1. Institute of Basic Medical Sciences; National Cheng Kung University; Tainan 70101 Taiwan
2. Department of Orthopaedic Surgery; National Cheng Kung University Hospital; College of Medicine; National Cheng Kung University; Tainan 70428 Taiwan
3. Department of Orthopedic Surgery; Tainan Hospital; Tainan 70101 Taiwan
4. Department of Orthopedics; E-Da Hospital; Kaohsiung 70824 Taiwan