What are the clinical implications of knee crepitus to individuals with knee osteoarthritis? An observational study with data from the Osteoarthritis Initiative

Abstract

BackgroundCrepitus is a common clinical feature of knee osteoarthritis. However, the importance of crepitus in the overall clinical presentation of individuals with knee osteoarthritis is unknown. Objective(s)(A) To compare function, pain and quality of life between individuals with knee osteoarthritis with and without crepitus; (B) to compare whether individuals with knee osteoarthritis in both knees, but crepitus in just one, differ in terms of function pain, and knee strength. Methods:Setting: Observational study. Participants: (A) A total of 584 participants with crepitus who had the same Kellgren–Lawrence grade on both knees were matched for gender, body mass index and Kellgren-Lawrence grade to participants without crepitus on both knees. (B) 361 participants with crepitus in only one knee and with the same Kellgren-Lawrence grade classification on both knees were included. Main outcome measure(s): A – Self-reported function, pain, quality of life, 20-m walk test and chair-stand test. B –Knee extensor and flexor strength, self-reported function and pain. ResultsA – Individuals with crepitus had lower self-reported function, quality of life and higher pain compared to those without crepitus (3–11%; small effect=0.17–0.41, respectively). No difference was found in objective function between groups. B – Self-reported function was lower in the limb with crepitus compared to the limb without crepitus (15%; trivial effect=0.09). No difference was found in pain and knee strength between-groups. Conclusion(s)Individuals with knee osteoarthritis and knee crepitus have slightly lower self-reported physical function and knee-related quality of life (small or trivial effect). However, the presence of knee crepitus is not associated with objective function or knee strength.