1. Department of Orthopaedic Surgery, Enshu Hospital, 1-1-1 Chuo, Naka-ku, Hamamatsu, Shizuoka 430-0929, Japan
2. Koide Clinic, Kosai, Shizuoka 431-0442, Japan
3. Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka 431-3192, Japan