Surgical and cement-related factors associated with symptomatic adjacent vertebral fractures after percutaneous kyphoplasty for osteoporotic vertebral compression fractures: a single-center retrospective nomogram study

Abstract

Symptomatic adjacent vertebral fracture (AVF) can occur after treatment with percutaneous kyphoplasty (PKP) for osteoporotic vertebral compression fracture (OVCF). This study examined surgical and cement-related factors associated with symptomatic AVF after PKP and developed an exploratory nomogram for postoperative risk stratification. We retrospectively analysed consecutive patients with OVCF who underwent PKP between January 2016 and June 2023 and completed 2-year follow-up. Baseline information, operative data, imaging variables, and laboratory findings were collected. Symptomatic AVF was defined as a new adjacent vertebral fracture confirmed by MRI after recurrent localised back pain during follow-up. Patients were categorised into AVF and non-AVF groups according to imaging-confirmed symptomatic AVF. Key variables were selected using least absolute shrinkage and selection operator (LASSO) regression, and a nomogram was constructed. Model discrimination, calibration, and clinical utility were evaluated using receiver operating characteristic curves, calibration curves, and decision curve analysis, respectively. In total, 463 patients were included, comprising 132 patients with symptomatic AVF and 331 without symptomatic AVF. Cement leakage, lower postoperative height restoration, smaller preoperative Cobb angle, cement diffusion quality, and endplate fracture were retained by LASSO regression and included in the final model. Good cement diffusion was associated with a lower AVF risk, whereas cement leakage and endplate fracture were associated with a higher AVF risk. The model showed high apparent discrimination in the internal training and validation cohorts. Five surgical and cement-related factors were associated with symptomatic AVF after PKP in this single-centre retrospective cohort. The internally assessed nomogram may support exploratory postoperative risk stratification and may assist clinicians in identifying patients who could benefit from closer postoperative assessment.