[Ultrasound diagnosis of congenital knee dislocation].

Since 1990, more than 50 children with hyperextended knee joints have been treated based on sonographic assessment. Ultrasound imaging has been useful for primary diagnosis, classification, and follow-up of conservative treatment. The image quality of sonographic documentation more or less equates the more expensive magnetic resonance imaging (MRI) and has become the golden standard of imaging hyperextended knee joints. There is almost no more need for plain X-rays.