Ultrasound detected changes in joint cartilage thickness in juvenile idiopathic arthritis

The purpose of this study was to investigate the changes in joint cartilage thickness in different subtypes of juvenile idiopathic arthritis (JIA) using ultrasound, comparing them with healthy children and to evaluate the relationship with disease duration and inflammatory markers.

We conducted a cross-sectional study comprising of 27 cases of JIA and 54 age- and sex-matched healthy children. Bilateral wrist, knee and ankle joint cartilage thicknesses were measured by ultrasound as per European League Against Rheumatism standard guidelines and compared them between JIA subtypes as well as between cases and control.

Descriptive analysis of the whole cohort revealed the mean age of the study population was 8.3 ± 3.2 years with mean cartilage thicknesses at the wrist, knee and ankle being 1.40 ± 0.89 mm, 1.57 ± 0.78 mm and 1.41 ± 0.85 mm, respectively. The median cartilage thicknesses of wrist, knee and ankle joints of JIA cases (n = 27) and healthy controls (n = 54) were 1.01, 1.35, 1.05 and 1.95, 2.00, 1.95, respectively. The joint cartilage thickness was significantly reduced in JIA in comparison to the healthy cohort (P < 0.01). Diseased boys suffered greater cartilage damage in knee joints compared to girls; the polyarticular variety of cases had thinner knee cartilage in comparison to the oligoarticular subtype. Further, it was found that joint cartilage destruction is independent of inflammatory markers and disease duration.

Significant cartilage thinning in addition was found in JIA children, particularly in the polyarticular subtype, and more in boys than girls, which is independent of disease duration and inflammatory markers, using ultrasound as a primary investigative tool.