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 (P=
.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 (P= .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.