1. Director, Department of Orthopaedic Surgery, Saiseikai Nara Hospital, Hachijo-cho, Nara-shi, Nara 630, Japan.
2. Department of Orthopaedic Surgery, Matsusaka Chuho Hospital, Kawai-cho, Matsusaka, Mie 515, Japan.
3. Department of Orthopaedic Surgery, Nara Medical University, Shijo-cho Kashihara, Nara 634, Japan.