Caprini Score-Guided Venous Thromboembolism Prophylaxis in Spine Instrumentation Surgery: A Comparative Analysis of Mechanical vs. Pharmacomechanical Strategies Across Etiological Subgroups

Background: Venous thromboembolism (VTE), encompassing deep venous thrombosis (DVT) and pulmonary embolism (PE), is a major source of morbidity and mortality in patients undergoing spine surgery.Although various risk factors for developing VTE have been identified, pharmacological prophylaxis is used selectively in spine surgery due to the risk of epidural hematoma.We report our institutional experience with VTE prophylaxis following spine instrumentation surgery across all surgical etiologies.Methods: A single-center retrospective cohort study of patients ≥18 years of age who underwent spine instrumentation surgery for degenerative, traumatic, or oncologic pathologies, and patients of all ages who underwent surgery for spinal deformity over a three-year period was performed.Caprini VTE risk score was used for individual risk stratification.Results: A total of 265 patients were included: degenerative (n=174, 65.7%), trauma (n=45, 17.0%), deformity (n=33, 12.5%), and tumor (n=13, 4.9%).The overall mean age was 46.1±17.5 years, and there were 133 male patients (50.2%).Significant differences existed across groups in age (Kruskal-Wallis H=97.4,p<0.001), index procedure characteristics, and VTE risk profiles.Mechanical prophylaxis alone was employed in 212 patients (80.0%), while 53 patients (20.0%) received combined pharmacomechanical prophylaxis.No patient (0%) in the mechanical-only group developed a perioperative VTE event or postoperative hematoma.One patient (1.9%) in the combined pharmacomechanical group developed a postoperative PE, arising in the context of a preoperative proximal DVT.Firth's penalized logistic regression identified polytrauma (OR 29.0, 95% CI 3.3-3835.0;p=0.001),Caprini score ≥7 (OR 8.8, 95% CI 3.8-20.9;p<0.001), and prior VTE history (OR 61.8, 95% CI 5.7-8406.4;p<0.001) as independent predictors of combined prophylaxis receipt.Conclusion: Mechanical prophylaxis, implemented as part of a structured protocol that included sequential pneumatic compression devices and standardized postoperative care, was associated with low VTE risk following spine instrumentation surgery.Individualized risk stratification using validated tools such as the Caprini score, combined with selective pharmacomechanical prophylaxis in high-risk patients, may optimize outcomes in this population.Prospective multicenter studies are needed to validate these findings.