Prevalence of the Rotator Cuff Tear Increases With Weakness in Hemiplegic Shoulder

OBJECTIVE To investigate the relationship between the rotator cuff tear (RCT) and the muscle strength in hemiplegic side, and the effects of paralysis on the affected shoulders in hemiplegic patients. METHODS A cross-sectional observational study performed in a university hospital was presented. The study enrolled 55 participants with hemiplegia of diverse degree of motor paresis, excluding those with bilateral lesions, history of major trauma or other co-existing musculoskeletal disorders of the shoulder. The main outcome measurements were muscle strength of the affected upper extremity (based on Medical Research Council scale), RCTs of the bilateral shoulders (by ultrasonography), and presence of shoulder pain, subluxation of the glenohumeral joint, passive range of motions, and subacromial spurs. RESULTS Comparing each side of the shoulders, the prevalence of shoulder pain and supraspinatus muscle tear was higher (p<0.0001, p=0.007), and the range of motion was restricted (p<0.0001, p<0.0001, p<0.0001, p<0.0001) in the affected side. There was a significant trend toward higher prevalence of RCT and shoulder subluxation in the weaker shoulder (p=0.019, p<0.0001). In a multivariate analysis, Manual Muscle Test grade of less than three was an independent risk factor for RCT (p=0.025). CONCLUSION RCT in hemiplegia had a linear trend with muscle weakness in the affected side and the degree of weakness was an independent risk factor for the occurrence of RCT. In addition, shoulder pain, limitation of range of motions, and RCT were more frequent on the hemiplegic side of the shoulders. It is the first study to reveal a linear trend between RCT and upper extremity weakness and will provide physicians an insight to the management of RCTs in hemiplegic patients.