1. Department of Orthopaedic Surgery, Osaka City General Hospital, Osaka, Japan
2. Department of Orthopaedic Surgery, Osaka City University Medical School, Osaka, Japan
3. Center for Senile Degenerative Disorders (CSDD), Osaka City University Medical School, Osaka, Japan
4. Search Institute for Bone and Arthritis Disease (SINBAD), Shirahama Foundation for Health and Welfare, Wakayama, Japan