The ultrasound scan in monitoring regenerated bone

The aim of this work was to delimit the diagnostic possibilities of the ultrasound scan in the evaluation of regenerated bone produced in bone lengthenings and transports. The study is based on 56 ultrasound scans of regenerated bone regarding 4 lengthenings and 18 bone transports. X-ray examinations were taken in 13 patients contemporarily with the ultrasound scans and a comparative and qualitative evaluation between the radiographic gap and the ultrasound one was made. The ultrasound scans allowed us to distinguish 3 kinds of regenerated bone: normal, cystic and hypertrophic. In 7 cases, at the proximal third of the tibia, a cyst in the regenerated bone was noticed on ultrasonography. The evaluation of these cysts after the slowing down of the distraction speed was satisfactory in the sense that they disappeared in the following examinations, their volume did not change and they did not interact with the following maturation and corticalization of the regenerated bone. In one case, at the proximal third of the tibia, we noticed two cysts that disappeared after regenerated bone compression while, after a new distraction made at a lower speed, a cyst appeared again maintaining its unchanged volume. The presence of one or more cysts indicates an initial crisis of the regenerated bone which could develop into a dangerous hypotrophy if the distraction speed remained unchanged. In 5 cases with a hypertrophic regenerated bone, a gap less than 10 mm was noticed. It was treated by accelerating the distraction speed. The ultrasound examination can offer a precise monitoring of distractional osteogenesis. Received: 27 November 2001, Accepted: 4 April 2002 Correspondence to: C. Iacobellis