The fusion rates at different times of cortical iliac crest autograft or allograft compared with cages after anterior cervical discectomy and fusion: a meta-analysis.

OBJECTIVE: The cortical iliac crest autograft (CICA)/structural allograft (SA) has still been recognized as the gold standard for the ACDF technique for its high degree of histocompatibility and osteoinduction ability though the flourishing and evolving cage development. However, there was no further indication for using CICA/SA in ACDF based on basic information of inpatients. Our operative experience implied that applying CICA/SA has an advantage on faster fusion but not the long-term fusion rate. Therefore, our study aimed to compare the fusion rates between CICA and cage, between SA and cage, and between CICA/CA and cage. METHODS: Based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), a comprehensive literature search of electronic databases including PubMed, Embase, Cochrane Library and Web of Science was conducted to identify these clinical trials that investigated the postoperative 3, 6, 12 and 24 months fusion rates of CICA/structural SA versus cage. Assessment of risk of bias, data extraction and statistical analysis were then carried out by two independent authors with the resolve-by-consensus method. The primary outcome was fusion rate at 3, 6, 12 and 24 months postoperatively. The secondary outcomes were also meta-analyzed such as hardware complications, operative duration and hospitalization time. Our meta-analysis was registered with PROSPERO (Identifier: CRD42022345247). RESULT: A total of 3451 segments (2398 patients) derived from 34 studies were included after the screening of 3366 articles. The segmental fusion rates of CICA were higher than cages at 3 (P = 0.184, I2 = 40.9%) and 6 (P = 0.147, I2 = 38.8%) months postoperatively, but not 12 (P = 0.988, I2 = 0.0%) and 24 (P = 0.055, I2 = 65.6%) months postoperatively. And there was no significant difference in segmental fusion rates between SA and cage at none of 3 (P = 0.047, I2 = 62.2%), 6 (P = 0.179, I2 = 41.9%) and 12 (P = 0.049, I2 = 58.0%) months after operations. As for secondary outcomes, the CICA was inferior to cages in terms of hardware complications, operative time, blood loss, hospitalization time, interbody height, disk height and Odom rating. The hardware complication of using SA was significantly higher than the cage, but not the hospitalization time, disk height, NDI and Odom rating. CONCLUSION: Applying CICA has an advantage on faster fusion than using a cage but not the long-term fusion rate in ACDF. Future high-quality RCTs regarding the hardware complications between CICA and cage in younger patients are warranted for the deduced indication.

Could the different surgical goals of fusion and non-fusion also be achieved in combination within the same patient? Clinical and radiological outcome of hybrid cervical spine surgery.

PURPOSE: Hybrid cervical spine surgery (HS) is a novel surgical strategy wherein an artificial disc replacement is done with a cervical fusion nearby with a stand-alone titanium cage to combine the advantages in both procedures. The aim of this study was to evaluate interactions of these devices within the same patient, and to analyze, if the different goal of each implant is accomplished. METHODS: Thirty-six patients were treated surgically within a non-randomized retrospective study framework with HS. Patients were examined preoperatively followed by clinical and radiological examination at least one year postoperative. Clinical outcome was detected with NDI, VAS arm/neck, pain self-assessment questionnaires and subjective patient satisfaction. Radiological assessments included RoM, segmental lordosis, cervical lordosis of C2-C7, subsidence, ap-migration and heterotopic ossifications (HO) at the cTDR levels. RESULTS: Statistically significant improvement of all clinical scores was observed (NDI 37.5 to 5.76; VASarm 6.41 to 0.69; VASneck 6.78 to 1.48). Adequate RoM was achieved at cTDR levels. RoM in the ACDF levels was reduced statistically significant (p < 0.001), and solid fusion (> 2°) was achieved in all evaluated fusion level. Global lordosis (C2-C7) increased statistically significant (2.4° to 8.1°). Subsidence and HO at the cTDR levels did not occur. CONCLUSIONS: HS results in preservation of the segmental motion in the cTDR and fast and solid fusion in the cage cohort simultaneously. Patient safety was proven. In carefully selected cases, HS is a safe and viable treatment option by choosing the right "philosophy" level per level.

Relationship between intervertebral disc height and post operative dysphagia secondary to single-level anterior cervical discectomy and fusion- a retrospective study.

BACKGROUND: One goal of Anterior Cervical Discectomy and Fusion (ACDF) is to restore the loss of intervertebral disc height (IDH) results from the degenerative process. However, the effects of IDH on postoperative dysphagia after ACDF remain unclear. METHODS: Based on the results of a one-year telephone follow-up, A total of 217 consecutive patients after single-level ACDF were enrolled. They were divided into dysphagia and non-dysphagia groups. The age, BMI, operation time and blood loss of all patients were collected from the medical record system and compared between patients with and without dysphagia. Radiologically, IDH, spinous process distance (SP) of the operated segment, and C2-7 angle (C2-7 A) were measured preoperatively and postoperatively. The relationship between changes in these radiological parameters and the development of dysphagia was analyzed. RESULTS: Sixty-three (29%) cases exhibited postoperative dysphagia. The mean changes in IDH, SP, and C2-7 A were 2.84 mm, -1.54 mm, and 4.82 degrees, respectively. Changes in IDH (P = 0.001) and changes in C2-7 A (P = 0.000) showed significant differences between dysphagia and non-dysphagia patients. Increased IDH and increased C2-7 A (P = 0.037 and 0.003, respectively) significantly and independently influenced the incidence of postoperative dysphagia. When the change in IDH was ≥ 3 mm, the chance of developing postoperative dysphagia for this patient was significantly greater. No significant relationship was observed between the change in spinous process distance (SP) and the incidence of dysphagia. The age, BMI, operation time and blood loss did not significantly influence the incidence of postoperative dysphagia. CONCLUSION: The change in IDH could be regarded as a predictive factor for postoperative dysphagia after single-level ACDF.

Machine learning models on a web application to predict short-term postoperative outcomes following anterior cervical discectomy and fusion.

BACKGROUND: The frequency of anterior cervical discectomy and fusion (ACDF) has increased up to 400% since 2011, underscoring the need to preoperatively anticipate adverse postoperative outcomes given the procedure's expanding use. Our study aims to accomplish two goals: firstly, to develop a suite of explainable machine learning (ML) models capable of predicting adverse postoperative outcomes following ACDF surgery, and secondly, to embed these models in a user-friendly web application, demonstrating their potential utility. METHODS: We utilized data from the National Surgical Quality Improvement Program database to identify patients who underwent ACDF surgery. The outcomes of interest were four short-term postoperative adverse outcomes: prolonged length of stay (LOS), non-home discharges, 30-day readmissions, and major complications. We utilized five ML algorithms - TabPFN, TabNET, XGBoost, LightGBM, and Random Forest - coupled with the Optuna optimization library for hyperparameter tuning. To bolster the interpretability of our models, we employed SHapley Additive exPlanations (SHAP) for evaluating predictor variables' relative importance and used partial dependence plots to illustrate the impact of individual variables on the predictions generated by our top-performing models. We visualized model performance using receiver operating characteristic (ROC) curves and precision-recall curves (PRC). Quantitative metrics calculated were the area under the ROC curve (AUROC), balanced accuracy, weighted area under the PRC (AUPRC), weighted precision, and weighted recall. Models with the highest AUROC values were selected for inclusion in a web application. RESULTS: The analysis included 57,760 patients for prolonged LOS [11.1% with prolonged LOS], 57,780 for non-home discharges [3.3% non-home discharges], 57,790 for 30-day readmissions [2.9% readmitted], and 57,800 for major complications [1.4% with major complications]. The top-performing models, which were the ones built with the Random Forest algorithm, yielded mean AUROCs of 0.776, 0.846, 0.775, and 0.747 for predicting prolonged LOS, non-home discharges, readmissions, and complications, respectively. CONCLUSIONS: Our study employs advanced ML methodologies to enhance the prediction of adverse postoperative outcomes following ACDF. We designed an accessible web application to integrate these models into clinical practice. Our findings affirm that ML tools serve as vital supplements in risk stratification, facilitating the prediction of diverse outcomes and enhancing patient counseling for ACDF.

Safety of anterior cervical corpectomy and fusion (ACCF) for the treatment of subaxial cervical spine injuries, a single center comparative matched analysis.

INTRODUCTION: Anterior Cervical Discectomy and Fusion (ACDF) and Anterior Cervical Corpectomy and Fusion (ACCF) are both common surgical procedures in the management of pathologies of the subaxial cervical spine. While recent reviews have demonstrated ACCF to provide better decompression results compared to ACDF, the procedure has been associated with increased surgical risks. Nonetheless, the use of ACCF in a traumatic context has been poorly described. The aim of this study was to assess the safety of ACCF as compared to the more commonly performed ACDF. METHODS: All patients undergoing ACCF or ACDF for subaxial cervical spine injuries spanning over 2 disc-spaces and 3 vertebral-levels, between 2006 and 2018, at the study center, were eligible for inclusion. Patients were matched based on age and preoperative ASIA score. RESULTS: After matching, 60 patients were included in the matched analysis, where 30 underwent ACDF and ACCF, respectively. Vertebral body injury was significantly more common in the ACCF group (p = 0.002), while traumatic disc rupture was more frequent in the ACDF group (p = 0.032). There were no statistically significant differences in the rates of surgical complications, including implant failure, wound infection, dysphagia, CSF leakage between the groups (p ≥ 0.05). The rates of revision surgeries (p > 0.999), mortality (p = 0.222), and long-term ASIA scores (p = 0.081) were also similar. CONCLUSION: Results of both unmatched and matched analyses indicate that ACCF has comparable outcomes and no additional risks compared to ACDF. It is thus a safe approach and should be considered for patients with extensive anterior column injury.

Alterations in Swallowing Six Weeks After Primary Anterior Cervical Discectomy and Fusion (ACDF).

This aim of this study is to characterize the nature and pathophysiology of dysphagia after ACDF surgery by precisely and comprehensively capturing within-subject changes on videofluoroscopy between preoperative and postoperative time points. 21 adults undergoing planned primary ACDF procedures were prospectively recruited and enrolled. Participants underwent standardized preoperative and six-week postoperative videofluoroscopic swallow studies. Videos were blindly rated using the Penetration-Aspiration Scale (PAS) and analysis of total pharyngeal residue (%C2-42), swallowing timing, kinematics, and anatomic change was completed. Linear mixed-effects modeling was used to explore the relationships between possible predictor variables and functional outcomes of interest that changed across timepoints. There was no change in PAS scores across timepoints. Total pharyngeal residue (%C2-C42) was increased postoperatively (p < 0.001). Our statistical model revealed significant main effects for timepoint (p = 0.002), maximum pharyngeal constriction area (MPCAN) (p < 0.001), and maximum thickness of posterior pharyngeal (PPWTMAX) (p = 0.004) on the expression of total pharyngeal residue. There were significant two-way interactions for timepoint and MPCAN (p = 0.028), timepoint and PPWTMAX (p = 0.005), and MPCAN and PPWTMAX (p = 0.010). Unsurprisingly, we found a significant three-way interaction between these three predictors (p = 0.027). Our findings suggest that in planned ACDF procedures without known complications, swallowing efficiency is more likely to be impaired than airway protection six weeks after surgery. The manifestation of impaired swallowing efficiency at this timepoint appears to be driven by a complex relationship between reduced pharyngeal constriction and increased prevertebral edema.

The effect of concurrent cervical spine degenerative disease on the outcome of rotator cuff repair: a national database study.

BACKGROUND: Cervical spine degenerative disease (CSD) can cause shoulder pain, potentially confounding the management of patients with rotator cuff tears. This study aimed to investigate the relationships between CSD and rotator cuff repair (RCR). METHODS: A national administrative database (PearlDiver) was used to study 4 patient cohorts: (1) RCR only (RCRo), (2) RCR with concurrent CSD (RCRC), (3) RCR after a cervical spine procedure (RCRA), and (4) RCR before a cervical spine procedure (RCRB). The outcomes of RCR were compared using multivariable logistic regression, controlling for age, sex, and Elixhauser Comorbidity Index, as well as preoperative opioid utilization in the analysis of opioid use. RESULTS: Between 2010 and 2021, a total of 889,977 patients underwent RCR. Of these patients, 784,230 (88%) underwent RCRo whereas 105,747 (12%) underwent RCRC, of whom 21,585 (2.4%) underwent cervical spine procedures (RCRA in 9670 [1.1%] and RCRB in 11,915 [1.3%]). At 2 years after RCR, compared with RCRo patients, RCRC patients had an increased risk of surgical-site infection (adjusted odds ratio [aOR] = 1.25, P = .0004), deep vein thrombosis (aOR = 1.17, P = .0002), respiratory complications (aOR = 1.19, P = .0164), and ipsilateral shoulder reoperations (débridement [aOR = 1.66, P < .0001], manipulation under anesthesia or arthroscopic lysis of adhesions [aOR = 1.23, P < .0001], distal clavicle excision [aOR = 1.78, P < .0001], subacromial decompression [aOR = 1.72, P < .0001], biceps tenodesis [aOR = 1.76, P < .0001], incision and drainage [aOR = 1.34, P = .0020], synovectomy [aOR = 1.48, P = .0136], conversion to shoulder arthroplasty [aOR = 1.62, P < .0001], revision RCR [aOR = 1.77, P < .0001], and subsequent contralateral RCR [aOR = 1.71, P < .0001]). At 2 years, compared with RCRC patients who did not undergo cervical spine procedures, RCRC patients who underwent cervical spine procedures had an increased risk of incision and drainage (aOR = 1.50, P = .0255), conversion to arthroplasty (aOR = 1.40, P < .0001), and revision RCR (aOR = 1.11, P = .0374), as well as a lower risk of contralateral RCR (aOR = 0.89, P = .0469). The sequence of cervical spine procedures did not affect the risk of shoulder reoperations. At 1 year, the risk of opioid use after RCR was less for RCRA patients compared with RCRB patients (aOR = 1.71 [95% confidence interval, 1.61-1.80; P < .0001] vs. aOR = 2.01 [95% confidence interval, 1.92-2.12; P < .0001]). CONCLUSION: Concurrent CSD has significant detrimental effects on RCR outcomes. Patients with concurrent CSD undergoing cervical spine procedures have a greater risk of ipsilateral shoulder reoperations but a decreased risk of contralateral RCR. The risk of prolonged opioid use was lower if RCR followed a cervical spine procedure. Concurrent CSD must be considered and possibly treated to optimize the outcomes of RCR.

How cervical curvature changes after ACAF and ACDF: a radiological retrospective study.

To assess changes in cervical curvature and demonstrate the feasibility of using ACAF technology to restore lordosis, imaging data from patients undergoing multilevel ACAF and ACDF surgeries were retrospectively analyzed. Forty-seven patients receiving multilevel ACAF and ACDF were included in the study. Total cervical curvature and anterior, middle, and posterior column curvature, spinal canal diameter, cervical range of motion, and surgical complications were measured and analyzed by non-parametric or chi-square tests before and after surgery. The Spearman correlation between imaging data was analyzed. Compared with ACDF, the operation time of the ACAF group was longer, the cervical motion was larger, the median and change value of the middle column curvature was larger, and the change value of the posterior column curvature was smaller (P < 0.05). The postoperative differences in cervical lordosis angle, vertebral canal diameter, and middle and posterior column curvature in the ACAF group were significantly greater than those in the ACDF group (p = 0.015). The expansion of vertebral canal diameter was significantly correlated with the difference in curvature between the middle and posterior columns (r = 0.523, P < 0.01), and the curvature of the anterior column was correlated with that of the middle and posterior columns (P < 0.05). The curvature change of the anterior column is closely related to the curvature change of the middle column and the posterior column. Compared with ACDF, ACAF expands the diameter and volume of the spinal canal by increasing the curvature of the middle column and reducing the anterior movement of the posterior column.

Anterior cervical tunnectomy and fusion (ACTF): a novel technique for cervical canal decompression.

OBJECTIVE: To describe a novel surgical technique note coined as anterior cervical tunnectomy and fusion (ACTF) which applying on removal of posterior vertebral bony protrusions or soft extrusions. METHODS: Total twenty-three patients from January 2016 to January 2021 who experienced with spinal cord compression and performed by ACTF were retrospectively reviewed. Herein, relevant information including patient's gender, age, BMI, intraoperative time, intraoperative blood loss, postoperative complications and postoperative hospitalized stay were collected. Furthermore, JOA and VAS score were both collected. Moreover, imaging parameters were measured and calculated on radiographs. Correlated data were analyzed by t test. Significance was considered when P < 0.05. RESULTS: All patients in this study were validated with favorable outcomes and none of postoperative complications. The Nurick grade of patients dramatically deceased postoperation (P < 0.001). And postoperative VAS score of patients (P < 0.001), as well as JOA score (P < 0.001), was given dramatical significance comparing to preoperation. Furthermore, occupying rate (OR) (P < 0.001) was obviously reduced while space available cord (SAC) (P < 0.001) and diameter of spinal cord (P < 0.001) was significantly increased postoperation. Meanwhile, disc height of involved segment, C2-7 SVA, and C2-C7 Cobb angle were measured on sagittal plane of lateral radiograph. Postoperative disc height of involved segment (P < 0.001) significantly elevated comparing to preoperation. However, there were no significance on C2-7 SVA (P = 0.460) and C2-C7 Cobb angle (P = 0.097). CONCLUSIONS: The novel surgical technique coined by ACTF is a practicable approach during taking charge of bony and soft narrowing behind vertebral space.

Anterior bone loss: A common phenomenon which should be considered as bone remodeling process existed not only in patients underwent cervical disk replacement but also those with anterior cervical diskectomy and fusion.

OBJECTIVE: Anterior bone loss (ABL) was considered as a non-progressive process secondary only to motion-preserving implant and has been noticed recently in cervical disk replacement (CDR) let alone patients with anterior cervical diskectomy and fusion (ACDF). Our purpose is to reveal this unnoticed phenomenon in ACDF and further explore its clinical and radiological outcomes. METHODS: A total of 77 patients underwent ACDF with a minimum follow-up of at least one year were retrospectively reviewed. The average follow-up time was 22.51 ± 16.31 months. There were 50 patients in group A with ABL, while there were 27 patients in group B without ABL. ABL was measured and classified into four grades according to Kieser's methods. Clinical evaluation, radiological parameters and fusion rate were recorded. RESULTS: The incidence of bone ABL was 64.9% of Zero-P and 55.2% of endplates. The incidence of upper and lower endplates was 61% and 49%, respectively, and such difference was not significant. Mild ABL occurred in 22%, moderate ABL in 38% and severe ABL of 40% patients underwent ACDF with ABL. ABL would not affect both clinical outcomes and fusion rate. However, ABL would result in a higher incidence of subsidence. CONCLUSION: ABL should be considered as a common phenomenon that both CDR and ACDF owned a non-progressive process which confined in one year. ABL would result in a higher incidence of subsidence. Luckily, this phenomenon does not have an effect on postoperative clinical and fusion rate.

A scoping review of the methods used to capture dysphagia after anterior cervical discectomy and fusion: the need for a paradigm shift.

OBJECTIVE: Dysphagia is the most commonly reported complication of annterior cervical discectomy and fusion (ACDF) surgery. However, the incidence of dysphagia post-ACDF varies widely-partly attributable to differing outcome measures used to capture dysphagia. Our objective was to conduct a scoping review of the literature to quantify which dysphagia outcome measures have been employed post-ACDF and examine trends by study design, year, and location. METHODS: After removing duplicates, 2396 abstracts were screened for inclusion. A total of 480 studies were eligible for full-text review. After applying exclusion criteria, data was extracted from 280 studies. We extracted the dysphagia outcome measure(s), study design (prospective vs retrospective), year, and location (country). Approximately 10% of studies were repeated for intra-rater agreement. RESULTS: In total, 317 dysphagia outcome measures were reported in 280 studies (primarily retrospective-63%). The largest proportion of outcome measures were categorized as "unvalidated patient-reported outcome measures" (46%), largely driven by use of the popular Bazaz scale. The next most common categories were "insufficient detail" and "validated patient-reported outcome measures" (both 16%) followed by "chart review/database" (13%) and instrumental assessment (7%). Studies examining dysphagia post-ACDF steadily increased over the years and the use of validated measures increased in the past 10 years. CONCLUSIONS: This scoping review of the literature highlights that nearly half of the ACDF dysphagia literature relies on unvalidated patient-reported outcome measures. The current understanding of the mechanism, timeline, and presentation of dysphagia post-ACDF are likely limited due to the metrics that are most commonly reported in the literature.

Adjacent segment mobility after ACDF considering fusion status at the implant insertion site.

PURPOSE: This paper sets out to analyse mobility changes in segments adjacent to the operated segment. Additionally, it investigates the relationship between the degree of fusion in the operated disc space and mobility changes in the adjacent segments. METHODS: In total, 170 disc spaces were operated on in 104 consecutive patients qualified for one- or two-level surgery. The degree of mobility of segments directly above and below the implant insertion site was calculated. Measurements were performed the day before the surgery and 12 months post-surgery. Functional (flexion and extension) radiographs of the cervical spine and CT scans obtained 12 months post-surgery were used to evaluate the fusion status. The results were subjected to statistical analysis. RESULTS: Statistically significant increase in mobility was recorded for the segments situated immediately below the operative site, with a mean change in mobility of 1.7 mm. Complete fusion was demonstrated in 101 cases (71.1%), and partial fusion in 43 cases (29.9%). In the complete fusion subgroup, the ranges of both flexion and extension in the segments directly below the operative site were significantly greater than those in the partial fusion (pseudoarthrosis) subgroup. CONCLUSION: The mobility of the adjacent segment below the implant insertion site was significantly increased at 12 months post-ACDF surgery. The range of this compensatory hypermobility was significantly greater in patients with complete fusion at the ACDF site than in cases of pseudoarthrosis. Implant subsidence was not associated with mobility changes in the segments directly above or directly below the site of ACDF surgery.

Factors influencing cage subsidence in anterior cervical corpectomy and discectomy: a systematic review.

PURPOSE: Various factors have been examined in relation to cage subsidence risk, including cage material, cage geometry, bone mineral density, device type, surgical level, bone graft, and patient age. The present study aims to compare and synthesize the literature of both clinical and biomechanical studies to evaluate and present the factors associated with cage subsidence. METHODS: A comprehensive search of the literature from January 2003 to December 2021 was conducted using the PubMed and ScienceDirect databases by following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Following the screening for inclusion and exclusion criteria, a total of 49 clinical studies were included. Correlations between clinical and biomechanical studies are also discussed. RESULTS: Patients treated with the cage and plate combination had a lower subsidence rate than patients with the stand-alone cage. Overall, Polyetheretherketone material was shown to have a lower subsidence rate than titanium and other materials. The subsidence rate was also higher when the surgery was performed at levels C5-C7 than at levels C2-C5. No significant correlation was found between age and cage subsidence clinically. CONCLUSIONS: Cage subsidence increases the stress on the anterior fixation system and may cause biomechanical instability. Severe cage subsidence decreases the Cobb angle and intervertebral height, which may cause destabilization of the implant system, such as screw/plate loosening or breakage of the screw/plate. Various factors have been shown to influence the risk of cage subsidence. Examining clinical research alongside biomechanical studies offers a more comprehensive understanding of the subject.

MRI-based vertebral bone quality score compared to quantitative computed tomography bone mineral density in patients undergoing cervical spinal surgery.

PURPOSE: The vertebral bone quality (VBQ) score based on magnetic resonance imaging (MRI) was introduced as a bone quality marker in the lumbar spine. Prior studies showed that it could be utilized as a predictor of osteoporotic fracture or complications after instrumented spine surgery. The objective of this study was to evaluate the correlation between VBQ scores and bone mineral density (BMD) measured by quantitative computer tomography (QCT) in the cervical spine. METHODS: Preoperative cervical CT and sagittal T1-weighted MRIs from patients undergoing ACDF were retrospectively reviewed and included. The VBQ score in each cervical level was calculated by dividing the signal intensity of the vertebral body by the signal intensity of the cerebrospinal fluid on midsagittal T1-weighted MRI images and correlated with QCT measurements of the C2-T1 vertebral bodies. A total of 102 patients (37.3% female) were included. RESULTS: VBQ values of C2-T1 vertebrae strongly correlated with each other. C2 showed the highest VBQ value [Median (range) 2.33 (1.33, 4.23)] and T1 showed the lowest VBQ value [Median (range) 1.64 (0.81, 3.88)]. There was significant weak to moderate negative correlations between and VBQ Scores for all levels [C2: p < 0.001; C3: p < 0.001; C4: p < 0.001; C5: p < 0.004; C6: p < 0.001; C7: p < 0.025; T1: p < 0.001]. CONCLUSION: Our results indicate that cervical VBQ scores may be insufficient in the estimation of BMDs, which might limit their clinical application. Additional studies are recommended to determine the utility of VBQ and QCT BMD to evaluate their potential use as bone status markers.

Is the anterior cervical dynamic plate fixation better than the anterior static plate fixation: a retrospective review with over 5 years follow-up.

BACKGROUND: To compare the clinical and radiologic outcomes after anterior cervical dynamic or static plate fixation for short segment cervical degenerative disc diseases (DDD) for more than 5 years. METHODS: Sixty-four patients who underwent anterior cervical one level discectomy or corpectomy with an anterior cervical plate system were followed for an average of 6.8 years for clinical and radiographic outcomes. Among the sixty-four patients, thirty-eight patients were fixed with a static plate (ORION and CSLP plate system) and the other twenty-six patients were fixed with a dynamic plate (ABC plate). Radiographic data were collected included the global sagittal alignment of the cervical spine (C2-C7), the local height and angle of the operated level pre-operatively, postoperatively and at last follow-up. A clinical assessment was performed at pre-operatively, three months postoperatively and final follow-up using the Japanese Orthopedic Association (JOA) /Visual Analogue Score(VAS)/ Neck Disablility Index(NDI) scoring system. RESULTS: The mean follow-up time was 6.8 years. At final review, there were two cases of suspicious pseudarthrosis which were from ABC plate fixation group while the other cases all gained solid fusion. The height of fusion segment gained significantly improvement for both dynamic and static plate group post-operation, and all groups demonstrated a significant loss in height postoperatively. Generally, for the one level ACDF group, the height decrease was 0.5 mm for static plate and 1.6 mm for dynamic group which was significantly different(p < 0.05). And for one level ACCF group, this type of difference was not seen in which decreasing was 1.7 mm for static group and 1.8 mm for dynamic group. Segmental lordosis of the fusion segments was increased significantly both post-operation and final follow-up than before-operation for both one and two segments fusion. Global cervical lordosis from C2-C7 was increased in the early postoperative period in all groups, and at final follow-up the total lordosis was still getting better compared with early postoperative period, but this increase was not statistically significant. Clinical assessment of JOA/NDI showed that there was significantly improvement 3-month post-operation compared with pre-operation, and the score could get a slight further improvement at the final follow-up. CONCLUSION: Our study demonstrated a statistically similar fusion rate between dynamic and static cervical plate fixation. However, the height gained with static plate fixation for single segment disease was maintained better than with dynamic plate fixation and there was no difference between JOA outcome scores between groups. Despite the reported improved biomechanics of dynamic plate fixation, further research needs to be done to show the clinical advantage of dynamic plate fixation.

Pseudoarthrosis after anterior cervical discectomy and fusion: rate of occult infections and outcome of anterior revision surgery.

BACKGROUND: Pseudoarthrosis after anterior cervical discectomy and fusion (ACDF) is relatively common and can result in revision surgery. The aim of the study was to analyze the outcome of patients who underwent anterior revision surgery for pseudoarthrosis after ACDF. METHODS: From 99 patients with cervical revision surgery, ten patients (median age: 48, range 37-74; female: 5, male: 5) who underwent anterior revision surgery for pseudoarthrosis after ACDF with a minimal follow up of one year were included in the study. Microbiological investigations were performed in all patients. Computed tomography (CT) scans were used to evaluate the radiological success of revision surgery one year postoperatively. Clinical outcome was quantified with the Neck Disability Index (NDI), the Visual Analog Scale (VAS) for neck and arm pain, and the North American Spine Society Patient Satisfaction Scale (NASS) 12 months (12-60) after index ACDF surgery. The achievement of the minimum clinically important difference (MCID) one year postoperatively was documented. RESULTS: Occult infection was present in 40% of patients. Fusion was achieved in 80%. The median NDI was the same one year postoperatively as preoperatively (median 23.5 (range 5-41) versus 23.5 (7-40)), respectively. The MCID for the NDI was achieved 30%. VAS-neck pain was reduced by a median of 1.5 points one year postoperatively from 8 (3-8) to 6.5 (1-8); the MCID for VAS-neck pain was achieved in only 10%. Median VAS-arm pain increased slightly to 3.5 (0-8) one year postoperatively compared with the preoperative value of 1 (0-6); the MCID for VAS-arm pain was achieved in 14%. The NASS patient satisfaction scale could identify 20% of responders, all other patients failed to reach the expected benefit from anterior ACDF revision surgery. 60% of patients would undergo the revision surgery again in retrospect. CONCLUSION: Occult infections occur in 40% of patients who undergo anterior revision surgery for ACDF pseudoarthrosis. Albeit in a small cohort of patients, this study shows that anterior revision surgery may not result in relevant clinical improvements for patients, despite achieving fusion in 80% of cases. LEVEL OF EVIDENCE: Retrospective study, level III.

Biomechanical effect of endplate defects on the intermediate vertebral bone in consecutive two-level anterior cervical discectomy and fusion: a finite element analysis.

BACKGROUND: Intermediate vertebral collapse is a newly discovered complication of consecutive two-level anterior cervical discectomy and fusion (ACDF). There have been no analytical studies related to the effects of endplate defects on the biomechanics of the intermediate vertebral bone after ACDF. This study aimed to compare the effects of endplate defects on the intermediate vertebral bone biomechanics in the zero-profile (ZP) and cage-and-plate (CP) methods of consecutive 2-level ACDF and to determine whether collapse of the intermediate vertebra is more likely to occur using ZP. METHODS: A three-dimensional finite element (FE) model of the intact cervical spine (C2-T1) was constructed and validated. The intact FE model was then modified to build ACDF models and imitate the situation of endplate injury, establishing two groups of models (ZP, IM-ZP and CP, IM-ZP). We simulated cervical motion, such as flexion, extension, lateral bending and axial rotation, and compared the range of motion (ROM), upper and lower endplate stress, fusion fixation device stress, C5 vertebral body stress, intervertebral disc internal pressure (intradiscal pressure, or IDP) and the ROM of adjacent segments in the models. RESULTS: There was no significant difference between the IM-CP model and the CP model in the ROM of the surgical segment, upper and lower endplate stress, fusion fixation device stress, C5 vertebral body stress, IDP, or ROM of the adjacent segments. Compared with the CP model, the endplate stress of the ZP model is significantly higher in the flexion, extension, lateral bending and axial rotation conditions. Compared with the ZP model, endplate stress, screw stress, C5 vertebral stress and IDP in IM-ZP were significantly increased under flexion, extension, lateral bending and axial rotation conditions. CONCLUSIONS: Compared to consecutive 2-level ACDF using CP, collapse of the intermediate vertebra is more likely to occur using ZP due to its mechanical characteristics. Intraoperative endplate defects of the anterior lower margin of the middle vertebra are a risk factor leading to collapse of the middle vertebra after consecutive 2-level ACDF using ZP.

Correlation Between Cervical Spine Sagittal Alignment and Clinical Outcome After Standalone Intersomatic Titanium Cage CeSPACE for Cervical Anterior Discectomy and Fusion in Cervical Degenerative Disk Diseases.

The aim of this study was to determine the relationship between cervical spine sagittal alignment and clinical outcomes after using a standalone intersomatic titanium cage CeSPACE for anterior cervical discectomy and arthrodesis. We present our clinical experience in a group of 180 patients with a mean follow-up for at least 2 years. Patients were evaluated by clinical and radiological assessment preoperatively, immediately after surgery and at regular follow-up. There were 97 male and 83 female patients (average age: 56.6 years) who were preoperatively affected by cervical radiculomyelopathy that was due to spondylosis or cervical disk herniation and who underwent surgical treatment. All patients underwent an anterior discectomy and interbody fusion through the positioning of one or more levels of the CeSPACE device. Compared with the preoperative scores, improvement was seen in postoperative visual analog scale (VAS) scores and Neck Disability Index (NDI) values. The standalone intersomatic titanium cage CeSPACE for anterior cervical discectomy and arthrodesis improved radiculomyelopathy and increased the probability of cervical kyphotic alignment. However, cervical sagittal alignment after surgery was not significantly associated with clinical outcomes in terms of postoperative improvement in VAS scores and NDI values. Similarly, the change in cervical sagittal alignment was not related to visual analog scale scores or Neck Disability Index values.

Three-level ACDF versus 3-level laminectomy and fusion: are there differences in outcomes? An analysis of the Quality Outcomes Database cervical spondylotic myelopathy cohort.

OBJECTIVE: The authors sought to compare 3-level anterior with posterior fusion surgical procedures for the treatment of multilevel cervical spondylotic myelopathy (CSM). METHODS: The authors analyzed prospective data from the 14 highest enrolling sites of the Quality Outcomes Database CSM module. They compared 3-level anterior cervical discectomy and fusion (ACDF) and posterior cervical laminectomy and fusion (PCF) surgical procedures, excluding surgical procedures crossing the cervicothoracic junction. Rates of reaching the minimal clinically important difference (MCID) in patient-reported outcomes (PROs) were compared at 24 months postoperatively. Multivariable analyses adjusted for potential confounders elucidated in univariable analysis. RESULTS: Overall, 199 patients met the inclusion criteria: 123 ACDF (61.8%) and 76 PCF (38.2%) patients. The 24-month follow-up rates were similar (ACDF 90.2% vs PCF 92.1%, p = 0.67). Preoperatively, ACDF patients were younger (60.8 ± 10.2 vs 65.0 ± 10.3 years, p < 0.01), and greater proportions were privately insured (56.1% vs 36.8%, p = 0.02), actively employed (39.8% vs 22.8%, p = 0.04), and independently ambulatory (14.6% vs 31.6%, p < 0.01). Otherwise, the cohorts had equivalent baseline modified Japanese Orthopaedic Association (mJOA), Neck Disability Index (NDI), numeric rating scale (NRS)-arm pain, NRS-neck pain, and EQ-5D scores (p > 0.05). ACDF patients had reduced hospitalization length (1.6 vs 3.9 days, p < 0.01) and a greater proportion had nonroutine discharge (7.3% vs 22.8%, p < 0.01), but they had a higher rate of postoperative dysphagia (13.5% vs 3.5%, p = 0.049). Compared with baseline values, both groups demonstrated improvements in all outcomes at 24 months (p < 0.05). In multivariable analyses, after controlling for age, insurance payor, employment status, ambulation status, and other potential clinically relevant confounders, ACDF was associated with a greater proportion of patients with maximum satisfaction on the North American Spine Society Patient Satisfaction Index (NASS) (NASS score of 1) at 24 months (69.4% vs 53.7%, OR 2.44, 95% CI 1.17-5.09, adjusted p = 0.02). Otherwise, the cohorts shared similar 24-month outcomes in terms of reaching the MCID for mJOA, NDI, NRS-arm pain, NRS-neck pain, and EQ-5D score (adjusted p > 0.05). There were no differences in the 3-month readmission (ACDF 4.1% vs PCF 3.9%, p = 0.97) and 24-month reoperation (ACDF 13.5% vs PCF 18.6%, p = 0.36) rates. CONCLUSIONS: In a cohort limited to 3-level fusion surgical procedures, ACDF was associated with reduced blood loss, shorter hospitalization length, and higher routine home discharge rates; however, PCF resulted in lower rates of postoperative dysphagia. The procedures yielded comparably significant improvements in functional status (mJOA score), neck and arm pain, neck pain-related disability, and quality of life at 3, 12, and 24 months. ACDF patients had significantly higher odds of maximum satisfaction (NASS score 1). Given comparable outcomes, patients should be counseled on each approach's complication profile to aid in surgical decision-making.

Pseudarthrosis after four-level anterior cervical discectomy and fusion without posterior fixation.

OBJECTIVE: Fusion rates and long-term outcomes are well established for anterior cervical discectomy and fusion (ACDF) of 3 levels or fewer, but there is a paucity of similar data on 4-level fusions. The authors evaluated long-term fusion rates and clinical outcomes after 4-level ACDF without supplemental posterior instrumentation. METHODS: The authors retrospectively reviewed patients who underwent 4-level ACDF at a single institution with at least 1-year of radiological follow-up. Fusion was determined by measuring change in interspinous distance at each segment on dynamic radiographs or by the presence of bridging bone on CT scans at minimum 1-year follow-up. Clinical outcomes were assessed using Neck Disability Index and Short Form-36. RESULTS: A total of 63 patients (252 levels) met the inclusion criteria for the study, with a mean follow-up of 2.6 years. Complete radiographic fusion at all 4 levels was observed in 26 patients (41.3%). Of the 37 patients (58.7%) with radiographic pseudarthrosis, there was a mean of 1.35 nonfused levels. The fusion rate per level, however, was 80.2% (202/252 levels). The most common level demonstrating nonunion was the distal segment (C6-7), showing pseudarthrosis in 29 patients (46.8%), followed by the most proximal segment (C3-4) demonstrating nonunion in 9 patients (14.5%). The mean improvement in Neck Disability Index and Short Form-36 was 15.7 (p < 0.01) and 5.8 (p = 0.14), respectively, with improvement in both scores surpassing the minimum clinically important difference. One patient (1.6%) required revision surgery for symptomatic pseudarthrosis, and 5 patients (7.9%) underwent revision for symptomatic adjacent-segment disease. Patient-reported outcomes results are limited by the low rate of 1-year follow-up (50.8%), whereas reoperation data were available for all 63 patients. CONCLUSIONS: More than half of patients undergoing 4-level ACDF without posterior fixation demonstrated pseudarthrosis of at least 1 level-most commonly the distal C6-7 level. One patient required revision for symptomatic pseudarthrosis. Patient-reported outcomes showed significant improvements at 1-year follow-up, but clinical follow-up was limited. This is the largest series to date to evaluate fusion outcomes in 4-level ACDF.