Acetabular osteolysis with cementless cups: a 5 to 7 year follow-up

We reviewed the results of 172 plasma-sprayed, titanium primary total hip arthroplasties inserted without cement and followed 5 to 7 years. Hips were replaced for a wide range of diagnoses and patient ages. No femoral components had been revised nor were considered unstable. Clinical results have been excellent; 88% of hips had either no or a slight amount of pain and only 5% of patients had thigh pain when specifically asked. Radiographically, this femoral component achieved stability after an initial subsidence in 9% of cases. Extensive femoral bone resorption was rare, and distal cortical hypertrophy was commonly seen. Pelvic osteolysis occurred in 16 (9%) cases and was considered major in 10 of these. It was the cause of failure of 3 acetabular components. Femoral endosteal lysis was not observed. We concluded that mechanical stability of the Mallory-Head titanium total hip prostheses is excellent. However, significant pelvic osteolysis has occurred commonly with this implant design, and will continue to pose major reconstructive problems in the future.