Muscle Strength After Anterior Shoulder Stabilization

Background: A number of reports have been made on the muscle strength at the last follow-up after arthroscopic or open Bankart repairs. Few have analyzed the change over time in muscle strength and compared the changes between different operative methods.

Hypothesis: Muscle strength recovers faster after arthroscopic Bankart repair than after open Bankart repair, and the final muscle strength is not different between the 2 procedures.

Study Design: Cohort study; Level of evidence, 2.

Methods: Sixty patients with anterior shoulder instability and an isolated Bankart lesion were enrolled for this study. Thirty patients underwent open Bankart repair (open group), and 30 patients went through arthroscopic Bankart repair (arthroscopic group).

Results: The open group demonstrated markedly weaker muscle strength during forward elevation than did the arthroscopic group up to 3 months after surgery, but the difference narrowed to about 5% at 6 months (P = .074). At 6 months after surgery, the muscle strength of the open group measured 85.8% ± 11.5% in forward elevation, 89.5% ± 10.3% in external rotation, and 89.3% ± 13.3% in internal rotation. The corresponding figures of the arthroscopic group were 90.6% ± 8.6%, 92.1% ± 9.1%, and 92.1% ± 11.7%. As for external and internal rotations, the open group demonstrated markedly weaker muscle strength 6 weeks after surgery, but the differences were reduced to about 6% and 4%, respectively, at 3 months (P = .092 and .163, respectively). There was no statistically significant difference in final muscle strength 12 months after the operation between the 2 groups (P = .503, .468, and .659, respectively).

Conclusion: Muscle strength recovered faster with an arthroscopic procedure than with an open procedure during the early postoperative periods, and strength was restored to the level of the unaffected side at 6 months postoperatively. In the group with open Bankart repairs, the muscle strength during forward elevation recovered slower than did external and internal rotation muscle strengths.