Factors associated with pain pressure threshold in both local and remote sites in knee osteoarthritis

Abstract

Background: Knee osteoarthritis (KOA) is a prevalent condition, and its most frequent symptom is pain that often leads to disability. Pain sensitization is a core feature of KOA, and it can be measured through quantitative sensory testing protocols such as pain pressure threshold (PPT). However, there is a lack of understanding about the factors that may influence changes in PPTs in the KOA population. Objective: To explore the clinical and functional factors associated with PPTs in a sample of people with chronic KOA pain and to compare models of local (knees) and remote (thenar regions) sites. Design: Cross-sectional analysis of a prospective cohort. Setting: Primary care in public institution. Participants: 113 adults with KOA. Intervention: N/A. Main Outcome Measures: Multivariable regression analyses evaluating demographic, clinical, and functional variables that could be associated with local and remote PPTs (main outcomes) were performed. Results: Both thenar region (adjusted-R2: 0.29) and knee (adjusted-R2: 0.45) models had the same significant negative association with being a female, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain levels (thenar: β: −0.15, p =.002; knee: β: −0.2, p