1. Department of Orthopaedics, Jinan Central Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
2. Department of Orthopaedics, Tengzhou Central People’s Hospital, Tengzhou, Shandong, China
3. Department of B-Ultrasound, The Fourth People’s Hospital of Jinan, Jinan, Shandong, China