1. Department of Orthopaedic Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan,
2. Department of Physical Therapy, Faculty of Health Care, Takasaki University of Health and Welfare, Takasaki, Gunma, Japan,
3. Department of Orthopaedic Surgery, Inoue Hospital, Takasaki, Gunma, Japan, and
4. Department of Diagnostic Radiology and Nuclear Medicine, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan