1. National Cancer Center, Orthopaedic Oncology Clinic, 111 Jungbalsanro, Ilsandong-gu, Goyang-si, Gyeonggi-do, 410-769, Republic of Korea.
2. Department of Orthopaedic Surgery, Seoul National University College of Medicine, 101 Daehangno, Chongno-gu, Seoul 110-744, Republic of Korea.