Primary Anterior Cervical Discectomy And Fusion Research Articles

Structural Allograft versus Polyetheretherketone Cage in Anterior Cervical Discectomy and Fusion: A Meta-Analysis

Polyetheretherketone (PEEK) cages and structural allografts (SAs) are commonly used in Anterior Cervical Discectomy and Fusion (ACDF), yet their postoperative results remain uncertain. This meta-analysis was conducted to determine whether there were any differences in outcomes between patients who received these two grafts in ACDF. We comprehensively searched electronic databases up to August 2023. Observational studies or randomized controlled trials reported postoperative outcomes, including fusion, subsidence, reoperation rates, and patient-reported outcomes through the Neck Disability Index (NDI), the Visual Analog Scale (VAS) for neck and arm pain, and the Japanese Orthopedic Association (JOA)/modified JOA score following primary ACDF using SA or PEEK cage. The results are presented in odds ratios (ORs) or mean differences with corresponding 95% confidence intervals (CIs). Eleven studies were included, with 1213 patients (788 receiving SAs and 425 receiving PEEK cages). Patients having SA had significantly higher fusion (OR: 1.84, 95% CI: 1.27-2.67, p = 0.001) and lower subsidence (OR: 0.50, 95%CI: 0.30-0.86, p = 0.01) rates when compared with the PEEK cage. There was no difference in revision rate between SA or PEEK cage (p = 0.88). Two grafts demonstrated similar clinical improvements in NDI (p = 0.31), VAS for the neck (p = 0.77) and arm pain (p = 0.22), and JOA/mJOA score (p = 0.99). SA demonstrates better fusion and lower subsidence rates than the PEEK cage in ACDF. Nevertheless, these two cages resulted in equally successful postoperative clinical performances.

Biomechanical Analysis of Hybrid Artificial Discs or Zero-Profile Devices for Treating 1-Level Adjacent Segment Degeneration in ACDF Revision Surgery.

Cervical hybrid surgery optimizes the use of cervical disc arthroplasty (CDA) and zero-profile (ZOP) devices in anterior cervical discectomy and fusion (ACDF) but lacks uniform combination and biomechanical standards, especially in revision surgery (RS). This study aimed to investigate the biomechanical characteristics of adjacent segments of the different hybrid RS constructs in ACDF RS. An intact 3-dimensional finite element model generated a normal cervical spine (C2-T1). This model was modified to the primary C5-6 ACDF model. Three RS models were created to treat C4-5 adjacent segment degeneration through implanting cages plus plates (Cage-Cage), ZOP devices (ZOP-Cage), or Bryan discs (CDA-Cage). A 1.0-Nm moment was applied to the primary C5-6 ACDF model to generate total C2-T1 range of motions (ROMs). Subsequently, a displacement load was applied to all RS models to match the total C2-T1 ROMs of the primary ACDF model. The ZOP-Cage model showed lower biomechanical responses including ROM, intradiscal pressure, maximum von Mises stress in discs, and facet joint force in adjacent segments compared to the Cage-Cage model. The CDA-Cage model exhibited the lowest biomechanical responses and ROM ratio at adjacent segments among all RS models, closely approached or lower than those in the primary ACDF model in most motion directions. Additionally, the maximum von Mises stress on the C3-4 and C6-7 discs increased in the Cage-Cage and ZOP-Cage models but decreased in the CDA-Cage model when compared to the primary ACDF model. The CDA-Cage construct had the lowest biomechanical responses with minimal kinematic change of adjacent segments. ZOP-Cage is the next best choice, especially if CDA is not suitable. This study provides a biomechanical reference for clinical hybrid RS decision-making to reduce the risk of ASD recurrence.

Revision Rates After Single-Level Cervical Disc Arthroplasty Versus Anterior Cervical Discectomy and Fusion: An Observational Study With 5-Year Minimum Follow-Up.

Retrospective Case-Control study. This study aimed to compare rates and risk factors for all-cause 5-year revisions for patients undergoing primary single-level cervical disc arthroplasty (CDA) versus Anterior Cervical Discectomy and Fusion (ACDF). Prospective studies have compared patient reported outcomes, adjacent segment degeneration, and long-term revisions between CDA and ACDF. Despite these high-level evidence studies, well-powered, large investigations have not been adequately reported. A nationwide database was queried for patients undergoing primary single level CDA or ACDF for degenerative cervical spine pathology. Further inclusion criteria consisted of patients having a minimum of 5-year follow-up. Patients undergoing CDA were 1:5 ratio matched to patients undergoing ACDF by age, sex, comorbidities, and overall Elixhauser comorbidity index (ECI). Objectives were to compare the rates and risk factors of all-cause 5-year revisions for those undergoing single level CDA versus ACDF. Multivariate logistic regression models computed odds ratios (OR) of revisions within 5 years. P values less than 0.001 were significant. A total of 32,953 patients underwent single level CDA (N=5,640) or ACDF (N=27,313) with 5-Year minimum follow-up. The incidence of all cause revisions within 5 years were 1.24% for CDA and 9.23% for ACDF (P<0.001). After adjustment, patients undergoing single level ACDF had significantly higher odds of all-cause revisions within 5 years (OR: 8.09; P<0.0001). Additional patient specific factors associated with revisions were a history of reported drug abuse (OR: 1.51; P<0.0001), depression (OR: 1.23; P<0.0001), cardiac arrythmias (OR: 1.21; P=0.0008), hypertension (OR: 1.20; P=0.0006), and tobacco use (OR: 1.18; P=0.0003). In this study of nearly 33,000 single level cervical spine surgeries with minimum 5-year follow-up, all-cause revision rates were significantly lower for patients undergoing CDA. Surgeons may use this data to counsel patients regarding 5-year revisions following single level CDA or ACDF. III.

Postoperative opioid consumption patterns diverge between propensity matched patients undergoing traumatic and elective cervical spine fusion

BACKGROUND CONTEXTProlonged opioid therapy following spine surgery is an ongoing postoperative concern. While prior studies have investigated postoperative opioid use patterns in the elective cervical surgery patient population, to our knowledge, opioid use patterns in patients undergoing surgery for traumatic cervical spine injuries have not been elucidated. PURPOSEThe purpose of this study was to compare opioid use and prescription patterns in the postoperative pain management of patients undergoing traumatic and elective cervical spine fusion surgery. STUDY DESIGNRetrospective cohort study. PATIENT SAMPLEAdult patients with traumatic cervical injuries who underwent primary anterior cervical discectomy and fusion (ACDF) or posterior cervical decompression and fusion (PCDF) during their initial hospital admission. The propensity matched, control group consisted of adult elective cervical fusion patients who underwent primary ACDF or PCDF. OUTCOME MEASURESDemographic data, surgical characteristics, spinal disease diagnosis, location of cervical injury, procedure type, operative levels fused, and Prescription Drug Monitoring Program (PDMP) data. PDMP data included the number of opioid prescriptions filled, preoperative opioid use, postoperative opioid use, and use of perioperative benzodiazepines, muscle relaxants, or gabapentin. Opioid consumption data was collected in morphine milligram equivalents (MME) and standardized per day. METHODSA 1:1 propensity match was performed to match traumatic injury patients undergoing cervical fusion surgery with elective cervical fusion patients. Traumatic injury patients were matched based on age, sex, CCI, procedure type, and cervical levels fused. Pre- and postoperative opioid, benzodiazepine, muscle relaxant, and gabapentin use were assessed for the traumatic injury and elective patients. T- or Mann-Whitney U tests were used to compare continuous data and Chi-Squared or Fisher's Exact were used to compare categorical data. Multivariate stepwise regression using MME per day 0 – 30 days following surgery as the dependent outcome was performed to further evaluate associations with postoperative opioid use. RESULTSA total of 48 patients underwent fusion surgery for a traumatic cervical spine injury and 48 elective cervical fusion with complete PDMP data were assessed. Elective patients were found to fill more prescriptions (3.19 vs 0.65, p=.023) and take more morphine milligram equivalents (MME) per day (0.60 vs 0.04, p=.014) within 1 year prior to surgery in comparison to traumatic patients. Elective patients were also more likely to use opioids (29.2% vs 10.4%, p=.040) and take more MMEs per day (0.70 vs 0.05, p=.004) within 30 days prior to surgery. Within 30 days postoperatively, elective patients used opioids more frequently (89.6% vs 52.1%, p<.001) and took more MMEs per day (3.73 vs 1.71, p<.001) than traumatic injury patients. Multivariate stepwise regression demonstrated preoperative opioid use (Estimate: 1.87, p=.013) to be correlated with higher postoperative MME per day within 30 days of surgery. Surgery after traumatic injury was correlated with lower postoperative MME use per day within 30 days of surgery (Estimate: −1.63 p=.022). CONCLUSIONCervical fusion patients with a history of traumatic spine injury consume fewer opioids in the early postoperative period in comparison to elective cervical fusion patients, however both cohorts consumed a similar amount after the initial 30-day postoperative period. Preoperative opioid use was also a risk factor for higher consumption in the short-term postoperative period. These results may aid physicians in further understanding patients’ postoperative care needs based on presenting injury characteristics and highlights the need for enhanced follow-up care for traumatic cervical spine injury patients after fusion surgery.

Predictors of failure after primary anterior cervical discectomy and fusion for subaxial traumatic spine injuries

IntroductionTraumatic subaxial fractures account for more than half of all cervical spine injuries. The optimal surgical approach is a matter of debate and may include anterior, posterior or a combined anteroposterior (360º) approach. Analyzing a cohort of patients initially treated with anterior cervical discectomy and fusion (ACDF) for traumatic subaxial injuries, the study aimed to identify predictors for treatment failure and the subsequent need for supplementary posterior fusion (PF).MethodsA retrospective, single center, consecutive cohort study of all adult patients undergoing primary ACDF for traumatic subaxial cervical spine fractures between 2006 and 2018 was undertaken and 341 patients were included. Baseline clinical and radiological data for all included patients were analyzed and 11 cases of supplementary posterior fixation were identified.ResultsPatients were operated at a median of 2.0 days from the trauma, undergoing 1-level (78%), 2-levels (16%) and ≥ 3-levels (6.2%) ACDF. A delayed supplementary PF was performed in 11 cases, due to ACDF failure. On univariable regression analysis, older age (p = 0.017), shorter stature (p = 0.031), posterior longitudinal ligament (PLL) injury (p = 0.004), injury to ligamentum flavum (p = 0.005), bilateral facet joint dislocation (p < 0.001) and traumatic cervical spondylolisthesis (p = 0.003) predicted ACDF failure. On the multivariable regression model, older age (p = 0.015), PLL injury (p = 0.048), and bilateral facet joint dislocation (p = 0.010) remained as independent predictors of ACDF failure.ConclusionsACDF is safe and effective for the treatment of subaxial cervical spine fractures. High age, bilateral facet joint dislocation and traumatic PLL disruption are independent predictors of failure. We suggest increased vigilance regarding these cases.

Elective Single-Level Primary Anterior Cervical Decompression and Fusion for Degenerative Spondylotic Cervical Myelopathy Is Associated With Decreased Resource Utilization Versus Posterior Cervical Decompression and Fusion.

Retrospective cohort study. To compare elective single-level anterior cervical discectomy and fusion (ACDF) versus posterior cervical decompression and fusion (PCDF) for degenerative cervical myelopathy (DCM) in terms of (1) cost, (2) length of hospital stay, and (3) discharge destination in Medicare patients. A sub-analysis of potential cost drivers was also performed. In the era of value-based medicine, there is substantial interest in reducing the cost of care. Both ACDF and PCDF are used to treat DCM but carry different morbidity and risk profiles that can impact hospital resource utilization. However, this has not been assessed on a national level. Patients undergoing single-level elective ACDF and PCDF surgery were identified using the 2019 Medicare Provider Analysis and Review (MedPAR) Limited Data Set (LDS) and Centers for Medicare and Medicaid Services (CMS) 2019 Impact File. Multivariate models of hospital cost of care, length of stay, and discharge destination were performed, controlling for confounders. A univariate sub-analysis of 9 revenue centers was performed. In all, 3942 patients met the inclusion criteria. The mean cost of elective single-level cervical fusion for myelopathy was $18,084±10,783, and the mean length of stay was 2.45±2.95d. On multivariate analysis, ACDF was independently associated with decreased cost of $5,814 ( P <0.001), shorter length of stay by 1.1 days ( P <0.001), and decreased risk of nonhome discharge destination by 58% (adjusted odds ratio: 0.422, P <0.001).On sub-analysis of 9 revenue centers, medical/surgical supply ($10,497, 44%), operating room charges ($5401, 23%), and accommodations ($3999, 17%) were the largest drivers of charge differences. Single-level elective primary ACDF for DCM was independently associated with decreased cost, decreased hospital length of stay, and a lower rate of nonhome discharge compared with PCDF. Medical and surgical supply, operating room, and accommodation differences between ACDF and PCDF are potential areas for intervention. Increased granularity in reimbursement structures is warranted to prevent the creation of disincentives to the treatment of patients with DCM with pathology that is better addressed with PCDF. Level-III Retrospective Cohort Study.

What Is the Evidence Supporting Osteobiologic Use in Revision Anterior Cervical Discectomy and Fusion?

Systematic literature review. To analyze the literature and describe the evidence supporting osteobiologic use in revision anterior cervical discectomy and fusion (ACDF) surgery. A systematic search of PubMed/MEDLINE, EMBASE, Cochrane library, and ClinicalTrials.gov databases was conducted for literature reporting the use of osteobiologics in revision ACDF. We searched for studies reporting outcomes of using any osteobiologic use in revision ACDF surgeries (independently of the number of levels) in the above databases. There are currently no studies in the literature describing the outcome and comparative efficacy of diverse osteobiologic agents in the context of revision ACDF surgery. A majority of the current evidence is based only upon studies involving primary ACDF surgery. The current study highlights the paucity of literature evidence on the role of diverse osteobiologics in revision ACDF, and foregrounds the need for high-quality evidence on this subject.

AO Spine Guideline for the Use of Osteobiologics (AOGO) in Anterior Cervical Discectomy and Fusion for Spinal Degenerative Cases.

Guideline. To develop an international guideline (AOGO) about the use of osteobiologics in anterior cervical discectomy and fusion (ACDF) for treating degenerative spine conditions. The guideline development process was guided by AO Spine Knowledge Forum Degenerative (KF Degen) and followed the Guideline International Network McMaster Guideline Development Checklist. The process involved 73 participants with expertise in degenerative spine diseases and surgery from 22 countries. Fifteen systematic reviews were conducted addressing respective key topics and evidence was collected. The methodologist compiled the evidence into GRADE Evidence-to-Decision frameworks. Guideline panel members judged the outcomes and other criteria and made the final recommendations through consensus. Five conditional recommendations were created. A conditional recommendation is about the use of allograft, autograft or a cage with an osteobiologic in primary ACDF surgery. Other conditional recommendations are about the use of osteobiologic for single- or multi-level ACDF, and for hybrid construct surgery. It is suggested that surgeons use other osteobiologics rather than human bone morphogenetic protein-2 (BMP-2) in common clinical situations. Surgeons are recommended to choose 1 graft over another or 1 osteobiologic over another primarily based on clinical situation, and the costs and availability of the materials. This AOGO guideline is the first to provide recommendations for the use of osteobiologics in ACDF. Despite the comprehensive searches for evidence, there were few studies completed with small sample sizes and primarily as case series with inherent risks of bias. Therefore, high-quality clinical evidence is demanded to improve the guideline.

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.

Association of Neighborhood Socioeconomic Deprivation With Utilization and Costs of Anterior Cervical Discectomy and Fusion.

A retrospective analysis. The aim of our study was to analyze the association of Area Deprivation Index (ADI) with the utilization and costs of elective anterior cervical discectomy and fusion (ACDF) surgery. ADI, a comprehensive neighborhood-level measure of socioeconomic disadvantage, has been shown to be associated with worse perioperative outcomes in a variety of surgical settings. The Maryland Health Services Cost Review Commission Database was queried to identify patients who underwent primary elective ACDF between 2013 and 2020 in the state. Patients were stratified into tertiles by ADI, from least disadvantaged (ADI1) to most disadvantaged (ADI3). The primary endpoints were ACDF utilization rates per 100,000 adults and episode-of-care total costs. Univariable and multivariable regression analyses were performed. A total of 13,362 patients (4984 inpatient and 8378 outpatient) underwent primary ACDF during the study period. In our study, there were 2,401 (17.97%) patients residing in ADI1 neighborhoods (least deprived), 5974 (44.71%) in ADI2, and 4987 (37.32%) in ADI3 (most deprived). Factors associated with increased surgical utilization were increasing ADI, outpatient surgical setting, non-Hispanic ethnicity, current tobacco use, and diagnoses of obesity and gastroesophageal reflux disease. Factors associated with lower surgical utilization were: non-white race, rurality, Medicare/Medicaid insurance status, and diagnoses of cervical disk herniation or myelopathy. Factors associated with higher costs of care were increasing ADI, older age, Black/African American race, Medicare or Medicaid insurance, former tobacco use, and diagnoses of ischemic heart disease and cervical myelopathy. Factors associated with lower costs of care were outpatient surgical setting, female sex, and diagnoses of gastroesophageal reflux disease and cervical disk herniation. Neighborhood socioeconomic deprivation is associated with increased episode-of-care costs in patients undergoing ACDF surgery. Interestingly, we found greater utilization of ACDF surgery among patients with higher ADI. 3.

Post-Operative Physical Therapy Following Cervical Spine Surgery: Analysis of Patient-Reported Outcomes.

Introduction Post-operative physical therapy (PT) following anterior cervical discectomy and fusion (ACDF) surgery is often performed to improve a patient's functional ability and reduce neck pain. However, current literature evaluating the benefits of post-operative PT using patient-reported outcomes (PROs) is limited and remains inconclusive. Here we compare post-operative improvement between patients who did and did not undergo formal PT after ACDF using Patient-Reported Outcomes Measurement Information System (PROMIS) scores. Methods A retrospective observational study examining patients who underwent one- or two-level primary ACDF or cervical disc replacement (CDR) at an academic orthopedic hospital and who had PROMIS scores recorded pre-operatively and through two-year follow-up. Patients were stratified according to whether or not they attended formal postoperative PT. PROMIS scores and patient demographics were compared using the Mann-Whitney U test, Fisher's exact test, chi-square test of independence, and Student's t-test within and between cohorts. Results Two hundred and twenty patients were identified. Demographic differences between PT and no PT groups include age (PT 54.1 vs. no PT 49.5, p=0.005) and BMI (PT 28.1 vs. no PT 29.8, p=0.028). The only significant difference in post-operative PROMIS scores was in physical health scores at three months post-operatively (no PT 43.9 vs. PT 39.1, p=0.008). Physical health scores improved from baseline to one-year follow-up in both cohorts (PT +3.5, p=0.025; no PT +6.6, p=0.008). There were no significant differences when comparing improvements in physical health scores between groups at six months and one year. Conclusion In conclusion, there was no significance to support the benefits of post-operative PT as measured by PROMIS scores. No significant differences in PROMIS were observed between groups from pre-operative baseline scores to six-month and one-year follow-ups.

Porous Polyetheretherketone Interbody Cages for Anterior Cervical Discectomy and Fusion at 3 or More Levels: Clinical and Radiographic Outcomes.

Anterior cervical discectomy and fusion (ACDF) at 3 or more levels remains challenging, with reported high pseudarthrosis rates and implant-related complications. Porous surface polyetheretherketone (PEEK) interbody cages are newer implants for ACDF with limited data available for their use in ACDF procedures at 3 or more levels. The objective of this study was to assess the clinical and radiographic outcomes of porous PEEK devices for ACDF at 3 or more levels. Retrospective case series. Consecutive patients who underwent primary ACDF for degenerative cervical disc disease at 3 or more levels with porous PEEK cages with anterior plate instrumentation were included. Clinical outcome scores, radiographic parameters, pseudarthrosis rates, and cage subsidence rates were assessed. Preoperative and postoperative clinical outcomes and radiographic measures were compared using paired t tests. A total of 33 patients with ACDF at 3 or more levels with porous PEEK cages were included, with minimum 1-year follow-up. Two patients had cage subsidence (6.1%), and 1 patient had pseudarthrosis (3.0%). There were significant postoperative increases in overall cervical lordosis, sagittal vertical axis, fusion segment lordosis, T1 slope, and disc height. Clinical outcomes showed significant improvement from the preoperative visit to the final postoperative follow-up. High rates of fusion (97.0%) were observed in this challenging patient cohort, which compares favorably with previously published rates of fusion in ACDF at 3 or more levels. The optimal management of cervical spinal pathology regarding approach, technique, and implants used is an active area of ongoing investigation. The high levels of radiographic and clinical success utilizing a relatively novel implant material in a high-risk surgical cohort reported here may influence surgical decision making.

Feasibility of Machine Learning in the Prediction of Short-Term Outcomes Following Anterior Cervical Discectomy and Fusion

Increased emphasis is being placed on efficiency and resource utilization when performing anterior cervical discectomy and fusion (ACDF), and accurate prediction of complications is increasingly important to optimize care. This study aimed to compare predictive models for postoperative complications following ACDF using machine learning (ML) models based on traditional comorbidity indices. In this retrospective case series, the American College of Surgeons National Surgical Quality Improvement Program database was queried between 2011 and 2017 for all elective, primary ACDF cases. Levels of surgery, use of interbody implants, and graft selection were calculated by procedural codes. Six ML algorithms were constructed using available preoperative and intraoperative features. The overall dataset was randomly split into training (80%) and validation (20%) subsets wherein the training subset optimized the model, and the validation subset was evaluated for accuracy. ML models were compared with models constructed from American Society of Anesthesiologists classification and frailty index alone. There were 42,194 ACDF cases eligible for inclusion. Mean age was 47.7 ± 11.6 years, body mass index was 30.4 ± 6.7, and levels of operation were 1.6 ± 0.7. ML algorithms uniformly outperformed comorbidity indices in predicting complications. Logistic regression ML algorithm was the best performing for predicting any adverse event (area under the curve [AUC] 0.73), transfusion (AUC 0.90), surgical site infection (AUC 0.63), and pneumonia (AUC 0.80). Gradient boosting trees ML algorithm was the best performing for predicting extended length of stay (AUC 0.73). ML algorithms modeled the development of postoperative adverse events with superior accuracy to that of comorbidity indices and may guide preoperative clinical decision making before ACDF.

Soft Cervical Orthosis Use Does Not Improve Fusion Rates After One-Level and Two-Level Anterior Cervical Discectomy and Fusion

To determine if postoperative soft cervical orthosis use affects arthrodesis rates on a per-level or construct basis after 1-level and 2-level anterior cervical discectomy and fusion (ACDF). Electronic medical records were queried for 1-level and 2-level primary ACDF between 2016 and 2019 at a single academic center. Surgeons prescribed either a soft cervical orthosis or no orthosis. Pseudarthrosis rates were evaluated by dynamic cervical spine radiographs with arthrodesis defined by <1 mm of interspinous motion. Continuous and categorical data were compared using analysis of variance or χ2 tests. Multivariate logistic regression analysis was used to examine independent predictors of pseudarthrosis. A total of 316 unique patients (504 instrumented levels) met the inclusion criteria. Eighty-four percent of patients were prescribed a soft cervical orthosis. Overall, arthrodesis occurred at 344 (80.9%) and 62 (78%) levels in patients with and without cervical orthosis, respectively. When evaluating patients placed in a cervical orthosis versus those who were not, there were no differences in pseudarthrosis or revision rates. Further, there were no differences in pseudarthrosis on a per-level basis. Further, cervical orthosis use was not an independent predictor of pseudarthrosis (odds ratio, 0.86; 95% confidence interval, 0.47-1.57; P=0.623) on multivariate analysis. Postoperative placement of soft cervical orthoses after 1-level or 2-level ACDF was not associated with improved arthrodesis or reduced rate of revision surgery.

Workers compensation patients experiencing depression report meaningful improvement in mental health scores after anterior cervical discectomy and fusion

BackgroundMental health has been demonstrated to affect postoperative outcomes. No prior literature has reported the relationship between preoperative mental health on outcomes following anterior cervical discectomy and fusion (ACDF) in the Workers Compensation (WC) population. MethodsWC claimants who underwent primary ACDF were identified from a single-surgeon retrospective database. Patients were separated by SF-12 MCS score into Depressed (<45.6) or Not Depressed (ND) (≥45.6) cohorts. Patient-reported Outcome Measurement Information System Physical Function (PROMIS PF), SF-12 Physical Component Score (SF-12 PCS), SF-12 MCS, visual analog scale (VAS) neck/arm pain, and Neck Disability Index (NDI) were collected and compared within and between groups. Minimum clinically important difference (MCID) achievement rates were compared between groups. ResultsDepressed patients had greater length of stay (p = 0.007) and postoperative narcotic consumption (p = 0.026). Depressed patients improved at 12-week to 2-year PROMIS PF, 6-month SF-12 PCS, 6-week to 6-month SF-12 MCS, 6-week to 6-month and 2-year VAS neck, all VAS arm, and 6-month NDI (p ≤ 0.045, all). ND patients improved at 12-week to 1-year PROMIS PF, 6-month to 2-year SF-12 PCS, 12-week to 1-year VAS neck, 6-week to 1-year VAS arm, and 12-week to 1-year NDI (p ≤ 0.044, all). Between groups, ND patients reported superior PROMIS PF, SF-12 MCS, VAS neck, VAS arm, and NDI scores at two or more periods (p ≤ 0.045, all). MCID achievement rate regarding SF-12 MCS was greater in the Depressed cohort at all postoperative points up to 1 year (p ≤ 0.020, all). ConclusionDepressed patients tended to have a greater length of stay and postoperative narcotic consumption immediately after surgery. Not depressed patients reported more favorable physical and mental function, pain, and disability scores preoperatively and postoperatively. Depressed patients reported greater MCID achievement in mental function following surgery. Depressed patients with WC have a greater likelihood of reporting tangible improvement in mental health scores following ACDF.

Prediction of Admission Costs Following Anterior Cervical Discectomy and Fusion Utilizing Machine Learning.

Retrospective case series. Predict cost following anterior cervical discectomy and fusion (ACDF) within the 90-day global period using machine learning models. The incidence of ACDF has been increasing with a disproportionate decrease in reimbursement. As bundled payment models become common, it is imperative to identify factors that impact the cost of care. The Nationwide Readmissions Database (NRD) was accessed in 2018 for all primary ACDFs by the International Classification of Diseases 10th Revision (ICD-10) procedure codes. Costs were calculated by utilizing the total hospital charge and each hospital's cost-to-charge ratio. Hospital characteristics, such as volume of procedures performed and wage index, were also queried. Readmissions within 90 days were identified, and cost of readmissions was added to the total admission cost to represent the 90-day healthcare cost. Machine learning algorithms were used to predict patients with 90-day admission costs >1SD from the mean. There were 42,485 procedures included in this investigation with an average age of 57.7±12.3 years with 50.6% males. The average cost of the operative admission was $24,874±25,610, the average cost of readmission was $25,371±11,476, and the average total cost was $26,977±28,947 including readmissions costs. There were 10,624 patients who were categorized as high cost. Wage index, hospital volume, age, and diagnosis-related group severity were most correlated with the total cost of care. Gradient boosting trees algorithm was most predictive of the total cost of care (area under the curve=0.86). Bundled payment models utilize wage index and diagnosis-related groups to determine reimbursement of ACDF. However, machine learning algorithms identified additional variables, such as hospital volume, readmission, and patient age, that are also important for determining the cost of care. Machine learning can improve cost-effectiveness and reduce the financial burden placed upon physicians and hospitals by implementing patient-specific reimbursement.

Hybrid surgery: a comparison of early postoperative outcomes between anterior cervical discectomy and fusion and cervical disc arthroplasty.

Hybrid surgery (HS) is the combination of anterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA) at different levels in the same operation. The aim of this study was to investigate perioperative variables, 30-day postoperative outcomes, and complications of HS in comparison with those of CDA and ACDF. The authors queried the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) registry for patients who underwent multilevel primary HS, CDA, and ACDF for degenerative disc disease from 2015 to 2019. The authors compared these three operations in terms of 30-day postoperative outcomes, specifically readmission and reoperation rates, discharge destination, and complications. This analysis included 439 patients who underwent HS, 976 patients who underwent CDA, and 27,460 patients who underwent ACDF. Patients in the HS and CDA groups were younger, had fewer comorbidities, and myelopathy was less often the indication for surgery compared with patients who underwent ACDF. For the HS group, the unplanned readmission rate was 0.7%, index surgery-related reoperation rate was 0.3%, and nonroutine discharge rate was 2.1%. Major and minor complications were also rare, with rates of 0.2% for each. The mean length of stay in the HS group was 1.5 days. The association of HS with better outcomes in univariate analysis was not evident after adjustment for confounding factors. The authors found that HS was noninferior to ACDF and CDA in terms of early postoperative outcomes among patients treated for degenerative disc disease.

Recovery of Physical Function Based on Body Mass Index Following Anterior Cervical Discectomy and Fusion.

Body mass index (BMI) serves as a risk factor for complications and poorer outcomes following anterior cervical discectomy and fusion (ACDF). This study investigates the association between BMI and Patient Reported Outcomes Measurement Information System physical function (PROMIS-PF) following ACDF. A prospectively maintained surgical registry was retrospectively reviewed for cervical spine surgeries between 2015 and 2019. Included patients underwent elective primary, single, or multilevel ACDF and were excluded for missing preoperative PROMIS-PF. Patients were stratified into 4 groups based on BMI score. Associations of demographic and perioperative characteristics with BMI groups were analyzed using either χ2 test or t test. PROMIS-PF was evaluated preoperatively and 6 weeks, 12 weeks, 6 months, 1 year, and 2 years postoperatively using linear regression. Delta improvement in PROMIS-PF was evaluated at all time points. The 128 study cohort had 74 patients the nonobese, 27 in the Obese I, 19 in the Obese II, and 8 in the Obese III groups. The mean age was 50.0 years and 57.0% were male. Gender, diabetic status, and Charlson Comorbidity Index (CCI) significantly differed by BMI groups but did not differ by perioperative characteristics. Preoperative PROMIS-PF did not significantly differ by group. Obese II and III groups had decreased PROMIS-PF compared to Obese I and nonobese groups at 1 year and 2 years. BMI groups had significantly different delta improvement at the 12 weeks (4.1 vs 10.1 vs 1.8 vs 4.3; P = 0.044) and 2 years (9.9 vs 7.1 vs 2.3 vs 3.0; P = 0.048). Among the assessed BMI subgroups, all experienced similar physical function scores during the preoperative and short-term time points. Patients with higher BMI demonstrated diminished physical function at long-term time points. While this study focused on evaluating obesity, longitudinal tracking of high-risk patients during the postoperative period remains important for optimal rehabilitation. 4. High BMI may predispose patients to lengthier recovery of physical function following ACDF.

Predictors of Dysphagia After Anterior Cervical Discectomy and Fusion: A Prospective Multicenter Study.

Multicenter prospective study. Our aim was to evaluate the incidence and predictors of postoperative dysphagia in patients undergoing anterior cervical discectomy and fusion (ACDF). Dysphagia is a common complication after ACDF that can have significant effect on patients' quality of life, but the frequency of occurrence and potential risk factors are not known. A multicenter prospective study was undertaken at three academic sites to evaluate patients undergoing ACDF between September 2018 and September 2020. Included patients were aged 18 to 80 years and were undergoing primary or revision ACDF for a degenerative condition. Dysphagia was assessed using the validated Eating Assessment Tool (EAT-10) questionnaire, with dysphagia defined as EAT-10 ≥ 3. A total of 170 patients (53.5% female; mean age at surgery 55.0 yr) were included. At preoperative baseline, 23 patients (13.5%) had dysphagia. Rates of dysphagia increased to 45.3% at 2 weeks postoperatively but gradually decreased to 15.3% at 24weeks. On univariate analysis, patients with dysphagia at 2weeks had longer operations (113.1 ± 58.4 vs. 89.0 ± 39.8 minutes, P = 0.003) and higher baseline dysphagia rates (18.2% vs. 6.2%, P = 0.018) and were more likely to be female (66.2% vs. 45.7%, P = 0.009). Patients with prolonged dysphagia had more levels fused (2.1 ± 1.0 vs. 1.7 ± 0.7, P = 0.020), longer operations (131.8 ± 63.1 vs. 89.3 ± 44.3 min-minutes, P < 0.001), and higher baseline dysphagia rates (32% vs. 7.1%, P < 0.001) and were more likely to be smokers (24% vs. 8%, P = 0.021). On multivariate analysis to determine associations with prolonged dysphagia, only smoking status (OR 6.2, 95% CI 1.57-24.5, P = 0.009) and baseline dysphagia (OR 5.1, 95% CI 1.47-17.6, P = 0.01) remained significant. Dysphagia is common immediately after ACDF, but rates of prolonged dysphagia are similar to preoperative baseline rates. We identified dysphagia rates over time and several patient factors associated with development of short- and long-term postoperative dysphagia.Level of Evidence: 3.

64. Impact of depression on patient reported outcomes following primary vs revision ACDF

<h3>BACKGROUND CONTEXT</h3> Depression has been associated with poorer outcomes following anterior cervical discectomy and fusion (ACDF). However, research examining the relationship between depression and patient reported outcome measures (PROMs) in revision ACDF procedures is limited. <h3>PURPOSE</h3> To assess the relationship of depressive symptoms with PROMs in patients undergoing either primary or revision ACDF procedures. <h3>STUDY DESIGN/SETTING</h3> Retrospective cohort. <h3>PATIENT SAMPLE</h3> 143 patients undergoing primary or revision, single- or multilevel ACDF procedures. <h3>OUTCOME MEASURES</h3> Demographic and perioperative characteristics, Patient Health Questionnaire-9 (PHQ-9), visual analog scale (VAS), Neck Disability Index (NDI). <h3>METHODS</h3> A prospective database was retrospectively reviewed for primary or revision, single- or multi-level ACDF procedures from 2016 to 2020. Patients lacking preoperative PHQ-9 surveys were excluded. Demographic and perioperative characteristics were recorded and analyzed using Fisher's exact test or t-test. Patient-reported outcome measures were collected preoperatively and postoperatively. Postoperative improvement from baseline scores (ΔPROM) was calculated at all postoperative timepoints. Differences in mean PROM and ΔPROM between groups and changes from baseline PROM scores within groups were assessed using student's t-test. Linear regression analyzed the impact of preoperative PHQ-9 on ΔPROM among primary and revision patients. <h3>RESULTS</h3> A total of 143 patients (121 primary and 22 revision) were included. Significant differences between groups were demonstrated at the preoperative timepoint for NDI (p=0.022). ΔPROM values did not significantly differ between groups. Regression analysis revealed significant relationships between preoperative PHQ-9 and ΔPHQ-9 at all timepoints, ΔVAS neck at 6-weeks and 6-months, ΔVAS arm at 6-months, and ΔNDI at 6-weeks and 6-months for the primary group (all p<0.05). Regression analysis revealed no significant associations for the revision group. <h3>CONCLUSIONS</h3> Primary or revision ACDF procedures did not significantly differ in depressive symptoms through 1-year. Primary ACDF patients significantly improved in all PROMs through all timepoints, while revision patients had limited improvement in PROMs. Preoperative depression may have a stronger association on postoperative outcomes for primary procedures. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.