1. Division of Orthopedic Surgery; Graduate School of Medical and Dental Sciences; Niigata University; Niigata Japan
2. Department of Orthopedic Surgery; Uonuma Kikan Hospital; Niigata Japan
3. Department of Orthopedic Surgery; Niigata Cancer Center Hospital; Niigata Japan
4. Department of Pathology; Graduate School of Medical and Dental Sciences; Niigata University; Niigata Japan