Comparison between pain intensity, functionality, central sensitization, and self-efficacy in individuals with unilateral or bilateral knee osteoarthritis: a cross-sectional study

OBJECTIVE: This study aimed to compare pain intensity, stiffness, functionality, central sensitization, and self-efficacy, between individuals with bilateral knee osteoarthritis and unilateral knee osteoarthritis. METHODS: We included sedentary participants with knee osteoarthritis. The diagnosis was defined by a specialist, in which there was a complaint of pain and/or altered function in the lower limbs (duration ≥3 months); morning stiffness; pain intensity ≥3; Kellgren-Lawrence 2–3° associated with X-ray; persistence of symptoms >3 months. We used the following tools: Western Ontario and McMaster Universities Arthritis Index, Numerical Pain Scale, Central Sensitization Inventory, and Pain Self-Efficacy Questionnaire. Intergroup comparisons were performed using the t-test. RESULTS: The sample consisted of 118 adult individuals, divided into two groups: bilateral knee osteoarthritis (n=59) and unilateral knee osteoarthritis (n=59). We observed a significant difference (p<0.05) and a large effect size (d≥0.8), in the comparisons between: stature, body mass index, physical function, central sensitization, and self-efficacy. CONCLUSION: Individuals with bilateral knee osteoarthritis have higher levels of central sensitization, impaired functionality, and a lower level of self-efficacy.