1. Department of Orthopaedic Surgery, Teikyo University Chiba Medical Center: 3426-3 Anesaki, Ichihara, Chiba 299-0111, Japan
2. Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, Chiba University, Japan
3. Personal Health Care Products Research Laboratories, KAO Corporation, Japan
4. Departments of Orthopaedic Surgery, Juntendo University School of Medicine, Japan