Aching Foot Makes OA-Related Knee Pain Worse
Written by Editor   
Wednesday, July 22, 2015 12:00 AM

A new study demonstrates that foot and ankle pain, affects about a quarter of patients suffering knee osteoarthritis (OA), with such pain exacerbating knee OA-related pain, symptom severity, and physical function.

"This finding highlights the fact that clinicians should consider evaluating the foot and ankle in people with knee OA and provide interventions for foot pain, if present," wrote the authors.

With international guidelines now recommending that clinicians identify and address different clinical OA characteristics, a greater understanding of the clinical presentation of patients with concurrent knee OA and foot pain is needed, according to the authors. To date, no study has explained the relationship between foot pain and knee OA-specific symptoms or function, they said.

For this new study, researchers used the publicly accessible database of the Osteoarthritis Initiative (OAI), a prospective multicenter cohort study of 4,796 people ages 45-79 years. 

The study, which included 1,255 patients, found that 25.3% reported pain in one or both feet. Patients with concurrent foot pain and knee OA were significantly more likely to be younger and female and to have a higher body mass index (BMI) than subjects with no foot pain. 

Bilateral pain was the most prevalent type of foot pain (54.9%) and contralateral foot pain the least prevalent (17.7%). Patients with knee OA and bilateral foot pain were significantly more likely to be women and to have a higher BMI.

Foot pain may be due to excessive pronation or other biomechanical factors. Such pronation -- and subsequent pain -- could be a compensatory response to OA-related knee pain. Alternatively, both foot and knee pain may be related to the presence of varus knee malalignment, said the authors.