Revision Rotator Cuff Repair With Versus Without an Arthroscopically Inserted Onlay Bioinductive Implant in Workers' Compensation Patients.

Background: The addition of onlay biological grafts to augment difficult rotator cuff repairs has shown encouraging results in a case series.

Purpose/hypothesis: The purpose of this study was to determine whether the addition of an onlay bioinductive implant would improve repair integrity, shear wave elastographic appearance of the repaired tendon and patch, and patient-rated and/or surgeon-measured shoulder function when used in workers' compensation patients undergoing revision arthroscopic rotator cuff repair. We hypothesized that the addition of the bioinductive implant would enhance repair integrity and clinical outcomes compared with standard repair.

Study Design: Cohort study; Level of evidence, 3.

Methods: A post hoc matched-cohort study was conducted on prospectively recruited workers' compensation patients who received a bioinductive implant for revision rotator cuff repair (n = 19). The control group was selected from consecutive workers' compensation revision rotator cuff repair patients before the introduction of bioinductive implants. Then, they were matched for age and tear size (n = 32). Kaplan-Meier curves were generated to compare the primary outcome of repair integrity between groups. The secondary outcomes were to evaluate the elastographic appearance of the tendon and patch in the bioinductive implant group and to compare patient-rated and surgeon-measured shoulder function between groups preoperatively and at 1 week, 6 weeks, 3 months, and 6 months postoperatively.

Results: No major complications associated with the bioinductive implants were identified. Six months after the revision rotator cuff repair, the retear rate in the bioinductive implant group was 16% (3/19), compared with 19% (6/32) in the age- and tear size-matched control group ( = .458). At the final follow-up, the retear rate in the bioinductive implant group was 47% (9/19) at a mean of 14 months compared with 38% (12/32) at a mean of 29 months in the control group ( = .489). The shear wave elastographic stiffness of repaired tendons augmented with the bioinductive implant remained unchanged at 6 m/s from 1 week to 6 months postoperatively, which is lower than the stiffness of 10 m/s in healthy tendons. There were no significant differences in patient-rated or surgeon-measured outcomes between groups 6 months postoperatively.

Conclusion: There were no differences in repair integrity or clinical outcomes between workers' compensation patients who underwent revision arthroscopic rotator cuff repair with an onlay bioinductive implant compared to those who underwent standard revision rotator cuff repair.