The role of altered knee gait mechanics in the initiation of tibiofemoral and patellofemoral osteoarthritis after anterior cruciate ligament reconstruction
Date
2022
Authors
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Publisher
University of Delaware
Abstract
Post-traumatic knee osteoarthritis (OA) after anterior cruciate ligament reconstruction (ACLR) is common. Alterations in knee gait mechanics, which are commonly observed after surgery, are hypothesized to be a mechanism responsible for eventual disease development. Advanced quantitative magnetic resonance imaging (qMRI) techniques can provide insights into cartilage health prior to irreversible morphometric signs of cartilage deterioration. Recent evidence indicates that patellofemoral OA after ACLR is at least as common as medial tibiofemoral OA and is associated with worse patient reported outcomes. Despite this, little is known about the mechanisms for disease development within this compartment of the knee. Thus, the goal of this work was to assess the role that altered knee gait mechanics play in the initiation of tibiofemoral and patellofemoral knee OA after ACLR. This was accomplished through a combination of subject-specific EMG-driven neuromusculoskeletal modeling techniques and qMRI. ☐ The first aim of this dissertation sought to assess how early changes in medial tibiofemoral interlimb loading patterns influenced long-term cartilage health. We found that loading patterns other than consistent interlimb symmetry may predispose medial tibiofemoral knee cartilage to long-term degradation. Thus, consistent interlimb loading symmetry may be an ideal target for explorative rehabilitation efforts aimed at preventing OA within this compartment of the knee. In the second aim of this dissertation, we characterized the loading environment of the patellofemoral compartment of the knee during walking gait at 3, 6, and 24 months after ACLR. We found that the involved limb’s patellofemoral compartment was underloaded, compared to the uninvolved limb, at 3 and 6 months after surgery. This underloading was resolved by 24 months. In the third aim of this dissertation, we assessed patellofemoral knee cartilage health 24-months after surgery and examined the associations between patellofemoral loading and other knee gait mechanics 3 months after surgery with these measures of long-term cartilage health. Alterations in knee cartilage health 24-months after ACLR were detected in the femoral trochlear cartilage of the involved limb but not in patellar cartilage. Smaller patellofemoral loads, smaller knee flexion angles and moments, and slower walking speeds 3 months after ACLR were associated with femoral trochlear cartilage degradation 24-months after surgery. This suggests that altered involved limb trochlear health is present 24-months after ACLR and may be related to how an individual walks 3 months after surgery. Altogether, the work of this dissertation furthers our understanding of the role altered knee gait mechanics play in the initiation of tibiofemoral and patellofemoral knee OA after ACLR. This information, in turn, may be used in the design of rehabilitation efforts aimed at preventing the onset of post-traumatic knee osteoarthritis.
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Keywords
Anterior cruciate ligament, Biomechanics, Osteoarthritis, Patellofemoral, Quantitative magnetic resonance imaging, Reconstruction