Lateral Extra-Articular Augmentation Is Associated With Improved Graft Survival After Revision Anterior Cruciate...

Revision anterior cruciate ligament reconstruction (ACLR) remains associated with higher graft-failure rates and greater residual rotational laxity than primary reconstruction. Although lateral extra-articular augmentation has been increasingly incorporated into revision surgery, evidence remains limited by confounding related to treatment allocation.

To evaluate the association between lateral extra-articular augmentation and graft survival after first-time single-stage revision ACLR using propensity score-based inverse probability of treatment weighting (IPTW), and to compare postoperative rotational laxity and patient-reported outcomes, with the direct comparison between lateral extra-articular tenodesis (LET) and anterolateral ligament (ALL) reconstruction considered exploratory. We hypothesized that lateral extra-articular augmentation would be associated with lower graft-failure risk and less residual rotational laxity than isolated revision ACLR.

A total of 364 consecutive patients undergoing first-time single-stage revision ACLR between January 2015 and December 2019 were screened at three high-volume knee centers. Sixty-four patients were excluded during eligibility assessment, leaving 300 eligible patients, all of whom were included in the final cohort. The observed treatment distribution was 100 isolated revision ACLRs, 100 revision ACLRs with LET, and 100 revision ACLRs with ALL reconstruction; these group sizes were not created by propensity-score matching, frequency matching, sampling, capping, or post hoc balancing. LET and ALL reconstruction were pooled as lateral extra-articular augmentation for the primary comparison. IPTW was used to improve balance in measured baseline characteristics. Secondary outcomes included residual pivot shift, instrumented anterior laxity, postoperative IKDC and KOOS Sport scores, and return to preinjury sport.

During a mean follow-up of 5.8 ± 1.1 years, graft failure occurred in 20 of 100 patients (20.0%) after isolated revision ACLR and 19 of 200 patients (9.5%) after lateral extra-articular augmentation. Five-year weighted graft survival was 79.9% after isolated revision and 90.6% after augmentation. Lateral augmentation was associated with a lower risk of graft failure (IPTW-adjusted HR, 0.46; 95% CI, 0.28-0.74; P = 0.002). Residual pivot shift was observed in 34 of 200 patients (17.0%) after augmentation and 34 of 100 patients (34.0%) after isolated revision ACLR (weighted OR, 0.42; 95% CI, 0.25-0.71; P = 0.001). Mean instrumented anterior laxity was 2.60 ± 1.00 mm after isolated revision ACLR and 2.25 ± 0.85 mm after augmentation; the device-adjusted difference was -0.21 mm (95% CI, -0.38 to -0.04; P = 0.015) and was not considered clinically interpretable. Postoperative IKDC and KOOS Sport scores showed small between-group differences. The exploratory LET-versus-ALL comparison did not identify a significant difference in graft-failure risk (HR, 0.91; 95% CI, 0.39-2.10; P = 0.82) and should not be interpreted as demonstrating equivalence.

In this propensity-weighted multicenter cohort, lateral extra-articular augmentation was associated with higher graft survival and less residual rotational laxity after first-time revision ACLR. The absolute difference in graft failure was 10.5 percentage points, whereas between-group differences in postoperative patient-reported outcomes and instrumented anterior laxity were small. The exploratory LET-versus-ALL comparison did not demonstrate equivalence. Because treatment allocation was nonrandomized and residual confounding may remain, the study demonstrates an association between lateral augmentation and lower graft-failure risk but cannot establish that augmentation itself caused the observed reduction in failures.

Level III, retrospective multicenter comparative cohort study.