Frequency and factors associated with neuropathic pain in patients with knee osteoarthritis

Abstract

Objective: To determine the frequency and factors associated with neuropathic pain in patients with knee osteoarthritis seen during rheumatology consultations. Methods: This was a descriptive and analytical cross-sectional study of patients with knee osteoarthritis who met the ACR criteria and who were seen in rheumatology consultations at a referral university hospital. A DN4 score greater than or equal to 4 was used to classify the pain as like neuropathic. Multivariable logistic regression analysis was used to determine adjusted ORs and 95% CI. Results: Three hundred and twenty-five patients with knee osteoarthritis were included in the study. The mean age of the patients was 57.85 ± 11.89 years. Neuropathic-like pain (DN4 ≥4) was identified in 32% of participants. Among DN4-positive individuals, the mean DN4 score was 6.51 ± 1.60 (range 4-10). The mean global WOMAC score was 30.98 ± 10.98. The mean score for pain under load according to the visual analog scale was 3.35 ± 1.376. After multivariable analysis, the associated factors with neuropathic-like pain were a history of knee trauma (OR = 4.525; 95%CI [1.497-13.678]; p = 0.007). Psychological history (OR = 9.941; 95%CI [3.066-32.235]; p < 0.001). Kellgren-Lawrence grades 3 and 4 (OR = 7.599; 95%CI [2.372-24.432]; p = 0.001) and WOMAC global score (OR = 1.093; 95%CI [1.053-1.134]; p < 0.001). Conclusion: A significant proportion of patients suffering from osteoarthritis of the knee experienced neuropathic-like pain, requiring the implementation of prevention and treatment strategies.