^aDepartment of Orthopedic Surgery, Seirei Sakura Citizen Hospital

^bChiba Child & Adult Orthopaedic Clinic (Chiba Pediatric Orthopaedic Group)

^cChiba Children’s Hospital, Chiba, Japan

Correspondence to Toshiaki Kotani, MD, Department of Orthopedic Surgery, Seirei Sakura Citizen Hospital, 2-36-2 Ebaradai Sakura-shi, Chiba 285-8765, Japan, Tel: +81 43 486 1151; fax: +81 43 486 8696; e-mail: [email protected]