Walking mechanics, second injury, early osteoarthritis development, and functional outcomes after anterior cruciate ligament (ACT) reconstruction
Date
2019
Authors
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Publisher
University of Delaware
Abstract
Anterior cruciate ligament (ACL) injury is extremely prevalent among active adolescents and young adults. ACL injury and ACL reconstruction (ACLR) dramatically increase an individual’s risk for poor outcomes, including second ACL rupture and early development of osteoarthritis (OA) when the individual is still a young adult. Aberrant movement patterns during walking may influence the risk for poor outcomes among individuals after ACLR. ☐ The long-term objective of this work is to improve functional outcomes and reduce second injury and early OA development after ACLR. This dissertation aimed to identify risk factors associated with second ACL injury (Aim 1) and early patellofemoral OA development (Aim 4), and to evaluate the effect of interventions (i.e., meniscus treatment and rehabilitation strategies) on a known risk factor for early tibiofemoral OA development (Aims 2 and 3) and functional outcomes (Aim 5). ☐ Individuals after primary, unilateral ACLR were recruited. Aims 1-3 and 5 were derived from the ACL-SPORTS clinical trial, which enrolled 80 athletes who were 3-9 months after ACLR. Aim 4 was derived from the Quantitative Magnetic Resonance Imaging (QMRI) and Biomechanical Modeling study, including participants 3 and 6 months after ACLR. All participants underwent detailed biomechanical motion analyses during walking. ACL-SPORTS participants also completed comprehensive clinical and functional evaluations, and QMRI participants also underwent sagittal QMRI analyses. For Aim 5, homogenous subsets of 2 previous “gold-standard” cohorts were used for comparison to the ACL-SPORTS cohort. ☐ The key findings of Aim 1 are that young female athletes after ACLR should delay their return to high-level sports even in the absence of gait impairments, strength deficits, and functional or clinical impairments. Aim 2 indicates that concomitant medial meniscus treatment at the time of ACLR influences walking mechanics and knee joint loading 6 months and 2 years after ACLR, potentially explaining the elevated risk for OA and informing future studies investigating tailored rehabilitation programs. Aim 3 suggests that return-to-sport training with and without perturbation training does not improve walking mechanics, but interlimb symmetry improves by 2 years after ACLR; future research should evaluate gait specific interventions. Aim 4 provides preliminary evidence of the association between walking mechanics and especially walking speed with cartilage degradation in the patellofemoral joint of individuals early after ACLR, a key preliminary step for reducing symptomatic OA. Finally, Aim 5 indicates that return-to-sport training leads to superior functional outcomes among young female athletes after ACLR. ☐ This dissertation work will guide physicians, rehabilitation specialists, and other healthcare professionals who rehabilitate the hundreds of thousands of individuals who tear their ACLs each year. This dissertation will help improve functional outcomes and reduce second ACL injury and early OA development and progression, lowering health-care costs and improving quality of life.