The impact of obesity on radiographic and clinical outcomes following adult spinal deformity surgery-a systematic review and meta-analysis

Abstract

Background context: Given the rising global prevalence of obesity, it is imperative to understand its effects on spine surgery outcomes. The influence of BMI on outcomes after adult spinal deformity (ASD) reconstruction has varied based on the center. The findings of this study may assist in the risk stratification process and informed patient surgeon counseling for ASD surgery.

Purpose: The aim of this study was to perform a systematic review and meta-analysis to describe the impact of body mass index (BMI) on clinical and radiographic outcomes after ASD correction surgery.

Study design/setting: A systematic review and meta-analysis.

Methods: This study followed the preferred reporting items for systematic reviews and meta-analyses guidelines (PRISMA). Studies reporting complication rates, sagittal alignment parameters, and PROMs for patients stratified by BMI that underwent spinal fusion procedures for the treatment of ASD were included. Pooled meta-analyses reporting odds ratios were performed for any complication, mechanical complication, medical complication, and infection variables. Pooled meta-analyses reporting standard mean differences were performed for pelvic incidence-lumbar lordosis (PI-LL) mismatch and sagittal vertebral axis (SVA) parameters in both preoperative and late postoperative settings. A qualitative analysis of PROMs data was conducted.

Results: The literature search identified 11 studies that compared outcomes of interest between low and high BMI cohorts, with a total of 3,150 patients. High BMI patient cohorts demonstrated significantly greater odds of developing any complication and mechanical complications. Despite a lack of difference in preoperative radiographic alignment, high BMI patient cohorts demonstrated significantly greater sagittal vertebral axis (SVA) and PI-LL mismatch at the final postoperative timepoint. Odds of pseudoarthrosis, revision, infection, and medical complications were not increased by high BMI. Estimated blood loss and operative time demonstrated no significant mean differences between the high and low BMI cohorts. High BMI cohorts reported higher postoperative ODI and VAS-legs scores compared to low BMI. No significant differences were reported in other PROMs measures.

Conclusions: These findings suggest that high BMI patients have an increased risk of developing mechanical complications and worse postoperative sagittal alignment in comparison to low BMI cohorts following ASD correction.

Keywords: ASD; Alignment; BMI; Complications; Correction; Deformity; Fusion; Scoliosis; Spine.