1. Department of Musculoskeletal Biomechanics and Surgical Development; Sapporo Medical University; Sapporo 060-8556 Japan
2. Department of Rehabilitation, Faculty of Health Science; Hokkaido Chitose College of Rehabilitation; Chitose 066-0055 Japan
3. Division of Radiology and Nuclear Medicine; Sapporo Medical University Hospital; Sapporo 060-8556 Japan
4. Department of Orthopaedic Surgery; Sapporo Medical University; Sapporo 060-8556 Japan