1. Department of Orthopaedic Surgery, Obihiro Kosei Hospital Hand Center, Obihiro, Japan
2. Department of Orthopaedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
3. Division of Biostatistics, Clinical Research and Medical Innovation Center, Hokkaido University Hospital, Sapporo, Japan
4. Department of Internal Medicine III, Obihiro Kosei Hospital, Obihiro, Japan