Multilevel Percutaneous Fenestrated Screw Fixation with Bone Cement Augmentation in Adult Lumbar Spinal Deformity

Abstract

Objective: Fenestrated screw fixation with bone cement augmentation has been demonstrated to increase the pullout strength. Bone cement augmentation is performed to prevent screw failure. Although bone cement screw fixation and fenestrated screw fixation have been compared in many studies, there has been no study on the clinical effects and complication in long level percutaneous bone cement screw fixation. The study aimed to investigate the safety and efficacy of multilevel percutaneous fenestrated screw fixation with bone cement augmentation in the adult lumbar spinal deformity.Methods: We performed a retrospective study of 15 patients who underwent multilevel percutaneous fenestrated screw fixation (PFSF) with bone cement augmentation in a single spine surgeon between January 2018 and December 2020. The incidence of screw failure, body mass index (BMI), bone mineral density (BMD), past history, Visual analogue scale (VAS) score, Oswestry disability index (ODI), sagittal vertical axis (SVA), pelvic Tilt (PT), pelvic incidence (PI), sagittal slope (SS), lumbar lordosis (LL) and Cobbs angle were investigated in the patients.Results: All patients underwent percutaneous screw fixation using a bone cement additive. Mean BMD was –2.0±0.8. The mean percutaneous fenestrated screw fixation level was 6. The mean VAS score changed from 7.14 preoperatively to 4.57 postoperatively (1 month after the surgery), to 3.71 at the last follow-up. The mean ODI changed from 45.21 preoperatively to 32.5 postoperatively, to 27.0 at the last follow-up. The mean LL changed from 23.6 preoperatively to 32.96 postoperatively, to 31.67 at the last follow-up. The mean PT changed from 32.67 preoperatively to 28.11 postoperatively, to 28.70 at the last follow-up. The mean PI - LL changed from 35.20 preoperatively to 22.56 postoperatively, to 22.76 at the last follow-up. The mean Cobb’s angle decreased from 18.30 preoperatively to 6.27 postoperatively, to 5.98 at the last follow-up. The mean SVA changed from 76.65 preoperatively to 46.15 postoperatively, to 48.46 at the last follow-up. The bony fusion rate was 73.3%. There were screw loosening in 4 patients, rod fracture in 1 patient and screw fracture in 3 patients. Among the 3 patients with screw fracture, 1 patient required reoperation. Cement leakage occurred towards the anterior body of the vertebrae in 2 patients but no symptoms were observed.Conclusion: Although the current study examined a small sample with relatively short term follow up periods, our study results demonstrate that multilevel PFSF with bone cement augmentation can result in good clinical and radiological outcomes for lumbar spinal deformity. However, larger size screws or smaller through-hole screws are required to prevent screw fracture.