Treatment of Symptomatic Varus Osteoarthritis of the Knee
Behandeling van symptomatische mediale gonartrose
Osteoarthritis (OA) is the 6th leading cause of Years Lost to Disability (YLD) at global level, accounting for 3% of total global YLDs. Knee OA is the most common joint disorder, and in the Netherlands approximately 17% of the population aged 45 years and over suffer from knee OA. It causes considerable pain and immobility, affects independence and psychosocial functioning, and in addition leads to financial losses. Many patients present with unicompartmental disease, and the medial compartment is almost 10 times more frequently involved than the lateral compartment. This thesis investigates both the non-operative and surgical treatment outcomes in active patients with symptomatic medial OA of the knee. The aim is to clarify indications for identified treatment modalities as controversy exists on how patient and/or intervention related factors affect the outcome of this disease. Furthermore, clearer indications will lead to better care, which may not only benefit the individual patient but also society as a whole because of expected savings in health care expenses and reduction of productivity losses. Patients with OA of the medial compartment often have varus malalignment; the mechanical axis and load bearing passes through the medial compartment. Some report that malalignment may even have an impact on the development and progression of knee OA. Although many consider whole leg radiographs in standing position (mechanical axis measurement) as the gold standard to determine knee alignment, in clinical practice, knee alignment is often assessed on shorter anterior-posterior knee radiographs (anatomic axis measurement) to cut expenses and cumbersome procedures. Significant correlation between mechanical and anatomic axis angles has been reported. Some suggest using anatomic axis measurement in research and clinical settings. In Chapter 2 we compare two different methods of anatomic axis assessment in a group of patients with known mechanical varus alignment, and determine whether or not anatomic axis measurement on standard short knee views can be used in clinical settings.