AB0977\u2005ULTRASOUND MEASUREMENT OF JOINT CARTILAGE THICKNESS IN HEALTHY ASIAN SCHOOL-AGED CHILDREN

Abstract

Background Degeneration of the osteocartilaginous structures due to synovial inflammatory process is a feature of juvenile idiopathic arthritis (JIA)1. While anthropometry difference has been reported between Asian and Caucasian2, Asian specific age- and gender-related normal standard reference values should be established before ultrasound (US) measurement of cartilage thickness (Cth) becomes standard procedure in the clinic. Objectives The standard cartilage thickness in Asian children population Methods A cross-sectional study was performed in 100 healthy Asian children (including 48 girls and 52 boys, age between 5 to 12 years-old). Bilateral knees, ankles, wrists, second metacarpophalangeals (MCPs) and proximal interphalangeals (PIPs) were measured using US. Children’s body weight and body height were also recorded for later adjustment. Results We observed no difference in the Cth between right and left knees, ankles and wrists but MCPs and PIPs. Cartilage thickness in the large joints such as ankles and knees differed between sexes (p<0.001), and the boys had thicker cartilage than those of the girls. Cartilage thickness decreases with increasing age after weight, height and BMI adjustment. A formula for calculating sex-specific cartilage thickness at different ages in childhood is suggested. Conclusion Cartilage thickness measurement with US in small joints may be biased. A standard reference of Cth for Asians in the knee, ankle and wrist joints between age 5- to 12 have been proposed. References [1] Naredo, E. et al. Longitudinal power Doppler ultrasonographic assessment of joint inflammatory activity in early rheumatoid arthritis: predictive value in disease activity and radiologic progression. Arthritis Rheum57, 116-124, doi:10.1002/art.22461 (2007). [2] Yue, B. et al. Differences of knee anthropometry between Chinese and white men and women. J Arthroplasty26, 124-130, doi:10.1016/j.arth.2009.11.020 (2011). Disclosure of Interests None declared