Acute correction of proximal tibial varus deformity in adolescent Blount disease with a low-profile Ilizarov frame

Abstract

Background: Adolescent tibia vara usually presents with genu varum deformity and is commonly associated with internal tibial torsion. The Ilizarov technique is one of the accepted techniques for correction of this deformity. Acute correction has the advantage of a shorter duration in the fixator and less patient discomfort. Using the Ilizarov construct with two rings decreases bulkiness of the frame and improves compliance. Methods: Thirteen male patients with adolescent Blount disease, seven of whom had bilateral deformities (total 20 knees), were managed by extra-focal tibial valgus lateral translation osteotomy with a low- profile Ilizarov frame fixation. The frame was removed after full union, and patients were followed-up for 18 mo. Patients were assessed clinically using intercondylar distance and radiographically by measuring the distal lateral femoral angle and proximal medial tibial angle on CT scanogram. Results: All patients achieved correction of the tibial varus deformity. The intercondylar distance improved from 12.1 cm on average preoperatively to 5 cm on average postoperatively. The mean preoperative deviation of the medial proximal tibial angle was 22 degrees while the mean postoperative deviation was 2.4 degrees (ranging from 0-8.5 degrees). The mean duration to union of the osteotomy was 9 wk (range, 7-10 wk). Pin track infection occurred in 8 limbs. Conclusions: Extra-focal percutaneous valgus lateral translation osteotomy and fixation with a low-profile Ilizarov frame allows accurate deformity correction, shorter duration in the fixator, and better patient comfort and satisfaction.