Tears at the rotator cuff footprint: prevalence and imaging characteristics in 305 MR arthrograms of the shoulder.

<bold>Objectives: </bold>To evaluate the prevalence, imaging characteristics and anatomical distribution of tears at the rotator cuff (RC) footprint with MR arthrography (MR-A) of the shoulder.<bold>Methods: </bold>MR arthrograms obtained in 305 patients were retrospectively reviewed. Partial articular-sided supraspinatus tendon avulsions (PASTA), concealed interstitial delaminations (CID), reverse PASTA lesions and full-thickness tears (FT) at the humeral tendon insertion were depicted. Anatomical locations were determined and depths of tears were classified.<bold>Results: </bold>112/305 patients showed RC tears, including 63 patients with 68 footprint tears. 34 PASTA lesions were detected with 20/34 involving the anterior supraspinatus (SSP) tendon and 17/34 PASTA lesions were grade I lesions. Most CID lesions (14/23) occurred at the posterior SSP and 20/23 were classified as grade I or II. 9 FT and 2 reverse PASTA lesions were found. Statistical analysis revealed no difference in anatomical location (p = 0.903) and no correlation with overhead sports activity (p = 0.300) or history of trauma (p = 0.928). There were significantly more PASTA lesions in patients < 40 years of age (p = 0.029).<bold>Conclusions: </bold>Most RC tears detected with MR-A involve the SSP footprint and are articular-sided with predominance in younger patients, but concealed lesions are not as uncommon as previously thought. [ABSTRACT FROM AUTHOR]