Neuropathic Pain Component Insights in Patients with Knee Osteoarthritis: An Observational Study

Osteoarthritis (OA) is one of the most leading cause of chronic disability in musculoskeletal area with pain as the main manifestation. Chronic pain often leads to an abnormal excitability in pain pathway, resulting a central sensitization which corresponding to neuropathic pain (NP). To date, the existence of neuropathic component in osteoarthritis of the knee remains controversial. METHODS: The cross-sectional study involved 74 patients of knee osteoarthritis who were diagnosed by using ACR classification criteria for osteoarthritis of the knee. The presence of NP component was assessed by DN4 and painDETECT questionnaire. All participant also completed the WOMAC score to evaluate their status of knee OA, and was divided into two groups, which were mild and severe OA. The prevalence of NP component within knee OA patients was evaluated and then compared between the mild and severe groups. RESULTS: 45,9% of the participants examined with DN4 score were likely to have the NP component, while the others were doubtful. On the other hand, painDETECT score revealed that 36,5% of the patients were likely to have NP component, 21,6% unclear, and 41,9% unlikely. Comparison between WOMAC score and DN4 showed that 67,6% of the severe population had NP component, significantly higher than the mild population, 24,3% (p<0,05). Alternatively, painDETECT score showed 13,5% likely to have NP component, 24,3% unclear, 62,2% doubtful in the mild population, while in the severe group 59,5% likely, 18,9% unclear, 21,6% unlikely (p<0,05). CONCLUSION: Knee osteoarthritis has a significantly high prevalence of neuropathic pain component. NP component prevalence appears higher in the severe OA population, whether it assessed by DN4 or painDETECT scoring.