The influence of medial reattachment of the torn cuff tendon for retracted rotator cuff tears.

We reattached the torn rotator cuff medial to the anatomic cuff insertion site if it was retracted. The purpose was to correlate the amount of medial reattachment of the cuff with shoulder function. We evaluated 63 shoulders in which repaired cuffs were followed with magnetic resonance imaging at a mean follow-up of 8 years. The amount of medial reattachment of the cuff tendon was determined by use of a T2-weighted oblique coronal view, which passed through the center of the humeral head, and was defined as the NCA angle (where N indicates the new cuff insertion point, C indicates the center of the humeral head, and A indicates the anatomic cuff insertion point). Theoretically, the more medially the cuff tendon was reattached, the greater the NCA angle. Neither the Japanese Orthopaedic Association shoulder score nor isometric strength of forward elevation was correlated with the NCA angle. The NCA angle was significantly correlated (P = .001) with the active forward elevation angle, which dramatically decreased at 30 degrees of the NCA angle, approximately 13 mm from the original cuff insertion point, assuming a humeral head radius of 25 mm.