A Prospective Study with Cage-Only or Cage-with-Plate Fixation in Anterior Cervical Discectomy and Interbody Fusion of One and Two Levels

Cage only or cage with plate fixation in anterior cervical discectomy and fusion surgery - analysis of a national multicenter dataset

BACKGROUND CONTEXT

Anterior Cervical Discectomy and Fusion (ACDF) is a surgical technique that can be used to treat several conditions of the cervical spine. Small sized studies have reported differences in radiological findings between cage only and cage with plate fusion techniques but no differences in clinical outcome, hence, larger studies are needed.

PURPOSE

The aim of this study was to compare the outcomes of ACDF between cage only and cage with plate fixation.

STUDY DESIGN

Retrospective study design on prospectively collected registry data.

PATIENT SAMPLE

Individuals treated for cervical degenerative radiculopathy, with ACDF using either cage only or cage with plate fixation were identified in the Swedish Spine registry (Swespine). Included individuals had available baseline and 1-year postoperative data for the Numeric Rating Scale (NRS) for neck and arm pain.

OUTCOME MEASURES

Patient reported outcome measures (PROMs) included were NRS for neck and arm pain, Neck Disability Index (NDI), and EuroQol-Visual Analogue Scale (EQ-VAS). Complications reported by clinicians and patients were also available in the Swespine registry, as well as the degree of satisfaction at the 1-year follow-up.

METHODS

Outcomes at the 1-year follow-up were compared between the cage only or cage with plate groups. In a secondary analysis, one or two levels of surgery was compared between the groups. The number of patients that reached the Minimum Clinically Important Difference (MCID) in improvement after treatment was calculated and compared between the groups. The Mann Whitney-U test was used for continuous variables and the Chi2 test for categorical variables.

RESULTS

The groups included 344 individuals instrumented with cage only, and 334 receiving cage with plate fixation. NDI improvement was -14.0 points (95% CI: -12.2-[-15.8]) in the cage only group and -17.9 points (95% CI: -16.1 - [-19.8]) points in the cage with plate group (p=.007). A lower rate of hoarseness postoperatively was reported by the cage only group (OR: 0.65 [0.45-0.93], p=.026). No differences were seen in other outcomes.

CONCLUSION

Clinical improvement was seen in both groups, but the improvement of NDI was better in the cage with plate group and the rate of hoarseness was lower in the cage only group.

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.

Construct Failure in Anterior Cervical Discectomy and Fusion: Incidence, Mode, and Time of Failure Within 2 Years

BACKGROUND

Despite progress in surgical approach and instrumentation, the risk of construct failure (CF) in anterior cervical discectomy and fusion (ACDF) remains. This study aims to report the time of failure, mode of failure, and reoperation rates in ACDF CFs.

METHODS

A systematic search was conducted through PubMed, Scopus, Embase, and Cochrane for articles relevant to ACDF CF. After stratifying CF (cage-related or screw-related), Welch's t-test, Mann-Whitney U test, and Levene's test of equal variance compared temporal (minimum endpoint, maximum endpoint, and range of failure) averages and variances. Spearman and Pearson correlation assessed relationships between surgical characteristics and outcomes with temporal characteristics. Multivariate linear regression was conducted evaluating the relationship among cage material, osteoporosis, plated versus standalone ACDF, and single-level versus multilevel ACDF with temporal characteristics.

RESULTS

From the 978 included patients, 132 (13.5%) presented with CF within 2 years, of which 9 (6.8%) required a secondary surgery. Screw-related failures occurred within 18 months, while cage-related failures occurred within 24 months. Compared to screw-related failures, cage-related failures had greater variability in the time range of failure (P = 0.004). Multivariate regression found that polyetheretherketone cages were associated with a later minimum endpoint of failure when compared to bioabsorbable grafts (r = 0.776; P = 0.045) among screw-related failures.

CONCLUSIONS

Among all CF patients, patients with cage-related failures are more likely to occur over a more spread-out time. Spine surgeons should be aware of these trends to determine if continued clinical observation or reoperation is necessary for CFs.

Postoperative complications of anterior cervical discectomy and fusion: A comprehensive systematic review and meta-analysis

Background

Anterior cervical discectomy and fusion (ACDF) is one of the most frequently performed spine procedures for different indications in the cervical spine. Various postoperative complications have been reported following the ACDF. This systematic review and meta-analysis aimed to calculate the incidence rate of different postoperative complications associated with ACDF surgery and also identify underlying risk factors for each complication.

Methods

A systematic review of the literature was performed in PubMed/MEDLINE, Embase, and the Cochrane Library for observational studies published between January 1996 and March 2023 and reporting postoperative complications associated with ACDF. Randomized controlled trials and interventional investigations were not included in this study. Meta-regression was also performed using generalized linear mixed models with a binomial probability distribution on various potential predicting factors.

Results

A total of 222 studies reporting the rate of complications associated with ACDF in 50,584 patients were included in the present study. The overall postoperative complication rate was 16%. The most common complications were excessive neck swelling (11.3%), pseudarthrosis (10.0%), dysphagia (9.5%), cage/graft subsidence (9.4%), worsening myelopathy (7.7%), and hoarseness (2.3%). The rate of nonhome discharge, readmission, and mortality were 13.8%, 3.7%, and 0.1% respectively. Based on meta-regression, more levels of fusion and increased age were significantly associated with an increase in the pooled overall postoperative complication rate. Moreover, the rate of some postoperative complications was significantly associated with a number of perioperative characteristics.

Conclusions

To our knowledge, this study has been the most extensive meta-analysis conducted on the existing literature regarding ACDF-related complications and potential risk factors. However, future high-quality prospective studies or clinical trials are highly required to provide further evidence and also validate the present findings.

Treatment of multilevel cervical disc disease with standalone cervical cages with or without anterior plating: A prospective randomized comparative study

Purpose

The purpose of the study was to compare the results of anterior cervical discectomy and fusion (ACDF) using standalone cages versus cages with anterior plating for multilevel cervical disc disease with a 2-year follow-up.

Background

ACDF is a commonly performed procedure in cases of neural compression caused by osteophytes or disc material. Some spine surgeons have reported unsatisfactory outcomes and fusion rates secondary to a high rate of cage subsidence and pseudoarthrosis. Internal fixation using anterior cervical plate has been developed as an adjunct to ACDF to enhance the stability provided by the intervertebral cages.

Patients and Methods

A total number of 60 consecutive patients diagnosed with multilevel cervical disc disease (two or more) underwent ACDF with or without additional anterior plating, between August 2021 and March 2022. Only 50 patients completed the follow-up which was ranged from 20 to 26 months.

Results

There were no significant differences between the two groups regarding age and sex. Comparing the pre and postoperative Visual Analog Scale (VAS) for both neck pain and brachialgia and neck disability index (NDI) in both groups was statistically significant. There was no significant statistical difference between the two groups regarding the postoperative clinical outcomes. There was a significant statistical difference in the fused segment lordotic angle (FSA) being greater in the plating group.

Conclusion

The use of stand-alone cages in two-level ACDF or more in our study had a shorter operative time and hospital stay when compared to ACDF with anterior plating with greater FSA in the plate group but with no difference in clinical outcome after 2-year follow-up.

Positive Cutibacterium acnes Intervertebral Discs Are Not Associated with Subsidence Following Anterior Cervical Discectomy and Fusion at 3 or 6 Months

Background/Objectives:Cutibacterium acnes (C. acnes), formerly known as Propionibacterium acnes (P. acnes), is an anaerobic, low-virulent bacterium that has been associated with postoperative infections of the shoulder, knee, and cervical spine. Recent studies have highlighted an association between C. acnes and the development of degenerative disc disease (DDD). The aim of this study is to ascertain whether C. acnes increases the risk of subsidence following anterior cervical discectomy and fusion (ACDF). Methods: After IRB approval, consecutive patients undergoing elective ACDF for DDD from 2017 to 2018 were enrolled in this prospective cohort study. Intervertebral disc samples were taken at each affected level and cultured. A total of 66 patients with radiographic follow-ups were included in the final analysis. The extent of subsidence and cervical lordosis was determined immediately postoperatively and at the 3- and 6-month follow-ups. Results: No significant difference in subsidence was observed at 3 months (p = 0.07) or 6 months (p = 0.11) between culture-positive and -negative cohorts. Additionally, there was no significant difference detected in the change in cervical lordosis observed at 3 months (p = 0.16) or 6 months (p = 0.27) between culture-positive and -negative cohorts. For the most inferiorly fused segment, there was a significant difference in subsidence observed at 3 months (1.5 mm, 95% CI: 0.2-2.7 mm, p = 0.02) but not at 6 months (p = 0.17). Conclusions: Intervertebral discs with a positive C. acnes culture were not associated with greater levels of subsidence at 3 or 6 months following ACDF for DDD. Further research is necessary to endorse these results and to gauge the clinical significance of C. acnes infection.

The Role of Osteobiologics in Augmenting Spine Fusion in Unplated Anterior Cervical Discectomy and Fusion Compared to Plated Constructs: A Systematic Review and Meta-analysis

STUDY DESIGN

Systematic review and meta-analysis.

OBJECTIVE

To compare clinical and radiographic outcomes as well as complications of unplated vs plated anterior cervical discectomy and fusion (ACDF) surgery considering the role of osteobiologics in single- and multi-level procedures.

METHODS

A systematic search of PubMed/MEDLINE, Scopus, CINAHL, EMBASE, CENTRAL, Cochrane and ClinicalTrials.gov databases was performed. Briefly, we sought to identify studies comparing unplated vs. plated ACDF for cervical degenerative disc disease reporting the use of osteobiologics in terms of clinical outcomes, radiographic fusion, and complications. Data on study population, follow-up time, type of cage and plate used, type of osteobiologic employed, number of levels treated, patient-reported outcomes (PROs), radiographic outcomes and complications were collected and compared. Relevant information was pooled for meta-analyses.

RESULTS

Thirty-eight studies met the inclusion criteria. No significant difference was found in terms of clinical outcomes between groups. Unplated ACDF was characterized by reduced blood loss, operation time and length of hospital stay. Fusion was achieved by the majority of patients in both groups, with no evidence of any specific contribution depending on the osteobiologics used. Dysphagia was more commonly associated with anterior plating, while cage subsidence prevailed in the unplated group.

CONCLUSION

Unplated and plated ACDF seem to provide similar outcomes irrespective of the osteobiologic used, with minor differences with doubtful clinical significance. However, the heterogeneity and high risk of bias affecting included studies markedly prevent significant conclusions.

Anterior Cervical Discectomy and Fusion With Structural Allograft is Associated With Lower Postoperative Health Care Utilization and Reoperations Compared With Cage Implants

BACKGROUND AND OBJECTIVES

Implants represent a large component of surgical cost, with several available options for anterior cervical discectomy and fusion (ACDF). Rising ACDF volume highlights the need for accurate cost characterization among implant configurations to inform efficient utilization.

METHODS

A cohort study of patients who underwent 1-level or 2-level ACDF in 2017 was conducted using the MarketScan national insurance databases, which contain deidentified clinical and financial data. Implant configurations included plate with cage, standalone cage, and plate with structural allograft. Patients who switched insurance providers within 2 years after surgery or underwent concurrent posterior cervical surgery, cervical disk arthroplasty, or cervical corpectomy were excluded. A combined plate/cage and standalone cage group was compared with the allograft group followed by the comparison of the plate/cage and standalone cage groups. In total, 30-day, 90-day, and 2-year aggregate costs; component costs of physical therapy, injections, medications, psychological treatment, and subsequent spine surgery; and reoperation rates were evaluated.

RESULTS

Of 1723 patients identified, 360 (20.9%) underwent surgery with plate/cage, 184 (10.7%) with standalone cage, and 1179 (68.4%) with allograft. Aggregate costs were lower in the allograft group compared with the combined cage group at 90 days ($36 428 vs $39 875, P = .04) and 2 years ($64 951 vs $74 965, P = .005) postoperatively. There were no significant differences in aggregate costs between the plate/cage and standalone cage groups. The 2-year reoperation rate was higher in the combined cage compared with the allograft group (23.9% vs 10.9%, P < .001) and was also higher in the standalone cage compared with the plate/cage group (32.0% vs 19.7%, P = .002).

CONCLUSION

Compared with alternative ACDF constructs, allograft is associated with lower postoperative costs and reoperation rates. Although costs are similar, reoperation rates are lower with plate/cage constructs compared with those of standalone cages. Surgeons should consider these financial and clinical differences when selecting implant configurations.

Comparing zero-profile and conventional cage and plate in anterior cervical discectomy and fusion using finite-element modeling

Conventional cage and plate (CCP) implants usually used in ACDF surgery, do have limitations such as the development of postoperative dysphagia, adjacent segment degeneration, and soft tissue injury. To reduce the risk of these complications, zero-profile stand-alone cage were developed. We used finite-element modeling to compare the total von Mises stress applied to the bone, disc, endplate, cage and screw when using CCP and ZPSC implants. A 3-dimensional FE (Finite element) analysis was performed to investigate the effects of the CCP implant and ZPSC on the C3 ~ T1 vertebrae. We confirmed that the maximum von Mises stress applied with ZPSC implants was more than 2 times greater in the endplate than that applied with CCP implants. The 3D analysis of the ZPSC model von Mises stress measurements of screw shows areas of higher stress in red. Although using ZPSC implants in ACDF reduces CCP implant-related sequalae such as dysphagia, we have shown that greater von Mises stress is applied to the endplate, and screw when using ZPSC implants. This may explain the higher subsidence rate associated with ZPSC implant use in ACDF. When selecting an implant in ACDF, surgeons should consider patient characteristics and the advantages and disadvantages of each implant type.

The influence of over-distraction on biomechanical response of cervical spine post anterior interbody fusion: a comprehensive finite element study

Introduction: Anterior cervical discectomy and fusion (ACDF) has been considered as the gold standard surgical treatment for cervical degenerative pathologies. Some surgeons tend to use larger-sized interbody cages during ACDF to restore the index intervertebral disc height, hence, this study evaluated the effect of larger-sized interbody cages on the cervical spine with ACDF under both static and cyclic loading. Method: Twenty pre-operative personalized poro-hyperelastic finite element (FE) models were developed. ACDF post-operative models were then constructed and four clinical scenarios (i.e., 1) No-distraction; 2) 1 mm distraction; 3) 2 mm distraction; and 4) 3 mm distraction) were predicted for each patient. The biomechanical responses at adjacent spinal levels were studied subject to static and cyclic loading. Non-parametric Friedman statistical comparative tests were performed and the p values less than 0.05 were reflected as significant. Results: The calculated intersegmental range of motion (ROM) and intradiscal pressure (IDP) from 20 pre-operative FE models were within the overall ranges compared to the available data from literature. Under static loading, greater ROM, IDP, facet joint force (FJF) values were detected post ACDF, as compared with pre-op. Over-distraction induced significantly higher IDP and FJF in both upper and lower adjacent levels in extension. Higher annulus fibrosus stress and strain values, and increased disc height and fluid loss at the adjacent levels were observed in ACDF group which significantly increased for over-distraction groups. Discussion: it was concluded that using larger-sized interbody cages (the height of ≥2 mm of the index disc height) can result in remarkable variations in biomechanical responses of adjacent levels, which may indicate as risk factor for adjacent segment disease. The results of this comprehensive FE investigation using personalized modeling technique highlight the importance of selecting the appropriate height of interbody cage in ACDF surgery.

The Effects of the Use of Single-Screw Plates (Univertebral Screw Plates) versus Double-Screw Plates (Bivertebral Screw Plates) on Fusion After One-Level or Two-Level Anterior Cervical Discectomy and Fusion

OBJECTIVE

In this study, we aimed to retrospectively analyze the effects of the use of univertebral screw plates (USPs) and bivertebral screw plates (BSPs) on fusion in patients who underwent anterior cervical discectomy and fusion (ACDF).

METHODS

Forty-two patients who were treated with USPs or BSPs after 1-level or 2-level ACDF and had a minimum follow-up period of 2 years were included in the study. Fusion and the global cervical lordosis angle were evaluated using direct radiographs and computed tomography images of the patients. The clinical outcomes were assessed using the Neck Disability Index and visual analog scale.

RESULTS

Seventeen patients were treated using USPs and 25 patients using BSPs. Fusion was achieved in all patients who underwent BSP fixation (1-level ACDF, 15 patients; 2-level ACDF, 10 patients) and 16 of the 17 patients who underwent USP fixation (1-level ACDF, 11 patients; 2-level ACDF, 6 patients). The plate of the patient with fixation failure had to be removed because it was symptomatic. A statistically significant improvement was observed in the immediate postoperative period and at the last follow-up in terms of global cervical lordosis angle, visual analog scale score, and Neck Disability Index of all patients who underwent 1-level or 2-level ACDF surgery (P < 0.05) CONCLUSIONS: Although USPs are less costly and easier to implant, the effect of USPs and BSPs on fusion and clinical outcomes is similar. Thus, surgeons may prefer to use USPs after 1-level or 2-level ACDF.

Thorough Comparative Analysis of Stand-Alone Cage and Anterior Cervical Plate for Anterior Cervical Discectomy and Fusion in the Treatment of Cervical Degenerative Disease: A Systematic Review and Meta-Analysis

In this systematic review and meta-analysis, we aim to thoroughly describe and objectively compare the efficacy of anterior cervical plate (ACP) and stand-alone cage (SAC). Although recognized as an effective procedure for cervical degenerative disease (CDD), a debate between the methods of anterior cervical discectomy and fusion exists. ACP provides stability to the fusion construct; however, some complications have been reported, such as dysphagia, adjacent disc disease, and soft tissue injury. To overcome these complications, a SAC was later introduced. A systematic search was conducted on the basis of PRISMA (preferred reporting items for systematic reviews and meta-analyses) guidelines to identify relevant studies through PubMed, Google Scholar, and Cochrane database. A total of 14 studies (960 patients) were included in the meta-analysis. Twenty outcomes were clinically and radiologically compared between the two procedures. ACP and SAC were comparable in terms of dysphasia rate, loss of segmental angle, loss of disc height, the Odom criteria, Robinson's criteria, hospital stay, Japanese Orthopaedic Association score, Neck Disability Index, Visual Analog Scale, and fusion time. However, SAC was superior in terms of shorter operation time, less blood loss, lower dysphagia rate, and lower rate of adjacent level disease, whereas ACP was advantageous in terms of lower subsidence rate, better maintenance of the cervical global and segmental angles and disc height, and higher fusion rate. Both procedures can be used in patients with CDD, although it might be more beneficial to choose ACP in patients with multi-level pathologies, wherein better mechanical stability is provided. However, SAC may be more beneficial to use in patients with comorbidities, anemia, or swelling problems because it offers lower complication rates.

Effects of Anterior Plating on Achieving Clinically Meaningful Improvement Following Single-Level Anterior Cervical Discectomy and Fusion

Objective

The clinical utility of anterior cervical plating for anterior cervical discectomy and fusion (ACDF) procedures remains controversial. This study aims to compare the impact of cervical plating on achievement of minimum clinically important difference (MCID) up to 2 years following ACDF.

Methods

Patients undergoing primary, single-level ACDF procedures were grouped based on whether their procedure included application of an anterior cervical plate. Demographics, preoperative spinal diagnoses, operative characteristics, and patient-reported outcome measures (PROMs) were compared between plating groups. Achievement of an MCID was assessed using the following previously established thresholds: 12-item Short Form health survey physical component summary (SF-12 PCS) 8.1, visual analogue scale (VAS) neck 2.6, VAS arm 4.1, Neck Disability Index (NDI) 8.5. Rates of MCID achievement were compared between groups.

Results

The cohort included 192 patients of whom 102 received plating and 90 received no plating. Plating status was significantly associated with Charlson Comorbidity Index and insurance status. Operative duration and estimated blood loss were significantly greater for the plating group. Both groups demonstrated significant improvements at the majority of postoperative timepoints. Significant intergroup differences in PROM improvement were demonstrated for VAS neck and NDI at 6 weeks. Rates of MCID achievement differed significantly between groups for NDI at 6 weeks, and 12 weeks, and SF-12 PCS overall.

Conclusion

Patients improved significantly in terms of pain, disability and physical function, regardless of plating status, and with the exception of early neck pain and disability, these improvements were similar between groups. Patients that underwent plating as part of their ACDF procedure achieved an MCID for physical function at lower rates overall.

Comparison of Clinical and Radiographic Outcomes After Standalone Versus Cage and Plate Constructs for Anterior Cervical Discectomy and Fusion

BACKGROUND

Anterior cervical discectomy and fusion (ACDF) has conventionally been performed using an allograft cage with a plate-and-screw construct. Recently, standalone cages have gained popularity due to theorized decreases in operative time and postoperative dysphagia. Few studies have compared these outcomes. Here, we directly compare the outcomes of plated versus standalone ACDF constructs.

METHODS

A single-center retrospective review of patients undergoing ACDF after June 2011 with at least 6 months of follow up was conducted. Clinical outcomes were analyzed and compared between standalone and plated constructs. Multivariate regression analysis of the primary outcome, need for revision surgery, as well as several secondary outcomes, procedure duration, estimated blood loss (EBL), length of hospital stay, disposition, and incidence of dysphagia, hoarseness, or surgical site infection, was completed.

RESULTS

A total of 321 patients underwent ACDF and met inclusion-exclusion criteria, with mean follow-up duration of 20 months. Forty-six (14.3%) patients received standalone constructs, while 275 (85.7%) received plated constructs. Fourteen (4.4%) total revisions were necessary, 4 in the standalone group and 10 in the plated group, yielding revision rates of 8.7% and 3.6%, respectively (P = .125). Mean EBL was 98 mL in the standalone group and 63 mL in the plated group (P = .001). Mean procedure duration was 147 minutes in the standalone group and 151 minutes in the plated group (P = .800). Mean hospital stay was 3.6 days in the standalone group and 2.5 days in the plated group (P = .270). There was no significant difference in incidence of dysphagia (P = .700) or hoarseness (P = .700).

CONCLUSIONS

Standalone ACDF demonstrates higher, but not statistically significant, revision rates than plate-and-screw constructs, without the hypothesized decreased incidence of dysphagia or hoarseness and without decreased procedure duration or EBL. Surgeons may consider limiting use of these constructs to cases of adjacent segment disease. Larger studies with longer follow up are necessary to make more definitive conclusions.

LEVEL OF EVIDENCE

4.

CLINICAL RELEVANCE

This study will help spine surgeons decide between using standalone or cage-and-plate constructs for ACDF.

Adjacent-Level Ossification Development in Single-Level Standalone Anterior Cervical Discectomy and Fusion Versus Anterior Cervical Discectomy and Fusion With Plate

STUDY DESIGN

Retrospective case control study.

OBJECTIVES

Adjacent-level ossification development (ALOD) is a distinct form of adjacent segmental degeneration that has been recognized to occur after anterior cervical discectomy and fusion (ACDF). It is unclear whether ACDF with plate versus standalone has an effect on rates of ALOD. This retrospective case-control study aims to assess the rate of ALOD in a large series of patients undergoing ACDF with and without plate and factors causing ALOD.

METHODS

Data was collected for patients undergoing ACDF from January 2009 to July 2016. Data collected was from multiple centers and included demographic data, surgical data, radiological imaging at time of surgery, and serial follow-up imaging. The radiology for ALOD was independently reviewed. Cohorts were divided into ACDF with plate (Group P = plate) and ACDF without plate (Groups S = standalone) and outcomes were compared.

RESULTS

There were 260 patients with 138 (53%) in Group P and 122 (47%) in Group S. ALOD was observed in 15.3% of patients overall, 29% in group P and 2.8% in group S (P < .001). Following multivariate adjustment, statistically significant association was found between use of plate and ALOD (odds ratio = 12.8, 95% confidence interval = 3.52-45.45, P < .001). Plate-to-disc distance <5 mm was significantly associated with ALOD (odds ratio = 13.5, 95% confidence interval = 3.83-47.62, P < .001).

CONCLUSION

The use of anterior plate with ACDF was associated with ALOD. Plate-to-disc distance <5 mm was significantly associated with ALOD even after adjustment for confounding factors. We conclude utilization of standalone cages or cages with plate with more than 5 mm distance from adjacent disc to minimize ALOD.

Long-term Outcome Following Three-Level Stand-Alone Anterior Cervical Discectomy and Fusion: Is Plating Necessary?

Background:

Anterior cervical discectomy with fusion (ACDF) is a proven method for the treatment of selected patients. The necessity of use of an anterior plate is controversial. The article aims to assess the fusion rates (FRs) and long-term outcomes following three-level ACDF.

Materials and Methods:

Data were collected from the medical records of patients operated on due to degenerative cervical disease. All patients were treated with three-level ACDF employing polyether ether-ketone cages without anterior plating. Visual analog scale (VAS), neck disability index (NDI), and plain radiographs were used in the clinical and radiological postsurgery assessment. Fusion evaluation was performed according to the <1 mm motion between spinous processes rule. Subsidence was defined as a more than 2 mm decrease in the interbody height.

Results:

A total of 234 treated levels on 78 patients were assessed. The mean presurgery NDI score was 23.07 ± 4.86, with a mean disability of 46.03% ± 9.64. The mean presurgery VAS score of the neck was 7.58 ± 0.85, while VAS score of the arm was 7.75 ± 1.008. Post surgery, NDI stated no disability, while VAS score of the neck and arm showed no presence of pain. The mean FR was 19.50 ± 21.71 levels per month, with a peak from 3^rd to 6^th month. Presurgery evaluation showed 12 (15.38%) patients with a high T2 sequence signal. Magnetic resonance imaging screening detected 31 (39.24%) patients with coexisting cervical and lumbar findings. Post surgery, transient dysphagia was reported by 1 patient (1.28%), while subsidence was registered in 15 (6.41%) levels, situated in 12 patients (15.38%), most often at C_6-7 (66.6%). Clinical and radiological follow-up extended to 69.47 ± 11.45 months.

Conclusion:

Multilevel stand-alone ACDF is a safe, cost-effective procedure providing favorable clinical and radiological results with minimal complications. The incidence of subsidence is usually clinically insignificant and can be decreased with a careful surgical technique.

Incidence of Subsidence of Seven Intervertebral Devices in Anterior Cervical Discectomy and Fusion: A Network Meta-Analysis

BACKGROUND

Subsidence is an incapacitating complication in anterior cervical discectomy and fusion (ACDF). However, the debate over which of the intervertebral devices is associated with lower incidence of subsidence remains to be settled.

METHODS

Seven dominant techniques comprising cage with plate (CP), iliac bone graft with plate (IP), Zero-profile cage with screws (Zero-P), ROI-C cages with clips (ROI-C), polyether ether ketone cage alone (PCA), iliac crest autogenous graft (ICAG), and titanium cage alone (TCA) were examined. The incidences of subsidence in the different groups were calculated and compared.

RESULTS

A total of 30 studies with 2264 patients were identified. Overall, the CP group presented the lowest incidence of subsidence, and its incidence was significantly lower than that in the Zero-P group, the PCA group, the ICAG group, and the TCA group (P < 0.05). The incidence of subsidence in the IP group was significantly lower than that in the PCA group, the ICAG group, and the TCA group (P < 0.05). In single-level ACDF, the CP group presented the lowest incidence of subsidence, and its incidence was significantly lower than that in the PCA group and the TCA group (P < 0.05). No difference was found between single-level and multilevel ACDF and the incidence of subsidence was higher in those undergoing single-level ACDF.

CONCLUSIONS

CP and IP resulted in a lower rate of subsidence than cage alone or ICAG. Zero-P and ROI-C cages led to similar subsidence rates with plate. All types of intervertebral device can be applied to both single-level and multilevel ACDF with comparable subsidence rate.

The outcomes of stand alone polyetheretherketone cages in anterior cervical discectomy and fusion

The procedure of anterior cervical discectomy and fusion is considered as the treatment of choice in degenerative disc disease, which material provides the best clinical and radiological fusion and other outcomes remains heavily debated. Materials that augment the process of fusion consist of bone grafting, titanium, polyetheretherketone (PEEK), or carbon cages. The application of PEEK cages has been recommended as it is radiolucent, and it has a modulus of elasticity that is similar to cortical bone. PEEK cages can be either filled with various materials or unfilled cages. Filled PEEK cages can include bone autografts, bone allografts, demineralized bone matrix, and other materials that facilitate fusion. This narrative review highlights that standalone filled PEEK cages were likely to have better radiological outcomes and satisfactory clinical outcomes for myelopathy when compared with standalone unfilled PEEK cages.

Does zero-profile anchored cage accompanied by a higher postoperative subsidence compared with cage-plate construct? A meta-analysis

Background

The zero-profile anchored cage (ZP) has been widely used for its lower occurrence of dysphagia. However, it is still controversial whether it has the same stability as the cage-plate construct (CP) and increases the incidence of postoperative subsidence. We compared the rate of subsidence after anterior cervical discectomy and fusion (ACDF) with ZP and CP to determine whether the zero-profile device had a higher subsidence rate.

Methods

We performed a meta-analysis of studies that compared the subsidence rates of ZP and CP. An extensive and systematic search covered the PubMed and Embase databases according to the PRISMA guidelines and identified ten articles that satisfied our inclusion criteria. Relevant clinical and radiological data were extracted and analyzed by the RevMan 5.3 software.

Results

Ten trials involving 626 patients were included in this meta-analysis. The incidence of postoperative subsidence in the ZP group was significantly higher than that in the CP group [15.1% (89/588) versus 8.8% (51/581), OR = 1.97 (1.34, 2.89), P = 0.0005]. In the subgroup analysis, we found that the definition of subsidence did not affect the higher subsidence rate in the ZP group. Considering the quantity of operative segments, there was no significant difference in the incidence of subsidence between the two groups after single-level fusion (OR 1.43, 95% CI 0.61–3.37, P = 0.41). However, the subsidence rate of the ZP group was significantly higher than that of the CP group (OR 2.61, 95% CI 1.55–4.40, P = 0.0003) after multilevel (≥ 2-level) procedures. There were no significant differences in intraoperative blood loss, JOA score, NDI score, fusion rate, or cervical alignment in the final follow-up between the two groups. In addition, the CP group had a longer operation time and a higher incidence of dysphagia than the ZP group at each follow-up time.

Conclusion

Based on the limited evidence, we suggest that ZP has a higher risk of postoperative subsidence than CP, although with elevated swallowing discomfort. A high-quality, multicenter randomized controlled trial is required to validate our results in the future.

Comparison of stand-alone cage and cage-with-plate for monosegmental cervical fusion and impact of virtual reality in evaluating surgical results

OBJECTIVES

After ventral decompression of monosegmental cervical spondylotic stenosis, a stand-alone cage (SC) or cage-with-plate (CP) can be inserted for fusion. Postoperative radiological evaluation can be achieved using different imaging modalities. We retrospectively compared complications, as well as clinical and radiological outcomes for both fusion techniques, and analyzed the possible role of virtual reality (VR) in evaluating the postoperative results.

PATIENTS AND METHODS

One hundred seventeen patients were included (SC/CP: 54/63). Complications, as well as clinical and radiological outcomes of both fusion techniques were compared. Computed tomography (CT) scans were visualized via VR to measure the smallest cross-sectional area of the intervertebral neuroforamen in the lateral resection region, and to assess the degree of the intersegmental ossification.

RESULTS

There were no significant differences between the two fusion techniques regarding perioperative complication rates, fusion rates, or pain parameter (visual analogue scale (VAS) of arm pain, neck disability index). However, advantages regarding subsidence, kyphosis, and VAS of neck pain were found when using the CP versus SC. Using the VR technique, there was no significant difference between the two fusion techniques in the mean size of the cross-sectional area at the end of follow-up.

CONCLUSION

Due to the long-term advantages of CP fusion, we prefer a monosegmental cervical spinal fusion using CP. Reconstruction of postsurgical two-dimensional CT images into three-dimensional images, and the spatial and anatomical presentation in VR models, improved the evaluation of these postoperative results.

Stand-Alone Cervical Cages in 2-Level Anterior Interbody Fusion in Cervical Spondylotic Myelopathy: Results from a Minimum 2-Year Follow-up

Study Design

A retrospective review of patients who underwent 2-level anterior cervical discectomy and fusion (ACDF) with standalone polyetheretherketone (PEEK) cages for cervical spondylotic myelopathy (CSM).

Purpose

To evaluate the efficacy of stand-alone PEEK cage in 2-level cervical interbody fusion for CSM.

Overview of Literature

ACDF is a standard surgical procedure to treat degenerative disc disease. However, the use of additional anterior plating for 2-level ACDF remains controversial.

Methods

We reviewed outcomes of patients who underwent 2-level ACDF with stand-alone PEEK cages for CSM over a 7-year period (2007–2015) in a regional hospital. Japanese Orthopaedic Association (JOA) score, fusion rate, subsidence rate, cage migration, and cervical alignment by the C2–7 angle as well as the local segmental angle (LSA) of the cervical spine were assessed.

Results

In total, 31 patients (mean age, 59 years; range, 36–87 years) underwent 2-level ACDF with a cage-only construct procedure between 2007 and 2015. The minimum follow-up was 24 months; mean follow-up was 51 months. C3–5 fusion was performed in 45%, C4–6 fusion in 32%, and C5–7 fusion in 23%. Mean JOA score improved from 10.1±2.2 to 13.9±2.1 (p<0.01) at the 24-month follow-up. Fusion was achieved in all patients. Subsidence occurred in 22.5% of the cages but was not associated with differences in JOA scores, age, sex, or levels fused. Lordosis of the C2–7 angle and LSA increased after surgery, which were maintained for up to 1 year but subsequently disappeared after 2 years, yet the difference was not statistically significant. No cage migration was noted; two patients developed adjacent segment disease requiring posterior laminoplasty 3 years after ACDF.

Conclusions

The use of a stand-alone PEEK cage in a 2-level cervical interbody fusion achieves satisfactory improvements in both clinical outcomes and fusion.

Comparison of the outcomes of cage-stand-alone with cage-with-plate fixation in one level and two levels for treating cervical disk diseases

Introduction:

Anterior cervical discectomy and fusion (ACDF) surgery is an accepted method for many spinal cord abnormalities. The purpose of this study was to evaluate the outcomes of treating patients with spinal cord lesions at one level or two levels through ACDF with cage-stand-alone (ACDF-CA) and ACDF with cage-with-plate fixation (ACDF-CP) surgery and comparing these results with each other.

Methods:

In this prospective, cross-sectional, descriptive study, eighty patients undergoing ACDF surgery were enrolled according to the inclusion and exclusion criteria. Demographic data, before and after surgery findings, and clinical symptoms were investigated. Data were collected by means of visual analog scale (VAS) and Neck Disability Index (NDI) questionnaires. The adverse effects and surgical outcomes were evaluated based on Odom's criteria and patients’ satisfaction. The collected data of the groups were then compared and assessed.

Results:

There was no significant difference between the groups in regards of gender, age, duration of surgery to visit, surgical level, preoperative and postoperative VAS and cervical range of motion, preoperative NDI, results based on Odom's criteria, and satisfaction of patients (P > 0.05). The VAS, NDI, and range of motion scores were significantly reduced in the four groups after the operation compared to the preoperative stage. Postoperative NDI scores in the ACDF-CA group at one level were significantly lower than other groups (P < 0.05).

Conclusion:

Both of the methods revealed acceptable outcomes in comparison to the preoperative stage, and despite some minor differences, there are generally no significant differences in outcomes and complications.

Clinical outcomes of locking stand-alone cage versus anterior plate construct in two-level anterior cervical discectomy and fusion: a systematic review and meta-analysis

BACKGROUND

Two-level cervical degenerative disc disease (cDDD) can be effectively treated by anterior cervical discectomy and fusion (ACDF) similarly to single-level cDDD. Traditionally an anterior plate construct (APC) approach has been utilized, but ACDF without plate with a locking stand-alone cage (LSC) approach has emerged as an alternative option. The aim of this study was to compare the clinical outcome of LSC and APC in contiguous two-level ACDF used to treat cDDD the current literature.

METHODS

Searches of seven electronic databases from inception to March 2018 were conducted following preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Extracted data were analysed using meta-analysis of proportions.

RESULTS

The nine observational studies that satisfied all criteria described a pooled cohort of 687 contiguous two-level cDDD cases managed by ACDF, with 302 (44%) and 385 (56%) managed by LSC and APC approaches, respectively. When compared with APC, LSC was associated with significantly increased subsidence likelihood (OR 2.75; p < 0.001), greater disc height (MD 0.60 mm; p = 0.04) and reduced cervical lordosis (MD - 2.52°; p = 0.04) at last follow-up. Operative outcomes, fusion rates, functional scores and postoperative dysphagia rates were comparable.

CONCLUSION

Although significant radiological differences were most evident, the comparability between LSC and APC in contiguous two-level ACDF with respect to all other clinical outcomes does not implicate one approach as clearly superior to the other in two-level ACDF. Larger, randomized studies with longer follow-up are required to delineate outcomes further to validate the findings of this study. These slides can be retrieved under Electronic Supplementary Material.