Neuropathic pain in knee osteoarthritis

BACKGROUND: This study aimed to investigate the relationship between the neuropathic pain in knee osteoarthritis with the body composition, anthropometric and postural features, physical function, and quality of life. METHODS: Patients with primary knee osteoarthritis, 50-70 years of age, were included in the study and divided into Group 1 with neuropathic pain and Group 2 with no neuropathic pain according to Douleur Neuropathique-4. The groups were compared in terms of demographic, clinical, radiological, laboratory findings and anthropometric measurements, body composition, physical function tests, osteoarthritis severity, quality of life, and posturography. RESULTS: 200 patients were included in the study. 98 (82.6% female) were in Group 1 and 102 (74.5% female) in Group 2. Age was higher in Group 1 compared to Group 2 [61 (50-70) and 57.5 (50-70), respectively, p = 0.03]. Symptom duration was also longer in Group 1 (5.21 ± 4.76 and 3.38 ± 3.58, p = 0.002). Body mass indices were 31.9 ± 5.6 and 30.1 ± 4.8 (p = 0.015). Kellgren-Lawrence class, Western Ontario and McMaster Osteoarthritis Index and Short Form-36 scores were more unfavorable in Group 1. Although fall risk was similar, stability and Fourier harmony indices were impaired in Group 1 compared to Group 2 especially when the visual and proprioceptive input was blocked. CONCLUSIONS: Almost half of the patients with knee osteoarthritis had neuropathic pain which was associated with longer symptom duration and higher age, lower education, higher body mass index, more severe radilogical findings, worse pain perception, lower physical function and quality of life, and lower stability.