1. Department of Orthopaedics, Ningbo University School of Medicine, Ningbo 315211, Zhejiang, China;
2. Department of Gynecology, Ninghai First Hospital, Ningbo 315600, Zhejiang, China; and
3. Department of Orthopaedics, Ningbo HwaMei Hospital, University of Chinese Academy of Sciences, Ningbo 315010, Zhejiang, China