1. Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan
2. Department of Orthopaedic Surgery, Seikeikai Hospital, Osaka, Japan
3. Department of Orthopaedic Surgery, Osaka General Hospital of West Japan Railway Company, Osaka, Japan
4. Department of Orthopaedic Surgery, Yodogawa Christian Hospital, Osaka, Japan