Scoping Review of Pain and Patient Characteristics and Physical Function Associated with Intermittent and Constant Pain in People with Knee Osteoarthritis

Purpose: We identified the pain and patient characteristics and physical function associated with intermittent and constant pain in people with knee osteoarthritis (OA). Method: The search strategy was conducted in MEDLINE, CINAHL, Embase, SPORTDiscus, Cochrane, and the Physiotherapy Evidence Database for articles published up to October 2018. We included observational studies, randomized controlled trials, reviews, qualitative studies, and case reports in English and French of adults with knee OA. Articles were screened by two independent reviewers, and disagreements were resolved by a third researcher. Results: Our search yielded 1,232 articles, and 4 articles were included in the review. Constant pain was related to limitations in daily activities, a higher Kellgren and Lawrence grade, a higher prevalence of comorbidities, and symptomatic knee OA and depressive symptoms. Intermittent pain was associated with limitations in high-impact activities, but greater time spent in moderate activities was reported. The evidence is contradictory as to whether intermittent or constant pain has a greater average severity. Conclusions: There was limited evidence available to determine the association of pain and patient characteristics and physical function with constant and intermittent pain in people with knee OA. Future research will help improve our understanding of these two pain patterns by examining their associations across a variety of pain and functional outcomes in people with knee OA.