Meniscus injuries are common in patients under the age of 20 (the 'young') and pose challenges on clinical examination making MRI important in the assessment of these patients. The differences between the young and adult meniscus are highlighted, specifically the ultrastructure, growth, vascularisation and attachments. The diagnostic criteria for meniscus tear are emphasised. The discoid meniscus is discussed in detail including clinical presentation, diagnostic criteria and associations.The differences in diagnostic criteria for a tear in a discoid meniscus vs non-discoid meniscus are highlighted including assessment for meniscus instability. Clinical cases are presented highlighting the imaging with arthroscopic correlation. Challenging non-discoid meniscus tear patterns are discussed including Wrisberg, ramp and radial tears.