Noisy knees not necessarily bad, but osteoarthritis link raises concerns

Researchers may have identified the long-debated cause of creaking, popping and clicking knees – common at any age, with or without an underlying knee injury – and whether it's something to be concerned about.

Many of us have experienced knee crepitus, the medical term for when your knees audibly crack, pop, click, grate or grind during movement. It’s a common phenomenon and can occur at any age – but does it signify something bad?

The underlying cause of knee crepitus remains a topic of debate. Then again, the scarcity of research on its causes means medical professionals can be at a loss when a patient asks, "What’s causing that creaking noise in my knees, and what can I do about it?" So, helpful researchers from La Trobe University in Melbourne looked at past studies into crepitus to see if they could pinpoint its cause.

“Health professionals often find it challenging to provide advice on the problem, owing to a lack of research on the meaning behind knee crepitus,” said Jamon Couch, from La Trobe’s Sport and Exercise Medicine Research Center and the study’s lead author.

The researchers reviewed 103 studies from 28 countries involving 36,439 participants, including 42,816 knees. Eighty-six studies assessed crepitus through a physical exam, 10 used self-reporting, four used both physical exam and self-reporting, and three didn’t describe an assessment method. Analyzing the data, they found that creaky knees were seen in 41% of the general population.

“Knee crepitus was common in those with and without a knee injury,” Couch said. “We discovered that 36% of people without a knee injury had creaky knees, although it was far more common in those with an injury to their knee cartilage. We found that knee crepitus was present in 81% of those with knee osteoarthritis.”

The link between noisy knees and osteoarthritis, including the presence of structural changes in the knee joint, was a concern for the researchers.

“One of the more concerning discoveries we made was that people with knee crepitus were more than three times as likely to be diagnosed with osteoarthritis and twice as likely to exhibit knee joint changes linked to osteoarthritis on magnetic resonance imaging (MRI) scans,” said Couch.

Although the increased risk of osteoarthritis is something to keep an eye on, the researchers recognize that the low to very low certainty of evidence informing their prevalence estimates and associated outcomes suggest that their results should interpreted with caution. Further research is needed.

“Although investigation of the long-term consequences of knee crepitus is ongoing, people should generally not be concerned about their noisy knees and be encouraged to continue to exercise,” Couch said. “If it’s not painful, it’s likely not doing any damage.”

The study was published in the British Journal of Sports Medicine.

Source: La Trobe University