1. Bone and Joint Research Center, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan, ROC
2. Department of Orthopedic Surgery, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan, ROC
3. College of Medicine, Chang Gung University, Taoyuan 333, Taiwan, ROC
4. Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University Taoyuan 333, Taiwan, ROC