Arthroscopy of the knee in children.

Diagnostic arthroscopy was performed in 174 consecutive patients under the age of 18 years. Eight arthroscopies were bilateral. The clinical diagnosis was confirmed in only three of 17 knees in children under aged 14 years and in 44 per cent of the knees in older children. The most commonly disproved diagnoses were torn meniscus and chondromalacia patella. Arthroscopy seldom changed the diagnosis in cases of osteochondritis dissecans. In 38 per cent of the knees, arthroscopy revealed no surgical treatable abnormality, and unnecessary arthrotomy was avoided. Arthroscopy in acute hemarthrosis revealed that ligamentous tears are rather common in children; in nine of 25 knees a partial or complete tear of the anterior cruciate ligament was demonstrated at arthroscopy. The clinical diagnosis was confirmed in eight knees in cases of hemarthrosis. There was no significant difference between the hemarthrosis group and the remaining group as regards a disproved clinical diagnosis. We conclude that arthrotomy should always be preceded by diagnostic arthroscopy in children and adolescents if the clinical diagnosis leaves any doubt.