Bone remodeling after leg lengthening: evaluation with plain radiographs, and computed tomography and magnetic resonance imaging scans.

Ten patients who had undergone leg lengthening were monitored with plain radiographs and computed tomography (CT) scans at 3-month intervals. Four of them were examined with magnetic resonance imaging (MRI) scans. When the external fixator was removed, MRI scans could not demonstrate any continuous fat signals in the lengthened region, suggesting the lack of medullary cavity. CT scans disclosed double cortex in three patients and irregular new bone formation in seven. At 6 months, a medullary cavity could be detected. Other aberrations were less evident. Remodeling of new bone material required at least 1 year.