Abstract
Objective: With advances in techniques, arthroscopic repair of isolated subscapularis tendon tears has become increasingly popular in recent years. The aim of this study was to analyze the clinical and structural results of arthroscopic repair versus the gold standard of open repair. It is a prospective cohort study with a control group; evidence level III. Methods: In a prospective study performed at two centers, 18 patients with an isolated subscapularis tear were treated with arthroscopic repair (ARG) and 16 patients with open repair (ORG) using a uniform single-row suture anchor repair technique in both groups. The subscapularis function was assessed using specific clinical tests (belly-press and lift-off tests), strength testing and shoulder function with the use of the Constant-Murley score (CMS). Standardized magnetic resonance imaging (MRI) was used to evaluate the postoperative subscapularis muscle-tendon status. Results: At a minimum follow-up of 48 months, the CMS increased from a mean of 54 points preoperatively to a mean of 86 points postoperatively in the ARG (p < 0.01) and from 50 points to 85 points postoperatively in the ORG (p < 0.01). Specific subscapularis tests (belly-press test and lift-off test) were significantly improved from the preoperative to the postoperative status in both repair groups (p < 0.05). Despite a subscapularis tendon healing rate of over 90% on MRI scans in both repair groups, the incomplete correction of specific muscle tests was a frequent postoperative finding. Conclusions: Arthroscopic repair of isolated subscapularis tears achieved equivalent clinical and structural results compared to the gold standard of open repair.