Gait Biomechanical Profiles Following Anterior Cruciate Ligament Reconstruction in Sexually-Immature Pediatrics

Aberrant gait biomechanics following ACL reconstruction (ACLR) are linked to knee osteoarthritis development in adult patients. However, limited research exists to characterize walking biomechanics profiles of pediatric ACLR patients. The study purpose was to determine (1) differences in biomechanical profiles between pediatric ACLR patients (Tanner Stage I-IV) and two comparison-control groups (i.e., uninjured, matched pediatrics, adult-matched ACLR); (2) associations between biomechanical and Knee Osteoarthritis Outcomes Score (KOOS)-Child outcomes in pediatric ACLR patients. Gait biomechanics were collected in pediatric ACLR (n = 25), pediatric controls (n = 25), and adult ACLR groups (n = 25). Pediatric patients completed the KOOS-Child at the same session. A functional mixed effects model determined between-group differences in biomechanical variables. Uncorrected partial correlations, controlling for gait speed, were utilized to determine the association between discrete biomechanics and KOOS-Child scores. Pediatric ACLR patients demonstrated lesser first and second peak vertical ground reaction force (vGRF) and greater midstance vGRF than pediatric controls. Pediatric ACLR patients exhibited lesser midstance and greater late stance vGRF compared to the adult ACLR group. Pediatric ACLR patients demonstrated lesser knee flexion angle, knee extension moment, and knee abduction moment profiles compared to pediatric controls and adult ACLR patients throughout the majority of the stance phase. Greater midstance vGRF was associated with greater KOOS-Child Quality of Life scores in the contralateral limb (r = 0.54, p = 0.006). Pediatric ACLR patients exhibit unique biomechanical profiles compared to pediatric controls and adult ACLR patients; however, the associations with patient-reported outcomes remain unclear. Pediatrics may experience an exaggerated response to ACLR that may impact knee joint health.