1. Department of Orthopaedic Surgery, Niigata Cancer Center Hospital, 2-15-3, Kawagishi-Cho, Niigata City 951-8510, Japan.
2. Division of Orthopaedic Surgery, Department of Regenerative and Transplant Medicine Niigata University, Graduate School of Medicine and Dental Science, 1 Asahimachi-dori, Niigata City 951-8510, Japan.