1. Center for Sports Medicine, Hokkaido University Hospital, Sapporo, Japan.
2. Faculty of Medicine and Graduate School of Medicine, Department of Orthopaedic Surgery, Hokkaido University, Sapporo, Japan.
3. Keiyu Orthopaedic Hospital, Tatebayashi, Japan.
4. Hokkaido Orthopaedic Memorial Hospital, Sapporo, Japan.
5. Mochida Pharmaceutical Co Ltd, Tokyo, Japan.