1. Departments of Orthopedic Surgery and Biochemistry, Tohoku University School of Medicine, Sendai; and the Department of Orthopedic Surgery; Iwate Medical School; Morioka Japan
2. Department of Orthopedic Surgery; Tohoku University School of Medicine
3. Department of Orthopedic Surgery; Iwate Medical School
4. Department of Biochemistry; Tohoku University School of Medicine