1. Department of Orthopaedic Surgery Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba City, 260-8677, Japan.
2. Division of Orthopaedic Surgery Chiba Children’s Hospital, 579-1 Heta-chou, Midori-ku, Chiba City, 266-0007, Chiba, Japan.
3. Division of Pediatric Orthopaedic Surgery Chiba Rehabilitation Center, 1-45-2 Honda-chou, Midori-ku, Chiba City, 266-0005, Chiba, Japan.
4. Division of Orthopaedic Surgery Narita Red Cross Hospital, 90-1 Iida-chou, Narita City, 286-8523, Chiba, Japan.