1 Department of Orthopedic Surgery, Haeundae Paik Hospital, Inje University College of Medicine, Busan, South Korea.
2 Division of Endocrinology and Metabolism, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, South Korea.
3 Department of Orthopedic Surgery, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea.
4 Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan, College of Medicine, Seoul, South Korea. Electronic address: jschang@amc.seoul.kr.