Osteonecrosis After Powered Core Decompression

A 44-year-old man with alcohol-related osteonecrosis of his left femoral head, Ficat Stage 2, was treated by femoral head decompression. During this procedure the ¼-inch trephine driven by a power reamer became lodged in the femoral head and became hot to the touch. The trephine eventually was removed with difficulty after the decompression was completed. Four and a half years later, the patient continued to have progressive pain and difficulty ambulating. A radiograph at the time revealed a wide zone of symmetric increased density about the core decompression track. A total hip arthroplasty was done, yielding the femoral head and neck for study. Histologic sections of the femoral head and neck showed that the entire length of the core decompression track in the specimen was surrounded by 2.7 cm of unrepaired necrotic bone. The evidence suggests that extensive additional necrosis was produced iatrogenically during the core decompression with the powered trephine. Necrosis secondary to either heat generation or increased pressure along the trephine track is presented as possible mechanisms for this unusual finding.