Fixator-Assisted Acute Femoral Deformity Correction and Consecutive Lengthening Over an Intramedullary Nail

Abstract

External fixators are being used frequently in standard limb-lengthening and deformity-correction procedures. Lengthening over an intramedullary nail has been a successful technique, and fixator-assisted intramedullary nailing has provided satisfactory results for the correction of selected deformities. We report a combined technique for the treatment of femoral deformities associated with shortening. Between 1997 and 2005, twenty-eight femora in twenty-five patients with a median age of twenty-seven years underwent reconstruction with an intramedullary nail and a unilateral fixator. The mean amount of shortening was 6.33 cm, and the mean preoperative mechanical axis deviation was 33.86 mm. Deformity correction was performed acutely and secured by the intramedullary nail, which was locked distally, and the same external fixator that was used for the deformity correction was utilized for lengthening. At the end of the distraction period, proximal locking screws were placed in the intramedullary nail and the external fixator was removed. At the time of follow-up, deformity correction and bone healing were assessed clinically and radiographically, complications were noted, and the functional results were assessed. The mean duration of follow-up was forty months. The mean duration of the external fixation was 83.29 days, and the mean external fixation index was 14.98 days/cm. The mean amount of lengthening was 6.02 cm. The mean amount of mechanical axis deviation at the end of the treatment was 11.29 mm. The mean bone healing index was 36.66 days/cm. A knee flexion contracture developed in one patient and resolved after intensive rehabilitation. One patient underwent two revisions because of Schanz screw displacement secondary to cortical fracture, and four patients with minor pin-track infections were treated successfully with local wound care and oral antibiotics. While femoral lengthening and deformity correction can be obtained with classic methods for application of an external fixator, the long period of external fixation, patient discomfort, and plastic deformation of the regenerated bone after removal of the fixator are major disadvantages. Two techniques, fixator-assisted nailing and lengthening over an intramedullary nail, were combined in this series. The duration of the external fixation was reduced compared with that required for classic treatment with an external fixator and patient comfort was increased. In addition, the intramedullary nail prevented fracture and deformation of the regenerated bone.