1. Division of Rheumatology, Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
2. Department of Orthopedic Surgery, Barun Mind Hospital, Daejeon, Korea.
3. Department of Internal Medicine, Graduate School, Kyung Hee University, Seoul, Korea.
4. Department of Orthopedic Surgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.