Pedicle Screw Fixation With Cement Augmentation Versus Without in the Treatment of Spinal Stenosis Following Posterior Spinal Fusion Surgery, Superiority According to Bone Mineral Density: A Three-Arm Randomized Clinical Trial

Abstract

To investigate whether cement augmentation has an impact on clinical and radiologic outcomes following posterior spinal fusion (PSF) in low-density bones and whether its performance is comparable to regular bone density. Between 2017 and 2021, 114 patients with spinal canal stenosis were enrolled to undergo PSF. They were initially stratified based on their bone mineral density: T-score≥-1.5: Group I (n=34), and T-score<-1.5: Group II (n=80). Furthermore, group II was randomly subdivided: II-A (unaugmented, n=35) and II-B (bone cement augmented, n=45). The primary and secondary endpoints of the study were evaluated using visual analog scales (VAS) and radiologic parameters, including screw loosening, screw or rod fractures, proximal junctional kyphosis (PJK), proximal junctional vertebral fracture (PJVF), and adjacent segment disease (ASD), at 1year postoperatively. All 3 groups showed improvement in VAS scores, but the most significant improvements were seen in groups I and II-B. Group II-B had lower incidence rates of ASD, PJVF, PJK, rod, and screw fracture compared to group II-A, but only screw loosening was statistically significant (P < 0.0001). Contrary, there were statistically significant differences in all variables except for ASD and screw fracture (P= 0.0576 and 0.670, respectively) when comparing groups I and II-A. In both groups I and II-A, screw loosening was the most common complication following PSF, while only 5.41% of patients in group II-B experienced it. The efficacy of cement augmentation in mitigating pain and screw loosening following PSF surgery in low-density bones is comparable to that of normal-density bone.