Anterior Cervical Discectomy And Fusion Surgery Research Articles

Using Machine Learning and Deep Learning Algorithms to Predict Postoperative Outcomes Following Anterior Cervical Discectomy and Fusion.

A retrospective cohort study from a multisite academic medical center. To construct, evaluate, and interpret a series of machine learning models to predict outcomes related to inpatient health care resource utilization for patients undergoing anterior cervical discectomy and fusion (ACDF). Reducing postoperative health care utilization is an important goal for improving the delivery of surgical care and serves as a metric for quality assessment. Recent data has shown marked hospital resource utilization after ACDF surgery, including readmissions, and ED visits. The burden of postoperative health care use presents a potential application of machine learning techniques, which may be capable of accurately identifying at-risk patients using patient-specific predictors. Patients 18-88 years old who underwent ACDF from 2011 to 2021 at a multisite academic center and had preoperative lab values within 3 months of surgery were included. Outcomes analyzed included 90-day readmissions, postoperative length of stay, and nonhome discharge. Four machine learning models-Extreme Gradient Boosted Trees, Balanced Random Forest, Elastic-Net Penalized Logistic Regression, and a Neural Network-were trained and evaluated through the Area Under the Curve estimates. Feature importance scores were computed for the highest-performing model per outcome through model-specific metrics. A total of 1026 cases were included in the analysis cohort. All machine learning models were predictive for outcomes of interest, with the Random Forest algorithm consistently demonstrating the strongest average area under the curve performance, with a peak performance of 0.84 for nonhome discharge. Important features varied per outcome, though age, body mass index, American Society of Anesthesiologists classification >2, and medical comorbidities were highly weighted in the studied outcomes. Machine learning models were successfully applied and predictive of postoperative health utilization after ACDF. Deployment of these tools can assist clinicians in determining high-risk patients. III.

Biomechanical performance of the novel assembled uncovertebral joint fusion cage in single-level anterior cervical discectomy and fusion: A finite element analysis.

Introduction: Anterior cervical discectomy and fusion (ACDF) is widely accepted as the gold standard surgical procedure for treating cervical radiculopathy and myelopathy. However, there is concern about the low fusion rate in the early period after ACDF surgery using the Zero-P fusion cage. We creatively designed an assembled uncoupled joint fusion device to improve the fusion rate and solve the implantation difficulties. This study aimed to assess the biomechanical performance of the assembled uncovertebral joint fusion cage in single-level ACDF and compare it with the Zero-P device. Methods: A three-dimensional finite element (FE) of a healthy cervical spine (C2-C7) was constructed and validated. In the one-level surgery model, either an assembled uncovertebral joint fusion cage or a zero-profile device was implanted at the C5-C6 segment of the model. A pure moment of 1.0Nm combined with a follower load of 75N was imposed at C2 to determine flexion, extension, lateral bending, and axial rotation. The segmental range of motion (ROM), facet contact force (FCF), maximum intradiscal pressure (IDP), and screw-bone stress were determined and compared with those of the zero-profile device. Results: The results showed that the ROMs of the fused levels in both models were nearly zero, while the motions of the unfused segments were unevenly increased. The FCF at adjacent segments in the assembled uncovertebral joint fusion cage group was less than that that of the Zero-P group. The IDP at the adjacent segments and screw-bone stress were slightly higher in the assembled uncovertebral joint fusion cage group than in those of the Zero-P group. Stress on the cage was mainly concentrated on both sides of the wings, reaching 13.4-20.4Mpa in the assembled uncovertebral joint fusion cage group. Conclusion: The assembled uncovertebral joint fusion cage provided strong immobilization, similar to the Zero-P device. When compared with the Zero-P group, the assembled uncovertebral joint fusion cage achieved similar resultant values regarding FCF, IDP, and screw-bone stress. Moreover, the assembled uncovertebral joint fusion cage effectively achieved early bone formation and fusion, probably due to proper stress distributions in the wings of both sides.

Unexpected Bone Formation after Stand-Alone Anterior Cervical Discectomy and Fusion Using Polyetheretherketone Cage with i-Factor

Several recent studies have revealed that anterior cervical discectomy and fusion (ACDF) with i-factor, a bone substitute material, is safe and effective, with a superior fusion rate. Clinical studies with i-factor have thus far been shown favorable results, despite theoretical concerns; moreover, no adverse events related to i-factor after ACDF have been reported. Herein, we discuss two cases that presented unexpected bone formation after ACDF using polyetheretherketone (PEEK) cage with i-factor. A 60-year-old male patient underwent stand-alone ACDF surgery at the C4–5–6–7 level. The appropriate PEEK cage was selected, filled with an i-factor 2.5 mL divided into 1/3 that was intermixed with autologous bone chips, The patient developed mild dysphagia 1 month after surgery. A simple cervical spine radiograph showed unexpected bone formation in the anterior portion of the vertebral body at C6 and C7 levels. A 67-year-old male patient underwent stand-alone ACDF surgery at the C3–4 level. The appropriate PEEK cage was selected, filled with 1 mL of i-factor 1 mL that was intermixed with autologous bone chips. The patient developed mild dysphagia 3 months after surgery. Computed tomography (CT) scan revealed the presence of a bridging bone at the graft level, but showed unexpected bone formation in the anterior portion of the vertebral body. The unexpected bone formation causing dysphagia that we observed may be due to the high potent bone-inductive capacity of i-factor, but instead because there are no guidelines on proper dosage and usage. Further biomechanical studies are required to determine the optimal dose and usage instruction of i-factor.

What Is the Evidence Surrounding the Cost-Effectiveness of Osteobiologic Use in ACDF Surgery? A Systematic Review of the Literature.

This study constitutes a systematic review of the literature. The aim of this study was to identify and present all available studies that report on the costs of osteobiologics used in anterior cervical discectomy and fusion (ACDF). The literature was systematically reviewed to identify studies with specific inclusion criteria: (1) randomized controlled trials and observational studies, (2) in adult patients, (3) with herniated disc(s) or degenerative cervical spine disease, (4) reporting on either direct or indirect costs of using specific osteobiologics in an ACDF operation. (5) Only studies in English were included. The quality of the included studies was assessed using the MINORS and RoB 2.0 tools. Overall, 14 articles were included; one randomized controlled trial and 13 observational studies. The most commonly used osteobiologics other than autograft/iliac crest bone graft (ICBG) were allograft and bone morphogenetic protein (BMP). None of the studies was reported to be industry-supported. There was considerable heterogeneity on the reported costs. Overall, most studies reported on surgery-related costs, such as anesthesia, operating room, surgical materials and surgeon's fee. Only two studies, both using allograft, reported the exact cost of the osteobiologic used (450 GBP, $700). Some of the studies reported on the cost of care during hospitalization for the surgical operation, such as radiology studies, emergency room costs, cardiologic evaluation, laboratory studies, pharmacy costs, and room costs. Only a few studies reported on the cost of follow-up, reoperation, and physical therapy and rehabilitation. Based on the data of this current systematic review, no recommendations can be made regarding the cost-effectiveness of using osteobiologics in ACDF. Given the high costs of osteobiologics, this remains a topic of importance. The design of future studies on the subject should include cost effectiveness.

Biomechanical analysis of customized cage conforming to the endplate morphology in anterior cervical discectomy fusion: A finite element analysis

In anterior cervical discectomy and fusion (ACDF), an interbody fusion device is an essential implant. An unsuitable interbody fusion device can cause postoperative complications, including subsidence and nonunion. We designed a customized intervertebral fusion device to reduce postoperative complications and validated it by finite element analysis. Herein, we built a non-homogeneous model of the C3-7 cervical spine. Three implant models (customized cage, commercial cage, and bone graft cage) were constructed and placed in the C45 cervical segment after ACDF surgery. The simulated range of motion (ROM), stress at the cage-bone interface, and stress on the cage and implants were compared under different conditions. The commercial cage showed maximum stress peaks at 40.3 MPa and 43.2 MPa in the inferior endplate of C4 and superior endplate of C5 under rotational conditions, higher compared to 29.7 MPa and 26.4 MPa, respectively, in the customized cage. The ROM was not significantly different between the three cages placed after ACDF. The stresses on the commercial cage were higher compared to the other two cages under all conditions. The bone graft in the customized cage was subject to higher stress than the commercial cage under all conditions, particularly lateral bending, wherein the maximum stress was 5.5 MPa. These results showed that a customized cage that better conformed to the vertebral anatomy was promising for reducing the risk of stress shielding and the occurrence of subsidence.

Cervical Radiculopathy: Focus on Factors for Better Surgical Outcomes and Operative Techniques.

For patients with cervical radiculopathy, most studies have recommended conservative treatment as the first-line treatment; however, when conventional treatment fails, surgery is considered. A better understanding of the prognosis of cervical radiculopathy is essential to provide accurate information to the patients. If the patients complain of persistent and recurrent arm pain/numbness not respond to conservative treatment, or exhibit neurologic deficits, surgery is performed using anterior or posterior approaches. Anterior cervical discectomy and fusion (ACDF) has historically been widely used and has proven to be safe and effective. To improve surgical outcomes of ACDF surgery, many studies have been conducted on types of spacers, size/height/position of cages, anterior plating, patients' factors, surgical techniques, and so forth. Cervical disc replacement (CDR) is designed to reduce the incidence of adjacent segment disease during long-term follow-up by maintaining cervical spine motion postoperatively. Many studies on excellent indications for the CDR, proper type/size/shape/height of the implants, and surgical techniques were performed. Posterior cervical foraminotomy is a safe and effective surgical option to avoid complications associated with anterior approach and fusion surgery. Most recent literature demonstrated that all three surgical techniques for patients with cervical radiculopathy have clear advantages and disadvantages and reveal satisfactory surgical outcomes under a proper selection of patients and application of appropriate surgical methods. For this, it is important to fully understand the factors for better surgical outcomes and to adequately practice the operative techniques for patients with cervical radiculopathy.

Is the Zero-P Spacer Suitable for 3-Level Anterior Cervical Discectomy and Fusion Surgery in Terms of Sagittal Alignment Reconstruction: A Comparison Study with Traditional Plate and Cage System.

The Zero-P spacer was primarily developed aiming to reduce the morbidity associated with the traditional anterior cervical plate. During the past decade, many authors have reported the use of Zero-P spacers for anterior cervical discectomy and fusion (ACDF) of one or two segments. Nevertheless, there is still a paucity of knowledge on the safety and feasibility of using Zero-P spacers for 3-level fixation. The objective of this study was to investigate the clinical and radiological outcomes, with a focus on the sagittal alignment reconstruction of 3-level ACDF surgery using Zero-P spacers versus those using a traditional plate and cage system. From Sep 2013 to Aug 2016, a total of 44 patients who received 3-level ACDF surgery due to cervical spondylotic myelopathy were recruited. The Zero-P spacer was used in 23 patients (group ZP) and the traditional plate and cage system in 21 (group PC). Clinical outcomes were analyzed by Neck Disability Index (NDI) and Japanese Orthopedic Association (JOA) scores, and dysphagia was evaluated using the Bazaz score. Radiological outcomes, including fusion rate, adjacent segment degeneration (ASD), and especially changes in cervical sagittal alignment, were analyzed. The NDI and JOA scores did not differ significantly between the two groups postoperatively (p > 0.05); however, there was significantly less dysphagia in patients using Zero-P spacers at the 3- and 6-month follow-up (p < 0.05). At the 24-month follow-up, the fusion rate and ASD were similar between the two groups (p > 0.05). Interestingly, patients using Zero-P spacers had a significantly lower postoperative C2-7 Cobb angle and fused segment Cobb angle, compared to those using a traditional plate and cage system (p < 0.05); meanwhile, the fused segment disc wedge was also found to be significantly smaller in patients using Zero-P spacers after surgery (p < 0.05). Moreover, we further divided patients into subgroups according to their cervical lordosis. In patients with a preoperative C2-7 Cobb angle ≤ 10°, significantly less cervical and local lordosis, as well as disc wedge, were seen in group ZP after surgery (p < 0.05), while in others with a preoperative C2-7 Cobb angle > 10°, no significant difference in postoperative changes of the cervical sagittal alignment was seen between group ZP and group PC (p > 0.05). Zero-P spacers used in 3-level ACDF surgery could provide equivalent clinical outcomes and a lower rate of postoperative dysphagia, compared to the traditional plate and cage system. However, our results showed that it was inferior to the cervical plate in terms of sagittal alignment reconstruction for 3-level fixation. We recommend applying Zero-P spacers for 3-level ACDF in patients with good preoperative cervical lordosis (C2-7 Cobb angle > 10°), in order to restore and maintain physiological curvature of the cervical spine postoperatively.

A 5-Year Cost-Utility Analysis Comparing Synthetic Cage vs Allograft Use in Anterior Cervical Discectomy and Fusion Surgery for Cervical Spondylotic Myelopathy.

Retrospective cost-utility analysis. To conduct a cost-analysis comparing SC versus Allo over a five-year time horizon. Synthetic cage (SC) and allograft (Allo) are two commonly used interbody choices for anterior cervical discectomy and fusion (ACDF) surgery. Previous analyses comparative analyses have reached mixed conclusions regarding their cost-effectiveness, yet recent estimates provide high-quality evidence. A decision-analysis model comparing the use of Allo versus SC was developed for a hypothetical 60-year-old patient with cervical spondylotic myelopathy (CSM) undergoing single level ACDF surgery. A comprehensive literature review was performed to estimate probabilities, costs (2020 USD) and Quality-Adjusted Life Years (QALYs) gained over a 5-year period. A probabilistic sensitivity analysis using a Monte Carlo Simulation of 1000 patients was carried out to calculate incremental cost effectiveness ratio (ICER) and net monetary benefits (INMB). One-way deterministic sensitivity analysis was performed to estimate the contribution of individual parameters to uncertainty in the model. The use of Allo was favored in 81.6% of the iterations at a societal willing-to-pay threshold (WTP) of 50,000 USD/QALY. Allo dominated (higher net QALYs and lower net costs) in 67.8% of the iterations. The INMB in the Allo group was 2,650 USD at a WTP threshold of 50,000 USD/QALY. One-way deterministic sensitivity analysis revealed that the cost of the index surgery was the only factor which significantly contributed to uncertainty. Cost-utility analysis suggests that Allograft maybe a more cost-effective option compared to synthetic cages in adult patients undergoing ACDF for CSM.

No Difference in Two-Year Revisions Between Hybrid Fusion and Two-Level Anterior Discectomy and Fusion: A National Database Study.

Retrospective Cohort. This study utilized a large national database to compare two-year revision rates, in addition to complications and costs, of hybrid surgery (HS) compared to two-level anterior cervical discectomy and fusion (ACDF). This study used the PearlDiver Mariner dataset selecting for patients aged 18 and older who had at least 90-day active longitudinal follow-up who underwent two-level ACDF or two-level Hybrid surgery (single level ACDF and single level CDA). Patients with prior spinal trauma, infection, cancer, or posterior fusion were excluded. Primary outcomes measures were 90-day major and minor medical complications, ED visits, readmissions, as well as two-year revisions. Patients were also assessed for postoperative dysphagia, incidental durotomy, vascular injury, 90-day surgical site, and implant complications. Additionally, hospitalization and postoperative costs were evaluated. There were 4570 two-level ACDF surgeries and 888 hybrid surgeries. After matching the cohorts, no statistical differences in demographics were found. There were no differences in reoperation rates at all measured time points nor 2-year complications. HS had a lower incidence of major (1.6% vs 3.1%, P = .003) and minor complications (3.0% vs 4.6%, P = .009) than ACDF. 90-day readmission was lower in the HS cohort (2.8% vs 4.2%), P = .024. HS was associated with reduced hospitalization costs -$2614 (-$3916 to -$904, P < .001). 3516 patients had ACDF, and 699 had HS with at least 2years of follow-up. Hybrid surgery is a safe and effective surgical treatment for cervical disease in appropriately selected patients.

Utility of Intraoperative Neurophysiologic Monitoring in Routine Anterior Cervical Spine Surgery

Introduction: Intraoperative neurophysiologic monitoring (IOM) is commonly used in spine surgery; advantages include identification of intraoperative neurologic decline that may be related to a remediable cause. Disadvantages include increased time and cost, morbidity associated with the monitoring procedure, and the potential for false positive alerts prompting unnecessary action. The study’s goal was to assess whether use of IOM in routine, uncomplicated cases of anterior cervical discectomy and fusion (ACDF) surgery was of demonstrable benefit. Methods: 50 consecutive patients were identified who underwent one-level ACDF with anterior instrumentation for cervical disc herniation with radiculopathy without myelopathy. For all cases, a NIMS tube was used to monitor laryngeal nerve function, and EMG, SSEP, and MEP modalities were monitored. Hospital and postoperative records were investigated for the presence of IOM alerts, whether corrective action was taken during surgery, and the presence of any postoperative neurologic deficits. Results: In all cases, there were no alerts of laryngeal nerve dysfunction, or SSEP/ MEP abnormality. In 12 cases, transient EMG irritation activity was documented; in no cases was there any change to the surgical procedure, such as abandonment of surgery, removal of implant, etc. There were no instances of new or worsened postoperative neurologic deficit, and clinical findings of vocal cord dysfunction. Conclusion: In ACDF with anterior instrumentation for cervical disc herniation with radiculopathy without myelopathy, IOM use did not convey any identifiable advantage. Therefore, the data does not support considering IOM to be required or standard of care for routine, uncomplicated ACDF surgery.

Autologous Bone Graft vs PEEK Cage in Patients with Cervical Spondylotic Myelopathy

Background: Cervical spine stenosis is one of the most common degenerative changes of cervical spondylotic myelopathy (CSM) and results in severe dysfunction of the cervical spinal cord. The conventional treatment of such degenerative cervical spine conditions is anterior cervical discectomy and fusion (ACDF). Strut graft remains the gold standard in ACDF with excellent patient recovery but has many shortcomings. Polyetheretherketone (PEEK) cages have recently become popular as a replacement for strut grafts in patients undergoing ACDF.&#x0D; Objective: This study was carried out to compare the clinical and radiographic outcomes of autologous bone grafts versus PEEK cages in patients undergoing ACDF surgery.&#x0D; Materials and Methods: It was a randomized controlled trial conducted at the Neurosurgery Department Punjab Institute of Neurosciences for three years. Patients who consented to be a part of this study and fulfilled our predefined inclusion criteria were recruited and randomized into 2 groups. One group underwent ACDF with auto bone graft whereas the other group underwent ACDF with PEEK cage.&#x0D; Results: A total of 198 subjects were included in this study. The mean age was calculated as 47.60 ± 9.17 years in the PEEK cage group and 46.74 ± 8.87 years in the Autologous bone graft group. Males accounted for 59.6% of the study population. The fusion rate was found to be higher in the PEEK cage group with a p-value of 0.002.&#x0D; Conclusion: PEEK cages are superior to strut grafts as they have lesser morbidity after ACDF surgery in patients with CSM.&#x0D;

Social Media Posts Pertaining to Anterior Cervical Discectomy and Fusion (ACDF) Surgery: A Cross-sectional Analysis of Patient and Surgeon Perceptions.

Cross-sectional study. To analyze publicly available content on a major social media outlet related to anterior cervical discectomy and fusion (ACDF) surgery based on perspective, location, timing, content, tone, and patient satisfaction. Social media offers a powerful platform for sharing the patient experience with the public through an unfiltered perspective. Social media content may influence future perceptions around surgical care and postings around ACDF have not been previously reported. A query of content from a major social media outlet was performed for the study period January 1, 2018, to January 1, 2020, and returned 6500 publicly available posts. Content was identified by the hashtags "#acdf" or "#acdfsurgery." Content was ranked by number of "likes." Of the 1500 most popular posts, 1136 related to ACDF surgery and were included. Post content was characterized and classified. Patients created 85% of ACDF-related content and spine surgeons created 11.8%. Most posts portrayed the patient experience in the postoperative period and depicted patients performing activities of daily living, participating in sports, or completing work activities (54.4%). The connotation of posts was deemed to be positive in 79.2% of cases. In regard to their care or state of health as it related to ACDF surgery, 59.8% of patients expressed satisfaction, whereas 14.1% expressed dissatisfaction. Female patients were >4 times as likely to express dissatisfaction (odds ratio=4.16, P =<0.0001), with their clinical course compared with their male counterparts. Patients were the source of most posts on a major social media outlet that pertained to ACDF surgery with a majority reporting positive tone and satisfaction. These mechanisms of communication offer surgeons unique insights into patient experience and may provide an opportunity for surgeons to assess patient feedback, influence patient perceptions, and enhance delivery of cervical spine care.

25. Perioperative complications associated with epidural injections followed by cervical decompression and fusion

<h3>BACKGROUND CONTEXT</h3> Cervical epidural steroid injections (CESIs) are widely used to alleviate pain caused by degenerative diseases of the cervical spine. However, some data suggest a potential link between CESIs and infection rates following fusion surgeries. No prior studies have assessed the association between CESI and other postoperative outcomes such as hematomas, revision rates, or wound complications following anterior cervical discectomy and fusion (ACDF) and posterior cervical decompression and fusion (PCDF). Therefore, using a national dataset, we aimed to explore whether an association exists between preoperative CESIs and a variety of serious complications following ACDF and PCDF surgery. <h3>METHODS</h3> In this retrospective cohort study, we queried the IBM MarketScan national claims dataset (after IRB approval) and included adult patients who had undergone inpatient or outpatient ACDF or PCDF surgery due to disc herniation, stenosis, radiculopathy, spondylosis, or myelopathy from January 2014 to September 2017. Current procedural terminology codes were used to identify patients who received a CESI within one year prior to their surgery. Multivariable logistic regression measured the association between preoperative CESI and postoperative rates of 90-day infection, hematoma, wound complications, revision surgery, or combined complications (the former first three complications). We report odds ratios (OR) and 95% confidence intervals (CI). <h3>RESULTS</h3> Among 44,777 ACDF patients, 31.2% (n=13,950) received a preoperative CESI. For PCDF, 3,284 patients underwent the surgery of which 22.3% (n=734) received a preoperative CESI. The median time from most recent CESI to ACDF surgery is 76 days (interquartile range 41-144 days) and 95 days (interquartile range 49-176 days) for PCDF. Among ACDF patients, preoperative CESI was associated with lower odds of developing a hematoma following ACDF (OR 0.60; 95% CI 0.37-0.99; p=0.0453); no significant associations existed for the other outcomes including infection (OR 0.98; 95% CI 0.77-1.26; p=0.8846), revision surgery (OR 0.94; 95% CI 0.71-1.23; p=0.6300), wound complications (OR 0.92; 95% CI 0.71-1.17; p=0.4865) or combined complications (OR 0.88; 95% CI 0.73-1.07; p=0.1904). In the PCDF cohort, no significant associations existed between preoperative CESI and post-PCDF infection (OR 1.26; 95% CI 0.82-1.95; p=0.2962), revision surgery (OR 1.96; 95% CI 0.91-4.18; p=0.0842), wound complications (OR 1.11; 95% CI 0.71-1.72; p=0.6608) or combined complications (OR 1.14; 95% CI 0.78-1.68; p=0.4929). <h3>CONCLUSIONS</h3> Our study is the first to assess a broad complication profile that includes hematoma rates, infection rates, revision rates, and wound complications following ACDF and PCDF surgeries. We found no association between preoperative CESI and the aforementioned complications following ACDF and PCDF which supports first-hand clinical outcomes. Future work will aim to delineate the role of timing of CESI before ACDF and PCDF surgery, and the impact of quantity of CESIs on complication risks. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

P94. Years of experience and primary specialty are correlated with total cost of ACDF surgeries for Medicare beneficiaries

<h3>BACKGROUND CONTEXT</h3> The high costs of spine surgery are multifactorial. Many studies suggest hospital, geographic, surgeon and patient-specific factors impact the cost of spine surgical care, but results vary significantly between studies using different datasets. <h3>PURPOSE</h3> Our goal was to identify the factors correlated with total costs for Medicare beneficiaries undergoing one of the most common spine surgical procedures, anterior cervical discectomy and fusion (ACDF). <h3>STUDY DESIGN/SETTING</h3> Retrospective cohort study. <h3>PATIENT SAMPLE</h3> We identified all patients undergoing ACDF (CPT code 22551) from the 20% sample Medicare carrier files from January 1, 2013, through December 31, 2015 (n = 15,456). Subjects were stratified by number of levels operated on. <h3>OUTCOME MEASURES</h3> Variables collected including hospital location, number of beds and wage index; patient age, sex, race and length of stay; physician industry payments, years since medical school and primary specialty. Outcomes were predictors of total cost and operating room cost of ACDF, and patient length of stay. <h3>METHODS</h3> Medicare carrier and MedPAR files were used to find the total charge, operating room charge and length of stay of each ACDF procedure. Charges were converted to costs using the hospital-specific cost-to-charge ratios from the IPPS Impact Files for each year. The Open Payments database and NPI National Downloadable File were used to identify the operating surgeon for each ACDF procedure. Univariate and multivariate analyses were used to identify patient-specific, hospital-specific and physician-specific factors associated with changes in cost of ACDF or patient length of stay. <h3>RESULTS</h3> Matching across all relevant files resulted in 5,202 1-level ACDF Medicare claims. The mean total cost for a 1-level ACDF from 2013-2015 was $13,592 (+/- $5,324). Multiple linear regression found that, after controlling for patient and hospital factors, the total cost of a 1-level ACDF was $677 higher when performed by an orthopedic surgeon than a neurosurgeon (p < 0.001). Multiple linear regression also found a significant negative association between years since the surgeon graduated medical school and total hospital cost of 1-level ACDF (p < 0.001). A significant positive association was found between hospital wage index and total cost of 1-level ACDF (p < 0.001). No significant relationship was found between total ACDF cost and patient age, race or sex. <h3>CONCLUSIONS</h3> Our multivariate analysis of hospital, surgeon, and patient-specific factors identifies that surgeon's primary specialty, surgeon's years of experience, and hospital wage index are significant factors impacting the total cost of ACDF surgery for Medicare beneficiaries. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Dysphagia as a Postoperative Complication of Anterior Cervical Discectomy and Fusion.

Anterior cervical discectomy and fusion (ACDF), despite its possible complications, remains the gold standard for the surgical treatment of patients with radiculopathy and/or myelopathy caused by cervical intervertebral disc herniation or spondylosis. Despite its high rate of incidence, postoperative dysphagia following ACDF is still poorly understood; its pathogenesis remains relatively unknown, and its risk factors are still a subject of debate.The aim of this study is to review the incidence, pathogenesis, diagnosis, and methods of prevention of dysphagia in ACDF patients. To this end, a literature review was conducted based on the PubMed internet database. Article titles were searched by using the following keywords: “dysphagia” and “anterior cervical discectomy and fusion” or “ACDF”. The search was limited to prospective clinical studies evaluating dysphagia after ACDF surgery. Studies published in non-English languages, retrospective studies, cadaveric studies, reviews, case reports, study protocols, and commentary studies were excluded.Initially, 335 studies were identified after a primary search. After the application of the exclusion criteria, 73 studies remained for the final analysis. This literature review focused on identifying the rate of dysphagia and the various risk factors leading to this complication by comparing and evaluating the current literature with a wide spectrum of heterogeneity concerning patients, surgeons, and surgical techniques. A mean dysphagia rate of 19.4% (95% CI: 9.6%-29.1%) based on the findings of the included studies correlating dysphagia directly with ACDF procedures was calculated. Various established risk factors leading to dysphagia include the female sex, smoking, the surgical approach, rhBMP-2 use, and multilevel surgery, while zero-profile devices seem to reduce dysphagia risk. The diagnosis is based on clinical and radiological findings, especially prevertebral soft-tissue swelling. However, videofluoroscopic and endoscopic studies have been recently used for the evaluation of dysphagia. The role of local administration of steroids in the prevention of dysphagia has not yet been clarified. This review underscores the prevailing rudimentary understanding of the problem of dysphagia after ACDF procedures and highlights the need for more sensitive, factor-specific studies for understanding the impact of various risk factors on the incidence rate of dysphagia.

Anterior Cervical Discectomy and Fusion Results in Clinically Significant Improvements in Patients With Preoperative Sleep Difficulties.

Individual items within the Patient Health Questionnaire-9 (PHQ-9) have not been assessed as predictors of postoperative outcomes. Our objective is to study the relationship between responses to individual PHQ-9 items and achievement of a minimum clinically important difference (MCID) following anterior cervical discectomy and fusion (ACDF). A prospective surgical database was reviewed for primary, single-level ACDF procedures performed for degenerative spinal pathology. Patient demographics, preoperative spinal pathology, and perioperative characteristics were recorded. Patient-reported outcome measures (PROMs) including PHQ-9, visual analog scale (VAS) neck and arm, Neck Disability Index, 12-item Short Form physical component score (SF-12 PCS), and Patient-Reported Outcomes Measurement Information System Physical Function were administered at preoperative and 6-week, 12-week, 6-month, 1-year, and 2-year postoperative timepoints. MCID achievement was determined by comparing postoperative PROM improvement from baseline to previously established values. Logistic regression assessed responses to each individual question of the preoperative PHQ-9 as predictors of MCID achievement in each other PROMs. Sixty-six ACDF patients were included with a mean age of 47.2 years. Herniated nucleus pulposus was the most common preoperative spinal diagnosis (95.6%). The mean operative duration was 50.3 minutes, the mean estimated blood loss was 27.5 mL, and most patients were discharged on postoperative day 0 (81.8%). A majority of patients achieved MCID for all measures except SF-12 PCS. PHQ-9 question 3 significantly predicted MCID achievement for VAS neck (P = 0.045), VAS arm (P = 0.049), and SF-12 PCS (P = 0.037). No other PHQ-9 items or overall PHQ-9 scores significantly predicted MCID achievement. Question 3 of the PHQ-9 regarding "trouble falling asleep, staying asleep, or sleeping too much" significantly predicted clinically meaningful improvement in neck pain, arm pain, and physical function following ACDF, although overall PHQ-9 scores did not. Providers should inform patients experiencing significant sleep-related difficulties that they may be especially likely to benefit from ACDF surgery. Evaluation of sleep from the PHQ-9 predicts clinically relevant improvement in neck pain, arm pain, and physical function in patients undergoing ACDF.

Risk of Dysphagia and Dysphonia in Patients With Prior Thyroidectomy Undergoing Anterior Cervical Discectomy and Fusion.

Retrospective cohort study using PearlDiver database. To evaluate the effect of prior thyroidectomy on complications of Anterior Cervical Discectomy and Fusion (ACDF) surgery. PearlDiver was used to identify patients without prior dysphagia or dysphonia undergoing ACDF between the years 2010-2020Q1. Patients with and without prior thyroidectomy were matched by levels of fusion, alcohol use, and gastroesophageal reflux disease in a 1:5 ratio. Postoperative outcomes were assessed for each cohort with multivariable logistic regression, controlling for age, sex, and Elixhauser Comorbidity Index. Between 2010 and 2019, matched cohorts of 792 ACDF patients with prior thyroidectomy and 3960 ACDF only patients were included in the study. Of patients with previous thyroidectomy undergoing ACDF, 16.3% experienced dysphagia at 1-year compared with 10.6% for patients undergoing ACDF only (aOR=1.39, P=.004). Patients with previous thyroidectomy also had higher odds of dysphonia at 1-year following ACDF, as compared to patients with ACDF alone (2.7% vs 1.2%, aOR=1.74, P= .048). Patients undergoing ACDF with prior thyroidectomy did not have increased risk of revision at 1 year (aOR=1.10, P=.698), 2 years (aOR=1.16, P=.457), or 5 years (aOR=1.20, P=.255) following surgery. There were no differences in postoperative opioid utilization rates at 1 month (aOR=2.07, P=.138), 3 months (aOR=2.45, P=.095), 6 months (aOR=1.34, P=.520), and 12 months (aOR=1.69, P=.202). Prior thyroidectomy was not associated with reintubation following ACDF (P=.995). Patients with prior thyroidectomy undergoing ACDF surgery experience increased odds of dysphagia and dysphonia at 1-year follow-up compared to those without prior thyroidectomy.

Chronic Opioid Use Prior to ACDF Surgery Is Associated with Inferior Postoperative Outcomes: A Propensity-Matched Study of 17,443 Chronic Opioid Users

Candidates for anterior cervical discectomy and fusion (ACDF) have a higher rate of opioid use than does the public, but studies on preoperative opioid use have not been conducted. We aimed to understand how preoperative opioid use affects post-ACDF outcomes. The MarketScan Database was queried from 2007 to 2015 to identify adult patients who underwent an ACDF. Patients were classified into separate cohorts based on the number of separate opioid prescriptions in the year before their ACDF. Ninety-day postoperative complications, postoperative readmission, reoperation, and total inpatient costs were compared between opioid strata. Propensity score-matched patient cohorts were calculated to balance comorbidities across groups. Of 81,671 ACDF patients, 31,312 (38.3%) were nonusers, 30,302 (37.1%) were mild users, and 20,057 (24.6%) were chronic users. Chronic opioid users had a higher comorbidity burden, on average, than patients with less frequent opioid use (P < 0.001). Chronic opioid users had higher rates of postoperative complications (9.1%) than mild opioid users (6.0%) and nonusers (5.3%) (P < 0.001) and higher rates of readmission and reoperation. After balancing opioid nonusers versus chronic opioid users along with demographic characteristics, preoperative comorbidity, and operative characteristics, postoperative complications remained elevated for chronic opioid users relative to opioid nonusers (8.6% vs. 5.7%; P < 0.001), as did rates of readmission and reoperation. Chronic opioid users had more comorbidities than opioid nonusers and mild opioid users, longer hospitalizations, and higher rates of postoperative complication, readmission, and reoperation. After balancing patients across covariates, the outcome differences persisted, suggesting a durable association between preoperative opioid use and negative postoperative outcomes.

Prospective, Randomized, Blinded Clinical Trial Comparing PEEK and Allograft Spacers in Patients Undergoing Anterior Cervical Discectomy and Fusion Surgeries.

Prospective, randomized, blinded clinical trial. To examine clinical and radiological outcomes in patients undergoing anterior cervical discectomy and fusion (ACDF) surgeries randomized to receive either polyether-ether-ketone (PEEK) or structural bone allografts. The biomechanical qualities as well as osteoconductive, osteogenic, and osteoinductive properties of various graft materials have been previously evaluated. There remain questions, however, as to whether there are any clinical and/or radiographic outcome differences in the selection of interbody graft types for ACDF. Patients undergoing one- to three-level ACDF with single anterior plate fixation were randomized (1:1 ratio) to receive either cortical allograft or PEEK interbody spacers. Radiographic and clinical outcomes were assessed at 3, 6, 12, and 24 months with an additional postoperative radiographic assessment. A total of 120 patients were enrolled and randomized. Comparing clinical outcomes, no differences in arm or neck pain scores were noted; however, there was a statistically significant (≤0.041) improvement in SF-36 PCS scores for the allograft group at all follow-up time points and a tendency toward lower disability scores. Overall, evidence of radiographic fusion was achieved in 87 (91.6%) patients: five (10.2%) and three (6.5%) patients had pseudoarthrosis (P = 0.72) in the PEEK and allograft groups, respectively. At 24 months' follow-up time, any cervical or segmental alignment restoration achieved with surgery was lost and no statistically significant changes were detected when all levels of surgery were included. Likewise, there were no statistically significant differences between the groups for anterior or posterior body height measurements at the 24 months' follow-up. Approximately 20% of patients had anterior and posterior subsidence, all grade 0 regardless of the group assignment. Comparable radiographic outcomes were observed for patients undergoing one- to three-level PEEK versus allograft-assisted ACDF surgeries. Although MCID comparisons suggest that allograft and PEEK-treated patients have similar clinical outcomes, testing that incorporates the magnitude of the change suggests that there may be a statistically significant greater magnitude of improvement for the allograft group patients, but further studies with a larger sample size would be helpful to determine if a true effect exists.

The impact of smoking and smoking cessation interventions on outcomes following single-level anterior cervical discectomy and fusion procedures

BackgroundWhile several studies explore the impact of smoking tobacco on spinal fusion outcomes, there is a paucity of literature on the influence of modern smoking cessation therapies on such outcomes in patients undergoing anterior cervical discectomy and fusion (ACDF). ObjectiveOur study explores the outcomes of single-level ACDF surgery in nonsmokers, active smokers, and smokers undergoing cessation therapy. MethodsMARINER30, an all-payer claims database, was utilized to identify patients undergoing single-level ACDF between 2010 and 2019. The primary outcomes were the rates of composite surgical complications, dysphagia, hematoma, symptomatic pseudarthrosis, instrumentation removal, need for revision surgery, and all-cause readmission rates within 30 and 90-days. ResultsThe matched population consisted of 5769 patients undergoing single-level ACDF with 1923 (33.33%) in each of the following groups: (1) nonsmokers; (2) active smokers; and (3) patients undergoing smoking cessation therapy. Nonsmokers had significantly lower rates of composite surgical complications (3.74% vs 13.05% vs 15.08%), revision surgery (4.06% vs 20.07% vs 22.88%), instrumentation removal (0.83% vs. 2.08% vs. 2.76%), and dysphagia (0.36% vs 0.99% vs 0.62%) when compared to patients in the active smoking and smoking cessation groups, respectively. ConclusionPatients using smoking cessation therapy were more likely to develop postoperative dysphagia and undergo revision surgery when compared to their actively smoking counterparts. While surgeons routinely recommend smoking cessation prior to surgery, the effects of smoking cessation therapies on surgical outcomes are not well characterized.