Predictive model for major complications 2 years after corrective spine surgery for adult spinal deformity.

PURPOSE: ASD surgery improves a patient's health-related quality of life, but it has a high complication rate. The aim of this study was to create a predictive model for complications after surgical treatment for adult spinal deformity (ASD), using spinal alignment, demographic data, and surgical invasiveness. METHODS: This study included 195 surgically treated ASD patients who were > 50 years old and had 2-year follow-up from multicenter database. Variables which included age, gender, BMI, BMD, frailty, fusion level, UIV and LIV, primary or revision surgery, pedicle subtraction osteotomy, spinal alignment, Schwab-SRS type, surgical time, and blood loss were recorded and analyzed at least 2 years after surgery. Decision-making trees for 2-year postoperative complications were constructed and validated by a 7:3 data split for training and testing. External validation was performed for 25 ASD patients who had surgery at a different hospital. RESULTS: Complications developed in 48% of the training samples. Almost half of the complications developed in late post-op period, and implant-related complications were the most common complication at 2 years after surgery. Univariate analyses showed that BMD, frailty, PSO, LIV, PI-LL, and EBL were risk factors for complications. Multivariate analysis showed that low BMD, PI-LL > 30°, and frailty were independent risk factors for complications. In the testing samples, our predictive model was 92% accurate with an area under the receiver operating characteristic curve of 0.963 and 84% accurate in the external validation. CONCLUSION: A successful model was developed for predicting surgical complications. Our model could inform physicians about the risk of complications in ASD patients in the 2-year postoperative period. These slides can be retrieved under Electronic Supplementary Material.

A Functional SNP in BNC2 Is Associated with Adolescent Idiopathic Scoliosis.

Adolescent idiopathic scoliosis (AIS) is the most common spinal deformity. We previously conducted a genome-wide association study (GWAS) and detected two loci associated with AIS. To identify additional loci, we extended our GWAS by increasing the number of cohorts (2,109 affected subjects and 11,140 control subjects in total) and conducting a whole-genome imputation. Through the extended GWAS and replication studies using independent Japanese and Chinese populations, we identified a susceptibility locus on chromosome 9p22.2 (p = 2.46 × 10(-13); odds ratio = 1.21). The most significantly associated SNPs were in intron 3 of BNC2, which encodes a zinc finger transcription factor, basonuclin-2. Expression quantitative trait loci data suggested that the associated SNPs have the potential to regulate the BNC2 transcriptional activity and that the susceptibility alleles increase BNC2 expression. We identified a functional SNP, rs10738445 in BNC2, whose susceptibility allele showed both higher binding to a transcription factor, YY1 (yin and yang 1), and higher BNC2 enhancer activity than the non-susceptibility allele. BNC2 overexpression produced body curvature in developing zebrafish in a gene-dosage-dependent manner. Our results suggest that increased BNC2 expression is implicated in the etiology of AIS.