Effect of Isolated Lateral In-Shoe Wedge on Reducing Pain in Medial Knee Osteoarthritis

Clinical Question

Is the use of an isolated lateral in-shoe heel wedge effective in reducing pain associated with medial knee osteoarthritis (OA)?

Background

OA is one of the most common degenerative joint diseases, causing pain and stiffness in the affected joints.5 OA of the knee affects approximately 10% of people over the age of 55, inciting responses such as pain, reduced activity, and instability.7 Conservative methods of intervention are necessary as there is no cure for OA, and total knee arthroplasty (TKA) procedures are reserved for severe presentations.2,6 LWIs placed inside the shoes are one treatment option that may reduce pain related to mild to moderate medial knee OA.

Search Strategy

Databases Searched: www.pubmed.gov, www.oandp.org, www.ebsco.com

Search Terms: lateral wedge, in-shoe, in shoe, osteoarthritis, pain, medial knee pain

Inclusion/Exclusion Criteria: 2016-present. English.

Excluded if study examined: external wedges, medial wedges, lateral knee pain, or did not measure pain.

 

Synthesis of Results

The findings of the seven studies were mixed as to whether an isolated LWI is effective in reducing pain associated with medial knee OA. Three studies found that use of isolated unilateral LWIs led to statistically significant reduction in pain as measured by the WOMAC,7 VAS,3 and an 11-point numerical rating scale.8 A fourth study6 found that use of isolated bilateral LWIs resulted in minimal clinically important difference (MCID) in the WOMAC pain score for 54% of users; however, overall, the change in WOMAC was not statistically significant. Three additional studies found that LWIs had no impact on pain, as measured by the VAS4,5, WOMAC5 , or an 11-point numerical rating scale.2 Multiple studies also reported the impact of LWI use on KAM; two reported a reduction in KAM2,7 with LWI use, while one reported no change.4 Two studies3,8 explored methods of prescreening participants for responsiveness to LWI treatment; while these studies did not demonstrate clinically significant efficacy of prescreening, investigators may continue to explore this possibility. Studies2,6 also compared LWIs to MLA-LWIs. Both found superior results with the addition of MLA support including an improved participant-reported comfort2 , higher incidence of pain reduction6 , and higher participant preference.6

Clinical Message

Recent literature suggests that the use of in-shoe LWIs is likely insufficient for pain relief associated with mild to moderate medial knee OA. This is in contrast to the original CAT addressing this question, which found that LWIs could offer a conservative, low-cost, and effective treatment for such pain.1 However, evidence published since 2016 suggests that more nuanced, robust, and customized care may be in order. Use of prescreening to determine which patients will respond positively to LWI treatment may warrant further exploration. Additionally, comparisons to MLA-LWIs suggest that these may be a more broadly effective, and still conservative, treatment to reduce pain. A focused appraisal of the literature on MLA-LWIs for treatment of medial knee OA is needed to confirm this.

_{Please address Correspondence to: mjhall@gillettechildrens.com}