Correction of axial mal-alignment of lower limb in adolescents

ABSTRACT

Twenty-one patients aged between eleven and seventeen years old, having knee deformities were treated by corrective osteotomies. Surgery was done for eighteen varus limbs in thirteen patients and ten valgus limbs in eight patients. Pre-operatively, a whole limb view was needed to evaluate the tibial and femoral proportions of the deformity as well as location of the apex of the deformity. Accordingly, seven patients had combined tibial and femoral osteotomies, two had bilateral procedures done for varus deformity, two had unilateral osteotomies for varus and three for valgus deformity. Nine patients had upper tibial metaphyseal osteotomies for varus deformity [three bilateral, six unilateral]. The remaining five patients had valgus deformity [two had bilateral correction and three were unilateral]. Thus a total of thirty-seven corrective osteotomies in twenty-eight limbs were done. All osteotomies were preplanned to determine the appropriate size and site. Correction was controlled intra-operatively by aiding devices under fluoroscopy control, T plate was the common implant used and correction was achieved by the help of plate tension device. Our objectives for correction were restoration of normal limb alignment as indicated by the relation between mechanical axis and joint line and normal co-linear relation between the joint centers of the hip, knee and ankle joints as indicated by the hip, knee, ankle angle. The final results showed correction of the deformity among the varus limbs from an average of -14.4 degrees preoperatively to -2.4 degrees post-operatively. While in the valgus limbs the average pre-operative valgus deformity was +12.9 degrees and +1.2 degrees post-operatively. The average estimated preoperative mechanical axis deviation was 111% and this was reduced to an average of 8.6% post-operatively. There were six cases of mal-correction [four tibial and two femoral], and the success rate according to our criteria was 79%