Imaging in bone lengthening. A review

Limb lengthening using callotasis needs careful preoperative planning and great care during the lengthening period. The most common method used to monitor limb lengthening is plain radiography, but the time of frame removal is still left to the judgment of the surgeon. This paper reviews some of the methods used experimentally and clinically to monitor the process, outlining their possible advantages and disadvantages for application in routine clinical practice. Considering availability, cost, and safety, an imaging protocol could involve preoperative assessment with computed tomography scan; immediate postoperative anteroposterior (AP) and lateral radiographs; weekly ultrasound scanning for the 1st 8 weeks; and monthly AP and lateral radiographs during the lengthening phase and if there is any clinical suspicion of complication during the consolidation phase. If available, dual energy bone densitometry can be performed every 2 to 4 weeks from 8 weeks, until removal of the fixator.