Mitigating Risk Factors for Disease Progression in Patients with Varus Gonarthrosis

Knee osteoarthritis (OA) is a leading cause of disability worldwide. Its growing burden is related to an aging population, obesity and physical inactivity. The progression of knee OA involves both biomechanical and systemic mechanisms. Known risk factors that might be altered through interventions include lower limb alignment, the distribution of loads across the knee during walking, body composition and muscular strength. The overall purpose of this thesis was to evaluate the effects of multi-modal, rehabilitative and surgical interventions that target different risk factors for disease progression in patients with medial compartment knee OA and varus mal-alignment (varus gonarthrosis). The thesis included three studies. Study 1 demonstrated that patients with substantial bilateral varus alignment who underwent unilateral medial opening wedge high tibial osteotomy (HTO) experienced large decreases in the external knee adduction moment during walking two years after surgery. However, they also experienced increased knee adduction moments in the mal-aligned, non-operated limb, explained most by increases in both body mass and gait speed. Study 2 demonstrated that body composition measurements in patients with knee OA using air displacement plethsmography (BodPod©)had excellent test-re-test reliability. It also provided estimates of measurement error and minimal detectable change to be used when evaluating body composition changes in individual patients with knee OA. Study 3 was a proof of principle study that demonstrated combined, multi-modal physiotherapy and medial opening wedge HTO decreased fat mass, increased muscular strength, decreased knee adduction moments and varus mal-alignment in patients with varus gonarthrosis. Rehabilitative intervention was required to improve body composition and strength, whereas surgical intervention was required to improve alignment and knee adduction moments. Overall, the results of these studies suggest that a combination of treatment approaches that target different risk factors for knee OA are necessary. Multi-modal rehabilitative and surgical intervention for patients with varus gonarthrosis is recommended