Association Between Pediatric International Knee Documentation Committee Score and Sagittal Knee Biomechanical Testing Following Anterior Cruciate Ligament Reconstruction

OBJECTIVE: The purpose of this study was to compare the Pediatric International Knee Documentation Committee (Pedi-IKDC) scores with sagittal knee kinematics and kinetics during the vertical drop jump test in pediatric athletes who had undergone primary unilateral anterior cruciate ligament reconstruction (ACLR) and determine if the two measures captured overlapping aspects of knee recovery. DESIGN: This is a retrospective cohort study. METHOD: Seventy pediatric athletes who recently underwent ACLR completed biomechanical testing and the Pedi-IKDC survey. Limb symmetry for peak knee flexion angle (PKF), peak external knee flexion moment (PEKFM), and integral of power absorption (IPA) were evaluated and compared to Pedi-IKDC score using multivariate linear regressions controlling for time since surgery. Inter-knee symmetry was calculated using a Limb Symmetry Index (LSI) by dividing the scores of the injured knee by the scores of the uninjured knee and multiplying by 100. RESULTS: There was a statistically significant positive relationship between Pedi-IKDC and LSI in PKF ( R 2 = .163, p =.001), PEKFM ( R 2 = .067, p = 0.033), and IPA ( R 2 = .087, p = .014), indicating that higher Pedi-IKDC scores were associated with greater biomechanical symmetry when controlled for time. There were weak and significant positive relationships between time since surgery and PEKFM ( R 2 = .172, p < .001) and IPA ( R 2 = .255, p < .001), indicating improved biomechanical testing the further along from surgery, but there was no statistical significance between time since surgery and Pedi-IKDC or PKF. CONCLUSIONS: Pedi-IKDC and drop jump biomechanics were weakly related but mainly captured different aspects of recovery after ACLR. They can be considered as complementary tools when evaluating patients post-ACLR. JOSPT Open 2025;3(2):171-177. Epub 4 December 2024. doi:10.2519/josptopen.2024.0073