Computer-assisted distraction osteogenesis by Ilizarov's method.

BACKGROUND

The Taylor spatial frame is a fixation device used to implement the Ilizarov method of bone deformity correction to gradually distract an osteotomized bone at regular intervals, according to a prescribed schedule.

METHODS

We modify conventional technique by: (a) preoperatively planning a virtual three-dimensional (3D) correction; (b) basing the correction on the actual location of the frame with respect to the anatomy, immediately compensating for frame mounting errors; and (c) calculating the correction based on 3D CT data rather than measurements from radiographs. We have performed a laboratory study using plastic phantoms, and a pilot clinical study involving five patients.

RESULTS

In 20 tibial phantom experiments, we achieved average correction errors of < 2 degrees total rotation and < 0.5 mm total lengthening. We observed clinically acceptable corrections with no complications in our pilot clinical study.

CONCLUSIONS

Our method achieved high accuracy and precision in a laboratory setting, and produced acceptable outcomes in a pilot clinical study.