Double-sided vertebral body tethering of double adolescent idiopathic scoliosis curves: radiographic outcomes of the first 13 patients with 2years of follow-up.

Abstract

In skeletally immature patients with adolescent idiopathic scoliosis (AIS), vertebral body tethering (VBT) as a fusionless minimally invasive treatment option has been shown to correct the deformity by growth modulation. This prospective cohort study aimed to present the minimum 2years' results of double-sided VBT applied to double curves of 13 skeletally immature patients with AIS. Thirteen skeletally immature patients with AIS and double curves were included. All patients were followed up within a brace for at least 6weeks. A decision to proceed with surgery was established after the detection of curve progression within the brace (> 40° thoracic, > 35° lumbar) with a minimum curve flexibility of 30%. Patients had an average age of 11.8years, average follow-up duration of 36.4months (range 24 to 46), average preoperative main thoracic/thoracolumbar or lumbar curve magnitudes of 48.2°/45.3°. An average of 11.8 levels of tethering was undertaken. Thoracic screws were placed thoracoscopically, while mini-thoracotomy/lumbotomy was added for thoracolumbar levels. Postoperatively, an average first erect thoracic/thoracolumbar major curve magnitudes of 17.3°/14.3° were acquired, while they improved to 9.7°/8.2° at the last follow-up. No neurologic or implant-related complications were acquired. Double-sided VBT was detected to provide 80% of thoracic (48.2° to 9.7°) and 82% of thoracolumbar-lumbar curve correction (45.3° to 8.2°) as a result of average two years. As being a growth modulating treatment option, double-sided VBT as applied under strict inclusion criteria was shown to be safe and effective for the correction of double curves in skeletally immature patients with AIS, by yielding a gradual, growth-assisted correction of both curves together with the preservation of coronal-sagittal balance without any major complications.