Pain as an indication of central sensitization in symptomatic knee osteoarthritis patients
Expanded distribution of pain is regarded as a sign of central sensitization (CS). The association between recording of symptoms and CS in people with knee osteoarthritis (OA) has been under-estimated. A study was employed to determine whether the area of pain assessed using pain drawings corresponds to CS and clinical symptoms in people with knee OA.
Total 53 people with knee OA scheduled to undergo primary total knee arthroplasty were investigated. All participants completed pain drawings by application of a novel digital device, completed self-administration questionnaires, and were analyzed by quantitative sensory testing. Separate pain frequency maps were made for women and men. Spearman correlation coefficients were computed to disclose possible correlations between pain area and quantitative sensory testing and clinical symptoms.
The outcomes suggested enlarged areas of pain by the pain frequency maps especially in women. These areas of pain were related with lower pressure pain thresholds at knee (rs=−.306, P<.05) and epicondyle (rs=−.308, P<.05), higher knee pain severity (rs=.325, P<.05) and stiffness (rs=.341, P<.05), and higher scores with Central Sensitization Inventory (rs=.456, P<.01). No important associations were seen between the area of pain and the rest of the clinical symptoms and measures of CS.
The limitations of study imply that predictive role of pain drawings cannot be drawn. Further assessment of reliability and validity of pain area extracted from pain drawings in people with knee OA is required. Thus, pain drawings may constitute an easy uncomplicated way for the early identification of CS in people with knee OA, but further research is needed.