Wear data and clinical results for a compression molded monoblock elliptical acetabular component: 5- to 9-year data.

Polyethylene wear rates correlate with osteolysis. Modular acetabular components may fail because of backside polyethylene wear or liner/shell dissociation. A monoblock acetabular component avoids these problems, and we report its midterm results. A total of 221 primary total hip arthroplasties with a titanium monoblock, elliptical acetabular component, performed by 1 surgeon, were followed up for a mean period of 7.2 years (range, 5-9 years). X-rays were scanned, digitized, and examined for osteolysis. Wear rates were determined with the Martell hip analysis software. No acetabular components were revised for polyethylene wear or dissociation, acetabular osteolysis, or loosening. Average yearly wear rate was 0.079 mm (range, 0-0.31 mm.) Midterm results with this monoblock design demonstrate excellent survival and absence of osteolysis.