Effect of Fatty Degeneration of the Infraspinatus on the Efficacy of Arthroscopic Patch Autograft Procedure for Large to Massive Rotator Cuff Tears

BACKGROUND: In a 2013 study involving 24 patients whose shoulders had large or massive rotator cuff tears (RCTs) and low-grade fatty degeneration of the infraspinatus (Goutallier stage 1 or 2), we reported significantly improved clinical results after an arthroscopic fascia lata autograft patch procedure, with a 79.2% rate of intact repairs. Based on that study, we began applying the fascia lata autograft patch procedure to shoulders with stage 3 or 4 degeneration of the supraspinatus and stage 3 or 4 degeneration of the infraspinatus. PURPOSE: To investigate the effects of the fascia lata autograft patch procedure on massive RCTs in shoulders with high-grade degeneration of the infraspinatus by comparing the clinical outcomes and structural features with those in shoulders with low-grade degeneration of the infraspinatus. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A case series of 45 consecutive patients with large to massive RCTs with high-grade fatty degeneration of the supraspinatus and either low-grade (group L; n=26 [the same patients as in our previous study plus 2 additional patients]) or high-grade (group H; n=19) fatty degeneration of the infraspinatus were treated with the fascia lata autograft patch procedure. Clinical (Constant and American Shoulder and Elbow Surgeons [ASES]) scores, structural outcomes on MRI, and muscle strength were assessed at a minimum 2-year follow-up and compared between the 2 groups. RESULTS: Patients in group L had a higher frequency of intact repairs than did those in group H (73.1% vs 10.6%; P<.001), as assessed by MRI. Clinical scores, range of motion, and muscle strength ratios were improved after surgery in both groups. However, at the final follow-up, the mean Constant (78.4 in group L vs 63.9 in group H; P<.0001) and ASES (91.3 in group L vs 73.6 in group H; P<.001) scores were significantly higher in group L than in group H. Moreover, there were significant between-group differences in the mean muscle strength ratio of the affected to healthy sides for both abduction (0.68 in group L vs 0.54 in group H) and external rotation (0.67 in group L vs 0.50 in group H) for abduction at the final follow-up (P<.0001 for both). CONCLUSION: The arthroscopic fascia lata autograft patch procedure was not as beneficial for massive RCTs with high-grade fatty degeneration of the supraspinatus and infraspinatus as other treatment options that produce similar functional results.