Objective      To establish standard reference values of normal epiphyseal cartilage and joint cartilage thicknesses of children at different ages

and found a basis of assessing the early changes in the cartilages of juvenile idiopathic arthritis (JIA) with ultrasound examination.       Methods      The thicknesses of the epiphyseal cartilage and joint cartilage were measured with ultrasonography in 503 healthy children

including 336 boys and 167 girls in our department from May to August 2015. They were divided into 4 groups according to their ages

infant and toddler group (1- to 3-year-old

n=120)

preschool group (3- to 6-year-old

n=136)

school-age group (6- to 10-year-old

n=124)

and adolescence group (10- to 16-year-old

n=123). The bilateral epiphyseal cartilage and joint cartilage thicknesses of the elbow

wrist

second metacarpophalangeal joint (MCP2)

third metacarpophalangeal joint (MCP3)

hip

knee and ankle joints were measured.       Results      The obtained cartilage thicknesses showed significant differences between different sexes and among different ages (P0.05 for all joints). Boys had thicker cartilage than girls at the same ages. A linear correlation was observed between cartilage thickness and age

and cartilage thickness was decreased with the increase of age in both sexes. There was no obvious difference between the right and left side of all the investigated joints (P0.05).       Conclusion      We establish standard reference values for the normal thicknesses of epiphyseal and joint cartilages in the elbow

wrist

MCP2

MCP3

hip

knee and ankle joints at different aged-children.