1. Himchan Hospital, Joint & Arthritis Research, Department of Orthopaedic Surgery, 404-3 Mok-dong, Yangcheon-gu, Seoul 158-806, Korea.
2. Himchan Hospital, Joint & Arthritis Research, Division of Rheumatology, 404-3 Mok-dong, Yangcheon-gu, Seoul 158-806, Korea.
3. Yonsei University College of Medicine, Department of Orthopaedic Surgery, 250 Seongsanno, Seodaemun-gu, Seoul 120-752, Korea.