Internal Derangement of the Knee in Children and Adolescents

TABLE I.-NON-ARTHRITIs KNEE CASES UNDER AGE OF 20 YEARS. Cases Congenitally abnormal external semilunar cartilage (13 cartilages) ...... ... 12 Fractures of normal semilunar cartilages (proved at operation. Int. = 12. Ext. = 10) 20 Loose bodies, result of direct external trauma ...... .. ... ... 2 Osteo-chondritis dissecans ... ... ... ... ... -... .. . ... 14 Coongenital absence of crucial ligaments ... ... ... .. .. .. 1 -Cysts of external semilunar cartilage .. ... ... ... .. . 3 " Snapping knee " not operated upon (probably abnormal ext. semilunar cartilages) ... 3 Slipping patella (operated upon) ... ... ... ... ... ... ... 8