Objective. To determine the magnetic resonance imaging (MRI), macroscopic, and microscopic characteristics of synovial membrane inflammation, to study the relationship between disease severity and the degree of synovial inflammation on MRI and on macroscopic and microscopic examination, and to look for colocalization of chondral lesions and synovial inflammation.Methods. Thirty-nine patients with knee osteoarthritis (OA) were classified into 2 groups according to the severity of cartilage lesions as revealed by chondroscopy. Group 1 (n ‫؍‬ 14) had mild cartilage lesion(s) without exposure of subchondral bone. Group 2 (n ‫؍‬ 25) had severe cartilage lesion(s) with focal or diffuse exposure of subchondral bone. Synovitis was evaluated on T1-weighted MRI sequences according to the degree of synovial thickening on a 4-point scale (ranging from 0 to 3) in 5 regions of interest. Synovial membrane was macroscopically scored, and biopsies were performed on the 5 preselected sites for histologic scoring.Results. The mean ؎ SD synovial thickening score on MRI was 1.55 ؎ 0.90, with no significant difference between groups 1 and 2. Intra-and interobserver reproducibility of the total synovial score was excellent, and interobserver reproducibility of the MRI grade was good. Conclusion. Synovitis may be present from the onset of OA and may be evaluated on MRI. MRI evaluation of synovitis could be used to classify OA patients in clinical trials and could help to identify those who could benefit from synovium-targeted therapy.Osteoarthritis (OA) is the most prevalent form of arthritis and a major cause of disability worldwide (1).

Bone mineral density (BMD) was measured in 1992-93 in 129 nuclear families, including 258 parents and 183 children, and was analyzed for familial resemblance factors. BMD measurements were adjusted on weight and age. Segregation analysis rejected the monogenic hypothesis and exhibited a strong polygenic component. Variance components analysis was then used to estimate the parameters of a multivariate normal model including an additive polygenic component, a common environment factor, and a residual specific to each individual. The genetic component was independent of sex and age. The common environmental factor was not significant. The variance of the residual specific factor appeared to be a quadratic function of age, reaching its minimum value at 26.4 years. Consequently, the maximum value for heritability (ratio of genetic variance to total variance) is observed at this age (h2 = 0.84). According to this model, the correlation between two relatives is a function of the ages of each individual in the pair.

Conclusion. These data suggest that detection of chromosomal B burgdorfen' DNA may be more efficient in ST than SF.