The study was conducted by Canadian researchers from University of British Columbia and the Arthritis Research Centre of Canada, both in Vancouver, and American researchers from the company Synarc in San Francisco, which specializes in clinical trials with medical imaging such as X-rays, MRI, PET and CT scans. It was funded by the Canadian Institutes of Health Research, which is the Canadian equivalent of the National Institutes of Health, and the Canadian Arthritis Network.
"The MRI is a much more sensitive tool to look at early changes," said Dr. Jolanda Cibere, a rheumatologist and research scientist at the University of British Columbia and lead author of the study.
"Most of the time physicians only get an X-ray and in these cases the X-ray would have shown nothing," she said. "That's a huge number of people that may not get diagnosed with OA if they were simply relying on an X-ray."
But using an MRI scan for the diagnosis of every person with OA isn't feasible either.
"If we look at how common OA is, based on these results clearly we need to find better ways to diagnose it, not rely only on X-rays," Cibere said. "We can't do MRI on everyone because it's too expensive."
OA is the most common form of arthritis, affecting 21 million adults, according to the Centers for Disease Control and Prevention. OA can occur at almost any joint but it's most common at the knee, affecting more than 10 million adults nationwide. OA occurs when the cartilage between two bones wears down and the bones start rubbing against each other. The result can be pain, swelling, stiffness and limitations in movement.
Cibere and her colleagues are currently working on new ways to diagnose the disease without having to use MRI and she says some factors that need to be taken into account are a person's age, body mass index (BMI) and certain signs in blood and urine tests which can show the degradation of cartilage. Besides age and BMI, other risk factors for having OA were pain frequency, stiffness and decreased knee function.
The fact that knee changes caused by OA don't appear on an X-ray means that the disease is in its early stages and hasn't damaged the joints too much yet. But that shouldn't push people into complacency, Cibere said.
"It's not too early to treat and we can treat pain by recommending building muscle strength, weight loss and exercise and those may have an impact on how people progress [with OA]," she said.
The findings of this study may be a cause for concern for many with knee pain but Cibere says such people shouldn't panic unnecessarily.
"Pain is often attributed to aging and therefore often does not get treated. But if the pain persists, it may be OA. I wouldn't say people should panic though, because there're things they can do even at the early stage," she said.
*Reprinted from the Missouri Arthritis Rehabilitation Research and Training Center
