States of contra-lateral rotator cuff – Based on bilateral shoulder ultrasound results of 401 patients

For patients with rotator cuff tear (RCT), the contra-lateral shoulders have higher risk of RCT than general population. It has been proved by several previous studies. The focus of this study is to obtain the data of contra-lateral rotator cuff tear in Chinese population, and to find the rules of contra-lateral rotator cuff tear through statistical analysis. From March 2016 to January 2020, patients who underwent shoulder arthroscopic surgery were included in the study, we conduct bilateral shoulder ultrasound before surgery, patients information collection include gender, age, occupation and whether received contra-lateral rotator cuff surgery within 1–3 years. The above information was statistically analyzed. According to the inclusion and exclusion criteria, 401 patients were included. The incidence of contra-lateral rotator cuff tear was 24.3%, 5.58% of them underwent contra-lateral rotator cuff repair surgery within 3 years. The degree of contra-lateral rotator cuff tear was positively correlated with the degree of the primary side; Patients with full-thickness rotator cuff tear were more likely to have contra-lateral rotator cuff tear than patients with partial rotator cuff tear. For patients with supraspinatus tendon tear, the contra-lateral rotator cuff tear risk increases, For patients with subscapularis muscle tear, the contra-lateral rotator cuff tear risk doesn't increases. Contra-lateral rotator cuff tear is related to age, the risk of contra-lateral rotator cuff tear is higher in elderly patients. The contra-lateral RCT data obtained in our study was 24.3%, significantly lower than that of previous studies. The reasons may include ethnic variation, lifestyle, and proportion of heavy physical labor. The condition of contra-lateral rotator cuff is closely related to affected side rotator cuff tear.