Vertical Ground Reaction Force 2 Years After Anterior Cruciate Ligament Reconstruction Predicts 10-Year Patient-Reported Outcomes.
Disruptions in knee biomechanics during walking following anterior cruciate ligament (ACL) injury have been suggested to lead to the development of premature knee osteoarthritis (OA) and to be potential markers of OA risk and targets for intervention. This study investigated if side-to-side differences in early stance peak vertical ground reaction force (vGRF) during walking 2 years after ACL reconstruction are associated with longer-term (10 years post-reconstruction) changes in patient-reported outcomes. Twenty-eight participants (mean age: 28.7±6.4 years) with primary unilateral ACL reconstruction underwent gait analysis for assessment of peak vGRF and completed KOOS and IKDC surveys at 2 years post-surgery (2.2±0.3 years) and completed surveys at follow-up 10 years post-surgery (10.5±0.9 years). Associations between changes (10 year – 2 year) in patient-reported outcomes and between limb-differences in vGRF were assessed with Pearson or Spearman’s rho correlation coefficients and exploratory backwards elimination multiple linear regression analyses. Differences in vGRF between symptomatic progressors and non-progressors were also assessed. Side-to-side difference in vGRF was related to the variability in longer-term changes in patient-reported outcome metrics and distinguished symptomatic progressors from non-progressors. Participants with higher vGRF in the ACLR limb versus the contralateral limb had worsening of IKDC (R=-0.391, p=0.040), KOOS Pain (ρ=-0.396, p=0.037), KOOS Symptoms (ρ=-0.572, p=0.001), and KOOS QOL (R=-0.458, p=0.014) scores at follow-up. Symptomatic progressors had greater vGRF in the ACLR limb as compared to the contralateral limb at baseline than non-progressors (p=0.023). Clinical Relevance: These data highlight associations between a simple-to-measure gait metric and the development of long-term clinical symptoms after ACL injury. This article is protected by copyright. All rights reserved.This article is protected by copyright. All rights reserved.