Accuracy of correction of complex lower-extremity deformities by the Ilizarov method

Abstract

Gradual mechanical distraction with the Ilizarov external fixator was used on 28 limbs in 23 patients to correct complex lower-extremity deformities of diverse causes. To determine the accuracy of realignment and deformity correction, the charts and radiographs were reviewed retrospectively. Preoperative long-standing anteroposterior radiographs of the entire lower extremity were compared with those obtained at the most recent follow-up visit. The parameters used to assess accuracy of correction were joint alignment and joint orientation. Alignment was determined by mechanical axis deviation (MAD) and mechanical tibiofemoral angle (mTFA). The preoperative MAD averaged 48 mm and the postoperative MAD 8.6 mm. The preoperative mTFA averaged 16 degrees and the postoperative mTFA 3 degrees. The result of deformity correction from early cases was compared with the result obtained from recent cases. Residual MAD averaged 13.2 mm in the early group and 6.4 mm in the recent group. Residual mTFA averaged 4.7 degrees in the early group and 2.2 degrees in the recent group. Gradual correction by dynamic external fixation can restore alignment and correct complex deformities with great accuracy. These results suggest the accuracy of correction increases with surgical experience.