Discoid meniscus is an uncommon dysplasia generally affecting the late
ral meniscus. Its congenital or acquired origin remains a question of
debate. We report 5 cases or lateral discoid meniscus in 4 girls and 1
boy, aged from 6 to 11 years. The main clinical signs were snapping k
nee and pain. The discoid meniscus appeared in MRI as an abnormally la
rge meniscus extending into the joint space. It appeared as a central
band giving increased signal in 3 out of 5 cases. The significance of
this probably trauma-induced image was uncertain. Surgery confirmed MR
I findings in 4 cases in which total resection of the meniscus was per
formed. No operation was performed in the fifth case.