Factors Related to Preoperative Shoulder Pain in Patients with Atraumatic Painful Rotator Cuff Tears

BACKGROUND: Patients with rotator cuff tears are usually afflicted with shoulder pain and disability. However, it is unclear which factors are related to shoulder pain in patients with rotator cuff tears. This study was therefore undertaken to determine the factors correlated with shoulder pain in patients with painful rotator cuff tears, but without any history of trauma. METHODS: We evaluated a cohort of 745 patients with painful rotator cuff tears having no trauma history, and analyzed the relationship between pain and multiple factors including demographic data, tear characteristics, and passive range of motion. Pain was analyzed with a questionnaire concerning the visual analogue scale (VAS) for pain. Tear characteristics were determined by evaluating tear size, muscle atrophy, number of torn tendons, and presence of arthritis. Multivariate linear regression analysis and chi-squared test were applied to evaluate the relationship between the VAS for pain and variable factors. RESULTS: Shoulder pain was associated with young age (p=0.01), male sex (p=0.01) and the presence of diabetes mellitus (p<0.001). Measurements of rotator cuff tear characteristics including tear size (p=0.53), muscle atrophy (p=0.16) and the number of torn tendons (p=0.34) did not correlate with shoulder pain. Symptom duration (p=0.60) and range of motion (p>0.05) also showed no correlation with VAS for pain. CONCLUSIONS: Young age, male sex and the presence of diabetes mellitus correlated positively with preoperative shoulder pain in patients with painful rotator cuff tears without a trauma history. Combined treatment of pain management and risk factor correction could be helpful to control preoperative shoulder pain.