Abdominal aortic calcification assessed on standard lateral lumbar radiographs as a screening tool for impaired bone status in spine surgery.

Abstract

The aim of this study was to determine whether the presence of abdominal aortic calcification (AAC) can predict patient bone status, represented by volumetric bone mineral density (vBMD) assessed with quantitative computed tomography (QCT). Patients undergoing lumbar fusion surgery at a tertiary care center between 2014 and 2021, with a preoperative lumbar CT-scan and lateral lumbar radiographs were retrospectively reviewed. A semi-quantitative measurement method for AAC (AAC 4, 8 and 24) was performed. QCT measurements were made for L1 and L2. Patients were divided into two groups depending on whether AAC was present. A one-way analysis of covariance was conducted to adjust for age. A multiple linear regression model was used to test if age, sex, BMI, diabetes, hypertension, smoking and presence of AAC could predict the vBMD. A receiver operating characteristic (ROC) analysis was conducted for predicting impaired bone status. 267 patients with a median age of 65.1years and BMI of 29.8kg/m2 were analyzed, 59.6% of patients had AAC. The group comparison showed that vBMD was significantly lower in patients with the presence of AAC (97.8mg/cm3 vs. 121.5mg/cm3). Age (β = - 0.360; p < 0.001) and presence of AAC (β = -0.206; p = 0.005) significantly predict vBMD as independent variables. Impaired bone status could be discriminated using AAC 4, 8 and 24 (cut off value 0.5) with a sensitivity of 70.1% and a specificity of 60.2%. The presence of AAC may identify patients at risk for impaired bone status. Preoperative evaluation of standard lumbar radiographs could be used as a potential diagnostic tool in assessing bone status.