Wedged Insoles for Management of Knee Osteoarthritis

Reduced Knee Joint Loading With Lateral and Medial Wedge Insoles for Management of Knee Osteoarthritis: a Randomized Controlled Trial

Canadian Institutes of Health Research (CIHR), Natural Sciences and Engineering Research Council, Canada, Alberta Innovates Health Solutions, Killam Trusts, New Balance Athletic Shoe, Inc.

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. The purpose of this study is to evaluate the influence of reduced KAMs on pain over 3-months for patients with knee OA. It is hypothesized that pain reduction will be directly related to KAM reduction. Forty-six 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, footwear comfort and injury history. Participants will be randomized into either a wait list control group (no insole) or experimental group (medial or lateral wedged insole), and monitored for 3 months. Changes to pain, function, comfort and physical activity from baseline to 3 months will be assessed within the control and experimental groups. Regression analyses will be conducted on the experimental group to determine if a relationship exists between reduced KAMs and reduced pain over 3 months. Comparisons will also be made between the control and experimental groups.

Osteoarthritis, Cartilage, Musculoskeletal, Biomechanics, Subtype, Footwear, Orthotics, Joint Loading

A waitlist control condition, where the participant receives no insole for 3 months. During this 3 month period, the participant will continue to be monitored for outcome variables.

Either a medially wedged or laterally wedged footwear insole (whichever reduces knee joint mechanical loading more, as determined from subject-specific biomechanical tests), constructed using a 3D printer will be inserted into each participant's shoe. The participant will be asked to utilize this insole as much as possible throughout the day over the course of 3 months.

Wedged insoles are designed to reduce frontal plane knee joint mechanical loads during gait. Specifically, they can alter the knee adduction moment during gait - a variable associated with progression of knee osteoarthritis. In the experimental arm of this study, participants will undergo biomechanical gait analysis to identify the wedged insole that reduces the moments the most. The two options are medial wedge, where the medial aspect of the foot is elevated relative to the lateral aspect, and the lateral wedge, where the lateral wedge is elevated relative to the medial aspect.

Other knee joint mechanical variables assessed using motion analysis (ex. varus thrust, knee adduction impulse).

Inclusion Criteria: Physician-diagnosed knee osteoarthritis (using American College of Rheumatology clinical and radiographic criteria) Kellgren-Lawrence grade 1, 2, 3 or 4 Primary symptoms and disease location must be attributed to medial tibiofemoral compartment KOOS pain of 75 points or lower (where 0 is worst pain and 100 is no pain) Exclusion Criteria: X-ray older than 2 years Viscosupplementation within past 6 months Cortisone injection in past 3 months Narcotic pain medication within past 3 months Use of knee unloading brace interventions in past 2 months Recent (past 6 months) knee or neuromuscular injury that could bias pain assessments or gait analysis results No KAM reduction with either lateral or medial wedge insole

Lewinson RT, Vallerand IA, Collins KH, Wiley JP, Lun VMY, Patel C, Woodhouse LJ, Reimer RA, Worobets JT, Herzog W, Stefanyshyn DJ. Reduced knee adduction moments for management of knee osteoarthritis:: A three month phase I/II randomized controlled trial. Gait Posture. 2016 Oct;50:60-68. doi: 10.1016/j.gaitpost.2016.08.027. Epub 2016 Aug 26.

Lewinson RT, Collins KH, Vallerand IA, Wiley JP, Woodhouse LJ, Reimer RA, Worobets JT, Herzog W, Stefanyshyn DJ. Reduced knee joint loading with lateral and medial wedge insoles for management of knee osteoarthritis: a protocol for a randomized controlled trial. BMC Musculoskelet Disord. 2014 Dec 3;15:405. doi: 10.1186/1471-2474-15-405.