Premature removal of the fixator after a lengthening procedure can result in gradual bending or acute fracture of the regenerate.
We reviewed the records of 26 patients who underwent 28 limb lengthenings between 1997 and 2005 to assess the post lengthening
regenerate fracture rate and bone healing index when using dual energy xray absorptiometry (DEXA) to aid in deciding on when
to remove the fixator. Sixteen male and 10 female patients with an average age at lengthening of 12.3 years underwent an average
lengthening of 5.2 cm (range, 3–9.1 cm). Nineteen femurs and nine tibiae were lengthened. Serial monthly DEXA scans were analyzed
for bone mineral density. Bone healing indices and post fixator removal complications were assessed. The fixators were removed
once the bone mineral density had plateaued to a less than 10% increase and plain radiographs showed no obvious defects precluding
fixator removal. There were no regenerate fractures and only one fracture in the proximal segment of the lengthened bone after
apparatus removal and the healing index for the series averaged 47 d/cm (range, 20–73 d/cm). Using serial DEXA scans during
the consolidation phase of lengthening has a low rate (3.6%) of fractures while maintaining an acceptable bone healing index
without excessively increasing fixation time.
Level of Evidence: Level IV, therapeutic retrospective study. See the Guidelines for Authors for a complete description of levels of evidence.
Each author certifies that he or she has no commercial associations (eg, consultancies, stock ownership, equity interest,
patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article.
Each author certifies that his or her institution has approved or waived approval for the human protocol for this investigation
and that all investigations were conducted in conformity with ethical principles of research.