Department of Orthopedic Surgery, Keio University, School of Medicine, Shinanomachi 35, Shinjukuku, Tokyo 160, Japan

Department of Orthopedic Surgery, Keio University, School of Medicine, Shinanomachi 35, Shinjukuku, Tokyo 160, Japan

Department of Orthopedic Surgery, Keio University, School of Medicine, Shinanomachi 35, Shinjukuku, Tokyo 160, Japan

Department of Orthopedic Surgery, Keio University, School of Medicine, Shinanomachi 35, Shinjukuku, Tokyo 160, Japan

Department of Orthopedic Surgery, Keio University, School of Medicine, Shinanomachi 35, Shinjukuku, Tokyo 160, Japan

Department of Tissue Physiology, Medical Research Institute, Tokyo Medical and Dental University, Kandasurugadai, Chiyodaku, Tokyo 101, Japan