips in 42 patients, primary osteoarthritis in six, rapidly destru ctive coxarthrosis in five, and osteonecrosis of the femoral head in two, T he average age of patients at the time of surgery was 67 years. The average duration of followup was 8 years, The rates of aseptic loosening and osteo lysis in the femoral side were 5.5% (three hips) and 12.7% (seven hips), re spectively, Three sockets were loosened, and no osteolysis was detected in the acetabular side, The mantle of cement in the femur was graded using the criteria described by Mulroy et al, Twenty-seven of 55 (49%) hips had regi ons with a thin cement mantle less than 1 mm in thickness or a defect in th e cement mantle, Osteolysis was detected in seven of the 27 (26 %) hips. Lo cations of osteolysis mere coincidental with those of thin cement mantle or defect with the exception of one hip, This study clearly shows that a thin cement mantle less than 1 mm in thickness and a defect in the cement mantl e lead to osteolysis.