1. Department of Orthopaedic Surgery, Nagoya University, Nagoya, Aichi, Japan
2. Department of Orthopaedic Surgery, Aichi Medical University, Aichigun, Aichi-ken, Japan
3. Department of Orthopaedic Surgery, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan
4. Department of Orthopaedic Surgery, Hamamatsu University, Hamamatsu, Shizuoka, Japan