Accuracy of Correction of Tibia Vara

Abstract

The purpose was to assess the accuracy of deformity correction achieved in patients with tibia vara using acute intraoperative correction compared with gradual postoperative correction. Acute correction (AC) group consisted of 14 patients (14 tibiae) with a mean age of 11.4 years and whose tibia vara was corrected acutely and held using an EBI external fixator. Gradual correction (GC) group consisted of 18 patients (18 tibiae) with a mean age of 10.2 years and whose tibia vara was corrected gradually using 6-axis deformity analysis and Taylor Spatial Frame. Deformity measurements were compared preoperatively, postoperatively, and at latest follow-up. At latest follow-up, medial proximal tibial angle deviation from normal was similar for the 2 groups; posterior proximal tibial angle was significantly greater in the AC group (5.6 degrees) than in the GC group (1.9 degrees). Mechanical axis deviation was significantly greater in the AC group (17.1 mm) than in the GC group (3.1 mm). Postoperatively, frequency of accurate translation corrections (achieved translation within 5 mm of preoperative required translation) was significantly greater in the GC group (18/18) than in the AC group (7/14). Frequency of accurate angulation corrections (medial proximal tibial angle within 3 degrees of normal and posterior proximal tibial angle within 5 degrees of normal) was significantly greater in the GC group (17/18) than in the AC group (7/14). For both groups, all tibiae with preoperative internal rotation deformity had accurate rotation correction. Correction of preoperative limb-length inequality was achieved in 5 of the 7 patients in the AC group and 11 of the 11 patients in the GC group. Gradual deformity correction is a more accurate treatment method of tibia vara than acute correction.