DISCOID MENISCI IN CHILDREN - MR FEATURES

Objective: To define the MR appearance of discoid meniscus in children . Materials and Methods: In 22 children (15 girls and 7 boys; age rang e 5-17 years; median age, 9 years) who were referred for evaluation of painful knees 27 discoid lateral menisci were identified. Meniscal sh ape and signal intensity and abnormalities of the surrounding structur es were evaluated and compared with adult standards. Clinical (11 knee s) or surgical (10 knees) follow-up was available on 16 patients (21 k nees). Results: The menisci were classified as slab type (no. 20) or w edge type (no. 7). Transverse diameter at the midbody was 22.4 mm (ran ge 10.5-36.7 mm) for discoid lateral menisci and 6 mm (range 5.1-28.3 mm) for medial menisci. Of 27 menisci, 23 had a central band of diffus ely increased signal. Extension of intrameniscal signal to the joint s pace was noted in 16 of 23 menisci. Of 9 patients with intrameniscal s ignal who underwent surgery, only 7 had tears. Associated popliteal cy sts occurred in 3 knees, No medial meniscal injury was observed. Concl usion: The characteristic MRI appearance of symptomatic discoid menisc us in children is that of a diffusely thick meniscus with a slab confi guration and diffusely increased intrameniscal signal that may or may not extend to the joint surface.