Anteroposterior inverted-U proximal tibial osteotomy without internal fixation for correction of angular and torsional deformities in children with infantile tibia vara

Background
An anteroposterior inverted-U proximal tibial osteotomy is a modification of the classical dome-shaped osteotomy. It improves the stability at the osteotomy site without losing the positive attributes of the dome osteotomy. There is no need for internal or external fixation when using this technique in children.
Aim of work
The primary objective of this study is to evaluate the efficiency of anteroposterior inverted-U proximal tibial osteotomy in achieving correction of the varus and internal tibial torsion in children with tibia vara and without the need of internal fixation.
Patients and methods
A total of 17 patients (24 legs) diagnosed as having infantile tibia vara were enrolled in this study. Their age ranged from 3 to 6 years, with a mean age of 4.02±0.84 years. Fourteen (58.3%) were male. The right side was affected in six (35.3%), whereas the left side was affected in four (16.7%), and seven (41.2%) were bilaterally affected. The patients were presented in different grades: nine (37.5%) grade I, 11 (45.8%) grade II, and four (16.7%) grade III. The anteroposterior inverted-U osteotomy was done in the form of two unicortical arcs. The first unicortical arc of perforations was made over the medial surface of the proximal tibia with its apex below the epiphysis and its base toward the shaft from posterior to anterior. Similar arc was performed over the lateral surface of the proximal tibia. The lowest parts of the medial and lateral arcs were connected to each other across the anterior border in front and across the posterior surface behind. The shape of the osteotomy with the downward projection of both posterior and anterior limbs prevents displacement of the osteotomy during the manual correction and the casting. Therefore, there was no need for any internal fixation of the osteotomy side.
Results
At the end of the follow-up period of 49.9±7.07 (36–60) months, a significant varus correction evidenced by a reduction in the mean intercondylar distance was noted postoperatively. The mean thigh-foot angle was much improved from −7.83±2.84° (5–15 in internal rotation) preoperatively to a postoperative value of 2.08±1.74° (0–5 in external rotation), indicating correction of the internal tibial torsion; this relation was statistically highly significant as well. The radiological parameters (tibiofemoral angle, mechanical axis deviation, and metaphyseal-diaphyseal angle) showed a significant improvement in the postoperative mean values when compared with the preoperative mean values. The tibia was well aligned in all the cases in the lateral view radiographs, and the cast was maintained in all the cases without change till the time of union.
Conclusion
From this study, it could be concluded that anteroposterior inverted-U osteotomy has a good safety profile and should recommend this technique to correct the varus and internal tibial torsion in children with tibia vara.