1. Department of Orthopaedic Surgery (Y.-K.L., K.-H.K.), Seoul National University Bundang Hospital, Seongnam-si 463-707, South Korea;
2. Department of Orthopaedic Surgery (Y.-C.H.), Chung-Ang University College of Medicine, Seoul 156-755, South Korea;
3. Department of Orthopaedic Surgery (B.J.K.), Gyeongsang National University School of Medicine, Gyeongsang National University Hospital, Jinju 660-702, South Korea;
4. Department of Orthopedic Surgery (J.S.C.), Asan Medical Center, College of Medicine, University of Ulsan, Seoul 138-736, South Korea