Summary

In the largest ever study of patients undergoing ACLR alone or ACLR with LEAP augmentation, LEAP augmentation was associated with a slightly increased risk of arthrofibrosis compared to ACLR alone.

Abstract

Introduction

While lateral extra-articular procedures (LEAPs)—such as the lateral extra-articular tenodesis (LET) and anterolateral ligament reconstruction (ALLR)—have demonstrated significant benefits in reducing rotational instability and retear rates following anterior cruciate ligament reconstruction (ACLR), existing studies have been underpowered to assess whether there is additional morbidly associated with these procedures. In particular, there is clinical concern that LEAPs may increase the risk of arthrofibrosis following ACLR. Therefore, the purpose of this study was to leverage the power of a large national sample to assess the risk of arthrofibrosis following concomitant ACLR+LEAP compared to ACLR alone. We hypothesized that ACLR+LEAP would be associated with increased risk of arthrofibrosis requiring intervention.

Methods

This was a retrospective cohort study of patients who underwent either ACLR+LEAP or ACLR alone from October 2015 through October 2022 in a large national insurance database in the United States (PearlDiver Inc., Colorado, USA). Multi-ligamentous knee injuries, fractures, and revision ACLRs were excluded. Demographic data, surgical information (including concomitant procedures), and comorbidities were collected. The primary outcome was arthrofibrosis requiring manipulation under anesthesia (MUA) and/or lysis of adhesions (LOA) at 1-year. Time-to-event analyses (i.e., Kaplan-Meier with Log-rank tests for unadjusted analysis and Cox proportional hazard models for adjusted analysis) were used to assess the risk of arthrofibrosis following ACLR+LEAP compared to ACLR alone. Comparisons in demographics were made with Student t-tests or Chi-squared tests, as appropriate.

Results

There was a total of 145,146 patients (1.2% ACLR+LEAP, 98.8% ACLR alone) with an average follow-up of 3.3 years. Patients undergoing ACLR+LEAP were younger (mean ± standard deviation 25.0 ± 11.2 years vs. 30.8 ± 13.6 years, p<0.001), more often male (51.2% vs. 48.1%, p=0.01), more often had meniscal repair (36.8% vs. 23.0%, p<0.001), and had a lower comorbidity burden (CCI 0.41 ± 0.82 points vs. 0.47 ± 0.92 points, p=0.007). Patients undergoing ACLR+LEAP had a significantly increased risk of arthrofibrosis requiring intervention at 6-months (2.4% vs. 1.3%, p<0.001), 1-year (2.9% vs. 1.7%, p<0.001), and 2-years (3.3% vs. 1.9%, p<0.001) compared to patients undergoing ACLR alone. These results held in adjusted analysis controlling for age, sex, concomitant procedures, obesity, smoking, comorbidities, and insurance status (hazard ratio 1.53, 95% CI 1.15-2.05, p=0.004).

Discussion

In this national sample of patients undergoing ACLR for primary ACL rupture, we found that the ACLR+LEAP was associated with a higher risk of arthrofibrosis compared to ACLR alone. Importantly, differences were relatively small (absolute risk difference ~1.2 percentage points at 1-year), and LEAPs remain a critical tool for high-risk patients. Nevertheless, these findings from the largest sample of LEAPs ever reported suggest that LEAPs are not entirely benign, underscoring the importance of both indications and rehabilitation protocols.