1. Department of Orthopaedic Surgery, Toyonaka Municipal Hospital, Toyonaka, Japan
2. Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Suita, Japan
3. Department of Orthopaedic Surgery, Kansai Rosai Hospital, Amagasaki, Japan
4. Department of Orthopedic Surgery, JCHO Hoshigaoka Medical Center, Hirakata, Japan