Sequential Rod Rolling for Surgical Correction of Lenke Type 2 Adolescent Idiopathic Scoliosis: A 3D Analysis.

Abstract

IntroductionMany options have been described to restore balance and create stable fusion in severe adolescent idiopathic scoliosis (AIS), including preoperative gravity halo traction, posterior vertebral column resection, and three column osteotomies. Unfortunately, each of these comes with risks of excess bleeding or neurological injury. The sequential rod rolling (SRR) technique uses a short stiff rod to distract and derotate the main thoracic (MT) curve, followed by a second full length rod on the opposite side to distract and derotate the proximal thoracic (PT) curve and finally a short rod on the convexity of the PT to offer a controlled correction of rigid deformities. The aim of this investigation is to describe the technique, its indications, the rotational correction achieved, and the complications observed when it is used in the treatment of severe pediatric AIS.Materials and methodA retrospective study was carried out to include all patients treated with SRR to manage a Lenke 2 curve between 2006 and 2018, in whom a 3D EOS reconstruction was available. The primary objective of this study was to measure the derotation of the apical vertebra of the PT achieved by the sequential rod technique. The secondary objectives include defining the morbidity and complications observed.ResultsSixteen patients with a mean age of 15 years were included. The mean pre-operative coronal angular deformity was 53° for the PT and 76° for the MT. The mean post-operative coronal angular deformity was 19° for the PT, 22° for the MT. The mean rotation preoperatively was 10° for the apical vertebra of the PT and 23° for the MT. The mean rotation postoperatively was 3° for the apical vertebra of the PT and 8° for the MT. Twelve patients had a 2-year post-operative follow-up. No proximal junctional kyphosis or complications were reported at the 2-year follow-up.ConclusionThis data show that SRR achieves a mean coronal PT correction of 66% and 72% for the MT curve. The average derotation is 7° for the PT and 15° for the MT. No complications were encountered. The SRR technique for Lenke 2 type AIS seems to be, according this study a safe and effective technique.