In patients who lack osteoarthritis symptoms, subjective crepitus — or hearing grating, cracking or popping sounds in or around a joint — in the knee can predict incident symptomatic OA, according to findings published in Arthritis Care and Research.
This was particularly true among patients with pre-existing tibiofemoral radiographic OA, but who did not have frequent knee pain.
“When we asked about crepitus — specifically, the question was, “Do you feel grinding, hear clicking or any other type of noise when your knee moves?” — we found that the greater the frequency that people reported this sound or feeling, the more likely they were to develop symptomatic knee osteoarthritis within the coming year,” Grace H. Lo, MD, MSc, of Baylor College of Medicine, in Houston, told Healio Rheumatology. “Furthermore, the group where this was most predictive was the group that already had radiographic evidence of osteoarthritis but just hadn’t complained of a lot of pain yet.”
To determine whether an association exists between “creaky knees” and incident symptomatic OA, the researchers reviewed data from the Osteoarthritis Initiative, a multicenter longitudinal U.S. cohort, focusing on 3,495 participants without baseline symptomatic OA. The researchers determined crepitus frequency using a question from the Knee Injury and Osteoarthritis Outcome Score at baseline, as well as at 12, 24 and 36 months. In addition, they assessed frequent knee pain and radiographs at baseline and at annual visits up to 48 months.
The researchers defined radiographic OA as a tibiofemoral Kellgren/Lawrence grade of 2 or higher, and symptomatic OA was established by the presence of frequent symptoms and radiographic OA. Lastly, they completed a repeated-measures analysis with a predictor of crepitus and outcome of incident symptomatic OA, adjusting for age, sex and BMI, using patients without crepitus as a reference group.
According to the researchers, the likelihood of incident symptomatic OA was high among patients with greater a frequency of crepitus (P < .0001). Patients with radiographic OA, but who lacked symptoms, at baseline, comprised 26% of the cohort, but more than 75% of the incident symptomatic OA cases, the researchers found.
“It turns out that the group who complain of crepitus frequently, who should be most concerned about it, are the ones who already have evidence of OA on their X-rays, but don’t have frequent knee pain yet,” Lo said. “These are the people at greatest risk for developing symptoms over the next year. So, in the context of a person who complains of crepitus, who doesn’t have frequent knee pain, getting a plain radiograph would help determine how soon they are likely to get symptoms.”
However, the researchers cautioned that their findings come with a major limitation — patellofemoral OA was not systematically evaluated within the Osteoarthritis Initiative.
According to Lo, the findings drive home the point that patients should communicate more with their physicians.
“I think that if people have creaky knees, and this can get them to talk to their doctors and they can try to address the issue, it’s a good thing,” she said. “There is also a growing idea that the time to intervene when it comes to osteoarthritis is early in the disease; if you wait until you are already symptomatic, then it might be too late. The best-case scenario would be that someone complains of the creaky knees, talks about it with their primary care doctor — and if the person is already overweight, discuss the potential benefits of working on weight loss — and this discussion motivates him/her to lose weight with diet and exercise.” – by Jason Laday
Disclosure: Lo reports support from the National Institute of Arthritis and Musculoskeletal and Skin Diseases. See the full study for additional authors’ disclosures.