Kotaro Satake1, Tokumi Kanemura1, Hidetoshi Yamaguchi1, Akiyuki Matsumoto2. 1. Department of Orthopaedic Surgery, Konan Kosei Hospital, 137 Takayamachi Ohmatsubara, Konan, Japan 483-8704. 2. Department of Orthopaedic Surgery, Nagoya University, 56 Tsurumacho Showa-ku, Nagoya, Japan 466-8550.