[Application of low intensity, pulsed ultrasound on distraction osteogenesis of the humerus. Case report].

Low intensity pulsed ultrasound accelerates fracture healing both clinically and experimentally. Based on recently published animal studies, an improvement in regenerative bone maturation after distraction osteogenesis due to low intensity, pulsed ultrasound is also expected. We report on an 18 year-old female patient suffering from an acquired shortening of the right upper arm of 10 cm after humeral osteitis as a baby. The patient was admitted to hospital for corticotomy and distraction osteogenesis at the afflicted humerus. Due to the published experimental results in animals which indicate an improvement in bone regeneration during callotasis with the additional application of low intensity, pulsed ultrasound, we decided to try this procedure. The calculated distraction consolidation index was 21 days/cm, which is below the mean of 30 days/cm reported in the literature for humeral lengthening by distraction osteogenesis. The calculated healing index according to Paley was 0.7 months/cm in our patient. Compared to reference data, in which a range of from 0.87 months/cm to 1.5 months/cm is reported, our patient showed an accelerated maturation of distraction callus. The duration of treatment of the patient was clearly shortened by the additional application of low intensity, pulsed ultrasound. If distraction osteogenesis is correctly indicated, the early use of low intensity, pulsed ultrasound should be considered, since an acceleration of callus formation with consecutive shortening of treatment time could be attained while wearing an external fixator, leading to a decrease in cumulative complications, such as pin tract infections. Further studies from our research group regarding this topic will follow.