Differences in Self-reported Signs Related to Central Sensitization and Pressure Pain Threshold Related to Knee Osteoarthritis and Sarcopenia

Abstract Purpose Neuroinflammation, which occurs in knee osteoarthritis and sarcopenia, has attracted attention as a mechanism of central sensitization, but the relationship between central sensitization and these conditions has not been widely studied. This study investigates differences in self-reported signs of central sensitization and pressure pain threshold in individuals with knee osteoarthritis and sarcopenia. Methods We examined 340 patients with knee osteoarthritis scheduled to undergo total knee arthroplasty. For comparison, 129 community-dwelling elderly individuals without a history of knee osteoarthritis or any other diagnosed illnesses were matched for age and sex. The stages of sarcopenia were classified according to the criteria of the Asian Working Group on Sarcopenia in Older People. Pain-related factors were assessed by measurements including pain intensity, pain catastrophizing scale, central sensitization inventory-9, and pressure pain threshold. A two-way analysis of covariance was performed to assess outcome measurements. Results The prevalence of sarcopenia among patients with knee osteoarthritis was 56.7%. Patients with knee osteoarthritis had significantly increased central sensitization inventory-9 compared with sarcopenia, and there was no significant pressure pain threshold between patients with knee osteoarthritis and sarcopenia. In addition, patients with knee osteoarthritis and sarcopenia had significantly higher levels of pain-related factors compared to those with robust. Conclusions When contemplated as an evaluative tool in clinical settings, the central sensitization inventory − 9 may offer greater ease of use and interpretability compared to pressure pain threshold assessments for appraising symptoms of central sensitization in patients with knee osteoarthritis.