1. Department of Orthopaedic Surgery, Chiba University School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba City, Japan 260.
2. Department of Orthopaedic Surgery, Sawara Prefectural Hospital, E 2285, Sawara City, Chiba, Japan 287.
3. Department of Orthopaedic Surgery, Narashino National Hospital, 1-1-1 Izumi-chou, Narashino City, Chiba, Japan 275.
4. Division of Orthopaedic Surgery, Chiba Children’s Hospital, 579-1, Heta-chou, Midori-ku, Chiba City, Japan 266.