Neuropathic Pain and Osteoarthritis of the Knee

Study results show that pain associated with osteoarthritis of the knee often exhibits neuropathic pain characteristics.

A team of researchers administered the Douleur Neuropathique in 4 questions (DN4) questionnaire to 2,167 patients with osteoarthritis (OA) of the knee when they were evaluated for orthopedic surgery or at a rehabilitation clinic, and correlated the DN4 scores with data from the patients’ medical files and those obtained during a single structured clinical interview.

After excluding patients whose knee pain might have been caused by factors other than osteoarthritis, the researchers found that one-third (33%) of patients had positive DN4 scores, indicating the presence of neuropathic pain characteristics.

In their discussion of these results in “High Prevalence of Neuropathic Pain Features in Patients with Knee Osteoarthritis: A Cross-Sectional Study,” published in Pain Practice, the authors wrote “Patients who scored positively in the DN4 had more severe pain, greater structural damage, and more potential confounders of neuropathic pain. Three potential confounders conveyed much of the variability explained by regression analyses. However, latent class analyses revealed that the concourse of other factors is required to explain the neuropathic pain qualities.”

They concluded that “A relevant proportion of patients with chronic pain associated with knee OA featured neuropathic pain qualities that were not explained by other conditions. The present research has provided reasonable epidemiological grounds to attempt their definite diagnosis and classification.