The influence of arthroscopic subscapularis tendon and capsule release on internal rotation strength in treatment of frozen shoulder.

BACKGROUND: Arthroscopic release of the capsule is a popular treatment option for chronic refractory frozen shoulder. Additional release of the intra-articular part of the subscapularis is controversial regarding possible impairment of subscapularis function.

HYPOTHESIS: Arthroscopic release of the intra-articular part of the subscapularis produces good clinical results and does not lead to reduced internal rotation strength.

STUDY DESIGN: Case series; Level of evidence, 4.

METHODS: Twenty-two patients were retrospectively evaluated 53 months (range, 12-106) after undergoing arthroscopic anterior capsular release, including release of the intra-articular portion of the subscapularis. Clinical outcome was evaluated using the American Shoulder and Elbow Surgeons score and the Constant score. Isometric and isokinetic strength for internal and external rotation were determined at the time of follow-up in both shoulders using a Cybex dynamometer.

RESULTS: The Constant score was improved significantly from 17.7 points to 82.8 points (P < .0001) and the American Shoulder and Elbow Surgeons score increased significantly from 23.5 points to 76.8 points (P < .0001). The mean range of motion was significantly improved for external rotation from 16 degrees to 58 degrees , from 66 degrees to 142 degrees for abduction, and from 76 degrees to 155 degrees for forward flexion. Isometric and isokinetic strength in the standard abduction position of the Cybex dynamometer showed no significant side-to-side difference.

CONCLUSION: Arthroscopic capsular release combined with a release of the intra-articular portion of the subscapularis tendon revealed good clinical results in the arthroscopic treatment of adhesive capsulitis without significant loss of internal rotation strength.