Summary

In this first study to investigate meniscal repair success rates when performed with concomitant PCL reconstruction, we find that concomitant PCLR is associated with significantly lower rates of revision meniscal surgery compared to meniscal repair alone.

Abstract

Introduction

Concomitant anterior cruciate ligament reconstruction (ACLR) is known to improve the success rates of meniscal repair (MR) compared to MR alone. However, whether posterior cruciate ligament reconstruction (PCLR) also leads to improved success rates of MR is unknown. The purposes of this study was to investigate whether concomitant PCLR is associated with improved success rates of MR. We hypothesized that, like ACLR+MR, PCLR+MR would be associated with lower rates of revision meniscal surgery compared to MR alone.

Methods

This was a retrospective cohort study of patients who underwent either PCLR+MR or MR alone from October 2015 through October 2020 with minimum 2-year follow-up in a large national insurance database in the United States (PearlDiver Inc., Colorado, USA). ACLR+MR was also investigated to provide reference data. Patients with concurrent extra-articular ligament reconstruction, revision meniscal procedures, and multi-ligamentous knee injuries were excluded (i.e., patients were undergoing isolated primary MR alone, isolated primary PCLR+MR alone, or isolated primary ACLR+MR alone). Demographic data, surgical information, and comorbidities were collected and analyzed. The primary outcome was revision meniscal procedures (meniscectomy, meniscal repair, and meniscal transplant) at 2-years. Time-to-event analyses (i.e., Kaplan-Meier for unadjusted analysis and Cox proportional hazard models for adjusted analysis) were used to assess the rate of revision meniscal procedures following MR alone, PLCR+MR, and ACLR+MR. Comparisons in demographics were made with Student t-tests or Chi-squared tests, as appropriate.

Results

There was a total of 46,226 patients (0.3% PCLR+MR, 51.5% MR alone, 48.2%, ACLR+MR) with an average follow-up of 4.2 years. Compared to MR alone, patients undergoing PCLR+MR were younger (mean ± standard deviation 27.0±13.3 years vs. 38.5±17.8 years, p<0.001), more often male (61.8% vs. 48%, p<0.001), and had a similar comorbidity burden (Charlson Comorbidity Index 0.63±1.22 points vs. 0.75±1.26 points, p=0.26). The 2-year meniscal revision rate for MR alone was 8.3% (95% confidence interval [CI]: 7.9%-8.6%) compared to 4.2% (95% CI: 0.8%-7.4%) for PCLR+MR. In adjusted analysis controlling for age, sex, and comorbidities, MR alone remained associated with significantly higher risk of revision meniscal surgery compared to PCLR+MR (hazard ratio [HR] 2.68, 95% CI 1.20-5.97, p=0.016). For reference, the ACLR+MR meniscal revision rate was 6.4% (95% CI: 6.3%-7%; MR alone vs. ACLR+MR HR 1.62, 95% CI 1.51-1.74, p<0.001). Similar results were seen when including conversion to arthroplasty as an additional revision procedure.

Discussion

In this study, we found that concomitant PCLR is associated with a significant reduction in meniscal revision rates following PCLR+MR compared to MR alone. These are the first data to assess MR outcomes in the setting of concomitant isolated PCLR. Although isolated PCLR (and by extension PCLR+MR) remains relatively rare, these data suggest that surgeons may have a similar or greater propensity towards performing MR vs. meniscectomy when performing PCLR as they do when performing ACLR. These data also are consistent with the hypothesis that tunnel drilling may provide biological benefits that lead to greater meniscal healing when performing ACLR, and now, PCLR.