Posterolateral corner reconstruction in combined injuries of the knee: Improved stability with Larson's fibular sling reconstruction and comparison with LaPrade anatomical reconstruction

Abstract

BACKGROUND: The goal of this prospective cohort study was to present the clinical results of a two-year follow-up of a Larson's posterolateral corner reconstruction (fibular sling) in patients with symptomatic instability of the knee. These data were compared with data of an anatomical reconstruction of the posterolateral corner as described by LaPrade et al. (combined tibial tunnel and fibular sling) [1]. METHODS: Eleven patients underwent a Larson's posterolateral corner reconstruction. Cruciate ligament ruptures were reconstructed if present. Multiple subjective knee outcome scores (VAS satisfaction score, Tegner, Lysholm, Noyes score, and IKDC subjective knee score) were obtained pre-operatively and two years after surgery. Laxity of the joint was measured using bilateral varus stress radiographs. RESULTS: All patients had concomitant ACL or PCL surgery. VAS satisfaction, the Tegner, Noyes and the IKDC subjective knee score all improved significantly. Median varus laxity of the injured knee on varus stress radiographs improved significantly from 6.2° (3.1-10.1) to 3.9° (1.1-5.7), p = .0076. Post-operative varus laxity did not return to the level of the uninjured knee: 2.7° (1-5.7), p = .028. In comparison with our data on the reconstruction technique according to LaPrade, no statistically significant differences in clinical outcome were observed. CONCLUSION: Reconstruction of the posterolateral corner in combined injuries of the knee using a Larson fibular sling technique results in improved varus stability but not to the level of the uninjured knee. Functional knee scores improved significantly. We found no differences in functional and radiological outcome between the Larson's fibular sling reconstruction and LaPrade anatomical reconstruction. LEVEL OF EVIDENCE: IV.