Durability of stand-alone anterolateral interbody fusion in staged minimally invasive circumferential scoliosis surgery with delayed posterior instrumentation due to medical necessity.

Abstract

Circumferential minimally invasive scoliosis surgeries are often staged, wherein anterior and/or lateral lumbar interbody fusion is followed by percutaneous posterior fixation days later. This study examines the impact on outcomes when posterior augmentation was delayed due to unexpected medical issues following the first stage, anterolateral procedure. A retrospective review was conducted of all patients undergoing minimally invasive circumferential deformity corrections from 2006 to 2019. Patients in whom planned posterior fixation was postponed due to medical necessity or safety concerns were identified. Perioperative surgical metrics and radiographic parameters were collected. Three of the six patients initially scheduled for circumferential fusion never underwent posterior augmentation due to symptomatic improvement (2.3, 5, and 10.7years of follow-up). The other three underwent posterior fixation once medically optimized after an average interval of 4.7months (range 3.2-7.8months) due to persistent symptoms. It was also observed that the average coronal malalignment in the postoperative period was 5.1cm in the group requiring further fixation and only 1.6cm in the group which did not. In select cases, the indirect decompression and stability conferred by minimally invasive anterolateral arthrodesis alone may afford adequate pain relief to delay or even avoid posterior fixation in patients with adult spinal deformity.