1. Department of Orthopaedic Surgery, Kang-Nam St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Seocho-gu, Seoul 137-040, Korea.
2. Department of Orthopaedic Surgery, Dongshin General Hospital, Hongeun-dong 430, Seodaemoon-gu, Seoul 120-848, Korea.