LAUSR

Background Fibromyalgia (FM) has been conceptualised as a central nervous system (CNS) disorder, characterised by augmented sensory processing and inability to modulate pain effectively[.1 Global mean prevalence of FM is 2.7% with female/male ratio of 4:1. Several studies highlight the importance of central sensitisation (CS) as a significant manifestation of neuropathic pain symptoms in knee osteoarthritis (OA).2–3 Possible similar mechanisms of chronic pain maintenance in OA – structural pathology, and FM – central sensitivity syndrome, provoke further interest in investigation of any links between these conditions. Therefore, prevalence of FM in patients with painful knee OA is of considerable interest. Objectives The purpose of this study was to evaluate the prevalence of fibromyalgia (FM) in patients with painful knee OA. Methods The study involved 92 patients (63 females and 29 males) with painful knee OAACR 1986 Osteoarthritis Knee Criteria) with non-surgical management aged 59.4±14.3 (M±SD) yrs.4 Radiographic findings for OA were classified according to Kellgren-Lawrence scale grading.5 FM was diagnosed in these subjects if both ACR 1990 and 2010 criteria were met.5–6 Results FM was diagnosed in 21painful knee OA patients (22.83%). Among female patients FM was confirmed in 19 from 63 subjects (30.16%) compared to 2 from 29 male patients (6.90%). No relationship was found between the radiologic stage of the knee OA and FM prevalence in the investigated subjects. Conclusions FM prevalence is relatively high in painful knee OA patients, mostly female. Further studies investigating possible FM impact on pain modulation, functional disability and quality of life in painful knee OA are needed. References [1] Petersel DL, Dror V, Cheung R. Central amplification and fibromyalgia: disorder of pain processing. J Neurosci Res. 2011;89:29–34. [2] Arendt-Nielsen L, Nie H, Laursen MB, Laursen BS, et al. Sensitization in patients with painful knee osteoarthritis. Pain. 2010 Jun;149(3):573–81. [3] Finan PH, Buenaver LF, Bounds SC, et al. Discordance between pain and radiographic severity in knee osteoarthritis: findings from quantitative sensory testing of central sensitization. Arthritis Rheum. 2013Feb;65(2):363–72. [4] Altman R, Asch E, Bloch D, et al. Development of criteria for the classification and reporting of osteoarthritis. Classification of osteoarthritis of the knee. Diagnostic and Therapeutic Criteria Committee of the American Rheumatism Association. Arthritis Rheum. 1986;29:1039–1049. [5] Kellgren JH, Lawrence JS. Radiological assessment of osteo-arthrosis. Ann Rheum Dis.1957;16:494–502. [6] Wolfe F, Smythe HA, Yunus MB, et al. The American College of Rheumatology 1990 criteria for the classification of fibromyalgia. Report of the Multicenter Criteria Committee. Arthritis Rheum1990;33:160–72. [7] Wolfe F, Clauw DJ, FitzCharles MA, et al. The American College of Rheumatology preliminary diagnostic criteria for fibromyalgia and measurement of symptom severity. Arthritis Care Res (Hoboken)2010;62:600–10. Disclosure of Interest None declared