1. Department of Knee Surgery, Luoyang Orthopedic Hospital of Henan Province, Orthopedic Hospital of Henan Province, Luoyang, China
2. Center for Cellular and Molecular Engineering, Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
3. Department of Orthopaedic Surgery, West China Hospital, Sichuan University, Chengdu, China
4. Institute for Tissue Engineering and Regenerative Medicine, The Chinese University of Hong Kong, Shatin, China