1. Department of Orthopaedic Surgery; Yamagata University Faculty of Medicine; Iida-Nishi 2-2-2; Yamagata; 990-9585; Japan
2. Department of Orthopaedic Surgery; Stanford University School of Medicine; Stanford; California
3. Department of Immunology; Faculty of Medicine and Dentistry; Palacky University; Olomouc; Czech Republic
4. Department of Orthopaedics; Teaching Hospital; Faculty of Medicine and Dentistry; Palacky University; Olomouc; Czech Republic