Summary

Patients who undergo combined ACL and anterolateral ligament reconstruction experience significantly better long-term ACL graft survivorship, a five-fold lower risk of graft rupture, lower overall rates of re-operation, and no increase in complications when compared to those who undergo isolated ACL reconstruction

Abstract

Introduction

Recent clinical studies have demonstrated significant advantages of combined anterior cruciate ligament and anterolateral ligament reconstruction (ACL+ALLR) over isolated ACL reconstruction (ACLR) with respect to reduced graft rupture rates, a lower risk of re-operation for secondary meniscectomy, improved knee stability, and higher rates of return to pre-injury levels of sport. However, due to the relative infancy of this procedure, long term studies have not yet been published, and it remains to be seen whether the reported advantages of the combined procedure are maintained at long term follow-up.

The primary objective of this study was to compare the long-term clinical outcomes of isolated ACLR versus combined ACL+ALLR. The hypothesis was that patients who underwent combined procedures would experience significantly lower ACL graft rupture rates at long term follow-up than their matched counterparts who underwent isolated ACLR.

Methods

Patients undergoing primary ACL+ALLR between January 2011 and March 2012 were propensity matched in a 1:1 ratio to patients who had undergone isolated ACL reconstruction during the same period. Face-to-face post-operative follow-up was undertaken at 3 and 6 weeks, and 3, 6, 12 and 24 months. Due to the geographically mobile nature of young populations (particularly notable at long-term follow up), and the impact of COVID-19, the final follow up was conducted using a standardized telemedicine interview (between April and May 2020), completion of PROMs questionnaires and review of medical notes. The telemedicine interview and notes review sought to determine whether patients had sustained a further ipsilateral knee injury, had experienced any symptoms of knee instability or stiffness, or had undergone any re-operations or complications. As a result of these follow-up arrangements, physical examination findings (range of motion and knee stability) are reported at two-years follow up. Complications, re-operations and outcome measures including Lysholm, Tegner, IKDC and KOOS are reported at the final follow-up. Graft survivorship was assessed using Kaplan-Meier analysis. Logistic regression was performed in order to account for the potential impact of activity level on graft rupture rates.

Results

86 matched pairs were included in the study. The mean duration of follow-up was 104.33±3.84 months (range 97-111 months). Patients who underwent combined ACL+ALLR experienced significantly better ACL graft survivorship (96.5% vs 82.6%, p=0.0027), lower overall rates of re-operation (15.3% vs 32.6%, p<0.05), lower rates of revision ACLR (3.5% vs 17.4%, p<0.05), and no increase in complications, when compared to those who underwent isolated ACLR. Patients undergoing isolated ACLR were at more than five-fold greater risk of graft rupture (OR, 5.549; 95%CI 1.431 to 21.511, p = 0.0132), regardless of their pre-injury activity level.

Conclusion

Patients who undergo combined ACL and anterolateral ligament reconstruction experience significantly better long-term ACL graft survivorship, lower overall rates of re-operation, and no increase in complications when compared to those who undergo isolated ACLR. In contrast, patients undergoing isolated ACLR had a greater than five-fold increased risk of undergoing revision surgery at a mean follow-up of 104.3 months.