MRI of symptomatic and asymptomatic full-thickness rotator cuff tears

BACKGROUND AND PURPOSE Why some full-thickness rotator cuff tears are symptomatic and others are asymptomatic is not understood. By comparing MRI findings in symptomatic and asymptomatic tears, we wanted to identify any tear characteristics that differed between groups. PATIENTS AND METHODS 50 subjects with asymptomatic and 50 subjects with symptomatic full-thickness tears were examined by MRI. Tear characteristics including tear size, tear location, the condition of the long head of the biceps, atrophy, and fatty degeneration of the muscles were compared between groups. RESULTS Single factor logistic regression analysis showed that there were statistically significant associations between symptoms and tear size exceeding 3 cm in the medial-lateral plane, positive tangent sign, and fatty degeneration exceeding grade 1 of the supraspinatus and infraspinatus muscles. INTERPRETATION We found associations between the symptomatic status of a rotator cuff tear and MRI-derived tear characteristics. The causal relationships are unclear.