1. Department of Orthopaedic and Spinal Surgery, Graduate SchoolTokyo Medical and Dental University1‐5‐45 Yushima, Bunkyo‐ku Tokyo 113‐8519 Japan
2. HOYA Technosurgical Corporation1‐1‐110, Tsutsujigaoka Akishima‐shi Tokyo 196‐0012 Japan
3. Department of Orthopaedic Research and Development, Graduate SchoolTokyo, Medical and Dental University1‐5‐45 Yushima, Bunkyo‐ku Tokyo 113‐8519 Japan