FORT LAUDERDALE, FLA. — Early screening of synovial fluid volume changes using magnetic resonance imaging could identify patients at risk for progressive knee osteoarthritis, according to interim findings of an ongoing study.
Synovial fluid volume decrease on MRI correlated with both osteophyte formation and joint space narrowing, whereas loss of cartilage volume did not predict progressive disease, Dr. Svetlana Krasnokutsky said during her presentation at the World Congress on Osteoarthritis.
Dr. Krasnokutsky and her associates are conducting a 2-year longitudinal biomarker study of 58 patients with knee osteoarthritis. She presented interim cross-sectional findings at the meeting, which was sponsored by the Osteoarthritis Research Society International.
At baseline, participants' mean age was 62 years, mean body mass index was 28 kg/m
Semiflexed, anterior-posterior radiographs of the knees at baseline will be repeated at 24 months. Also, 3T MRI with gadolinium will be performed at baseline and 24 months to measure cartilage, synovium, and bone marrow volumes. “X-rays are insensitive to a substantial portion of cartilage loss that can be seen on MRI,” said Dr. Krasnokutsky of New York University, New York.
The interim analysis indicates that total cartilage volume does not correlate with the Kellgren-Lawrence (KL) score. “We expected to see a decrease in cartilage volumes in the femur and tibia as the KL score increased, but we did not.” In addition, total cartilage volume did not correlate with KL score, joint space width, or osteophyte score.
In contrast, increasing synovial volume correlated with severity of knee osteoarthritis by KL score. “Synovitis is a biomarker of advancing disease and is a parallel feature of the failing joint,” Dr. Krasnokutsky said. Synovial volume correlated modestly with bone marrow lesion volume. However, it did not correlate to the Western Ontario and McMaster Universities osteoarthritis index pain score.