[Traumatic dislocation of the hip in a 3-year-old boy with a painful knee].

A 3-year-old boy had pain on the medial side of his left knee after his father fell on him. When the pain still persisted 4 days later, further diagnostics revealed dislocation of the hip. The pain disappeared and function was restored after closed reposition under fluoroscopic control followed by immobilisation with a plaster cast. Traumatic dislocation of the hip in childhood is a relatively rare injury, but may have far-reaching consequences. As the sensitivity to pain in children differs from that in adults, an examiner must be on the alert for a traumatic dislocation of the hip whenever a child presents with a fitting history and dysfunction ofthe leg, regardless of the localisation of the pain. Pain in the knee is often reported in case of hip disorders. Avascular necrosis of the caput femoris is a well-known and dreaded complication of traumatic dislocation of the hip in children. The risk of complications is certainly increased sharply if the hip luxation goes unnoticed and reposition takes place after more than 6 hours. Closed reposition as rapidly as possible or alternatively open reposition of the dislocated hip under general anaesthesia is the indicated treatment.