Cement Leakage in Cement-Augmented Fenestrated Pedicle Screws for Osteoporotic Spine: Risk Stratification with Quantitative Computed Tomography Analysis.

Background/Objectives: Cement-augmented fenestrated pedicle screws (CAFPSs) are widely used to enhance fixation strength in osteoporotic vertebrae; however, cement leakage remains a major concern because it can lead to severe complications. This study aimed to clarify the frequency, patterns, and risk factors of cement leakage using postoperative computed tomography (CT). Methods: A total of 302 screws placed in 79 osteoporotic patients who underwent spinal fixation with CAFPSs between March 2022 and December 2024 were retrospectively analyzed. Cement leakage was evaluated using postoperative CT, and risk factors were examined by logistic regression and receiver operating characteristic (ROC) curve analysis. Results: Cement leakage was observed in 46 patients (58.2%) and 71 screws (23.5%), but no severe complications such as symptomatic pulmonary embolism occurred. Multivariate analysis identified right-sided screw insertion (OR = 2.498, 95% CI: 1.270-4.913, p = 0.008) and shorter lateral cortical wall distance (OR = 0.547, 95% CI: 0.469-0.638, p < 0.001) as independent risk factors. ROC curve analysis demonstrated high predictive accuracy for lateral cortical wall distance (area under the curve = 0.842), with a cutoff value of 9.21 mm (sensitivity = 0.845; specificity = 0.719). Cement leakage occurred significantly more frequently in the thoracic spine than in the lumbar spine (34.2% vs. 17.0%, p < 0.001). Conclusions: Right-sided screw insertion and shorter lateral cortical wall distance were identified as major risk factors for cement leakage with CAFPSs. Quantitative CT-based assessment may contribute to risk stratification and optimization of screw placement planning to improve surgical safety.