Arthroscopic treatment of isolated tendon tears may improve shoulder function

Bartl C. Am J Sports Med. 2011. doi: 10.1177/0363546510396317

Improved shoulder function and a low re-rupture rate can be achieved through the arthroscopic repair of isolated subscapularis tendon tears, according to this study by German researchers.

Still, the authors noted, there is a “significant” strength deficit found in the postoperative subscapularis when compared to the contralateral shoulder, and 25% of patients engaged in a postoperative course have demonstrated atrophy of the upper subscapularis muscle.

The researchers performed a prospective study on 21 patients who underwent arthroscopic repair for isolated subscapularis tendon tears at a mean of 5.8 months after initial injury. Clinical tests and the Constant Scoring system were used to assess subscapularis muscle function. A custom-built force measurement plate was used to measure postoperative subscapularis strength. Postoperative MRI was used to gauge the structural integrity of the repair.

At a mean follow-up of 27 months, the authors reported that the average Constant Score increased from 50 points preoperatively to 82 points postoperatively.

“Most positive preoperative lift-off and belly-press tests were reversed by surgery, with a rate of five (24%) persistent positive tests after surgery,” the authors wrote, adding that operated shoulders demonstrated a significant reduction in subscapularis strength through the belly-press and lift-off positions when compared to contralateral shoulders.

Intact repairs were identified in 20 patients through the use of MRI, and upper subscapularis muscle atrophy was identified in about a quarter of patients — and all patients who demonstrated a positive postoperative belly-press test.