Non-traumatic osteonecrosis involving the femoral head frequently occurs in young patients especially due to steroids administration or other some reasons. In cases of extensive lesion of the weight-bearing area, collapse is usually progressive. Preservation of the joint in young patients to avoid joint replacement procedures is important and widely accepted. Transtrochanteric rotational osteotomy for the femoral head osteonecrosis is ideal procedure moving the remained viable femoral head area to the loaded portion below the acetabular roof, thus hip joints can be preserved for long term by remodeling even if the stage is progressed preoperatively. This procedure is technically difficult, but should be common in orthopaedic surgeons.