1. Department of Orthopaedic Surgery, Seoul National University College of Medicine, Seoul, Korea
2. Department of Orthopaedic Surgery, Sang-Gye Paik Hospital, Inje University College of Medicine, Seoul, Korea
3. Department of Orthopaedic Surgery, Eulji University College of Medicine, Seoul, Korea
4. Department of Orthopaedic Surgery, Daejin Medical Center, Seoul, Korea