Summary

A single-stage approach to revision ACL reconstruction is associated with excellent clinical results when an outside-in drilling technique is utilized. The presence of pre-operative tunnel widening does not significantly influence patient reported outcome measures, knee stability, graft rupture rates or non-graft rupture related re-operation rates.

Abstract

Introduction

Pre-operative tunnel widening is a frequently reported indication for performing a two-stage revision anterior cruciate ligament reconstruction (R-ACLR) instead of a single-stage procedure. However, the strength of the available evidence to support a two-stage strategy is low. The main purpose of this study was to evaluate the clinical outcomes of a single-stage only approach to R-ACLR. It was hypothesized that this approach would be associated with significant improvements from baseline in patient reported outcome measures (PROMS) and knee stability, and also that there would be no significant differences in any post-operative outcomes between patients with and without pre-operative tunnel widening.

Methods

A retrospective analysis of a large series of consecutive patients undergoing R-ACLR, with a minimum follow-up of two years, was conducted. Pre-operative tunnel widening was assessed using digital radiographs. All patients underwent single-stage surgery, with an outside-in technique, even if they had tunnel widening. Clinical outcomes were compared according to whether tunnel widening was present (either tunnel = 12mm) or not (both tunnels <12mm). Comparisons between variables were assessed with the Chi-square or Fisher’s exact tests for categorical variables and the Student’s t test or Wilcoxon test for quantitative variables.

Results

409 consecutive patients with a mean follow-up of 69.6 ± 29.0 months were included in the study. At two years following R-ACLR, there was a significant reduction in the side-to-side AP laxity difference from 7.7 ± 2.2 mm pre-operatively to 1.2 ± 1.1 mm (p < .001). The mean IKDC and all KOOS subscales exceeded the patient acceptable symptom state (PASS) thresholds defined for primary ACLR. There were no significant differences between groups with respect to antero-posterior side-to side laxity difference, graft rupture rates, non-graft rupture related re-operations, or contralateral ACL injury rates. There was also no significant difference between groups, exceeding minimal detectable change thresholds, for any of the PROMS recorded (ACL-RSI, Lysholm, Tegner, IKDC, KOOS).

Conclusions

A single-stage approach to revision ACL reconstruction is associated with excellent clinical results when an outside-in drilling technique is utilized. The mean IKDC and all KOOS subscales exceeded the patient acceptable symptom state (PASS) thresholds defined for primary ACLR. The presence of pre-operative tunnel widening did not significantly influence PROMS, knee stability, graft rupture rates or non-graft rupture related re-operation rates. This suggests that two-stage R-ACLR is rarely warranted