Glenohumeral Translations are Only Partially Restored after Repair of a Simulated Type II Superior Labral Lesion

Background The effect on joint stability of repair of type II superior labrum and biceps anchor lesions is unknown. Hypothesis Increased translations of the glenohumeral joint after a simulated type II lesion will be reduced after the lesion is repaired. Study Design Controlled laboratory study. Methods A robotic/universal force-moment testing system was used to simulate load-and-shift and apprehension tests on eight cadaveric shoulders to determine joint kinematics of the shoulder after venting, creation of a type II lesion, and repair of the lesion. Results At 30° of abduction, anterior translation of the vented joint in response to an anterior load was 18.7 ± 8.5 mm and was significantly increased to 26.2 ± 6.5 mm after simulation of a type II lesion. Repair did not restore anterior translation (23.9 ± 8.6 mm) to that of the vented joint. The inferior translation that also occurred during application of an anterior load was 3.8 ± 4.0 mm in the vented joint and increased significantly to 8.5 ± 5.4 mm with a simulated type II lesion. After repair, the inferior translation decreased significantly to 6.7 ± 5.3 mm. Conclusions Repair of a type II lesion only partially restored glenohumeral translations to that of the vented joint. Clinical Relevance Surgical techniques including improved repair of passive stabilizers injured in the type II lesion should be considered.