Patient Selection and Reoperation After Cement-Augmented Pedicle Screw Fixation in the Thoracolumbar Spine: A...

Background/Objectives: Poor bone quality compromises pedicle screw fixation, and cement augmentation of fenestrated screws improves fixation at the screw-bone interface. Whether low interface-failure rates translate into low all-cause reoperation rates in routine practice is not established. We characterized the institutional use of cement-augmented fenestrated pedicle screws, the retrospectively measured vertebral computed tomography (CT) attenuation of selected patients, and subsequent interface failure and reoperation. Methods: We reviewed all patients undergoing thoracolumbar pedicle screw fixation between January 2016 and June 2022 at one tertiary referral center. Vertebral attenuation was measured retrospectively in Hounsfield units (HU) at L1 through L4. Outcome proportions are reported with Wilson 95% confidence intervals. Comparisons across surgical indications used exact tests with Holm correction and were treated as exploratory. Cement leakage and other cement-specific safety events could not be ascertained and were not study outcomes. Results: Cement augmentation was used in 101 of 2285 screened patients (4.4%), and 68 met the criteria for the outcome cohort (median follow-up, 44.9 weeks). Median attenuation was 94 HU, and 35 of 53 measurable patients (66.0%) fell below 110 HU, whereas formal densitometry was documented in 3. Screw loosening and pullout each occurred in three patients (4.4%), and reoperation for any cause occurred in nine (13.2%). Reoperation was more frequent among deformity constructs (30.4%) than for trauma (6.1%) or oncologic disease (0%); omnibus exact p = 0.016, although this result did not remain significant after Holm correction (adjusted p = 0.10). Conclusions: Cement augmentation was applied selectively, and retrospective CT measurements identified low vertebral attenuation in most measurable patients, despite infrequent formal densitometry. Failure at the screw-bone interface was infrequent, whereas all-cause reoperation remained clinically relevant and varied by surgical context. This study describes the selection and outcomes after augmentation but cannot establish comparative effectiveness or the safety of the augmentation technique.