Vertical ground reaction force 2 years after anterior cruciate ligament reconstruction predicts 10‐year patient‐reported outcomes

Abstract

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 Knee Injury and Osteoarthritis Outcome Score (KOOS) and International Knee Documentation Committee (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 (10–2 years) in patient‐reported outcomes and between limb‐differences in vGRF were assessed with Pearson or Spearman's ρ correlation coefficients and exploratory backwards elimination multiple linear regression analyses. Differences in vGRF between symptomatic progressors and non‐progressors were also assessed. The 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 reconstructed (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 quality of life (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). These data highlight associations between a simple‐to‐measure gait metric and the development of long‐term clinical symptoms after an ACL injury.

ACL special issue, editors

“…The eleven invited original data articles, and other articles accepted for this issue, run the gamut from epidemiology 8 to imaging 9–11 rehabilitation 12–15 and biomechanics 16,17 from some of the best and brightest minds in this area. Work from the laboratories of Dr. Elizabeth Wellsandt 18 and Dr. Susan Sigward 19 add to the growing body of work that cites underloading rather than overloading of the involved limb after ACL injury as problematic 20,21 .…”