Traumatic rotator cuff tears with concomitant shoulder dislocation: tear characteristics and postsurgical outcomes.

Background: Arthroscopic rotator cuff repair has been shown to have favorable outcomes following traumatic rotator cuff tear with concomitant shoulder dislocation. The aim of this study was to compare outcomes and tear characteristics between patients who underwent arthroscopic rotator cuff repair following traumatic tear with shoulder dislocation to those without dislocation.

Methods: A retrospective review of 226 consecutive patients with traumatic rotator cuff tears who underwent arthroscopic repair between 2013 and 2017 with a minimum of 1-year follow-up was performed. Patients with traumatic dislocations and concomitant rotator cuff tears were placed in the Dislocation & Tear cohort (DT cohort) and were matched 1:2 with a second cohort sustaining traumatic cuff tears without dislocation (T cohort). Primary outcomes were injury characteristics including tendon involvement and atrophy and tear size and thickness. Secondary outcomes were postoperative strength and range of motion (ROM) in forward flexion (FF), external rotation (ER), and internal rotation (IR); patient-reported outcomes including Subjective Shoulder Value, visual analog scale, and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form; complications including repair failure (defined as symptomatic retear confirmed on postoperative magnetic resonance imaging), infection, adhesive capsulitis, and impingement; and rates of revision surgery.

Results: There were 18 patients in the DT Cohort and 36 patients in the T Cohort with no significant differences in time to final follow-up (50.4 ± 24.5 months vs. 49.0 ± 30.4 months, P = .73). The DT cohort displayed a larger mean tear size (34 ± 12 mm vs. 19 ± 12 mm, P = .01) and had greater infraspinatus involvement (78% vs. 36%, P = .004) and subscapularis involvement (72% vs. 39%, P = .02) than the T cohort. With regard to strength, postoperative ER strength was less likely to be 5/5 in the DT Cohort (53% vs. 94% of patients with 5/5 strength, P = .002) compared with the T cohort. With regard to ROM, the DT cohort had significantly lower preoperative FF (90° ± 55° vs. 149° ± 33°, P < .001), ER (36 ± 21° vs. 52° ± 14°, P = .02), and IR (5.4 ± 2.1 vs. 7.5 ± 1.2, P = .002) compared with the T cohort but had similar FF, ER, and IR outcomes postoperatively. There were no differences between the groups for complications and postoperative patient-reported outcomes.

Conclusion: Traumatic rotator cuff tears with concomitant dislocations are associated with larger tear size and greater infraspinatus and subscapularis involvement than traumatic tears without dislocation. Arthroscopic repair of this injury is associated with lower preoperative ROM in FF, ER, and IR, as well as lower postoperative ER strength compared with traumatic tears without dislocation. Nonetheless, excellent patient-reported outcomes can be achieved following arthroscopic repair similar to patients without dislocation.