Lengthening and plating decreases time for external fixation, carries high varus deformity risk

Harbacheuski R. Clin Orthop Relat Res. 2011. doi:10.1007/s11999-011-2178-2.

While increasing the frame length and inserting a locked plate in an external circular fixator during distraction and consolidation bone lengthening phases shortens the time patients wear the frame, it also contributes to a high incidence of varus deformity, according to recent research.

Ryhor Harbacheuski, MD, and colleagues compared results in a retrospective study between a patient group that underwent the lengthening and and then plating technique (LAP) and a second group that used the classical method for bone lengthening. Researchers studied the length of time patients spent with a frame, complications of each technique, the external fixation index, joint range of motion and bone healing index of both groups.

The LAP group spent less time in the frame at 4.5 months compared wit 6.2 months in the control group. They also had a lower external fixation index, at 1.5 months/cm, where the control had an index of 2 months/cm. Although no deep infections occurred in either group, there were 12 pin-tract infections in the control compared with 2 infections in the LAP group. Of 27 extremities studied in each group, malalignment occurred in 7 patients in the LAP group and 6 in the control group.

Malalignment in the LAP group was severe enough to cause plates to break in 2 patients, according to the abstract.

“Stronger plates may help deformity and allow earlier removal of the frame,” the authors wrote.