Establishment and Validation of Nomograms and Web Calculators for Different Cement Leakage Risk Types in Pedicle Screw Augmentation for Degenerative Lumbar Stenosis in Osteoporotic Vertebrae.

Background: The use of cement in pedicle screw augmentation (PSA) enhances the pullout force of pedicle screws in vertebrae affected by osteoporosis. Risks involved in the use of cement for PSA include nerve injury and vascular damage caused by cement leakage.

Methods: This study included all patients who received PSA for degenerative lumbar stenosis in osteoporotic vertebrae from January 2014 to May 2022. Postoperative computed tomography was used to assess cement leakage. Correlation analysis and logistic regression analyses were used to establish the associated clinical or radiological factors, which were then used to construct nomograms and web calculators.

Results: The study comprised 181 patients including 886 screws inserted into 443 vertebrae. Perivertebral cement leakage was significantly associated with female sex, decreased bone mineral density, solid screws, and scattered cement distribution. Cement leakage through segmental veins (type S, 72.1%), leakage through basivertebral veins (type B, 23.9%), and instrument-related leakage (type I, 13.9%) accounted for most cement leakage. Patients with lower bone mineral density and scattered cement distribution were more likely to experience type S or type B leakage. Our analysis data showed that cement augmentation with cannulated and fenestrated screws tended toward concentrated cement distribution. Creation and verification of each nomogram additionally showcased the prognostic capability and medical significance of the corresponding model.

Conclusions: Nomograms and web-based calculators can accurately forecast the probability of cement leakage. PSA should be routinely performed using cannulated and fenestrated screws, along with a moderate amount of high-viscosity cement, with continuous monitoring using fluoroscopy.