Knee osteoarthritis progression can be predicted by MRI findings of medial collateral ligament edema, bone marrow lesions, and being female, according to a study presented at the RSNA meeting Thursday morning.

Of 123 patients in the study, 44 showed progressive knee osteoarthritis and 79 did not. Medial collateral ligament edema, bone marrow lesions, and the female sex were independent predictors of knee osteoarthritis progression, said Dr. Peter Pham, the presenter of the research and a radiology resident at Loma Linda University in Loma Linda, CA.

A retrospective cohort study of 123 patients with knee pain was chosen for inclusion in the study by querying the Loma Linda radiology information system from 2000 to 2008. An initial knee radiograph and MRI less than 12 months apart were included as well as radiographic follow-up more than 24 months after the initial MRI. The researchers then categorized the patients as progressive or nonprogressive based on an evaluation of joint space narrowing, subchondral irregularity, or osteophytes between initial and follow-up radiographs.

The researchers measured the association between each MRI finding and progression score by using a chi-square analysis and calculating an odds ratio.

What they found is if a patient received an MRI today and also had medial collateral ligament edema, for instance, approximately 16 months from today that person would have about twice the risk of knee osteoarthritis progression.

The MR images were also analyzed for meniscal tear, meniscal subluxation, chondromalacia, bone marrow edema, subchondral cysts, joint effusion, and synovial thickening, but none of those predicted knee OA progression as well as medial collateral ligament edema, bone marrow lesions, and female sex.