Fig. 1.

Collin classification of rotator cuff tear size. T2 MRI sagittal oblique images demonstrating the Collin classification of rotator cuff tear size. The rotator cuff is divided into five sections: lower subscapularis, upper subscapularis, supraspinatus, infraspinatus, and teres minor. The classification system consists of five rotator cuff tear types: type A involves upper subscapularis and supraspinatus; type B involves the entire subscapularis and supraspinatus; type C involves upper subscapularis, supraspinatus, and infraspinatus; type D involves supraspinatus and infraspinatus; and type E involves supraspinatus, infraspinatus, and teres minor