1. Faculty of Medicine, Department of Orthopaedic Surgery, Saga University, Saga, Japan
2. Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
3. Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
4. Faculty of Medicine, Department of Pathology & Microbiology, Saga University, Saga, Japan