1. Hokkaido University Graduate School of
Medicine, North-15, West-7, Kita-ku, Sapporo, Hokkaido
060-8638, Japan.
2. Orthopaedic Hokushin Hospital, Kikusuimotomachi
3-3, Sapporo, Hokkaido
003-0823, Japan.
3. Japan Community Health Care Organization
Hokkaido Hospital, Nakanoshima 1-8, Sapporo, Hokkaido
062-8618, Japan.