1. Department of Orthopaedic Surgery, National Hospital Organization, Osaka Minami Medical Center , Osaka, Japan
2. Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine , Osaka, Japan
3. Department of Orthopaedic Surgery, Amagasaki Chuo Hospital , Hyogo, Japan
4. Department of Orthopaedic Surgery, Osaka Rosai Hospital , Osaka, Japan
5. Department of Orthopaedic Surgery, National Hospital Organization, Osaka-Toneyama Medical Center , Osaka, Japan
6. Department of Orthopaedic Surgery, Nippon Life Hospital , Osaka, Japan