Investigation of exercise, nutrition, and high tibial osteotomy interventions for patients with medial dominant knee osteoarthritis

Purpose: To evaluate the effectiveness of two distinct interventions in improving outcomes for patients with knee osteoarthritis (OA) and varus alignment: 1) a 12-week minimally supervised therapeutic exercise program with nutrition recommendations, 2) and high tibial osteotomy (HTO). Methods: This dissertation involved four studies. Participants were recruited as part of two separate ongoing prospective cohort studies evaluating clinical, biomechanical, and physiological outcomes following a) a 12-week exercise and nutrition program (studies 1-2) or b) HTO (studies 3-4) for knee OA. For studies 1 & 2, we evaluated change in physiological measures (body composition, muscle strength, gait biomechanics), patient-reported measures (pain, function, quality of life, perceived exertion) and performance-based measures, and explored associations among variables. For studies 3 & 4, we evaluated responder criteria at 2 years after HTO, the rate of conversion from HTO to total knee replacement (TKR), and changes in patient-reported outcomes and gait biomechanics at 2, 5 and 10 years after HTO. We also evaluated associations between demographics and biomechanics with various clinical outcomes (i.e., responder criteria, TKR, clinically important improvements in patient-reported outcomes). Results: For the exercise and nutrition program, patients worked harder while experiencing decreases in exercise-induced pain. Patients also experienced substantial improvements in physiological measures (body composition, muscle strength, gait speed), and patient-reported and performance-based outcomes. While physiological measures were associated with patient-reported and performance-based outcomes, magnitudes of association were small. Following HTO, 78% of patients were responders to surgery at 2 years. There were also 5% of patients who went on to a TKR at 5 years, and 20% at 10 years after HTO. Substantial improvements in pain and function, and reductions in knee joint moments (i.e., >40%) were also maintained up to 10 years post-HTO. Changes in gait biomechanics were associated future TKR and meaningful improvements in pain and function. Conclusions: We showed a therapeutic exercise and nutrition program similar to everyday physical therapy practice can be effective in improving various patient outcomes. We also showed HTO leads to substantial long-term improvements and may delay the need for TKR, suggesting HTO may provide an opportunity for secondary prevention of OA.