Comparison of Clinical Outcomes Following Anterior Cervical Discectomy and Fusion with Zero-Profile Anchored Spacer-ROI-C-Fixation and Combined Intervertebral Cage and Anterior Cervical Discectomy and Fusion: A Retrospective Study from a Single Center

Evaluation of bony fusion after anterior cervical discectomy: a systematic literature review and meta-analysis

Significant variability exists in reported fusion rates in the cervical spine after anterior discectomy. Here we review fusion assessment methods, timing of fusion with various intervertebral devices, and examine correlations with clinical outcomes. PubMed, Medline, Embase, Web of Science, Cochrane Library, and Emcare were searched on December 9 2024 for studies involving 1- or 2-level anterior cervical discectomy with quantitative fusion assessment via CT or X-ray. A meta-analysis was conducted using a random-effects model to pool fusion rates and their 95% confidence intervals (CIs) at different follow-up points, for different cage types and different cut-off values evaluating fusion. Sixty-four included studies evaluated 5633 patients. Pooled fusion rates increased over time: 55.6% (95% CI: 43.5%, 67.2%) of patients demonstrated fusion at three months, 74.4% (67.6%, 80.1%) at six months, 88.1% at 12 months (85.1%, 90.6%), and 91.8% (89.1%, 93.9%) at 24 months. Subgroup analysis revealed variation in fusion rates depending on cage type, with titanium cages yielding slightly higher rates at all follow-up times. Sensitivity analysis with fusion criteria showed that a cut-off value < 2 mm for interspinous distance yielded lower fusion rates than the cut-off < 2° for Cobb angle at 6 (70% vs. 77.3%), 12 (83.9% vs. 91.1%) and 24 months (89.5% vs. 91.7%). Results on the correlation between fusion and clinical outcomes were inconsistent. Fusion rates improved over time, approaching 56% at 3 months and 90% at 12 months. Notably, to alleviate heterogeneity across studies, there is a dire need to harmonize reporting guidelines in future research.

Long-term effectiveness of stand-alone anchored spacer in multilevel anterior cervical discectomy and fusion compared with cage-plate system: a systematic review and meta-analysis

OBJECTIVE

For anterior cervical discectomy and fusion (ACDF), stand-alone anchored spacers (SAAS) and cage-plate system (CPS) are currently employed. However, controversy remains over the effectiveness and security of these two apparatuses in multilevel ACDF. The aim of this study was to demonstrate the global long-term effectiveness and safety of SAAS versus CPS with multilevel ACDF.

METHODS

We conducted a systematic review of studies comparing SAAS with CPS for multilevel ACDF using four electronic databases. Data from this meta-analysis were analyzed with Stata MP 17.0.

RESULTS

A total of nine trials comprising 584 patients were selected for inclusion. SAAS significantly reduced operative time, intraoperative bleeding and the incidence of postoperative dysphagia compared with CPS. The SAAS group exhibited significantly smaller cervical sagittal angle (CSA) and fusion segmental height (FSH) compared to CPS group. At final follow-up, the rate of cage sinking was higher in SAAS group compared to CPS group. At the endpoint, there was no difference in JOA score, NDI score, fusion rate or the incidence of adjacent segment degeneration (ASD).

CONCLUSIONS

SAAS provided comparable long-term effectiveness and safeness for multilevel ACDF regarding JOA scores, NDI scores, fusion rates and ASD rates at endpoint compared to CPS. In comparison to CPS, SAAS demonstrated significant advancement in the reduction of operative time, intraoperative blood loss and the incidence of postoperative dysphagia. As a consequence, SAAS appeared more desirable than CPS among people who needed multilevel ACDF. Yet in long-term observation, SAAS was inferior to CPS in maintaining CSA and FSH and in preventing cage descent. However, whether or not radiographic abnormality has an impact on clinical presentation awaits confirmation from research with more longitudinal follow-up.

Methods of diagnosis and rehabilitation of dysphagia in patients with spinal cord injury: a systematic review

INTRODUCTION

Latest epidemiological metrics put a global prevalence of 20.6 million people suffering from spinal cord injury (SCI), leading to a burden of functional disability, deterioration in quality of life and reduced life expectancy. A thorough statement of diagnostic methods and treatment protocols for swallowing disorders after SCI stands as a major priority to streamline patient care and cost-sharing. Here we have provided a systematic overview of the evidence on diagnostic and rehabilitation protocols of dysphagia in the SCI population.

EVIDENCE ACQUISITION

The literature was searched in six electronic databases up to April 30th, 2024. Screening the 521 retrieved articles for inclusion criteria resulted in the selection of 43 studies that reported assessment tools and rehabilitation protocols for dysphagia in patients with SCI. Two researchers extracted the data in parallel, and inter-rater reliability (IRR) was used to estimate inter-coder agreement and then κ statistic to measure accuracy and precision. Based on PRISMA concepts and quality assessment steps, a k coefficient of at least 0.9 was obtained in all data extraction steps. All reports were assessed for risk of bias using the NIH Quality Assessment Toolkit. The study protocol was registered on PROSPERO (CRD42023449137).

EVIDENCE SYNTHESIS

Dysphagia assessment methods were collected and grouped into four different macro categories (clinical assessment, rating scale, self-reported questionnaire, and instrumental assessment). It was found that the Bedside Swallow Evaluation (BSE) for the clinical assessment category (50%), the Bazaz score (32.5%) for the rating scale category, the Eating Assessment Tool-10 (EAT-10) (44.4%) for the self-reported questionnaire category, and the Videofluoroscopic Study of Swallowing (VFSS) (48.9%) for the instrumental assessment category were the most representative tools. The rehabilitation protocols described included either an early oral feeding exclusion or a consistency-modified oral intake, postural adaptations, oxygen therapy with a high-flow nasal cannula combined with indirect/direct therapy, specific exercises, and neuromuscular electrical stimulation.

CONCLUSIONS

Methods of diagnosis and rehabilitation protocols for dysphagia in SCI patients appear inconsistent. Further rigorous studies are needed to achieve better clinical handling in SCI settings while lowering the load of patient morbidity and related healthcare costs.

Comparative efficacy of zero-profile implant and conventional cage-plate implant in the treatment of single-level degenerative cervical spondylosis: a systematic review and meta-analysis

BACKGROUND

In recent years, the zero-profile implant (Zero-p) has emerged as a promising internal fixation technique. Although studies have indicated its potential superiority over conventional cage-plate implant (Cage-plate) in the treatment of degenerative cervical spondylosis, there remains a lack of definitive comparative reports regarding its indications, safety, and efficacy.

METHODS

A computerized search was conducted on English and Chinese databases, including PubMed, Web of Science, Cochrane Library, EMBASE, CNKI, Wanfang and VIP. Additionally, a manual search was meticulously carried out on Chinese medical journals, spanning from the inception of the respective databases until August 2023. The meta-analysis utilized a case-control study approach and was executed through the utilization of RevMan 5.3 software. Stringent quality evaluation and data extraction procedures were implemented to guarantee the reliability and validity of the findings.

RESULTS

Nine high-quality studies with 808 patients were included. Meta-analysis showed that the operation time (MD = - 13.28; 95% CI (- 17.53, - 9.04), P < 0.00001), intraoperative blood loss (MD = - 6.61; 95% CI (- 10.47, - 2.75), P = 0.0008), incidence of postoperative dysphagia at various time points: within the first month after surgery (OR = 0.36; 95% CI (0.22, 0.58), P < 0.0001), 1-3 months after surgery (OR = 0.20; 95% CI (0.08, 0.49), P = 0.0004), the final follow-up (OR = 0.21; 95% CI (0.05, 0.83), P = 0.003) and the rate of postoperative adjacent disc degeneration (OR = 0.46; 95% CI (0.25, 0.84), P = 0.01) were significantly lower in the Zero-p group than in the Cage-plate group. Additionally, was also significantly lower in the Zero-p group. However, there were no significant differences in the JOA score, the final follow-up NDI score, surgical segmental fusion rate, postoperative height of adjacent vertebrae, or postoperative subsidence rate between the two groups.

CONCLUSION

In summary, when treating single-segment degenerative cervical spondylosis, both internal fixation techniques are reliable and effective. However, Zero-P  implant offer several advantages over cage-plate implant, including shorter operation duration, less intraoperative blood loss, reduced postoperative dysphagia, and slower adjacent disc degeneration. Additionally, Zero-P implant has a broader application space, making them a preferred choice in certain cases.

Comparative analysis of risk factors associated with degeneration of adjacent segments: zero-profile anchored spacer vs. anterior cervical plate and cage construct

Objective

Anterior cervical discectomy and fusion (ACDF) is an established treatment for cervical degenerative disc disease, but cervical spine surgery may affect sagittal alignment parameters and induce adjacent segment degeneration (ASD). This study aimed to determine the risk factors for developing ASD following anterior cervical plate and cage (ACPC) compared with the use of zero-profile anchored spacer (ROI-C).

Methods

A retrospective contrastive study included 105 patients who underwent ACPC or ROI-C between January 2014 and October 2019 at our treatment centre. There were 50 cases in the ROI-C group and 55 patients in the ACPC group. Clinical and radiological results and the incidence of ASD were assessed after surgery. All patients were further divided into the ASD and non-ASD groups for subgroup analysis.

Results

At each follow-up time, there was no statistically significant in radiographic parameters between the two groups. The overall ASD rate was higher in the ACPC group than in the ROI-C group (65.5% vs. 44.0%, p = 0.027). The low preoperative Cobb angle, low preoperative segment angle (SA), and loss of Cobb (ΔCobb) were significantly correlated with ASD. However, clinical outcomes were not associated with ASD at any postoperative follow-up visit.

Conclusion

Equally good therapeutic effects were achieved with both the ROI-C and ACPC. The occurrence of ASD was considerably higher in the ACPC group than in the ROI-C group. The preoperative Cobb angle, preoperative SA, and ΔCobb were the most associated with an increase in the risk of ASD.

Assessing Surgical Outcomes for Cage Plate System versus Stand-Alone Cage in Anterior Cervical Discectomy and Fusion: A Systematic Review and Meta-Analysis

BACKGROUND

Anterior cervical discectomy and fusion (ACDF) is a common surgical procedure for addressing cervical spine conditions. It involves the utilization of either cage plate system (CPS) or stand-alone cage (SC). The objective of our study is to compare perioperative complications, patient-reported clinical outcomes measures, and radiographic outcomes of SC versus CPS in ACDF.

METHODS

We carried out a literature search in PubMed, Embase, Cochrane library, Web of science, Medline, and Google Scholar. All studies comparing the outcomes between CPS versus SC in ACDF were included.

RESULTS

Forty-one studies, 33 observational and 8 randomized clinical trials met the inclusion criteria. We found that both devices demonstrated comparable effectiveness in monosegmental ACDF with respect to Japanese Orthopedic Association Score, Neck Disability Index score, visual analog score, and fusion rates. CPS demonstrated superior performance in maintaining disc height, cervical lordosis, and exhibited lower incidence rates of cage subsidence. SC showed significant advantages over CPS in terms of shorter surgical duration, less intraoperative bleeding, shorter duration of hospitalization, as well as lower incidence rates of early postoperative dysphagia and adjacent segment disease.

CONCLUSIONS

Most of the included studies had monosegmented fusion, and there wasn't enough data to set recommendations for the multisegmented fusions. Larger studies with longer follow-up are necessary to draw more definitive conclusions to provide evidence for clinicians to make clinical decisions.

Are all Cages Created Equal? Analysis of Cervical Cage Malfunctions Using FDA MAUDE Database

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To characterize failure rates of cervical cages based on manufacturer and design characteristics using the nationwide database of reported malfunctions.

BACKGROUND

The Food and Drug Administration (FDA) aims to ensure the safety and efficacy of cervical interbody implants postimplantation; however, intraoperative malfunctions may be overlooked.

MATERIALS AND METHODS

The FDA's Manufacturer and User Facility Device Experience database was queried for reports of cervical cage device malfunctions from 2012 to 2021. Each report was categorized based on the failure type, implant design, and manufacturer. Two market analyses were performed. First, "failure-to-market share indices" were generated by dividing the number of failures per year for each implant material by its yearly US market share in cervical spine fusion. Second, "failure-to-revenue indices" were calculated by dividing the total number of failures per year for each manufacturer by their approximate yearly revenue from spinal implants in the US. Outlier analysis was performed to generate a threshold value above which failure rates were defined as greater than the normal index.

RESULTS

In total, 1336 entries were identified, and 1225 met the inclusion criteria. Of these, 354 (28.9%) were cage breakages, 54 (4.4%) were cage migrations, 321 (26.2%) were instrumentation-related failures, 301 (24.6%) were assembly failures, and 195 (15.9%) were screw failures. Poly-ether-ether-ketone implants had higher failure by market share indices for both migration and breakage compared with titanium. Upon manufacturer market analysis, Seaspine, Zimmer-Biomet, K2M, and LDR exceeded the failure threshold.

CONCLUSION

The most common cause of implant malfunction was breakage. Poly-ether-ether-ketone cages were more likely to break and migrate compared with titanium ones. Many of these implant failures occurred intraoperatively during instrumentation, which underscores the need for FDA evaluation of these implants and their accompanying instrumentation under the appropriate loading conditions before commercial approval.

Zero-profile anchored spacer versus conventional plate-cage construct in bilevel anterior cervical discectomy and fusion: a systematic review and meta-analysis

BACKGROUND

Zero-profile anchored spacers (ZAS) and plate-cage constructs (PCC) are currently employed when performing anterior cervical discectomy and fusion (ACDF). Nevertheless, the efficacy and safety of both devices in bilevel ACDF remain controversial. The goal of our meta-analysis is to assess the overall long-term efficacy and security among ZAS and PCC in bilevel ACDF.

METHODS

A search of four electronic databases was conducted to identify researches that compared ZAS with PCC for bilevel ACDF. Stata MP 17.0 software was used for this meta-analysis.

RESULTS

Nine researches with a total of 580 patients were involved. In comparison to PCC, ZAS significantly reduced intraoperative bleeding and postoperative dysphagia rates. No significant differences were found concerning operation time, JOA score, NDI score, cervical Cobb angle, fusion rates, the incidence of adjacent segmental degeneration (ASD) and implant sinking rates at last follow-up.

CONCLUSION

Compared to PCC, ZAS achieved similar efficacy and security in bilevel ACDF with respect to operative time, JOA score, NDI score, cervical Cobb angle, fusion rates, implant sinking rates and ASD rates at final follow-up. It is worth noting that ZAS offered considerable benefits over conventional PCC for the reduction of intraoperative bleeding and postoperative dysphagia. Therefore, for patients requiring bilevel ACDF, ZAS seems superior to PCC. Given the limitations of our study, larger prospective randomised controlled trials are needed to establish reliable proof to consolidate our conclusions.

Self-locking stand-alone cage versus cage-plate fixation in monosegmental anterior cervical discectomy and fusion with a minimum 2-year follow-up: a systematic review and meta-analysis

BACKGROUND

Currently, self-locking stand-alone cages (SSC) are commonly applied in anterior cervical discectomy and fusion (ACDF), as are cage-plate constructs (CPC). However, it remains controversial concerning the long-term effectiveness of both apparatuses. Our purpose is to compare long-term effectiveness of SSC with CPC in monosegmental ACDF.

METHODS

Four electronic databases were queried to identify studies comparing SSC versus CPC in monosegmental ACDF. The meta-analysis was carried out with the use of the Stata MP 17.0 software package.

RESULTS

Ten trials with 979 patients were included. Compared to CPC, SSC significantly reduced operative time, intraoperative blood loss, duration of hospitalisation, cervical Cobb angle at final follow-up, 1-month postoperative dysphagia rate, and incidence of adjacent segment degeneration (ASD) at final follow-up. No significant difference was found regarding 1-month postoperative cervical Cobb angle, JOA scores, NDI scores, fusion rate and cage subsidence rate at final follow-up.

CONCLUSION

Both devices achieved similar long-term effectiveness in monosegmental ACDF regarding JOA scores, NDI scores, fusion rate and cage subsidence rate. SSC had significant advantages over CPC in reducing surgical duration, intraoperative bleeding, duration of hospitalisation, as well as rates of dysphagia and ASD after surgery. Therefore, SSC is a better option than CPC in monosegmental ACDF. However, SSC is inferior to CPC in maintaining cervical curvature at long-term follow-up. Whether radiological changes affect clinical symptoms needs confirmation in trials with longer follow-up.

Comparing Clinical and Radiographic Outcomes Between the Self-locking Stand-alone Cage and Conventional Cage-plate Construct: A Five-year Retrospective Cohort Study

STUDY DESIGN/SETTING

A retrospective cohort study.

OBJECTIVE

To evaluate the clinical efficacy of the self-locking stand-alone (SA) cage and conventional cage-plate construct (CPC) in treating degenerative cervical spondylosis with a five-year follow-up.

SUMMARY OF BACKGROUND DATA

The SA approach was designed to reduce complications associated with traditional anterior cervical discectomy and fusion. These techniques have been shown to have satisfactory short-term clinical outcomes. Literature describing the mid-term clinical outcomes of SA cage is limited.

MATERIALS AND METHODS

We retrospectively analyzed patients with cervical spondylosis who had received an SA device or CPC between 2014 and 2016 at the Xijing Hospital. Participants were matched for sex, age, and operative level. Differences in clinical and radiographic outcomes and the occurrence of postoperative complications between the two groups were analyzed.

RESULTS

In total, 207 patients were included (101 with SA and 106 with CPC), the median follow-up for both groups were 60.2 and 60.9 months. Both groups exhibited significant improvements in all measured values compared with the preoperative values. The SA group had a shorter operation time, less intraoperative blood loss, and a significantly lower incidence of dysphagia after surgery than the CPC group ( P <0.05). At the last visit, cage subsidence was 6.9% and 3.8% in the SA and CPC groups, respectively ( P =0.365). The radiographic adjacent segment degeneration (ASD) was significantly lower in the SA group than in the CPC group (6.9% vs. 27.4%, P <0.01). No symptomatic ASD was observed in the SA group, and six (5.7%) cases occurred in the CPC group ( P =0.029).

CONCLUSIONS

In this study, the SA cage showed similar efficacy to that of the conventional CPC in treating cervical spondylosis using anterior cervical discectomy and fusion, with a significant reduction in the incidence of immediate postoperative dysphagia and mid-term ASD.

Zero-profile implant versus conventional cage-plate construct in anterior cervical discectomy and fusion for the treatment of single-level degenerative cervical spondylosis: a systematic review and meta-analysis

BACKGROUND

The clinical outcomes of single-level anterior cervical discectomy and fusion (ACDF) with the Zero-profile (Zero-p) were evaluated in comparison with the anterior cervical cage-plate construct (CPC).

METHODS

We performed a systematic search covering PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, Medline, China National Knowledge Infrastructure (NCKI), Wan Fang Database, and Wei Pu Database. Articles focused on single-level ACDF or data of the single - level that can be extracted were included, and articles that did not directly compare Zero-p and CPC were excluded. Twenty-seven studies were included with a total of 1866 patients, 931 in the Zero-p group and 935 in the CPC group. All outcomes were analyzed using Review Manager 5.4.

RESULTS

The meta-analysis outcomes indicated that operative time (WMD = - 12.47, 95% CI (- 16.89, - 8.05), P < 0.00001), intraoperative blood loss (WMD = - 13.30, 95% CI (- 18.83, - 7.78), P < 0.00001), risk of adjacent segment degeneration (ASD) (OR 0.31, 95% CI (0.20, 0.48), P < 0.0001), risk of dysphagia of short-term (OR 0.40, 95% CI (0.30, 0.54), P < 0.0001), medium-term (OR 0.31, 95% CI (0.20, 0.49), P < 0.0001), and long-term (OR 0.29, 95% CI (0.17, 0.51), P < 0.0001) of Zero-p group were significantly lower. The JOA score of Zero-p group at the final follow-up was significantly higher (WMD = - 0.17, 95% CI (- 0.32, - 0.03), P = 0.02). There were no significant differences in length of stay (LOS), Neck Disability Index (NDI), Visual Analogue Score (VAS), fusion rate, segmental Cobb angle, cervical Cobb angle, prevertebral soft tissue thickness (PSTT), SF-36, subsidence, implant failure, and hoarseness between the two groups. This study was registered with PROSPERO, CRD42022347146.

CONCLUSION

Zero-p group reduced operative time, intraoperative blood loss, JOA score at follow-up and reduced the incidence of dysphagia and postoperative ASD, but the two devices had the same efficacy in restoring the cervical curvature, preventing the cage subsidence, and in postoperative VAS, NDI, LOS, PSTT, SF-36, fusion rate, implant failure, and hoarseness in single-level ACDF. The use of Zero-p in single-level ACDF was recommended.