1 Department of Orthopedic Surgery, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Korea; Department of Orthopaedic Surgery, Daejeon Eulji Medical Center, Eulji University School of Medicine, Daejeon, Korea.
2 Department of Anesthesiology and Pain Medicine, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Korea.
3 Department of Orthopaedic Surgery, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Korea.
4 Department of Orthopaedic Surgery Asan Medical Center College of Medicine University of Ulsan Seoul, Korea.