1. Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University , Fukuoka , Japan
2. Department of Orthopaedic Surgery, Fukushima Medical University School of Medicine , Fukushima , Japan
3. Department of Anatomic Pathology , Pathological Sciences, Graduate School of Medical Sciences, , Fukuoka , Japan
4. Kyushu University , Pathological Sciences, Graduate School of Medical Sciences, , Fukuoka , Japan