Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement
Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.
Prevalence of MRI-Detected Joint Pathology of the Knee in a Population-Based Sample: Framingham Osteoarthritis Study.
Niu3, Jingbo, Zhang1, Yuqing, Guermazi4, Ali, Roemer4, Frank W., Felson2, David T.
Magnetic resonance imaging (MRI) allows direct visualization of cartilage and other soft tissues and is becoming a common method to image knees osteoarthritis (OA) in studies. MRI-detected intraarticular pathology may be common in persons without disease. Previous work has shown that meniscal tears are common even in persons without radiographic OA. For other features, this is unknown because little population based data are available on the prevalence of pathologic lesions.
Residents (age >= 50) in Framingham, MA were contacted by random-digit telephone dialing advertising a study of health in general and of bone health. Of 1039 subjects recruited, 992 had MRIs (1.5 T) on the knee(s) without contraindication to acquisition and MRI of one knee, right side preferred, was read. MRI features were scored using the WORMS system by two MSK radiologists. Each MRI feature was scored at multiple subregions in a knee. Kappa statistics for inter-rater reliability were 0.510.82 depending on feature. The presence of a lesion was defined by the worst score among subregions exceeding a pre-defined cut-point. We estimated sex- and age-specific prevalence of each lesion in the whole knee, then in the tibiofemoral (TF) and patellofemoral (PF) joint separately. We calculated the age-standardized prevalence of each lesion in men and women respectively, using the age distribution in the whole sample as the standard. Finally, we repeated the analysis among subjects without radiographic TF OA (K/L grade 01) and without radiographic PF OA, respectively.
Included in the analyses were 992 subjects (57% women, 93% White, mean age: 62.5 years, sd=8.8, range 5092; mean BMI: 28.6 kg/m2, sd=5.6). 791 (80%) had no radiographic TF OA, and 895 (90%) had no PF OA. The prevalence of each lesion detected on MRI increased with age among men. However, in women, the prevalence reached a plateau at age 65 then either leveled off or slightly decreased. As shown in the table, age standardized prevalence of MRI features was high and similar between men and women. The prevalence of MRI features in the TF joint was similar to or higher than that in the PF joint except for cartilage lesion in women. Over 70% of knees showed at least erosions of cartilage, about 60% showed at least small bone marrow lesions, roughly 1/4 knees showed at least moderate osteophytes, and over 40% showed synovitis or effusions. In knees without radiographic TF or PF OA, over 40% had cartilage lesion and over 30% had bone marrow lesion.
Pathologic lesions typical of osteoarthritis are common on MRIs among people aged 50 and older drawn from the community, even among subjects without radiographic OA. The prevalence of MRI lesions increased with age and was similar between men and women.
Table age-standardized prevalence of MRI features by gender (as % of knees)
To cite this abstract, please use the following information:
Niu, Jingbo, Zhang, Yuqing, Guermazi, Ali, Roemer, Frank W., Felson, David T.; Prevalence of MRI-Detected Joint Pathology of the Knee in a Population-Based Sample: Framingham Osteoarthritis Study. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :197