MR imaging after rotator cuff repair: full-thickness defects and bursitis-like subacromial abnormalities in asymptomatic subjects

Objective. To determine the prevalence and extent of residual defects or re tears and bursitis-like subacromial abnormalities on MR images after rotato r cuff repair in asymptomatic subjects, and to define the clinical relevanc e of these findings. Design and patients. Fourteen completely, asymptomatic patients and 32 pati ents with residual symptoms were investigated 27-53 months (mean 39 months) after open trans-osseous reinsertion of the rotator cuff. Coronal T2-weigh ted turbo spin-echo and turbo STIR or T2weighted fat-suppressed MR images w ere obtained. The prevalence and extent of residual defects or retears of t he rotator cuff and bursitis-like subacromial abnormalities were determined . Results. Residual defects or retears were detected in three (21%) and bursi tis-like abnormalities in I C (100%) of the 14 asymptomatic patients. Fifte en (47%) residual defects or retears and 31 (97%) bursitis-like abnormaliti es were diagnosed in the 32 patients with residual symptoms. The size of th e residual defects/retears was significantly smaller in the asymptomatic gr oup (mean 8 mm, range 6-11 mm) than in the symptomatic group (mean 32 mm, r ange 7-50 mm) (t-test, P=0.001). The extent of the bursitis-like subacromia l abnormalities did not significantly differ (t-lest, P>0.05) between asymp tomatic (mean 28x3 mm) and symptomatic patients (mean 32x3 mm). Conclusion. Small residual defects or retears (<I cm) of the rotator cuff a re not necessarily associated with clinical symptoms. Subacromial bursitis- like MR abnormalities are almost always seen after rotator cuff repair even in patients without residual complaints. They may pel-sist for several yea rs after rotator cuff repair and appear to be clinically irrelevant.