Noisy knees may be an early sign of osteoarthritis, new research suggests.
People who hear grating, cracking or popping sounds in and around their knee joints are more likely to develop the condition, say scientists.
Researchers conducted a multi-centre observational study that included almost 3,500 participants at high risk of knee osteoarthritis.
The chances of them developing pain symptoms over a period of up to four years increased with greater frequency of knee noise.
It doubled when the noises were heard “often” and trebled for patients who said they “always” experienced them.
The findings, published in the journal Arthritis Care & Research, may lead to new ways of diagnosing and treating osteoarthritis earlier, said the researchers.
US lead author Dr Grace Lo, from Baylor College of Medicine in Houston, Texas, said: “Many people who have signs of osteoarthritis on X-rays do not necessarily complain of pain, and there are no known strategies for preventing the development of pain in this group of people.
“This study suggests that if these people have noisy knees, they are at higher risk for developing pain within the next year compared with the people who do not have noisy knees.
“Future studies that target people who have X-ray signs of osteoarthritis, and who do not complain of pain but do report noisy knees, hold the promise of identifying interventions that can prevent knee pain.”
Osteoarthritis is caused by wear and tear damaging the surfaces of joints and tends to affect older people.
A third of people aged 45 and over in the UK have sought treatment for osteoarthritis, a total of 8.75 million.
The condition is not the same as rheumatoid arthritis, which is an auto-immune disease.