MRIs can spot the warning signs of knee osteoarthritis in people who have normal X-rays, researchers report.
They looked at 849 people, average age of 60, who showed no evidence of arthritis in either knee in X-rays. They were deemed at high risk due to factors such as being overweight or having a history of knee pain and knee injuries.
The Northwestern University team also assessed cartilage damage, bone marrow lesions and meniscus tears on MRI images taken three years apart. If the MRIs showed worsening damage during that time, the patients were at increased risk of developing knee arthritis or symptoms such as pain, stiffness and/or swelling.
Depending on the type of lesion revealed by MRI, the risk of developing knee arthritis within three years was three to 20 times greater, the researchers said.
"These worsening lesions are an early warning sign and an opportunity to intervene before a person develops the debilitating disease," lead investigator Dr. Leena Sharma, a rheumatologist and professor of medicine, said in a university news release.
"If we employ aggressive prevention strategies in persons with these lesions before they develop knee osteoarthritis, we may be able to delay disease development or alter its course," she added.
Those preventive measures include weight control and avoiding potentially harmful physical activity.
The study was published recently in the Annals of the Rheumatic Diseases.Read more:
How exercise eases knee osteoarthritis
Future knee implants will be made by silkworms