The Comparison of Spinopelvic Parameters, Complications, and Clinical Outcomes After Spinal Fusion to S1 with or without Additional Sacropelvic Fixation for Adult Spinal Deformity

Abstract

Study Design. Systematic review and meta-analysis.Objective. The purpose of the study was to compare the outcomes and after spinal fusion with or without iliac screw (IS) insertion for patients with adult spinal deformity (ASD). Summary of Background Data. The number of patients undergoing multilevel spinal stabilization for the treatment of ASD is growing. However, the selection of spinopelvic fixation for ASD patients with long fusion is controversial. Methods. A comprehensive literature search was performed without time restriction according to the guidelines from the Cochrane Collaboration in May 2020 using PubMed, EMBASE, and the Cochrane Library. The comparison of the two types of fixation was evaluated by spinopelvic parameters, incidence rate of complications, rate of revision, and clinical outcomes at the last follow-up. Results. The literature search identified 422 records, of which eight studies were included for meta-analysis with a total of 439 patients. All the included studies provided level III evidence. There was no significant difference in the sagittal vertical axis, pelvic incidence, the proximal junctional kyphosis rates, the pseudarthrosis rates, the revision rates, and the clinical outcomes at the last follow-up between those who receive sacrum fixation and sacropelvic fixation. Nevertheless, greater lumbar lordosis (LL) (weighted mean difference [WMD], 4.15; 95% confidence interval [CI] 2.46-5.84, P < 0.01), greater sacral slope (SS) (WMD, 2.32; 95% CI 1.21-3.43, P < 0.01), and lower rate of the distal instrumentation instability (odds ratio, 0.25; 95% CI 0.10-0.61, P ¼ 0.002) were observed in IS group between the comparison. Conclusion. The clinical outcomes in the IS group were similar to those in the non-IS group, but the application of the IS significantly restored LL, prevented decompensation, and reduced the occurrence of the distal instrumentation instability. Therefore, the IS may be a good choice for the operative treatment of ASD patients with sagittal malalignment and other risks of lumbosacral fracture, metal breakage, and screw pullout.

Biomechanical evaluation of multiple pelvic screws and multirod construct for the augmentation of lumbosacral junction in long spinal fusion surgery

“…Several studies reported a high incidence of lumbosacral pseudarthrosis with S1-PS alone (19.0%–83.0%) or additional SPF (10.5%–33.3%) ( Kim et al, 2006a ; Kim et al, 2006b ; Finger et al, 2014 ; Guevara-Villazón et al, 2020 ; Eastlack et al, 2022 ). A meta-analysis by Han et al reported that there was no significant difference in the pseudarthrosis rate between patients with or without SPF ( Han et al, 2021 ). Therefore, advanced SPF technique by multiple pelvic screws or multirod construct was tried to solve this problem.…”

Implantatversagen bei Instrumentierungen am lumbosakralen Übergang und Becken – Ursachen und Behandlungskonzepte

“…Trikortikale Schrauben zeigen ein doppelt so hohes Einbringedrehmoment verglichen mit bikortikalen Schrauben [11]. Biomechanische Untersuchungen belegen, dass durch die bilaterale bikortikale Verankerung der S1 Pedikelschrauben, im besten Fall in der Promontoriumspitze, die biomechanische Stabilität, gegenüber der nicht bikortikalen Verankerung der S1 Pedikelschrauben, signifikant erhöht wird [4].…”

“…Außerdem scheint die alleinige Instrumentierung auf S1, vor allem bei langstreckigen Instrumentierungen, ein Risikofaktor für ein Implantatversagen darzustellen. Im Vergleich zu alleiniger Verwendung von Pedikelschrauben in S1 lässt sich bei additiver sakropelviner Fixierung bei langstreckigen Instrumentierungen eine signifikant niedrigere Rate an Implantatversagen nachweisen [4]. Weiterhin korreliert die Inzidenz der Non-Fusion im lumbosakralen Übergangsbereich mit der Anzahl der instrumentierten Segmente.…”

“…Um die Lastaufnahme wiederherzustellen, das Fusionspotential zu vergrößern und um das frontale und sagittale Profil optimal zu rekonstruieren, sollte die interkorporelle Fusion mit abstützenden interkorporell liegenden Implantaten sowie interkorporell eingebrachten Fusionsmaterial angestrebt werden. Neben der bilateral bikortikalen Verankerung der S1 Schrauben, im besten Fall in der trikortikalen Verankerung in der Promontoriumspitze, erhöhen additive spinopelvine Fixationstechniken die biomechanische Stabilität [4].…”

Direct Iliac Screw vs Sacral-2-Alar-Iliac Screws Technique for Sacropelvic Fixation: Technical Nuances and a Review of the Literature

“…1,[5][6][7][8] Currently, the most common techniques for SP fixation are the direct iliac screws and S2AI screws, both of which achieve the highest rates of SP fixation and represent biomechanically superior surgical modalities when compared with the former techniques. 3,9,10 Since the introduction of these 2 techniques, continuous refinement has been implemented to maximize favorable outcomes (eg, modified subcrestal insertion technique of conventional iliac screws, robotic and freehand-assisted S2AI screws insertion, and augmented reality-navigated screw insertion). [11][12][13] While the current literature outlines the benefits of the direct iliac screws and S2AI screws, the current data available are lacking solid evidence as to which technique is clinically superior.…”