[Ultrasound follow-up of callus distraction--an alternative to roentgen diagnosis?].

In a prospective study 20 patients were regularly monitored with sonograms in four planes and radiographs during distraction osteogenesis of the lower limb. Ultrasonography is more sensitive than radiography in identifying new bone formations during distraction, in measuring the length of the distraction gap, and in detecting early bone healing complications, and can therefore reduce the need for radiographs. Radiographs are necessary to assess the time of fixator removal and the axis of the leg.