Complications following posterior spinal fusion for adolescent idiopathic scoliosis: a retrospective cohort study using the modified Clavien-Dindo-Sink system.

Abstract

Published complication rates after posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) range from 1 to 22%. Complications are often minor and may be underestimated in registries. This study describes complications of PSF for AIS, classifies them according to a Clavien-Dindo-Sink (CDS) system, and investigates risk factors for occurrence of a complication. This retrospective cohort study at two academic centers included all AIS patients aged 10-18 who underwent primary PSF 4/2014-12/2019. Data included demographics, comorbidities, curve magnitude, Lenke classification, levels osteotomized/fused, implant density, 90-day emergency department visits, readmissions, reoperations, and complications as defined by Harms Study Group. Among 424 patients, mean age was 14.7, mean BMI 22, 77% were female, and 57% had no comorbidities. There were 270 complications (0.64 per patient); 198 patients (47%) had ≥ 1 complication; and 63 patients (15%) had CDS grade ≥ II complications (deviation from standard postoperative course). Complications not related to persistent pain occurred in 103 patients (24%). Ninety-three percent of complications did not require readmission or reoperation (CDS I-II). Within 90 days, 8% presented to an ED, 2% required readmission, and 2% required reoperation. Common complications were back pain > 6 weeks postoperatively (26%), surgical site complications (7%), and ileus/prolonged constipation (3%). Risk factors for experiencing any complication were BMI ≥ 34 (OR 3.44) and Lenke 6 curve (OR 1.95). One in four AIS patients experiences a complication not related to persistent pain after primary PSF, higher than rates published from self-reported registries. Obesity and Lenke 6 curve may increase risk. While most do not require readmission or surgery, 15% of patients have their postoperative course altered by complications. III-retrospective cohort study.