Cement Augmentation of Pedicle Screw Constructs as a Modifier of Hardware Failure Risk in Instrumented Metastatic Spine Surgery: A Systematic Review and Meta-Analysis

Cement Augmentation of Pedicle Screw Constructs as a Modifier of Hardware Failure Risk in Instrumented Metastatic Spine Surgery: A Systematic Review and Meta-Analysis | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Cement Augmentation of Pedicle Screw Constructs as a Modifier of Hardware Failure Risk in Instrumented Metastatic Spine Surgery: A Systematic Review and Meta-Analysis Ying-Ching Li, Cheng-Yu Li, Sheng-Han Huang, Hong Kai Wang, Kuan-Hung Chen Kuan-Hung Chen, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9415578/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 4 You are reading this latest preprint version Abstract Purpose Hardware failure (HF) after instrumented fixation for spinal metastases affects 2–22% of patients. Despite growing adoption of cement-augmented pedicle screw fixation (CAPS), no meta-analysis has quantified its effect on HF rates. We aimed to provide pooled HF estimates for CAPS versus conventional fixation and explore the Spinal Instability Neoplastic Score (SINS) as a potential effect modifier. Methods A systematic review and meta-analysis were conducted following PRISMA 2020 guidelines, searching five databases through April 2026. Pooled HF rates were computed using Freeman-Tukey double arcsine transformation with DerSimonian-Laird random-effects models. Sensitivity analysis was performed restricting to SINS-reporting studies. Certainty of evidence was assessed using GRADE. Results Thirteen studies (n = 886) met eligibility criteria. The pooled HF rate was 4.3% (95% CI 1.8–7.9%; I² = 46.8%) in CAPS arms (k = 10, n = 349) versus 12.5% (95% CI 2.9–27.5%; I² = 93.3%) in non-augmented controls (k = 5, n = 537). The sole comparative study demonstrated OR 0.13 (95% CI 0.02–0.81; p = 0.029). Sensitivity analysis restricted to SINS-reporting studies confirmed stability (4.5%, I² = 23.4%). All outcomes were rated low to very low certainty. Conclusion CAPS is associated with an approximately threefold lower HF rate compared to conventional fixation in metastatic spine surgery (4.3% vs. 12.5%), with immediate implications for intraoperative implant strategy. INPLASY registration: INPLASY202640045. cement augmentation hardware failure meta-analysis pedicle screw spinal metastases systematic review Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Spinal metastases are the most common site of skeletal metastatic involvement, affecting up to 70% of patients with advanced malignancy and representing a leading cause of cancer-related morbidity through pain, neurological compromise, and mechanical instability [ 1 ]. Instrumented posterior pedicle screw fixation has become a cornerstone of the multidisciplinary management of metastatic spinal cord compression and symptomatic instability [ 2 , 3 ]. Hardware failure (HF) — encompassing screw loosening, pullout, rod fracture, cage migration, and progressive kyphosis — remains one of the most consequential mechanical complications after instrumented metastatic spine surgery, with reported rates of 1.9–22.4% [ 4 ]. Patients with spinal metastases typically have limited physiological reserve and shortened survival, rendering revision surgery a morbid and often clinically untenable undertaking. The Spinal Instability Neoplastic Score (SINS), developed by the Spine Oncology Study Group, quantifies the degree of spinal instability attributable to metastatic involvement through tumour location, pain characteristics, lesion morphology, alignment, vertebral body collapse, and posterior element involvement [ 5 , 6 ]. As a composite surrogate for structural compromise, SINS is increasingly recognised as a potential risk stratification tool for hardware-related complications; however, its interaction with implant strategy remains poorly defined [ 7 ]. Cement-augmented pedicle screw fixation (CAPS) — the injection of polymethylmethacrylate (PMMA) through fenestrated or cannulated pedicle screws — substantially increases screw pullout strength by creating a composite screw-cement-bone interface [ 8 ]. Although a growing body of single-centre observational data suggests reduced HF rates with CAPS, this evidence remains fragmented across small retrospective series with heterogeneous populations and HF definitions [ 9 , 10 ]. Notably, the adoption of CAPS has accelerated substantially over the past decade, with fenestrated screw systems now commercially available from all major spinal implant manufacturers; yet this widespread clinical uptake has occurred in the absence of any pooled quantitative evidence or formal certainty of evidence assessment to support or refute the practice. This systematic review and meta-analysis aimed to: (1) provide the first pooled quantitative estimates of HF rates in CAPS versus non-augmented fixation for spinal metastases; (2) estimate the effect of CAPS on HF risk through available direct comparative data; (3) assess robustness through pre-specified sensitivity analysis; and (4) explore SINS as a potential effect modifier. Methods We hypothesised that CAPS is associated with lower HF rates compared to conventional fixation in metastatic spine surgery, and that SINS may modify this effect. This review was conducted and reported per PRISMA 2020 guidelines [ 11 ] and registered with INPLASY (INPLASY202640045). Eligibility Criteria Studies enrolling adults (≥ 18 years) with spinal metastases undergoing instrumented pedicle screw fixation that reported HF outcomes were eligible. Studies were classified as CAPS if PMMA was injected through fenestrated or cannulated screws. Case reports (n ≤ 5), pure vertebroplasty/kyphoplasty studies, non-separable mixed populations, and conference abstracts were excluded. Information Sources and Search Strategy Five databases were searched from inception through April 2026: PubMed/MEDLINE, Embase, Cochrane CENTRAL, Web of Science, and Scopus, using three Boolean concept blocks: population, intervention, and outcome. Backward citation tracking supplemented the electronic search. Full strategies are provided in Online Resource 5. Study Selection and Data Extraction Two reviewers independently screened records and extracted data using a pre-piloted standardised form. Disagreements were resolved by a third reviewer. Risk of bias was assessed using the Newcastle-Ottawa Scale (NOS), with pre-specified thresholds of ≥ 7 (good), 5–6 (fair), and < 5 (poor). Statistical Analysis Pooled HF rates were computed separately for CAPS and non-augmented arms using the Freeman-Tukey double arcsine transformation with DerSimonian-Laird random-effects models [ 12 , 13 ]. The REML estimator was applied as a sensitivity check. For direct comparative data, odds ratios were computed with continuity correction (0.5). Heterogeneity was quantified using I², Cochran Q, and τ²; 95% prediction intervals were computed. Leave-one-out sensitivity analysis was performed. As the CAPS arm comprised k = 10 studies, Egger’s regression and Begg’s rank correlation tests were applied. A pre-specified sensitivity analysis was performed restricting to SINS-reporting studies. Certainty of evidence was assessed using GRADE [ 14 ]. All analyses were performed in Python 3.12. Results Study Selection and Characteristics The search retrieved 96 records; after deduplication and screening, 13 studies met eligibility criteria (Fig. 1 ). Studies were published 2015–2025, comprising 886 patients across the United States (k = 8), Germany (k = 1), South Korea (k = 1), China (k = 1), and Singapore (k = 2). Eight were single-arm CAPS series, two were direct comparative studies, and three were single-arm non-augmented controls. Median follow-up ranged from 4.9 to 25.3 months. SINS data were available in five studies. Study characteristics are summarised in Table 1 . Table 1 Characteristics of included studies (n = 13) CAPS cement-augmented pedicle screw, HF hardware failure, SINS Spinal Instability Neoplastic Score, NR not reported, SA single arm, NOS Newcastle-Ottawa Scale Study (Year) Country Surgery Type N (CAPS/Ctrl) HF Events HF Rate % SINS NOS Moussazadeh 2015 USA Perc CAPS (SA) 44/— 1/— 2.3/— 10 6 Kim 2017 Korea Perc + VP (SA) 14/— 0/— 0/— NR 6 Barzilai 2019 USA Perc CAPS (SA) 53/— 4/— 7.5/— NR 6 Massaad 2021 USA Open sep (SA) 69/— 0/— 0/— NR 6 Newman 2021 USA Open CAPS (SA) 44/— 4/— 9.1/— 10 6 Patel 2021 USA Open PSF (Comp) 10/9 0/0 0/0 NR 5 Wagner 2021 Germany MIS CFRP (SA) 51/— 6/— 11.8/— NR 5 Cady-McCrea 2021 USA Open corp (SA) 8/— 0/— 0/— NR 5 Feng 2022 China CAPS vs CPS (Comp) 28/24 1/7 3.6/29.2 11.4/10.8 7 Bardeesi 2025 USA Open CFRP (SA) 28/— 0/— 0/— 8.5 6 Longo 2019 USA Conv screws (Ctrl) —/58 —/8 —/13.8 NR 5 Kumar N 2021 Singapore Conv screws (Ctrl) —/246 —/55 —/22.4 NR 6 Kumar N 2023 Singapore Conv screws (Ctrl) —/200 —/~4 —/~2 13 3 Risk of Bias One study (Feng 2022) was rated good quality (NOS ≥ 7); eleven were rated fair (NOS 5–6); and one (Kumar 2023) was rated poor (NOS < 5). No RCTs were identified. Comparability domain scores were uniformly low across all studies (Fig. 3 ). Hardware Failure Rates — Cement-Augmented Arm Ten datasets from eight independent studies contributed to the CAPS analysis (k = 10, N = 349, events = 16). The pooled HF rate was 4.3% (95% CI 1.8–7.9%; τ² = 0.026, I² = 46.8%, Q = 16.91, df = 9, p = 0.050). The 95% prediction interval ranged from 0.1% to 14.8%. Individual HF rates ranged from 0% to 11.8% (Fig. 2 a). Hardware Failure Rates — Non-Cement Control Arm Five datasets contributed to the control analysis (k = 5, N = 537, events = 74). The pooled HF rate was 12.5% (95% CI 2.9–27.5%; I² = 93.3%, Q = 59.36, p < 0.001). Considerable heterogeneity was attributable primarily to divergent HF definitions (Online Resource 1): broad radiographic criteria yielded 22.4%, while symptomatic-only reporting yielded approximately 2.0% (Fig. 2 b). Direct Comparative Analysis Feng et al. [ 10 ] reported 1 HF event in 28 CAPS patients versus 7 in 24 conventional patients, yielding OR 0.13 (95% CI 0.02–0.81; p = 0.029). Patel et al. [ 19 ] reported zero events in both arms. Given single-study eligibility for OR computation, a formal pooled OR is not reported. Sensitivity Analysis and Publication Bias Leave-one-out analysis demonstrated robust stability of the CAPS estimate (range 3.5–5.9%). Restricting analysis to SINS-reporting studies (k = 4, N = 144) yielded 4.5% (95% CI 1.4–9.1%; I² = 23.4%), closely concordant with the primary estimate and with notably reduced heterogeneity (Online Resource 2). Egger’s test (p = 0.085) and Begg’s test (p = 0.528) showed no significant funnel plot asymmetry (Fig. 5 ). Certainty of Evidence All outcomes were rated low to very low certainty (Table 2 ). The CAPS rate was downgraded for risk of bias and imprecision; the control rate additionally for serious inconsistency; the direct comparative OR for single-study derivation. Table 2 GRADE summary of findings CI confidence interval, HF hardware failure, OR odds ratio. All outcomes start at LOW (observational). ↓ downgrade Outcome Studies, N GRADE Downgrade Estimate (95% CI) Direction Comments HF — Cement arm k = 10, N = 349 ⊕⊕⊖⊖ LOW RoB↓ Imprec↓ 4.3% (1.8–7.9%) Lower vs ctrl I²=46.8% HF — Control arm k = 5, N = 537 ⊕⊖⊖⊖ V.LOW RoB↓ Incon↓ Imprec↓ 12.5% (2.9–27.5%) Reference I²=93.3% HF — Direct OR k = 1, N = 52 ⊕⊖⊖⊖ V.LOW RoB↓ Indir↓ Imprec↓ OR 0.13 (0.02–0.81) Favours CAPS Single study HF — SINS-only k = 4, N = 144 ⊕⊖⊖⊖ V.LOW RoB↓ Indir↓ Imprec↓ 4.5% (1.4–9.1%) Consistent I²=23.4% Discussion This meta-analysis represents the first quantitative synthesis of HF rates in CAPS versus conventional fixation specifically within the metastatic spine surgery population. Across 13 studies comprising 886 patients, CAPS was associated with a pooled HF rate of 4.3%, approximately threefold lower than the 12.5% observed in non-augmented controls, a finding robust across leave-one-out (3.5–5.9%) and SINS-restricted (4.5%, I² reduced to 23.4%) sensitivity analyses. The magnitude of this risk differential — an absolute reduction of approximately 8 percentage points and a relative reduction of approximately 66% — is clinically substantial and comparable to or exceeding the effect sizes reported for other hardware-protective strategies in spinal surgery, such as interbody cage supplementation or extended fixation constructs. The clinical significance extends beyond complication reduction. Unlike degenerative spinal surgery, where HF is rarely life-threatening and revision typically feasible, HF in the metastatic population carries distinctly different consequences. Patients with spinal metastases often have ECOG performance status ≥ 2, limited physiological reserve, and median survival measured in months, rendering revision surgery frequently untenable. HF in this context manifests as recurrent pain, loss of ambulatory capacity, or neurological deterioration — outcomes that are catastrophic given the inherent difficulty of re-intervention. The approximately threefold HF reduction with CAPS therefore translates directly into preserved quality of life and avoidance of high-risk secondary procedures. No prior systematic review has examined the effect of cement augmentation on HF as a primary outcome or provided formal certainty of evidence assessment for this clinical question. This gap is consequential because CAPS entails additional operative time, implant cost, and non-trivial risks — yet without pooled data, surgeons have been unable to objectively weigh these trade-offs. Our findings provide the first effect estimates and certainty ratings needed for evidence-based decision-making. Practically, these data support consideration of CAPS as a default strategy in instrumented metastatic spine surgery, particularly for patients with lytic vertebral destruction, SINS ≥ 7, and anticipated survival exceeding three months. For patients with blastic metastases and intact posterior elements, the incremental benefit may be smaller and must be weighed against procedural risks. This stratified approach should be refined as SINS-stratified outcomes data accumulate. A distinctive feature of this review is the explicit integration of SINS as a potential effect modifier. The SINS-restricted sensitivity analysis demonstrated a stable CAPS estimate with reduced heterogeneity (I² from 46.8% to 23.4%), suggesting that SINS-reporting studies form a more homogeneous evidence base. However, SINS data were available in only 5 of 13 studies, precluding formal subgroup comparison and leaving the clinically important question of whether higher-instability patients derive disproportionately greater benefit unanswered. This gap constitutes a critical finding: the current literature has failed to capture the information necessary for personalised cement augmentation decisions. The specific hypothesis — whether CAPS provides disproportionately greater HF protection in patients with SINS ≥ 13 compared to those with SINS 7–12 — remains the most clinically important unanswered question in this domain and is now quantitatively addressable based on the pooled estimates provided herein. The considerable control-arm heterogeneity (I² = 93.3%) warrants careful discussion. This heterogeneity was attributable primarily to fundamental inconsistency in HF definitions across studies (Online Resource 1). Broad radiographic criteria captured all construct failures including angular deformity exceeding 5° (yielding 22.4%), while symptomatic-only reporting yielded approximately 2.0% — a nearly elevenfold difference. This illustrates a fundamental deficiency in spinal oncology research methodology. The field currently lacks a consensus definition of hardware failure analogous to the standardised radiographic and clinical criteria used to define pseudarthrosis or adjacent segment disease in degenerative surgery. One of the most actionable contributions of the present work is the quantitative demonstration of how this definitional heterogeneity translates into clinically meaningless meta-analytic estimates for the non-augmented group, thereby underscoring the urgent need for a consensus, tiered HF reporting framework. Importantly, radiographic HF is not a static endpoint but a time-dependent process with direct clinical implications within the typical survival window of metastatic spine disease. Kumar et al. (2021) reported a median time to hardware failure of 5.0 months — well within the survival horizon of a patient with 10-month median survival. Initially radiographic loosening progresses through screw toggle, pedicle tract widening, and loss of fixation, culminating in recurrent pain, progressive kyphotic deformity, and neurological deterioration. The symptomatic-only rate of ~ 2% reported by Kumar et al. (2023) likely reflects ascertainment bias: patients with progressive radiographic loosening who were managed conservatively or who died from systemic disease progression before becoming overtly symptomatic were not captured. For these reasons, the radiographic definition — which captures the full spectrum of construct compromise — remains the more clinically informative outcome measure, and the 4.3% versus 13.8–22.4% comparison using comparable radiographic definitions represents the most valid estimate of the cement augmentation effect. Methodological strengths include a five-database search spanning three continents and twelve years of practice; use of the Freeman-Tukey transformation appropriate for zero-event proportions; narrow leave-one-out range (3.5–5.9%); and the first application of GRADE to this clinical question, enabling clinicians to calibrate confidence in the pooled estimates. Specifically, the Freeman-Tukey double arcsine transformation avoids the boundary violations that affect alternative methods such as logit or arcsine transformations alone when multiple studies report zero events. The SINS-restricted sensitivity analysis provided convergent validation of the primary finding with reduced heterogeneity, lending additional credibility to the cement-arm estimate. Limitations include the exclusively observational evidence base, precluding causal inference regarding the effect of CAPS on HF. The indirect comparison is methodologically weaker than pooled head-to-head evidence, and residual confounding cannot be excluded. Critically, however, the direction of the most plausible confounding bias favours a conservative interpretation: surgeons likely preferentially use CAPS in patients with greater instability, poorer bone quality, and more extensive lytic destruction — precisely the patients at highest baseline risk of HF. This channelling bias would be expected to attenuate rather than amplify the observed protective effect, suggesting that the true benefit of CAPS may exceed our pooled estimate. Follow-up was heterogeneous and often short (4.9–25.3 months), potentially underestimating late HF. SINS data were available in only 5 of 13 studies. These limitations must be weighed alongside the procedural risks of cement augmentation itself when interpreting clinical applicability. The risk–benefit calculus requires explicit disaggregation by event type and definition. Cement-related pulmonary embolism (PE), cited at ≤ 2% in our review, refers to clinically significant symptomatic events; the majority of cement extravasation (≥ 95%) is asymptomatic and detected incidentally on postoperative imaging. In the three largest CAPS series in our dataset (Massaad 2021, n = 69; Newman 2021, n = 44; Bardeesi 2025, n = 28), zero cases of clinically significant PE were reported. Under a worst-case composite analysis — CAPS hardware failure (4.3%) plus symptomatic PE (≤ 2%) versus symptomatic-only control HF (~ 2%) — the apparent risk differential narrows. However, the clinical consequences of these events are fundamentally non-equivalent: symptomatic HF in a patient with 10-month median survival typically precipitates irreversible loss of ambulatory capacity with no realistic salvage option, whereas symptomatic cement PE, while serious, is treatable and rarely fatal with contemporary controlled injection techniques under fluoroscopic guidance. Prospective comparative studies comparing CAPS to conventional fixation should mandate SINS documentation, stratified reporting by SINS category (≤ 6, 7–12, ≥ 13), and adoption of a standardised HF definition. Registry-based initiatives integrating SINS with implant strategy would provide the infrastructure for a definitive synthesis. Conclusion This meta-analysis provides the first pooled quantitative evidence that CAPS is associated with an approximately threefold lower HF rate compared to conventional fixation in metastatic spine surgery (4.3% vs. 12.5%), a finding directionally confirmed by the sole direct comparative study (OR 0.13, 95% CI 0.02–0.81). This estimate is robust to leave-one-out sensitivity analysis and convergent with the SINS-restricted subanalysis. Given that HF in patients with limited survival directly precipitates loss of ambulatory capacity, recurrent pain, and neurological deterioration, even low-certainty estimates of this magnitude have immediate implications for intraoperative implant strategy. The magnitude of benefit depends on which HF definition is applied: using comparable radiographic definitions, the risk reduction is approximately threefold; using symptomatic-only definitions, the differential narrows but must be weighed against the non-equivalent clinical consequences of hardware failure versus cement-related complications. These data support consideration of cement augmentation as a default fixation strategy, particularly in patients with lytic vertebral destruction and compromised bone quality. This review simultaneously identifies two actionable priorities: adoption of a consensus, tiered HF definition and mandatory SINS reporting in all prospective studies to enable personalised, instability-stratified cement augmentation decision-making. Declarations Author Contribution Conceptualization: Y-C Li, Y-J Lu. Literature search and data extraction: Y-C Li, C-Y Li, S-H Huang, Y-P Kang. Risk of bias assessment: Y-C Li, H-K Wang. Statistical analysis: Y-C Li. Writing — original draft: Y-C Li. Writing — review and editing: all authors. Supervision: K-H Chen, P-W Hsu, Y-J Lu. All authors read and approved the final manuscript. References Siegel RL, Miller KD, Jemal A (2023) Cancer statistics, 2023. CA Cancer J Clin 73:17–48 Laufer I, Rubin DG, Lis E et al (2013) The NOMS framework: approach to the treatment of spinal metastatic tumors. Oncologist 18:744–751 Bauer H, Tomita K, Kawahara N et al (2002) Surgical strategy for spinal metastases. Spine 27:1124–1126 Kumar N, Tan JYH, Zaw AS et al (2016) The importance of implant choice in the risk of construct failure in the surgical management of spinal metastasis. Spine J 16:471–481 Fisher CG, DiPaola CP, Ryken TC et al (2010) A novel classification system for spinal instability in neoplastic disease. Spine 35:E1221–E1229 Fourney DR, Frangou EM, Ryken TC et al (2011) Spinal instability neoplastic score: an analysis of reliability and validity. 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Eur J Surg Oncol 47:1522–1533 Higgins JPT, Thomas J, Chandler J et al (2023) Cochrane Handbook for Systematic Reviews of Interventions, version 6.4. Cochrane Additional Declarations No competing interests reported. Supplementary Files ESM1.pdf ESM2.tiff ESM3.tiff ESM4.tiff ESM5.pdf OnlineResources.docx Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 26 Apr, 2026 Editor assigned by journal 17 Apr, 2026 Submission checks completed at journal 17 Apr, 2026 First submitted to journal 14 Apr, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9415578","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":629847101,"identity":"fbae4ada-689c-4a62-b071-d8ef86aa50fb","order_by":0,"name":"Ying-Ching Li","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA/ElEQVRIiWNgGAWjYBACxgYeBmYos/HBhx82YMYBYrRIMDAwHzac2ZMGFsOrhYEBroUtTZqH7TBYDK8W5vbeY48L2+7U8UufMTbg4Tlvt7b9MNCWGptonA7rOZduPLPtmYRkX47hAwmL28nbziQCtRxLy23ApWVGjpk0b9thCYMzPMYGBjy3k80OALUwNhwmrMX+DI+ZRALbuWSz8w+J1GLAw5YmcYDtgJ3ZDUK29Jwxk+Y5d1hyxhlgIDf2JCeY3QDakoDHL4btPUAtZYf5+XsYGx//+WFnb3Y+/eGDDzU2uLWgSySCBRJwKAcBeXQBezyKR8EoGAWjYIQCAPGYYS90lsTCAAAAAElFTkSuQmCC","orcid":"","institution":"Chang Gung Memorial Hospital","correspondingAuthor":true,"prefix":"","firstName":"Ying-Ching","middleName":"","lastName":"Li","suffix":""},{"id":629847104,"identity":"7d8402fb-4d93-4752-b876-a50afa9afa69","order_by":1,"name":"Cheng-Yu Li","email":"","orcid":"","institution":"Chang Gung Memorial Hospital","correspondingAuthor":false,"prefix":"","firstName":"Cheng-Yu","middleName":"","lastName":"Li","suffix":""},{"id":629847109,"identity":"330842c3-3378-45be-961b-641b6a60b32d","order_by":2,"name":"Sheng-Han Huang","email":"","orcid":"","institution":"Chang Gung Memorial Hospital","correspondingAuthor":false,"prefix":"","firstName":"Sheng-Han","middleName":"","lastName":"Huang","suffix":""},{"id":629847115,"identity":"0000c717-06e2-45ff-b43a-3d10a5baa252","order_by":3,"name":"Hong Kai Wang","email":"","orcid":"","institution":"Chang Gung Memorial Hospital","correspondingAuthor":false,"prefix":"","firstName":"Hong","middleName":"Kai","lastName":"Wang","suffix":""},{"id":629847117,"identity":"7270f4e8-92c7-4a77-b571-8cc16e3502d4","order_by":4,"name":"Kuan-Hung Chen Kuan-Hung Chen","email":"","orcid":"","institution":"Chang Gung Memorial Hospital","correspondingAuthor":false,"prefix":"","firstName":"Kuan-Hung","middleName":"Chen Kuan-Hung","lastName":"Chen","suffix":""},{"id":629847118,"identity":"ad6a0d71-a620-445c-87a9-9c9b8e63b1cf","order_by":5,"name":"Yan-Po Kang","email":"","orcid":"","institution":"Chang Gung Memorial Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yan-Po","middleName":"","lastName":"Kang","suffix":""},{"id":629847122,"identity":"48e6618e-9e68-4799-a034-5615fe330720","order_by":6,"name":"Peng-Wei Hsu","email":"","orcid":"","institution":"Chang Gung Memorial Hospital","correspondingAuthor":false,"prefix":"","firstName":"Peng-Wei","middleName":"","lastName":"Hsu","suffix":""},{"id":629847128,"identity":"9b9ceed0-5773-45e5-b299-8d874eeb4c16","order_by":7,"name":"Yu-Jen Lu","email":"","orcid":"","institution":"Chang Gung Memorial Hospital","correspondingAuthor":false,"prefix":"","firstName":"Yu-Jen","middleName":"","lastName":"Lu","suffix":""}],"badges":[],"createdAt":"2026-04-14 12:40:17","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9415578/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9415578/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":109101869,"identity":"62c8caf8-c5d0-4624-9dd2-40757091851e","added_by":"auto","created_at":"2026-05-12 14:30:27","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":4933494,"visible":true,"origin":"","legend":"\u003cp\u003ePRISMA 2020 flow diagram. Total 96 records identified; 13 studies included.\u003c/p\u003e","description":"","filename":"Fig1.png","url":"https://assets-eu.researchsquare.com/files/rs-9415578/v1/00085590ebdad20f6813a7b1.png"},{"id":109101846,"identity":"aa749518-841f-4291-8772-285fdcf1de3e","added_by":"auto","created_at":"2026-05-12 14:30:03","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":584337,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ea \u003c/strong\u003eForest plot — cement-augmented arm (k = 10). Pooled estimate 4.3% (95% CI 1.8–7.9%); 95% prediction interval 0.1–14.8%.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eb \u003c/strong\u003eForest plot — non-augmented control arm (k = 5). Pooled rate 12.5% (95% CI 2.9–27.5%); I² = 93.3%.\u003c/p\u003e","description":"","filename":"Fig2.png","url":"https://assets-eu.researchsquare.com/files/rs-9415578/v1/8c2e6429acfb190904ed45b1.png"},{"id":109101968,"identity":"6658d402-79a2-4e43-a6ca-c6a7ae3eb324","added_by":"auto","created_at":"2026-05-12 14:30:35","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":3998089,"visible":true,"origin":"","legend":"\u003cp\u003eNewcastle-Ottawa Scale quality assessment for all 13 included studies.\u003c/p\u003e","description":"","filename":"Fig3.png","url":"https://assets-eu.researchsquare.com/files/rs-9415578/v1/70ebfc9676a5c88a21b415ad.png"},{"id":109101947,"identity":"04d8bb59-607d-49dc-add0-97f7293f1991","added_by":"auto","created_at":"2026-05-12 14:30:34","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":2648362,"visible":true,"origin":"","legend":"\u003cp\u003eLeft: indirect comparison of pooled HF rates. Right: leave-one-out sensitivity analysis (range 3.5–5.9%).\u003c/p\u003e","description":"","filename":"Fig4.png","url":"https://assets-eu.researchsquare.com/files/rs-9415578/v1/999ca86710986194d87122d6.png"},{"id":109101867,"identity":"c8034c7b-06b5-4082-9d3f-8d92691ebb69","added_by":"auto","created_at":"2026-05-12 14:30:26","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":1570570,"visible":true,"origin":"","legend":"\u003cp\u003eFunnel plot — cement arm (k = 10). Egger’s p = 0.085; Begg’s p = 0.528.\u003c/p\u003e","description":"","filename":"Fig5.png","url":"https://assets-eu.researchsquare.com/files/rs-9415578/v1/0ebdc3cd3745113325f544cc.png"},{"id":109102208,"identity":"24e6dfae-dcc4-4f4d-b04a-68def5afc5fa","added_by":"auto","created_at":"2026-05-12 14:31:37","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":14317853,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9415578/v1/bb02e58a-6b4a-4651-8e9a-dce085e806a3.pdf"},{"id":109101844,"identity":"51c2bc49-5d13-4da3-ac73-5d671cfab7e1","added_by":"auto","created_at":"2026-05-12 14:29:57","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":71640,"visible":true,"origin":"","legend":"","description":"","filename":"ESM1.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9415578/v1/de16da1d8d1cd9f3678c812b.pdf"},{"id":109101864,"identity":"eafbbcb0-40e9-4184-976c-deb1a4cce885","added_by":"auto","created_at":"2026-05-12 14:30:25","extension":"tiff","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":317042,"visible":true,"origin":"","legend":"","description":"","filename":"ESM2.tiff","url":"https://assets-eu.researchsquare.com/files/rs-9415578/v1/49c240a1b683fef560d2c3e6.tiff"},{"id":109101865,"identity":"f1b6fc2c-fc3c-4393-89a0-304153a844f1","added_by":"auto","created_at":"2026-05-12 14:30:25","extension":"tiff","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":278824,"visible":true,"origin":"","legend":"","description":"","filename":"ESM3.tiff","url":"https://assets-eu.researchsquare.com/files/rs-9415578/v1/aa2479cc7aad95a232ba7b32.tiff"},{"id":109101848,"identity":"bd7f3d5e-109e-4223-928b-01830cbe0dbb","added_by":"auto","created_at":"2026-05-12 14:30:04","extension":"tiff","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":239616,"visible":true,"origin":"","legend":"","description":"","filename":"ESM4.tiff","url":"https://assets-eu.researchsquare.com/files/rs-9415578/v1/5394d0ff112bdc689b032765.tiff"},{"id":109101834,"identity":"87d194bb-5e3f-490c-ba49-b082d0665f41","added_by":"auto","created_at":"2026-05-12 14:29:53","extension":"pdf","order_by":5,"title":"","display":"","copyAsset":false,"role":"supplement","size":41568,"visible":true,"origin":"","legend":"","description":"","filename":"ESM5.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9415578/v1/d82b13671de0be43352935ca.pdf"},{"id":109101866,"identity":"c89932a1-97dc-482b-a4a2-fd20f2ab3383","added_by":"auto","created_at":"2026-05-12 14:30:25","extension":"docx","order_by":6,"title":"","display":"","copyAsset":false,"role":"supplement","size":13771,"visible":true,"origin":"","legend":"","description":"","filename":"OnlineResources.docx","url":"https://assets-eu.researchsquare.com/files/rs-9415578/v1/a449add92a5595de29a9ff67.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Cement Augmentation of Pedicle Screw Constructs as a Modifier of Hardware Failure Risk in Instrumented Metastatic Spine Surgery: A Systematic Review and Meta-Analysis","fulltext":[{"header":"Introduction","content":"\u003cp\u003eSpinal metastases are the most common site of skeletal metastatic involvement, affecting up to 70% of patients with advanced malignancy and representing a leading cause of cancer-related morbidity through pain, neurological compromise, and mechanical instability [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Instrumented posterior pedicle screw fixation has become a cornerstone of the multidisciplinary management of metastatic spinal cord compression and symptomatic instability [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eHardware failure (HF) \u0026mdash; encompassing screw loosening, pullout, rod fracture, cage migration, and progressive kyphosis \u0026mdash; remains one of the most consequential mechanical complications after instrumented metastatic spine surgery, with reported rates of 1.9\u0026ndash;22.4% [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Patients with spinal metastases typically have limited physiological reserve and shortened survival, rendering revision surgery a morbid and often clinically untenable undertaking.\u003c/p\u003e \u003cp\u003eThe Spinal Instability Neoplastic Score (SINS), developed by the Spine Oncology Study Group, quantifies the degree of spinal instability attributable to metastatic involvement through tumour location, pain characteristics, lesion morphology, alignment, vertebral body collapse, and posterior element involvement [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. As a composite surrogate for structural compromise, SINS is increasingly recognised as a potential risk stratification tool for hardware-related complications; however, its interaction with implant strategy remains poorly defined [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eCement-augmented pedicle screw fixation (CAPS) \u0026mdash; the injection of polymethylmethacrylate (PMMA) through fenestrated or cannulated pedicle screws \u0026mdash; substantially increases screw pullout strength by creating a composite screw-cement-bone interface [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Although a growing body of single-centre observational data suggests reduced HF rates with CAPS, this evidence remains fragmented across small retrospective series with heterogeneous populations and HF definitions [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Notably, the adoption of CAPS has accelerated substantially over the past decade, with fenestrated screw systems now commercially available from all major spinal implant manufacturers; yet this widespread clinical uptake has occurred in the absence of any pooled quantitative evidence or formal certainty of evidence assessment to support or refute the practice.\u003c/p\u003e \u003cp\u003e This systematic review and meta-analysis aimed to: (1) provide the first pooled quantitative estimates of HF rates in CAPS versus non-augmented fixation for spinal metastases; (2) estimate the effect of CAPS on HF risk through available direct comparative data; (3) assess robustness through pre-specified sensitivity analysis; and (4) explore SINS as a potential effect modifier.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eWe hypothesised that CAPS is associated with lower HF rates compared to conventional fixation in metastatic spine surgery, and that SINS may modify this effect. This review was conducted and reported per PRISMA 2020 guidelines [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] and registered with INPLASY (INPLASY202640045).\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eEligibility Criteria\u003c/h2\u003e \u003cp\u003eStudies enrolling adults (\u0026ge;\u0026thinsp;18 years) with spinal metastases undergoing instrumented pedicle screw fixation that reported HF outcomes were eligible. Studies were classified as CAPS if PMMA was injected through fenestrated or cannulated screws. Case reports (n\u0026thinsp;\u0026le;\u0026thinsp;5), pure vertebroplasty/kyphoplasty studies, non-separable mixed populations, and conference abstracts were excluded.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eInformation Sources and Search Strategy\u003c/h3\u003e\n\u003cp\u003eFive databases were searched from inception through April 2026: PubMed/MEDLINE, Embase, Cochrane CENTRAL, Web of Science, and Scopus, using three Boolean concept blocks: population, intervention, and outcome. Backward citation tracking supplemented the electronic search. Full strategies are provided in Online Resource 5.\u003c/p\u003e\n\u003ch3\u003eStudy Selection and Data Extraction\u003c/h3\u003e\n\u003cp\u003eTwo reviewers independently screened records and extracted data using a pre-piloted standardised form. Disagreements were resolved by a third reviewer. Risk of bias was assessed using the Newcastle-Ottawa Scale (NOS), with pre-specified thresholds of \u0026ge;\u0026thinsp;7 (good), 5\u0026ndash;6 (fair), and \u0026lt;\u0026thinsp;5 (poor).\u003c/p\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis\u003c/h2\u003e \u003cp\u003ePooled HF rates were computed separately for CAPS and non-augmented arms using the Freeman-Tukey double arcsine transformation with DerSimonian-Laird random-effects models [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. The REML estimator was applied as a sensitivity check. For direct comparative data, odds ratios were computed with continuity correction (0.5). Heterogeneity was quantified using I\u0026sup2;, Cochran Q, and τ\u0026sup2;; 95% prediction intervals were computed. Leave-one-out sensitivity analysis was performed. As the CAPS arm comprised k\u0026thinsp;=\u0026thinsp;10 studies, Egger\u0026rsquo;s regression and Begg\u0026rsquo;s rank correlation tests were applied. A pre-specified sensitivity analysis was performed restricting to SINS-reporting studies. Certainty of evidence was assessed using GRADE [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. All analyses were performed in Python 3.12.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\n \u003ch2\u003eStudy Selection and Characteristics\u003c/h2\u003e\n \u003cp\u003eThe search retrieved 96 records; after deduplication and screening, 13 studies met eligibility criteria (Fig. \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Studies were published 2015\u0026ndash;2025, comprising 886 patients across the United States (k\u0026thinsp;=\u0026thinsp;8), Germany (k\u0026thinsp;=\u0026thinsp;1), South Korea (k\u0026thinsp;=\u0026thinsp;1), China (k\u0026thinsp;=\u0026thinsp;1), and Singapore (k\u0026thinsp;=\u0026thinsp;2). Eight were single-arm CAPS series, two were direct comparative studies, and three were single-arm non-augmented controls. Median follow-up ranged from 4.9 to 25.3 months. SINS data were available in five studies. Study characteristics are summarised in Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eCharacteristics of included studies (n\u0026thinsp;=\u0026thinsp;13) \u003cem\u003eCAPS cement-augmented pedicle screw, HF hardware failure, SINS Spinal Instability Neoplastic Score, NR not reported, SA single arm, NOS Newcastle-Ottawa Scale\u003c/em\u003e\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003ccolgroup cols=\"8\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" colname=\"c1\"\u003e\n \u003cp\u003eStudy (Year)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colname=\"c2\"\u003e\n \u003cp\u003eCountry\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colname=\"c3\"\u003e\n \u003cp\u003eSurgery Type\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colname=\"c4\"\u003e\n \u003cp\u003eN (CAPS/Ctrl)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colname=\"c5\"\u003e\n \u003cp\u003eHF Events\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colname=\"c6\"\u003e\n \u003cp\u003eHF Rate %\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colname=\"c7\"\u003e\n \u003cp\u003eSINS\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colname=\"c8\"\u003e\n \u003cp\u003eNOS\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colname=\"c1\"\u003e\n \u003cp\u003eMoussazadeh 2015\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c2\"\u003e\n \u003cp\u003eUSA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c3\"\u003e\n \u003cp\u003ePerc CAPS (SA)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c4\"\u003e\n \u003cp\u003e44/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c5\"\u003e\n \u003cp\u003e1/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c6\"\u003e\n \u003cp\u003e2.3/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c7\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colname=\"c1\"\u003e\n \u003cp\u003eKim 2017\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c2\"\u003e\n \u003cp\u003eKorea\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c3\"\u003e\n \u003cp\u003ePerc\u0026thinsp;+\u0026thinsp;VP (SA)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c4\"\u003e\n \u003cp\u003e14/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c5\"\u003e\n \u003cp\u003e0/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c6\"\u003e\n \u003cp\u003e0/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c7\"\u003e\n \u003cp\u003eNR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colname=\"c1\"\u003e\n \u003cp\u003eBarzilai 2019\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c2\"\u003e\n \u003cp\u003eUSA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c3\"\u003e\n \u003cp\u003ePerc CAPS (SA)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c4\"\u003e\n \u003cp\u003e53/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c5\"\u003e\n \u003cp\u003e4/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c6\"\u003e\n \u003cp\u003e7.5/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c7\"\u003e\n \u003cp\u003eNR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colname=\"c1\"\u003e\n \u003cp\u003eMassaad 2021\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c2\"\u003e\n \u003cp\u003eUSA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c3\"\u003e\n \u003cp\u003eOpen sep (SA)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c4\"\u003e\n \u003cp\u003e69/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c5\"\u003e\n \u003cp\u003e0/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c6\"\u003e\n \u003cp\u003e0/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c7\"\u003e\n \u003cp\u003eNR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colname=\"c1\"\u003e\n \u003cp\u003eNewman 2021\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c2\"\u003e\n \u003cp\u003eUSA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c3\"\u003e\n \u003cp\u003eOpen CAPS (SA)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c4\"\u003e\n \u003cp\u003e44/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c5\"\u003e\n \u003cp\u003e4/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c6\"\u003e\n \u003cp\u003e9.1/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c7\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colname=\"c1\"\u003e\n \u003cp\u003ePatel 2021\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c2\"\u003e\n \u003cp\u003eUSA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c3\"\u003e\n \u003cp\u003eOpen PSF (Comp)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c4\"\u003e\n \u003cp\u003e10/9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c5\"\u003e\n \u003cp\u003e0/0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c6\"\u003e\n \u003cp\u003e0/0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c7\"\u003e\n \u003cp\u003eNR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colname=\"c1\"\u003e\n \u003cp\u003eWagner 2021\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c2\"\u003e\n \u003cp\u003eGermany\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c3\"\u003e\n \u003cp\u003eMIS CFRP (SA)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c4\"\u003e\n \u003cp\u003e51/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c5\"\u003e\n \u003cp\u003e6/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c6\"\u003e\n \u003cp\u003e11.8/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c7\"\u003e\n \u003cp\u003eNR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colname=\"c1\"\u003e\n \u003cp\u003eCady-McCrea 2021\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c2\"\u003e\n \u003cp\u003eUSA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c3\"\u003e\n \u003cp\u003eOpen corp (SA)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c4\"\u003e\n \u003cp\u003e8/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c5\"\u003e\n \u003cp\u003e0/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c6\"\u003e\n \u003cp\u003e0/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c7\"\u003e\n \u003cp\u003eNR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colname=\"c1\"\u003e\n \u003cp\u003eFeng 2022\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c2\"\u003e\n \u003cp\u003eChina\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c3\"\u003e\n \u003cp\u003eCAPS vs CPS (Comp)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c4\"\u003e\n \u003cp\u003e28/24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c5\"\u003e\n \u003cp\u003e1/7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c6\"\u003e\n \u003cp\u003e3.6/29.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c7\"\u003e\n \u003cp\u003e11.4/10.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colname=\"c1\"\u003e\n \u003cp\u003eBardeesi 2025\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c2\"\u003e\n \u003cp\u003eUSA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c3\"\u003e\n \u003cp\u003eOpen CFRP (SA)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c4\"\u003e\n \u003cp\u003e28/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c5\"\u003e\n \u003cp\u003e0/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c6\"\u003e\n \u003cp\u003e0/\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c7\"\u003e\n \u003cp\u003e8.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colname=\"c1\"\u003e\n \u003cp\u003eLongo 2019\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c2\"\u003e\n \u003cp\u003eUSA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c3\"\u003e\n \u003cp\u003eConv screws (Ctrl)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c4\"\u003e\n \u003cp\u003e\u0026mdash;/58\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c5\"\u003e\n \u003cp\u003e\u0026mdash;/8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c6\"\u003e\n \u003cp\u003e\u0026mdash;/13.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c7\"\u003e\n \u003cp\u003eNR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colname=\"c1\"\u003e\n \u003cp\u003eKumar N 2021\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c2\"\u003e\n \u003cp\u003eSingapore\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c3\"\u003e\n \u003cp\u003eConv screws (Ctrl)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c4\"\u003e\n \u003cp\u003e\u0026mdash;/246\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c5\"\u003e\n \u003cp\u003e\u0026mdash;/55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c6\"\u003e\n \u003cp\u003e\u0026mdash;/22.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c7\"\u003e\n \u003cp\u003eNR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colname=\"c1\"\u003e\n \u003cp\u003eKumar N 2023\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c2\"\u003e\n \u003cp\u003eSingapore\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c3\"\u003e\n \u003cp\u003eConv screws (Ctrl)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c4\"\u003e\n \u003cp\u003e\u0026mdash;/200\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c5\"\u003e\n \u003cp\u003e\u0026mdash;/~4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c6\"\u003e\n \u003cp\u003e\u0026mdash;/~2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c7\"\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003ch3\u003eRisk of Bias\u003c/h3\u003e\n\u003cp\u003eOne study (Feng 2022) was rated good quality (NOS\u0026thinsp;\u0026ge;\u0026thinsp;7); eleven were rated fair (NOS 5\u0026ndash;6); and one (Kumar 2023) was rated poor (NOS\u0026thinsp;\u0026lt;\u0026thinsp;5). No RCTs were identified. Comparability domain scores were uniformly low across all studies (Fig. \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\n\u003ch3\u003eHardware Failure Rates \u0026mdash; Cement-Augmented Arm\u003c/h3\u003e\n\u003cp\u003eTen datasets from eight independent studies contributed to the CAPS analysis (k\u0026thinsp;=\u0026thinsp;10, N\u0026thinsp;=\u0026thinsp;349, events\u0026thinsp;=\u0026thinsp;16). The pooled HF rate was 4.3% (95% CI 1.8\u0026ndash;7.9%; \u0026tau;\u0026sup2; = 0.026, I\u0026sup2; = 46.8%, Q\u0026thinsp;=\u0026thinsp;16.91, df\u0026thinsp;=\u0026thinsp;9, p\u0026thinsp;=\u0026thinsp;0.050). The 95% prediction interval ranged from 0.1% to 14.8%. Individual HF rates ranged from 0% to 11.8% (Fig. \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e2\u003c/span\u003ea).\u003c/p\u003e\n\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\n \u003ch2\u003eHardware Failure Rates \u0026mdash; Non-Cement Control Arm\u003c/h2\u003e\n \u003cp\u003eFive datasets contributed to the control analysis (k\u0026thinsp;=\u0026thinsp;5, N\u0026thinsp;=\u0026thinsp;537, events\u0026thinsp;=\u0026thinsp;74). The pooled HF rate was 12.5% (95% CI 2.9\u0026ndash;27.5%; I\u0026sup2; = 93.3%, Q\u0026thinsp;=\u0026thinsp;59.36, p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Considerable heterogeneity was attributable primarily to divergent HF definitions (Online Resource 1): broad radiographic criteria yielded 22.4%, while symptomatic-only reporting yielded approximately 2.0% (Fig. \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e2\u003c/span\u003eb).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\n \u003ch2\u003eDirect Comparative Analysis\u003c/h2\u003e\n \u003cp\u003eFeng et al. [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] reported 1 HF event in 28 CAPS patients versus 7 in 24 conventional patients, yielding OR 0.13 (95% CI 0.02\u0026ndash;0.81; p\u0026thinsp;=\u0026thinsp;0.029). Patel et al. [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e] reported zero events in both arms. Given single-study eligibility for OR computation, a formal pooled OR is not reported.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\n \u003ch2\u003eSensitivity Analysis and Publication Bias\u003c/h2\u003e\n \u003cp\u003eLeave-one-out analysis demonstrated robust stability of the CAPS estimate (range 3.5\u0026ndash;5.9%). Restricting analysis to SINS-reporting studies (k\u0026thinsp;=\u0026thinsp;4, N\u0026thinsp;=\u0026thinsp;144) yielded 4.5% (95% CI 1.4\u0026ndash;9.1%; I\u0026sup2; = 23.4%), closely concordant with the primary estimate and with notably reduced heterogeneity (Online Resource 2). Egger\u0026rsquo;s test (p\u0026thinsp;=\u0026thinsp;0.085) and Begg\u0026rsquo;s test (p\u0026thinsp;=\u0026thinsp;0.528) showed no significant funnel plot asymmetry (Fig. \u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\n \u003ch2\u003eCertainty of Evidence\u003c/h2\u003e\n \u003cp\u003eAll outcomes were rated low to very low certainty (Table \u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). The CAPS rate was downgraded for risk of bias and imprecision; the control rate additionally for serious inconsistency; the direct comparative OR for single-study derivation.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eGRADE summary of findings \u003cem\u003eCI confidence interval, HF hardware failure, OR odds ratio. All outcomes start at LOW (observational). \u0026darr; downgrade\u003c/em\u003e\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003ccolgroup cols=\"7\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" colname=\"c1\"\u003e\n \u003cp\u003eOutcome\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colname=\"c2\"\u003e\n \u003cp\u003eStudies, N\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colname=\"c3\"\u003e\n \u003cp\u003eGRADE\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colname=\"c4\"\u003e\n \u003cp\u003eDowngrade\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colname=\"c5\"\u003e\n \u003cp\u003eEstimate (95% CI)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colname=\"c6\"\u003e\n \u003cp\u003eDirection\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colname=\"c7\"\u003e\n \u003cp\u003eComments\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colname=\"c1\"\u003e\n \u003cp\u003eHF \u0026mdash; Cement arm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c2\"\u003e\n \u003cp\u003ek\u0026thinsp;=\u0026thinsp;10, N\u0026thinsp;=\u0026thinsp;349\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c3\"\u003e\n \u003cp\u003e\u0026oplus;\u0026oplus;⊖⊖ LOW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c4\"\u003e\n \u003cp\u003eRoB\u0026darr; Imprec\u0026darr;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c5\"\u003e\n \u003cp\u003e4.3% (1.8\u0026ndash;7.9%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c6\"\u003e\n \u003cp\u003eLower vs ctrl\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c7\"\u003e\n \u003cp\u003eI\u0026sup2;=46.8%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colname=\"c1\"\u003e\n \u003cp\u003eHF \u0026mdash; Control arm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c2\"\u003e\n \u003cp\u003ek\u0026thinsp;=\u0026thinsp;5, N\u0026thinsp;=\u0026thinsp;537\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c3\"\u003e\n \u003cp\u003e\u0026oplus;⊖⊖⊖ V.LOW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c4\"\u003e\n \u003cp\u003eRoB\u0026darr; Incon\u0026darr; Imprec\u0026darr;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c5\"\u003e\n \u003cp\u003e12.5% (2.9\u0026ndash;27.5%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c6\"\u003e\n \u003cp\u003eReference\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c7\"\u003e\n \u003cp\u003eI\u0026sup2;=93.3%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colname=\"c1\"\u003e\n \u003cp\u003eHF \u0026mdash; Direct OR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c2\"\u003e\n \u003cp\u003ek\u0026thinsp;=\u0026thinsp;1, N\u0026thinsp;=\u0026thinsp;52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c3\"\u003e\n \u003cp\u003e\u0026oplus;⊖⊖⊖ V.LOW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c4\"\u003e\n \u003cp\u003eRoB\u0026darr; Indir\u0026darr; Imprec\u0026darr;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c5\"\u003e\n \u003cp\u003eOR 0.13 (0.02\u0026ndash;0.81)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c6\"\u003e\n \u003cp\u003eFavours CAPS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c7\"\u003e\n \u003cp\u003eSingle study\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colname=\"c1\"\u003e\n \u003cp\u003eHF \u0026mdash; SINS-only\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c2\"\u003e\n \u003cp\u003ek\u0026thinsp;=\u0026thinsp;4, N\u0026thinsp;=\u0026thinsp;144\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c3\"\u003e\n \u003cp\u003e\u0026oplus;⊖⊖⊖ V.LOW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c4\"\u003e\n \u003cp\u003eRoB\u0026darr; Indir\u0026darr; Imprec\u0026darr;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c5\"\u003e\n \u003cp\u003e4.5% (1.4\u0026ndash;9.1%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c6\"\u003e\n \u003cp\u003eConsistent\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\" colname=\"c7\"\u003e\n \u003cp\u003eI\u0026sup2;=23.4%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n\u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis meta-analysis represents the first quantitative synthesis of HF rates in CAPS versus conventional fixation specifically within the metastatic spine surgery population. Across 13 studies comprising 886 patients, CAPS was associated with a pooled HF rate of 4.3%, approximately threefold lower than the 12.5% observed in non-augmented controls, a finding robust across leave-one-out (3.5\u0026ndash;5.9%) and SINS-restricted (4.5%, I\u0026sup2; reduced to 23.4%) sensitivity analyses. The magnitude of this risk differential \u0026mdash; an absolute reduction of approximately 8 percentage points and a relative reduction of approximately 66% \u0026mdash; is clinically substantial and comparable to or exceeding the effect sizes reported for other hardware-protective strategies in spinal surgery, such as interbody cage supplementation or extended fixation constructs.\u003c/p\u003e \u003cp\u003eThe clinical significance extends beyond complication reduction. Unlike degenerative spinal surgery, where HF is rarely life-threatening and revision typically feasible, HF in the metastatic population carries distinctly different consequences. Patients with spinal metastases often have ECOG performance status\u0026thinsp;\u0026ge;\u0026thinsp;2, limited physiological reserve, and median survival measured in months, rendering revision surgery frequently untenable. HF in this context manifests as recurrent pain, loss of ambulatory capacity, or neurological deterioration \u0026mdash; outcomes that are catastrophic given the inherent difficulty of re-intervention. The approximately threefold HF reduction with CAPS therefore translates directly into preserved quality of life and avoidance of high-risk secondary procedures.\u003c/p\u003e \u003cp\u003e No prior systematic review has examined the effect of cement augmentation on HF as a primary outcome or provided formal certainty of evidence assessment for this clinical question. This gap is consequential because CAPS entails additional operative time, implant cost, and non-trivial risks \u0026mdash; yet without pooled data, surgeons have been unable to objectively weigh these trade-offs. Our findings provide the first effect estimates and certainty ratings needed for evidence-based decision-making.\u003c/p\u003e \u003cp\u003ePractically, these data support consideration of CAPS as a default strategy in instrumented metastatic spine surgery, particularly for patients with lytic vertebral destruction, SINS\u0026thinsp;\u0026ge;\u0026thinsp;7, and anticipated survival exceeding three months. For patients with blastic metastases and intact posterior elements, the incremental benefit may be smaller and must be weighed against procedural risks. This stratified approach should be refined as SINS-stratified outcomes data accumulate.\u003c/p\u003e \u003cp\u003eA distinctive feature of this review is the explicit integration of SINS as a potential effect modifier. The SINS-restricted sensitivity analysis demonstrated a stable CAPS estimate with reduced heterogeneity (I\u0026sup2; from 46.8% to 23.4%), suggesting that SINS-reporting studies form a more homogeneous evidence base. However, SINS data were available in only 5 of 13 studies, precluding formal subgroup comparison and leaving the clinically important question of whether higher-instability patients derive disproportionately greater benefit unanswered. This gap constitutes a critical finding: the current literature has failed to capture the information necessary for personalised cement augmentation decisions. The specific hypothesis \u0026mdash; whether CAPS provides disproportionately greater HF protection in patients with SINS\u0026thinsp;\u0026ge;\u0026thinsp;13 compared to those with SINS 7\u0026ndash;12 \u0026mdash; remains the most clinically important unanswered question in this domain and is now quantitatively addressable based on the pooled estimates provided herein.\u003c/p\u003e \u003cp\u003eThe considerable control-arm heterogeneity (I\u0026sup2; = 93.3%) warrants careful discussion. This heterogeneity was attributable primarily to fundamental inconsistency in HF definitions across studies (Online Resource 1). Broad radiographic criteria captured all construct failures including angular deformity exceeding 5\u0026deg; (yielding 22.4%), while symptomatic-only reporting yielded approximately 2.0% \u0026mdash; a nearly elevenfold difference. This illustrates a fundamental deficiency in spinal oncology research methodology. The field currently lacks a consensus definition of hardware failure analogous to the standardised radiographic and clinical criteria used to define pseudarthrosis or adjacent segment disease in degenerative surgery. One of the most actionable contributions of the present work is the quantitative demonstration of how this definitional heterogeneity translates into clinically meaningless meta-analytic estimates for the non-augmented group, thereby underscoring the urgent need for a consensus, tiered HF reporting framework.\u003c/p\u003e \u003cp\u003eImportantly, radiographic HF is not a static endpoint but a time-dependent process with direct clinical implications within the typical survival window of metastatic spine disease. Kumar et al. (2021) reported a median time to hardware failure of 5.0 months \u0026mdash; well within the survival horizon of a patient with 10-month median survival. Initially radiographic loosening progresses through screw toggle, pedicle tract widening, and loss of fixation, culminating in recurrent pain, progressive kyphotic deformity, and neurological deterioration. The symptomatic-only rate of ~\u0026thinsp;2% reported by Kumar et al. (2023) likely reflects ascertainment bias: patients with progressive radiographic loosening who were managed conservatively or who died from systemic disease progression before becoming overtly symptomatic were not captured. For these reasons, the radiographic definition \u0026mdash; which captures the full spectrum of construct compromise \u0026mdash; remains the more clinically informative outcome measure, and the 4.3% versus 13.8\u0026ndash;22.4% comparison using comparable radiographic definitions represents the most valid estimate of the cement augmentation effect.\u003c/p\u003e \u003cp\u003eMethodological strengths include a five-database search spanning three continents and twelve years of practice; use of the Freeman-Tukey transformation appropriate for zero-event proportions; narrow leave-one-out range (3.5\u0026ndash;5.9%); and the first application of GRADE to this clinical question, enabling clinicians to calibrate confidence in the pooled estimates. Specifically, the Freeman-Tukey double arcsine transformation avoids the boundary violations that affect alternative methods such as logit or arcsine transformations alone when multiple studies report zero events. The SINS-restricted sensitivity analysis provided convergent validation of the primary finding with reduced heterogeneity, lending additional credibility to the cement-arm estimate.\u003c/p\u003e \u003cp\u003eLimitations include the exclusively observational evidence base, precluding causal inference regarding the effect of CAPS on HF. The indirect comparison is methodologically weaker than pooled head-to-head evidence, and residual confounding cannot be excluded. Critically, however, the direction of the most plausible confounding bias favours a conservative interpretation: surgeons likely preferentially use CAPS in patients with greater instability, poorer bone quality, and more extensive lytic destruction \u0026mdash; precisely the patients at highest baseline risk of HF. This channelling bias would be expected to attenuate rather than amplify the observed protective effect, suggesting that the true benefit of CAPS may exceed our pooled estimate. Follow-up was heterogeneous and often short (4.9\u0026ndash;25.3 months), potentially underestimating late HF. SINS data were available in only 5 of 13 studies. These limitations must be weighed alongside the procedural risks of cement augmentation itself when interpreting clinical applicability.\u003c/p\u003e \u003cp\u003eThe risk\u0026ndash;benefit calculus requires explicit disaggregation by event type and definition. Cement-related pulmonary embolism (PE), cited at \u0026le;\u0026thinsp;2% in our review, refers to clinically significant symptomatic events; the majority of cement extravasation (\u0026ge;\u0026thinsp;95%) is asymptomatic and detected incidentally on postoperative imaging. In the three largest CAPS series in our dataset (Massaad 2021, n\u0026thinsp;=\u0026thinsp;69; Newman 2021, n\u0026thinsp;=\u0026thinsp;44; Bardeesi 2025, n\u0026thinsp;=\u0026thinsp;28), zero cases of clinically significant PE were reported. Under a worst-case composite analysis \u0026mdash; CAPS hardware failure (4.3%) plus symptomatic PE (\u0026le;\u0026thinsp;2%) versus symptomatic-only control HF (~\u0026thinsp;2%) \u0026mdash; the apparent risk differential narrows. However, the clinical consequences of these events are fundamentally non-equivalent: symptomatic HF in a patient with 10-month median survival typically precipitates irreversible loss of ambulatory capacity with no realistic salvage option, whereas symptomatic cement PE, while serious, is treatable and rarely fatal with contemporary controlled injection techniques under fluoroscopic guidance.\u003c/p\u003e \u003cp\u003eProspective comparative studies comparing CAPS to conventional fixation should mandate SINS documentation, stratified reporting by SINS category (\u0026le;\u0026thinsp;6, 7\u0026ndash;12, \u0026ge;\u0026thinsp;13), and adoption of a standardised HF definition. Registry-based initiatives integrating SINS with implant strategy would provide the infrastructure for a definitive synthesis.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis meta-analysis provides the first pooled quantitative evidence that CAPS is associated with an approximately threefold lower HF rate compared to conventional fixation in metastatic spine surgery (4.3% vs. 12.5%), a finding directionally confirmed by the sole direct comparative study (OR 0.13, 95% CI 0.02\u0026ndash;0.81). This estimate is robust to leave-one-out sensitivity analysis and convergent with the SINS-restricted subanalysis. Given that HF in patients with limited survival directly precipitates loss of ambulatory capacity, recurrent pain, and neurological deterioration, even low-certainty estimates of this magnitude have immediate implications for intraoperative implant strategy. The magnitude of benefit depends on which HF definition is applied: using comparable radiographic definitions, the risk reduction is approximately threefold; using symptomatic-only definitions, the differential narrows but must be weighed against the non-equivalent clinical consequences of hardware failure versus cement-related complications. These data support consideration of cement augmentation as a default fixation strategy, particularly in patients with lytic vertebral destruction and compromised bone quality. This review simultaneously identifies two actionable priorities: adoption of a consensus, tiered HF definition and mandatory SINS reporting in all prospective studies to enable personalised, instability-stratified cement augmentation decision-making.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eConceptualization: Y-C Li, Y-J Lu. Literature search and data extraction: Y-C Li, C-Y Li, S-H Huang, Y-P Kang. Risk of bias assessment: Y-C Li, H-K Wang. Statistical analysis: Y-C Li. Writing \u0026mdash; original draft: Y-C Li. Writing \u0026mdash; review and editing: all authors. Supervision: K-H Chen, P-W Hsu, Y-J Lu. All authors read and approved the final manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eSiegel RL, Miller KD, Jemal A (2023) Cancer statistics, 2023. CA Cancer J Clin 73:17\u0026ndash;48\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLaufer I, Rubin DG, Lis E et al (2013) The NOMS framework: approach to the treatment of spinal metastatic tumors. Oncologist 18:744\u0026ndash;751\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBauer H, Tomita K, Kawahara N et al (2002) Surgical strategy for spinal metastases. Spine 27:1124\u0026ndash;1126\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKumar N, Tan JYH, Zaw AS et al (2016) The importance of implant choice in the risk of construct failure in the surgical management of spinal metastasis. Spine J 16:471\u0026ndash;481\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFisher CG, DiPaola CP, Ryken TC et al (2010) A novel classification system for spinal instability in neoplastic disease. Spine 35:E1221\u0026ndash;E1229\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFourney DR, Frangou EM, Ryken TC et al (2011) Spinal instability neoplastic score: an analysis of reliability and validity. J Clin Oncol 29:3072\u0026ndash;3077\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKwan MK, Muralidharan A, Hasan MS et al (2025) SINS intermediate-category patients with metastatic spinal tumors: a systematic review. Global Spine J 15:218\u0026ndash;232\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCook SD, Salkeld SL, Stanley T et al (2004) Biomechanical study of pedicle screw fixation in severely osteoporotic bone. Spine J 4:402\u0026ndash;408\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMassaad E, Bhatt D, Kiapour A et al (2021) Safety and efficacy of cement augmentation with fenestrated pedicle screws for tumor-related spinal instability. Neurosurg Focus 50:E17\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFeng Q, Zhang Z, Wang D, Feng J (2022) Comparing the efficacy and safety of cement-augmented fenestrated pedicle screws and conventional pedicle screws in surgery for spinal metastases. Transl Cancer Res 11:2831\u0026ndash;2839\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePage MJ, McKenzie JE, Bossuyt PM et al (2021) The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ 372:n71\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDerSimonian R, Laird N (1986) Meta-analysis in clinical trials. Control Clin Trials 7:177\u0026ndash;188\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFreeman MF, Tukey JW (1950) Transformations related to the angular and the square root. Ann Math Stat 21:607\u0026ndash;611\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGuyatt GH, Oxman AD, Vist GE et al (2008) GRADE: an emerging consensus on rating quality of evidence and strength of recommendations. BMJ 336:924\u0026ndash;926\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBarzilai O, McLaughlin L, Lis E et al (2019) Utility of cement augmentation via percutaneous fenestrated pedicle screws for stabilization of cancer-related spinal instability. Oper Neurosurg 17:232\u0026ndash;239\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim P, Kim SW (2017) Bone cement-augmented percutaneous screw fixation for malignant spinal metastases: is it feasible? J Korean Neurosurg Soc 60:601\u0026ndash;606\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMoussazadeh N, Rubin DG, McLaughlin L et al (2015) Short-segment percutaneous pedicle screw fixation with cement augmentation for tumor-induced spinal instability. Spine J 15:1609\u0026ndash;1617\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNewman WC, Amin AG, Villavieja J et al (2021) Short-segment cement-augmented fixation in open separation surgery of metastatic epidural spinal cord compression. Neurosurg Focus 50:E16\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePatel S, Parola R, Rosinski CL et al (2021) Fenestrated pedicle screws in spinal oncology. Int J Spine Surg 15:563\u0026ndash;571\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWagner A, Haag E, Joerger AK et al (2021) Cement-augmented carbon fiber-reinforced pedicle screw instrumentation for spinal metastases. World Neurosurg 155:e407\u0026ndash;e418\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCady-McCrea CI, Gilbert JC, Galgano MA (2021) Cement-augmented and dual-headed posterior screw reconstruction after corpectomy for metastatic tumor resection. World Neurosurg 154:e574\u0026ndash;e582\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBardeesi A, Wilson S, Ward J et al (2025) Separation surgery with cement-augmented short-segment fixation for spinal metastasis. Neurosurg Focus 58:E14\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKumar N, Tan JYH, Vellayappan BA et al (2023) Overview on the management of metastatic spine disease. J Bone Oncol 38:100460\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKumar N, Malhotra R, Zaw AS et al (2021) Evolution in treatment strategy for metastatic spine disease. Eur J Surg Oncol 47:1522\u0026ndash;1533\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHiggins JPT, Thomas J, Chandler J et al (2023) Cochrane Handbook for Systematic Reviews of Interventions, version 6.4. Cochrane\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"european-spine-journal","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"esjo","sideBox":"Learn more about [European Spine Journal](http://link.springer.com/journal/586)","snPcode":"586","submissionUrl":"https://submission.springernature.com/new-submission/586/3","title":"European Spine Journal","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"cement augmentation, hardware failure, meta-analysis, pedicle screw, spinal metastases, systematic review","lastPublishedDoi":"10.21203/rs.3.rs-9415578/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9415578/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e \u003cb\u003ePurpose\u003c/b\u003e Hardware failure (HF) after instrumented fixation for spinal metastases affects 2\u0026ndash;22% of patients. Despite growing adoption of cement-augmented pedicle screw fixation (CAPS), no meta-analysis has quantified its effect on HF rates. We aimed to provide pooled HF estimates for CAPS versus conventional fixation and explore the Spinal Instability Neoplastic Score (SINS) as a potential effect modifier.\u003c/p\u003e \u003cp\u003e\u003cb\u003eMethods\u003c/b\u003e A systematic review and meta-analysis were conducted following PRISMA 2020 guidelines, searching five databases through April 2026. Pooled HF rates were computed using Freeman-Tukey double arcsine transformation with DerSimonian-Laird random-effects models. Sensitivity analysis was performed restricting to SINS-reporting studies. Certainty of evidence was assessed using GRADE.\u003c/p\u003e \u003cp\u003e \u003cb\u003eResults\u003c/b\u003e Thirteen studies (n\u0026thinsp;=\u0026thinsp;886) met eligibility criteria. The pooled HF rate was 4.3% (95% CI 1.8\u0026ndash;7.9%; I\u0026sup2; = 46.8%) in CAPS arms (k\u0026thinsp;=\u0026thinsp;10, n\u0026thinsp;=\u0026thinsp;349) versus 12.5% (95% CI 2.9\u0026ndash;27.5%; I\u0026sup2; = 93.3%) in non-augmented controls (k\u0026thinsp;=\u0026thinsp;5, n\u0026thinsp;=\u0026thinsp;537). The sole comparative study demonstrated OR 0.13 (95% CI 0.02\u0026ndash;0.81; p\u0026thinsp;=\u0026thinsp;0.029). Sensitivity analysis restricted to SINS-reporting studies confirmed stability (4.5%, I\u0026sup2; = 23.4%). All outcomes were rated low to very low certainty.\u003c/p\u003e \u003cp\u003e \u003cb\u003eConclusion\u003c/b\u003e CAPS is associated with an approximately threefold lower HF rate compared to conventional fixation in metastatic spine surgery (4.3% vs. 12.5%), with immediate implications for intraoperative implant strategy. INPLASY registration: INPLASY202640045.\u003c/p\u003e","manuscriptTitle":"Cement Augmentation of Pedicle Screw Constructs as a Modifier of Hardware Failure Risk in Instrumented Metastatic Spine Surgery: A Systematic Review and Meta-Analysis","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-05-12 14:27:13","doi":"10.21203/rs.3.rs-9415578/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-04-26T20:27:37+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-04-17T09:15:59+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-04-17T09:15:54+00:00","index":"","fulltext":""},{"type":"submitted","content":"European Spine Journal","date":"2026-04-14T12:27:47+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"european-spine-journal","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"esjo","sideBox":"Learn more about [European Spine Journal](http://link.springer.com/journal/586)","snPcode":"586","submissionUrl":"https://submission.springernature.com/new-submission/586/3","title":"European Spine Journal","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"02a45b7e-2a17-4106-b7c2-a52ee09105d2","owner":[],"postedDate":"May 12th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-18T11:53:12+00:00","versionOfRecord":[],"versionCreatedAt":"2026-05-12 14:27:13","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9415578","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9415578","identity":"rs-9415578","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}