Prediction of rotator cuff repair results by magnetic resonance imaging.

Thirty chronic rotator cuff tears were repaired consecutively and evaluated prospectively using a precise anatomic description of the tear that included the rotator interval, the Constant functional score, and an assessment of the tendon state and the atrophy of the supraspinatus muscle by preoperative and postoperative magnetic resonance imaging. Early correlations (mean followup, 21.1 months) attempted to define predictive factors of the final outcome of the repair, physical factors indicative of final tendon state, and postoperative evolution of supraspinatus atrophy. Magnetic resonance imaging oblique sagittal views showed that supraspinatus atrophy correlated with the sagittal and coronal extent of the tear and represented a strong predictive factor of postoperative retearing. At followup, 15 (50%) cuffs were continuous and thick, seven (23%) were continuous but thin, and six (20%) were retorn. Two (7%) cuffs had been repaired only partly. In the group with a persistent tear, flexion strength and differential Constant score were correlated with the final tendon state with no excellent or good results, and with less than 4 kg of strength. Supraspinatus atrophy improved in 18 of the 22 postoperative continuous cuffs, but never decreased in persistent tears, although there was pain relief and functional gain.