1. Department of Orthopedic Surgery, Graduate School of Medical Sciences, Nagoya City University, Nagoya 467-8601, Japan
2. Department of Pediatrics, Graduate School of Medical Sciences, Nagoya City University, Nagoya 467-8601, Japan
3. Department of Pediatrics, Nagoya City University, West Medical Center, Nagoya 462-8508, Japan
4. Department of Orthopaedic Surgery, Kanazawa University, Kanazawa 920-8641, Japan