Comparison the Effectiveness of Lateral Wedge Insole with and without Longitudinal Arch Support on Ankles' Function and Pain in People with Medial Knee Osteoarthritis

Lateral wedge insole (LWI) is one of the therapeutic interventions in the management of medial compartment knee osteoarthritis. The aim of this study was to investigate the effect of the LWI with and without a medial arch on the pain and the ankle function in patients with medial compartment knee osteoarthritis.

Methods and Materials:

 Twenty-six people with medial knee osteoarthritis were assigned. All participants were asked to complete the questionnaires of the Foot and Ankle Outcome Survey (FAOS) and the Visual Analog Scale (VAS) in the first session. Then, participants were divided into two groups. The first group was given a LWI and the second group a LWI with the medial arch support. After a 6-weeks use of the insoles, participants were asked to complete the questionnaires again.

The use of LWI and arch support did not alter all items of the FAOS including the stiffness, pain, activity level, sports restriction, and quality of life restrictions and the VAS score after six weeks compared with the first session (P>0.05), but the using only LWI increased all subscales of FAOS and VAS score after six weeks wearing the insole (P<0.05) and there was no significant change just in the stiffness subscale (P=0.6). Also, the difference between the two groups was significant by increase of all outcomes using only the LWI compared with the LWI along with an arch support (P<0.05).

Using a LWI in isolation can result in pain and discomforting in the ankle joint. However, LWI combined with arch support could prevent joint stiffness, pain and discomforting in the ankle joint of patients with medial knee osteoarthritis.