FATTY MUSCLE INFILTRATION IN CUFF TEAR: PRE AND POST OPERATIVE EVALUATION BY MRI

Objective: To evaluate the fatty infiltration and atrophy of the supraespinatus in the pre- and postoperative of a rotator cuff lesion (RCL), by MRI. Methods: Ten patients with full-thickness rotator cuff tears who had undergone surgical arthroscopic rotator cuff repair between September and December 2011 were included. This is a prospective study, with analysis and comparison of fatty infiltration and atrophy of the supraespinatus. The occupation ratio was measured using the magic selection tool in Adobe Photoshop CS3 (R) on T1 oblique sagittal Y-view MRI. Through Photoshop, the proportion occupied by the muscle belly regarding its fossae was calculated. Results: There was a statistically significant increase in the muscle ratio (p=0.013) comparing images pre and postoperative, analyzed by the Wilcoxon T test. Conclusion: The proportion of the supraspinal muscle above the pit increases in the immediate postoperative period, probably due to the traction exerted on the tendon at the time of repair.