Abstract
The results produced by bipolar endoprosthesis with or without cement for avascular necrosis of the femoral head was examined. The prosthesis used Omnifit system, usually without cement except 4 joints. Eighteen joints which consisted of 14 of men and 4 of women followed up with the average duration of 29 months (range: 14 to 48). The average age at surgery was 48 years (range: 24 to 75). The preoperative radiological condition of the hip joint was classified as stage III in 11 joints and stage IV in 7. According to the clinical evaluation system of the Japanese Orthopedic Association (JOA), the mean scores were 49 points preoperatively and 86 points at follow up examination. Radiologically, the migration over 4mm of the outher head proximally or of the prosthetic stem distally was demonstrated in one joint, and in three joints, respectively. The magnitude of the migration was considered to relate to such factors as preoperative articular deterioration, steroid therapy, and thineer femoral cortical bone. Although those radiological findings did not seem to affect the clinical evaluation of this short term, they will be the important factors which influence the long term results.
