1. Department of Orthopaedic Surgery, Myongji Hospital, 55 Hwasu-ro 14 Beon-gil, Deokyang-gu, Goyang 412-826, Republic of Korea
2. Department of Orthopaedic Surgery and Rare Diseases Institute, Korea University Medical Center, Guro Hospital, 80 Guro-dong, Guro-gu, Seoul 152-703, Republic of Korea
3. Department of Orthopaedic Surgery, Soonchunhyang University Bucheon Hospital, 170 Jomaru-ro, Wonmi-gu, Bucheon, Gyeonggi-do 420-767, Republic of Korea