Normal meniscal dimensions at different patient ages—MRI evaluation

Objective: The purpose of this work is to evaluate the normal meniscal and tibial dimensions in relation to age and gender in different children using conventional MRI sequences. Materials and methods: Morphometric measurements of the menisci were retrospectively performed on knee MRIs of children (< 18 years). All knee MRIs over a 7-year period were collected. Exclusion criteria included: prior knee surgery or diseases involving the knee joint. A total of 186 children were included, 110 boys and 76 girls, with a mean age of 8.2 years (range, 0.3–17.8 years). Menisci and tibial measurement changes with age and gender as well as differences between the medial and lateral menisci were evaluated. Results: The medial menisci measurements increased with age (p value < 0.001). The lateral menisci measurements increased with age (p value < 0.001), except for the coronal meniscal width (p = 0.084). Coronal and sagittal percentage of meniscal coverage of the tibia decreased with age (p < 0.001). Medial menisci have greater sagittal width and anterior horn height than lateral menisci (p value < 0.001). Lateral menisci are larger in their coronal width and height, and sagittal posterior horn height in comparison to medial menisci (p < 0.001). Conclusions: Menisci increase in all dimensions in correlation with age; except in the coronal meniscal width, which is a useful dimension to diagnose discoid meniscus on MRI, based on this, it would seem that the currently published size criteria, based on adults, could be applicable to children. The tibia has a faster rate dimension increase in correlation with age in comparison to the menisci.