The Influence of Joint Loading in Post-Traumatic Knee Osteoarthritis Development
Abstract
Post-traumatic osteoarthritis (PTOA) occurs in most individuals after severe knee injuries such as anterior cruciate ligament (ACL) ruptures, leading to significant pain, symptoms, functional limitations, and reduced quality of life. A deeper understanding of the mechanisms that drive PTOA progression after knee injury is essential to develop effective treatment and prevention strategies. The purpose of this thesis was to investigate the influence of joint loading on PTOA development and the clinical characteristics of individuals with PTOA.
Chapter 2 is a systematic review that compared physical activity levels of individuals with ACL reconstruction (ACLR) to international guidelines and to those of uninjured controls. Individuals with ACLR achieved recommended moderate-to-vigorous physical activity levels, but not daily steps, and were less physically active than uninjured controls. Therefore, individuals with ACLR may obtain additional knee health benefits by increasing daily steps, and they should be advised by clinicians to stay active in safe and feasible ways to optimize their long-term knee health.
Chapter 3 investigated between-limb differences in gait biomechanics and cartilage morphology and associations between these outcomes at seven years after ACLR. Gait biomechanics were symmetric, but cartilage thickness and composition differed between limbs with certain regions showing signs of compromised morphology. There were multiple associations between gait biomechanics and cartilage outcomes. These results demonstrated potential degenerative cartilage changes at seven years after ACLR that may be influenced by gait biomechanics.
Chapter 4 compared clinical characteristics between individuals with knee OA with and without previous PTOA-associated injuries. Individuals with PTOA-associated injuries had superior physical and psychological health outcomes and higher physical activity levels than those without PTOA-associated injuries. Thus, individuals with PTOA have unique clinical characteristics and may require interventions with less emphasis on physical activity behaviours than those with non-traumatic osteoarthritis.
Overall, our findings suggest that joint loading may influence PTOA outcomes after severe knee injuries and that individuals with PTOA may benefit from different clinical management strategies than those with non-traumatic osteoarthritis. This thesis provides a strong basis for further investigation of the biomechanical mechanisms potentially driving PTOA development and exploration of tailored interventions for the PTOA population.