Triplanar correction of adolescent idiopathic scoliosis by asymmetrically shaped and simultaneously applied rods associated with direct vertebral rotation: clinical and radiological analysis of 36 patients

Purpose: Aim of this study was to investigate the effectiveness of a new surgical corrective manoeuvre for adolescent idiopathic scoliosis (AIS) by asymmetrically shaped and simultaneously applied rods and in combination with direct vertebral rotation, to control both the triplanar deformity and the kyphosis apex location. Methods: We retrospectively reviewed 36 patients who undergo surgical treatment using simultaneous translation on two differently contoured rods, in combination with direct vertebral rotation. Patients were divided into three main groups according to the scoliotic curve type. Results: The average follow-up was 1.8 years (range 1–3 years). Mean thoracic Cobb angle decreased from 64.6° to 17.0 (p < 0.05). Mean lumbar Cobb angle decreased from 54.9 to 13°. T5–T12 kyphosis values improved from 16.2 to 22.8° (p < 0.05). Apical vertebral rotation decreased from 25.3 to 9.7°. Mean total SRS-22 score values improved from 2.3 on pre-operative to 3.8 at the last available follow-up. Two major and two minor perioperative complications were recorded. Nor deformity progression or screw pull-out or non-union was recorded at the last available follow-up. Conclusions: The corrective manoeuvre using two differently contoured rods simultaneously in combination with direct vertebral rotation can provide a good triplanar deformity correction and improve patient’s quality of life and self-image perception in mild-to-moderate AIS. Moreover, the described technique allows the positioning of the desired kyphosis apex at a different level from the scoliosis apex. This procedure allows a better sagittal contour restoration while maintaining a comparable amount of correction on the frontal and axial plane of the already available techniques. Graphical Abstract: These slides can be retrieved under Electronic Supplementary Material.