Deformity correction and lengthening of lower legs with an external fixator

Deformities combined with shortening in 34 lower limb segments of 28 patients were treated with an Ilizarov external fixator or a Taylor spatial frame at the same level as the osteotomy. We compared an acute correction group (A) with a gradual correction group (G) in patients undergoing deformity correction followed by lengthening. We retrospectively examined the amount of deformity correction, length gained, distraction index, maturation index, and external fixation index in both groups. The mean age of subjects was 12.9 years for A, 17.9 years for G. The mean deformity correction was 17.8° for A, 25.1° for G. Mean lengthening was 5.5 cm for A, 5.0 cm for G. Mean distraction index was 16.4 days/cm for A, 10.6 days/cm for G (P<0.05). Mean maturation index was 40.5 days/cm for A, 29.5 days/cm for G (P=0.081). Mean external fixation index was 58.6 days/cm for A, 42.5 days/cm for G (P<0.05). The distraction index and external fixation index differences between the two groups were statistically significant. Gradual correction may represent a better approach than acute correction with the use of external fixators to treat deformity combined with shortening.