The extent of osteocyte death in the proximal femur of patients with osteonecrosis of the femoral head

Our aim was to assess the local extent of osteocyte death in the proximal f emur of 16 patients with osteonecrosis of the femoral head. We performed hi stological examination of the femoral heads and cancellous bone biopsies fr om four regions of the proximal femur in patients undergoing total hip arth roplasty. A control group consisted of 19 patients with osteoarthritis. All histological specimens were examined in a blinded fashion. Extensive osteonecrosis was shown in the proximal femur up to 4 cm below th e lesser trochanter in the group with osteonecrosis. There was an overall s tatistically significant difference in the extent of osteocyte death distal to the femoral head between the two groups (p < 0.001). We discuss the imp lications of these findings as possible contributing factors in regard to t he early failure of total hip arthroplasty reported in patients with osteon ecrosis of the femoral head.