Knee osteoarthritis (OA) is commonly treated using laterally wedged insoles. Although these insoles typically reduce knee abduction moments (KAM) - a variable associated with knee osteoarthritis - and thus are believed to be beneficial for OA management, recent research has indicated that in some cases lateral wedge insoles actually increase knee joint loads. In such cases, a medial wedge may be more appropriate. In addition, recent research has begun to indicate that separate subtypes of osteoarthritis exist, and that these different subtypes may respond differently to a mechanical intervention such as a wedged insole. These subtypes include metabolic-OA (linked to obesity), post-traumatic OA (linked to knee injury), and genetic-OA (linked to family history).

The purposes of this study are to (a) evaluate the influence of reduced KAMs loading on pain over 6-months for patients with knee OA, and (b) evaluate how patients from different OA subtypes respond to a mechanical treatment (i.e. wedged insole). It is hypothesized that pain reduction and function improvement will be directly related to KAM reduction.

One-hundred and thirty participants with knee OA will be recruited to participate. Each will undergo biomechanical gait analysis to determine the wedge type that most greatly reduces knee adduction moments. In addition, each participant will undergo a Dual Energy X-Ray Absorptiometry (DXA) scan to quantify adiposity. Finally, participants will complete a series of questionnaires to evaluate pain, function, physical activity, diet and family and injury history. Participants will be randomized into either a control group (sham insole) or experimental group (wedged insole), and monitored for 6 months.

Comparisons will be made between the control and experimental group to determine if reduced knee adduction moments contribute to reduced pain and improved function over 6 months. In addition, patients will be stratified based on OA subtype to determine if treatment response is dependent on OA subtype.

Read more: