Anterior Cervical Spine Fusion Research Articles

Comparison of RVU Reimbursement in Anterior or Posterior Approach for Single- and Multilevel Cervical Spinal Fusion.

Retrospective database study. This study aims to quantify and compare mean work RVUs (wRVUs), mean operative time (OpTime), and wRVUs/min in single- and multilevel anterior and posterior cervical spine fusions performed between 2011 and 2020. Prior research has demonstrated inconsistencies in technical skill, operative time, and surgical difficulty with reimbursement in various orthopedic subspecialties. Although trends investigating physician effort and reimbursement have been investigated in lumbar spine surgery, less research has examined these relationships with respect to cervical spine procedures. The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) was queried for Current Procedural Terminology (CPT) codes reflecting anterior cervical discectomy and fusion (ACDF), posterior cervical decompression and fusion (PCDF), and the number of levels involved. The cohort was stratified into 10 groups: single-level, 2-level, 3-level, 4-level, 5+ level anterior or posterior cervical fusions. Mean operative times, mean wRVUs, and wRVU/min were calculated and compared by Student t test. A total of 100,997 patients met inclusion criteria in this study, of which 79,141 (78.36%) underwent ACDF, whereas 21,836 (21.62%) underwent PCDF. One- and 2-level fusions were most common in both ACDF and PCDF. In 1-, 3-, 4-, and 5+ level fusion, the anterior approach demonstrated significantly lower mean wRVU (P<0.001). In 1-, 2-, and 3-level fusions, the anterior approach had significantly lower operation times (P<0.001). The anterior approach demonstrated significantly higher wRVU/min in 1- and 2- levels (P<0.001) but lower wRVU/min in 3- and 4-level fusions (P<0.001). Clear discrepancies exist between surgical approach and levels of fusion in cervical spine procedures incongruous with markers of surgical difficulty, physician effort, or expertise required. These specific results suggest that the complexity of multi-level anterior cervical fusions are not effectively accounted for by existing RVU measures.

A comparison of dysphagia rates between long-segment anterior versus posterior cervical fusion.

The goal of this study was to compare rates of dysphagia and patient-reported outcomes (PROs) following long-segment (≥ 3 levels) anterior cervical spinal fusion (ACF) and posterior cervical spinal fusion (PCF) at 3 and 12 months postoperatively. PROs were also compared for patients with dysphagia versus those without dysphagia. A prospectively collected quality improvement database was used to identify patients who had a long-segment cervical spinal fusion. Cohorts were divided into ACF and PCF groups. Eating Assessment Tool-10 scores and PROs were obtained for all patients preoperatively and at 3 and 12 months postoperatively to compare. Multivariate analysis was also performed to evaluate risk factors for dysphagia. A total of 132 patients met the inclusion criteria, 77 of whom had undergone ACF and 55 of whom had undergone PCF. Dysphagia rates between ACF and PCF cohorts were similar at baseline (13.0% vs 18.2%, p = 0.4). New-onset dysphagia rates were also comparable at 3-month follow-up (39.7% vs 23.1%, p = 0.08) and 12-month follow-up (32.6% vs 32.4%, p > 0.99). Patients who underwent PCF had worse Neck Disability Index (NDI) scores at 3 months than did patients with ACF (13.67 ± 9.49 vs 10.55 ± 6.24, respectively; p = 0.03). There were significantly higher NDI scores for patients with dysphagia at 3 months in both the ACF and PCF groups and at 12 months for those in the PCF group. Analogously, EuroQol-5 Dimensions scores were worse for patients with dysphagia; however, this was only significant for patients in the ACF group at 3 months. There were no significant risk factors for the development of dysphagia found on multivariate analysis. Similar rates and severity of dysphagia were seen following ACF and PCF at 3- and 12-month follow-up. This suggests that long-term dysphagia following cervical fusion surgery may be due to structural changes from the fusion rather than the surgical approach. However, the ACF cohort was significantly younger, and this may have partially accounted for the findings. PROs were also compared for patients with and without dysphagia, demonstrating worsened outcomes in some domains for patients who presented with dysphagia at 3- and 12-month follow-up. This suggests that dysphagia may be associated with a decreased quality of life after cervical fusion.

Two Cases of Dysphagia as a Secondary Postoperative Complication after Anterior Cervical Spine Fusion

Two Cases of Dysphagia as a Secondary Postoperative Complication after Anterior Cervical Spine Fusion

Titanium Hypersensitivity Diagnosed by Patch Testing After Anterior Cervical Spine Fusion.

Titanium Hypersensitivity Diagnosed by Patch Testing After Anterior Cervical Spine Fusion.

P125. Development of a novel ensemble machine learning algorithm for prediction of complications and readmission after anterior cervical spinal fusion

<h3>BACKGROUND CONTEXT</h3> Anterior cervical spinal fusion procedures have grown in prevalence due to excellent outcomes, low risk of perioperative outcomes and reduced length of hospitalization. The average age and comorbidity burden of patients undergoing anterior cervical fusion has increased. Given the significant cost and morbidity associated with developing major perioperative complications and unplanned readmissions, accurate risk stratification of patients undergoing this procedure is of great utility. Advanced machine learning (ML) methods have become increasingly employed in spinal surgery due to their ability to recognize complex, non-linear relationships between variables. ML models for preoperative risk stratification of patients undergoing anterior cervical fusion remain limited. <h3>PURPOSE</h3> We aim to develop a novel ensemble ML algorithm for prediction of major perioperative complication and readmission after anterior cervical fusion. Our secondary aim is to compare its performance against benchmark ML models and logistic regression (LR). <h3>STUDY DESIGN/SETTING</h3> Retrospective, cohort study. <h3>PATIENT SAMPLE</h3> Patients 18 years or older at a non-federal California hospital who underwent anterior cervical spinal fusion. <h3>OUTCOME MEASURES</h3> Readmission within 30 days, major perioperative complications (venous thromboembolism within 30 days, myocardial infarction within 7 days, pneumonia within 7 days, systemic infection within 7 days, surgical site bleeding within 90 days, and wound complications within 90 days). <h3>METHODS</h3> This is a retrospective cohort study of adult patients who underwent anterior cervical fusion at any California hospital between 2015-2017. We developed a ML-based model predicting complication risk using AutoPrognosis, an automated ML framework that configures an optimally performing ensemble of ML-based prognostic models. We compared our model with LR and four standard ML models (XGBoost, Gradient Boosting, AdaBoost, Random Forest). Predictive performances were assessed using area under the receiver operating characteristic curve (AUROC). Calibration was assessed using Brier scores. We ranked the contribution of the included features to model performance. <h3>RESULTS</h3> Of the 23,184 patients who met inclusion criteria, there were 1,886 cases of major complication or readmission (8.13%). The ensemble AutoPrognosis model had superior risk prediction (AUROC 0.724 + 0.015) compared to LR (0.717 + 0.012). Furthermore, our model outperformed the four standard ML algorithms. The AutoPrognosis model was well-calibrated (Brier score 0.069 + 0.01). The variables that are most important for AutoPrognosis include patient sex, workers' compensation insurance, age, malnutrition, and chronic obstructive pulmonary disease. Teaching hospital status, schizophrenia, and quadriplegia are also among the 10 most important features for AutoPrognosis model performance but not for LR. <h3>CONCLUSIONS</h3> We report the use of a novel ensemble ML algorithm for prediction of major perioperative complications after anterior cervical fusion. This algorithm is well-calibrated and demonstrates excellent risk prediction, superior to LR and four standard ML algorithms. By automating the choice of appropriate model as well as tuning of model hyperparameters, AutoPrognosis can be used by clinicians who may not possess an in-depth knowledge of ML methods – facilitating the use of advanced ML methods in mainstream clinical research. Notably, the predictors most important for AutoPrognosis are different from those for LR. This suggests that the superior discriminative capability of AutoPrognosis results from not just its ability to select among different ML models but also by capturing complex non-linear relationships between variables that LR is unable to capture. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

262. Does preoperative bone mineral density impact fusion success in anterior cervical spine surgery: a prospective cohort study

<h3>BACKGROUND CONTEXT</h3> Patients with osteoporosis have an imbalance in anabolic versus catabolic bone homeostasis. It has been theorized that osteoporosis may impact fusion rates in lumbar spine surgery. However, to our knowledge this has not been investigated in cervical spine surgery. As our population ages, we are encountering ever increasing numbers of patients with osteoporosis and osteopenia coming in for elective surgery. <h3>PURPOSE</h3> The purpose of this study is to identify risk factors for pseudarthrosis in patients undergoing anterior cervical spine surgery. <h3>STUDY DESIGN/SETTING</h3> This was a prospective, single-center study conducted at an academic medical center between 2002 and 2018. <h3>PATIENT SAMPLE</h3> Seventy-nine patients who underwent 1-4 level anterior cervical spine fusions between the years of 2002-2018, and had a bone mineral density examination performed preoperatively, completed the study with one year of clinical and radiographic follow-up. <h3>OUTCOME MEASURES</h3> Bone density as measured by T-score, Hounsfield units and fusion status were measured. <h3>METHODS</h3> We prospectively collected and analyzed data on patients undergoing anterior cervical spine fusions involving between 1-4 levels between the years of 2002-2018 in which a bone mineral density (BMD) examination was clinically indicated. Based on the World Health Organization (WHO) classification using DEXA scan for measurement of BMD, normal bone density was defined as T-score greater than or equal to -1 SD, osteopenia as having a T-score less than -1 and greater than -2.5 SD, and osteoporosis as having a T-score less than or equal to -2.5 SD. Patients were followed for a minimum of one year. CT scans performed postoperatively were used to evaluate fusion. Three Hounsfield unit measurements were obtained on the vertebrae above and below the fusion levels and averaged. A total of 79 patients completed the study with one-year of clinical and radiographic follow-up. BMD, number of levels fused, smoking status, age, sex and ACE inhibitors/ARBs were analyzed to assess their impact on fusion success. Fusion was established when there was continuous bone bridging between the vertebrae on CT scan. Multivariate analysis was performed to identify potential risk factors for pseudarthrosis utilizing JMP 10.0.0 statistical software. (SAS Institute Inc, Carey, North Carolina). <h3>RESULTS</h3> Fourteen patients (18%) developed pseudarthrosis at one-year postoperatively. The mean age at surgery was 58.8 ±10.5 (30 to 84 years). The mean BMD was -0.45 ±1.4 (-3 to 4). Osteopenia and osteoporosis were identified as risk factors for pseudarthorsis at a minimum of 1 year follow up. Number of levels fused, smoking status, Hounsfield units, ACE/ARB medications, age or gender were not statistically significant risk factors correlated with development of pseudarthrosis although the study may have been underpowered to detect these differences. <h3>CONCLUSIONS</h3> This study suggests that preoperative osteopenia or osteoporosis may be correlated with a higher incidence of pseudarthrosis in anterior cervical spine surgery, even more so than smoking or number of levels fused. While the number of patients enrolled in this study is small, the results are convincing enough to warrant screening and treatment of osteoporosis as well as the optimization of preoperative bone stock in all potential candidates for cervical spine fusion. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Perioperative Corticosteroids Reduce Dysphagia Severity Following Anterior Cervical Spinal Fusion: A Meta-Analysis of Randomized Controlled Trials.

The anterior approach to the cervical spine is commonly used to treat cervical pathology. It is, however, associated with high rates of dysphagia, which may be associated with substantial patient morbidity. Perioperative corticosteroid administration has been advocated to decrease dysphagia rates; its efficacy, however, remains uncertain. We conducted a meta-analysis of randomized trials to determine the efficacy of perioperative corticosteroid administration in reducing postoperative dysphagia as well as any adverse effects, such as pseudarthrosis and infection. We conducted a systematic search of electronic databases (MEDLINE, Embase, CENTRAL [Cochrane Central Register of Controlled Trials], ClinicalTrials.gov) to identify randomized controlled trials (RCTs) that evaluated corticosteroids versus any comparator for prevention of postoperative dysphagia after anterior cervical spine procedures. Two independent reviewers used the GRADE (Grades of Recommendation Assessment, Development and Evaluation) criteria to assess eligibility and risk of bias, perform data extraction, and rate the quality of evidence. The primary outcome was severity of postoperative dysphagia. We conducted meta-analyses of dysphagia (both overall and by delivery method), pseudarthrosis, and postoperative infection. After screening of 927 articles, a total of 7 studies were eligible for final inclusion. These included 431 patients, of whom 247 received corticosteroids and 184 received placebo or a control treatment. Moderate-quality evidence demonstrated a significant improvement in postoperative dysphagia rates (odds ratio, 0.35; 95% confidence interval, 0.20 to 0.63; p < 0.001), and this finding was robust to both permutation analyses and sensitivity analyses removing the studies with a high risk of bias. There was no significant difference between intravenous and local steroid administration (p = 0.16). There were no documented infections. There was no significantly increased risk of pseudarthrosis in those receiving steroids compared with placebo or a control treatment (p = 0.13). This meta-analysis found moderate-quality evidence supporting the use of perioperative corticosteroid administration as an adjunct to anterior cervical spinal procedures. Patients treated with corticosteroids intravenously or locally had significantly decreased severity of dysphagia. Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Use of tissue sealant patch (TachoSil) in the management of cerebrospinal fluid leaks after anterior cervical spine discectomy and fusion

Purpose The purpose of this study was to evaluate a fast, sutureless technique to repair anterior cervical dural tears. Anterior cervical discectomy and fusion (ACDF) is a commonly performed procedure for the treatment of cervical degenerative diseases. Although uncommon, incidental durotomy with cerebrospinal fluid (CSF) leak during ACDF is a potentially serious complication. Yet, its technical management for the prevention of CSF leak is controversial. Methods Between September 2012 and June 2018 we encountered seven cases (2 female/5 male) presenting with intraoperative CSF leaks secondary to incidental dural tears during ACDF surgery. All the cases were surgically treated using a topical fibrin sealant patch (TachoSil) with high adesive strength and fibrin glue (Tisseel). Intraoperative source of leakage, time to leakage control, quantity of Sealant Sponge used and postoperative complications were evaluated. Results Dural tears were tipically the result of dissection of adherent posterior longitudinal ligament and/or calcified disc from the cervical dural sac to allow full decompression of the spinal cord. Effective repair of dural tear defined as cessation of CSF leak after topical sealant agents application was achieved no later than one minute in all cases. Evident clinical and/or radiological postoperative CSF leak was used to determine the patient’s postoperative result. Postoperative CSF leak was not evident during a minimum 6 months follow up. Conclusions In the present study, we have reported our experience with a new sealing technique to manage CSF leaks from iatrogenic cervical dural lacerations. Tachosil tissue sealant patch is a rapid sutureless technique that may help in repairing introperatively incidental dural tears, thus reducing the risk of postoperative CSF leaks. To our knowledge, this is the first series to report the use of Tachosil adhesive sealant patch for the treatment of incidental dural tears during anterior cervical discectomy.

237. Individual plates vs single plate for multilevel fixation results in superior biomechanics in anterior cervical fusion surgery

BACKGROUND CONTEXT Anterior cervical discectomy and fusion (ACDF) has been the gold standard surgical treatment for degenerative conditions of the cervical spine, including degenerative disc disease, cervical spondylotic myelopathy, and cervical disc prolapse. This procedure remains the preferred treatment technique particularly for more elderly patients or those with a contraindication to total disc replacement. Multilevel anterior cervical spine fusion with single plates are associated with hardware failure and screw pullout due to stress shielding and excessive loading. Given the lever arm of longer plates and multiple fusion surfaces, pseudarthrosis rates are higher than single level cases. The biomechanics of a new approach using segmental fixation versus convention fixation using a long plate is compared using computational modeling. PURPOSE To compare the biomechanics of multilevel cervical spine fixation using segmental plating versus single plating. STUDY DESIGN/SETTING Computational modeling using cadaver-validated finite element model of cervical spine PATIENT SAMPLE N/A OUTCOME MEASURES Biomechanical data including segmental range of motion and pull-out load on screws METHODS A cadaver-validated finite element (FE) model of C3-C7 spine was used. The model included all crucial anatomical components including, vertebral bones, intervertebral ligaments and connecting tissues, intervertebral disc, facet joints and uncinate processes. The model was validated by comparison of segmental range of motion against data obtained from a cadaver experiment of cervical spine. The validated model was then used to simulate the fixation across C4-C6 using anterior plating, screw and interbody fixation with PEEK cages following simulation of the surgical procedure including total annulectomy and removal of ACL ligaments and the index levels. Two surgical cases were simulated: fixation with two individual plates (each with three screws) vs fixation with single long plate and 6 screws. Anatomical loading of 70N compressive follower load plus 1.5Nm bending moment were applied to the constructs to simulate physiological flexion, extension, lateral bending and axial rotation motions. Segmental motion and screw load data were compared among constructs. RESULTS Fixation at the index levels resulted in significant reduction in range of motion with 60% reduction in extension,85% in left and right axial rotation (LR&RR),63% in left and right lateral bending (LB&RB) and 80% in flexion. The range of motion in the multi-plate construct was similar to the long plate construct in all loadings. At the upper adjacent segment, both constructs yielded a slight increase in ROM in flexion, extension and lateral bending motions (3-10%). The screws in the long plate construct had significantly greater pull out force ranging from 35-82N in extension versus 10-60N in the multi-plate constructs. In axial rotation the ranges of forces were 18-139N in long plate versus 15-70N in multi-plate constructs. The load ranges were similar in both constructs in flexion and lateral bending. CONCLUSIONS Cervical segmental plating allows the ability to treat each level individually yielding in improvement in ability of restoring natural lordosis and biomechanics. When instrumenting across more than one level in ACDF, the individual multi-plates demonstrate superior biomechanics versus the conventional single long plate constructs by ensuring load sharing versus stress shielding. The screw in segmental plating experience lower axial forces resulting in lower risk of screw pull-out post-surgery. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Dysphonia, dysphagia, and injury of recurrent laryngeal nerve with anterior cervical spinal fusion

Dysphagia, dysphonia and injuries of the recurrent laryngeal nerve still remain the most frequent complications of anterior cervical spinal fusion despite rich world experience, high technological level of anterior supporting complex surgeries. These complications very seldom lead to life-threatening situations, but they reduce patients’ quality of life during the early post-surgical period and patients’ satisfaction with the results of the surgery. The main reasons of intraoperative damage of esophagus, larynx and recurrent laryngeal nerve, methods of dysphagia and dysphonia prevention are described in this work.

Orthopaedics and neurosurgery: Is there a difference in surgical outcomes following anterior cervical spinal fusion?

ObjectiveThe superiority of neurosurgical over orthopaedic spinal procedures is a point of contention. While there is the perception that neurosurgeons are more specifically trained to deal with spinal pathology, no study has directly compared outcomes of spinal surgeries performed by both groups. MethodsWe sought to evaluate the differences in length of surgery, hospital stay, complications, mortality, and readmission for anterior cervical decompression and fusion (ACDF) performed by neurosurgeons versus orthopaedic surgeons. Results17,967 ACDF procedures were analyzed. Neurosurgeons performed 74.3% of the fusions with a trend towards longer operative times and significantly more patients that were discharged to extended care facilities. There was no significant difference in the length of stay, overall complications, mortality, readmission, or reoperation when comparing the two specialties. ConclusionDespite a significantly higher volume of ACDF performed by neurosurgeons, outcomes are comparable following orthopaedic and neurosurgical procedures.

The Utility of Cervical Spine Bracing As a Postoperative Adjunct to Multilevel Anterior Cervical Spine Surgery.

Use of cervical bracing/collar subsequent to anterior cervical spine discectomy and fusion (ACDF) is variable. Outcomes data regarding bracing after ACDF are limited. Here, we study the impact of bracing on short-term outcomes related to safety, quality of care, and direct costs in multilevel ACDF. Retrospective cohort analyses of all consecutive patients undergoing multilevel ACDF with or without bracing from 2013 to 2017 was undertaken (n = 616). Patient demographics and comorbidities were analyzed. Tests of independence and logistic regressions were used to assess differences in length of stay (LOS), discharge disposition (home, assisted rehabilitation facility [ARF], or skilled nursing facility [SNF]), quality-adjusted life year (QALY), direct cost, readmission within 30 days, and emergency room (ER) visits within 30 days. Amongst the study population, 553 were braced and 63 were not braced. There was no difference in comorbidities (P > .05) such as obesity, smoking, chronic obstructive pulmonary disease, hypertension, coronary artery disease, congestive heart failure, and problem list number. A significant difference in American Society of Anesthesiologists (ASA) score was found, with more ASA 2 patients in the braced cohort and more ASA 3 patients in the unbraced cohort (P = .007). LOS was extended for the unbraced group (median 156.9 ± 211.4 versus 86.67 ± 130.6 h, P = .003), and ER visits within 30 days were 0.21 times less likely in the braced group (P = .006). There was no difference in readmission (P = .181), QALY gain (P = .968), and direct costs (P = .689). Bracing following multilevel cervical fixation does not alter short-term postoperative course or reduce the risk for early adverse outcomes in a significant manner.

Pulmonary Embolism as a Complication Following Anterior Cervical Discectomy and Fusion in a Patient with a History of COVID-19: A Case Report and Literature Review

This is a case report of an otherwise healthy 45-year-old male patient with a history of COVID-19, who later underwent an Anterior Cervical Spine Decompression and Fusion of level three to four for progressing neurological symptoms. The patient was readmitted eleven days postoperatively for shortness of breath and found to have a Pulmonary Embolism. The patient was at low risk for postoperative VTE, with no known current significant risk factors. He had a history of COVID-19, along with lab values and imaging that have been shown in other case series to help support the link between covid-19 and hypercoagulable state. We hope to support this hypothesis, and bring light to future larger scale studies, in order to better understand this disease and effectively create a preoperative assessment to identify such patients at risk, along with post-operative protocols for these patients having procedures in the future. To our knowledge, this is the first reported case of confirmed postoperative DVT/PE in an otherwise low-risk patient, who had a history of COVID-19 with full recovery. The rarity of this complication, along with options for how to risk-stratify these patients should be formally addressed, especially in those who require urgent spine surgery. These options are discussed, reviewed, and remarks as to where further attention and research is needed is addressed. Keywords: Anterior Cervical Discectomy and Fusion; COVID-19; Pulmonary Embolism.

Contained-Delivery Route and the Administration of Postoperative Steroids Following Anterior Cervical Spinal Fusion With Low-dose rhBMP-2 Reduces the Magnitude of Respiratory Compromise.

Retrospective chart review of patients who underwent anterior cervical discectomy and fusion (ACDF) using low-dose recombinant human bone morphogenic protein (rhBMP)-2. Determine whether severity and incidence of respiratory complications after ACDF surgery are decreased when using a low-dose BMP-infused sponge within a constrained carrier and postoperative IV and oral steroids. Many physicians avoid using BMP in anterior cervical spine fusions because of concern for an increased incidence of dysphagia, significant prevertebral swelling, and airway edema compromise. Pilot studies have shown that the local application of steroids may decrease the incidence of postoperative airway edema and dysphagia. We performed a retrospective study to evaluate the safety of immediate postoperative tapered steroid use following low-dose rhBMP-2 completely contained inside either an allograft or PEEK cage in reducing the severity and incidence of respiratory complications following ACDF. Forty-seven patients between 33 and 74 years of age, undergoing 1-, 2-, 3-, or 4-level ACDFs augmented with a fraction of a small sponge of rhBMP-2 (0.525 mg/level) within an allograft or PEEK cage and prescribed IV and oral postoperative steroids between January 1, 2008 and November 1, 2016. The incidence of complications such as dyspnea, dysphagia, airway issues, edema ectopic bone osteolysis, radiculitis, and nonunion were collected using medical charts. Additional data regarding length of hospital stay and readmissions were also recorded. No life-threatening respiratory events, such as prolonged intubation, re-intubation, or readmission for labored breathing, were observed. No complications referable to steroids such as delayed healing, uncontrollable blood sugar, or diabetes were encountered in this series. This study provides evidence that a tapered dose of steroids and a contained delivery route significantly decreases postoperative respiratory compromise incidence and magnitude following anterior cervical spine fusion using low-dose rhBMP-2.

Biomechanical investigation of extragraft bone formation influences on the operated motion segment after anterior cervical spinal discectomy and fusion

Although the clinical importance of extragraft bone formation (ExGBF) and bridging (ExGBB) has been reported, few studies have investigated the biomechanical influences of ExGBF on the motion segment. In this study, ExGBF was simulated at the C5-C6 motion segment after anterior cervical discectomy and fusion using a developed finite element model and a sequential bone-remodelling algorithm in flexion and extension. The computer simulation results showed that extragraft bone was primarily formed in the extension motion and grew to form ExGBB. A stepwise decrease in the intersegmental rotation angle, maximum von Mises stress and strain energy density on the trabecular bone with ExGBF were predicted in extension. When ExGBB was formed in the trabecular bone region, the intersegmental rotation angle slightly decreased with additional bone formation. However, the stress and strain energy density on the trabecular bone region decreased until ExGBB reached the peripheral cortical margin. The results offer a rationale supporting the hypothesis that mechanical stimuli influence ExGBF. ExGBF was helpful in increasing the stability of the motion segment and decreasing the fracture risk of trabecular bones, even in cases in which ExGBB was not formed. ExGBB can be classified as either soft or hard bridging based on a biomechanical point of view.

The Utility of Cervical Spine Bracing as a Postoperative Adjunct to Single-level Anterior Cervical Spine Surgery.

Background Context:Use of cervical bracing/collar subsequent to anterior cervical spine discectomy and fusion (ACDF) is variable. Outcomes data regarding bracing after ACDF are limited.Purpose:The purpose of the study is to study the impact of bracing on short-term outcomes related to safety, quality of care, and direct costs in single-level ACDF.Study Design/Setting:This retrospective cohort analysis of all consecutive patients (n = 578) undergoing single-level ACDF with or without bracing from 2013 to 2017 was undertaken.Methods:Patient demographics and comorbidities were analyzed. Tests of independence (Chi-square, Fisher's exact, and Cochran–Mantel–Haenszel test), Mann–Whitney–Wilcoxon tests, and logistic regressions were used to assess differences in length of stay (LOS), discharge disposition (home, assisted rehabilitation facility-assisted rehabilitation facility, or skilled nursing facility), quality-adjusted life year (QALY), surgical site infection (SSI), direct cost, readmission within 30 days, and emergency room (ER) visits within 30 days.Results:Among the study population, 511 were braced and 67 were not braced. There was no difference in graft type (P = 1.00) or comorbidities (P = 0.06–0.73) such as obesity (P = 0.504), smoking (0.103), chronic obstructive pulmonary disease hypertension (P = 0.543), coronary artery disease (P = 0.442), congestive heart failure (P = 0.207), and problem list number (P = 0.661). LOS was extended for the unbraced group (median 34.00 + 112.15 vs. 77.00 + 209.31 h, P < 0.001). There was no difference in readmission (P = 1.000), ER visits (P = 1.000), SSI (P = 1.000), QALY gain (P = 0.437), and direct costs (P = 0.732).Conclusions:Bracing following single-level cervical fixation does not alter short-term postoperative course or reduce the risk for early adverse outcomes in a significant manner. The absence of bracing is associated with increased LOS, but cost analyses show no difference in direct costs between the two treatment approaches. Further evaluation of long-term outcomes and fusion rates will be necessary before definitive recommendations regarding bracing utility following single-level ACDF.

Comparison of the long-term outcomes of total arthroplasty and anterior spinal fusion in the treatment of cervical degenerative disc disease: a metaanalysis

The study aim was to perform a meta-analysis based on the results of randomized clinical trials comparing long-term outcomes of total intervertebral disc arthroplasty (TA) and anterior cervical spinal fusion (ACSF) in the surgical treatment of cervical degenerative disc disease. We searched Pubmed, EMBASE, ELibrary, and Cochrane Library databases for randomized clinical trials reported between 2008 and August 2018. The relative risk and 95% confidence interval were calculated for dichotomous variables; for continuous variables, we used the standardized mean difference and their 95% CI with application of a random effects model. The metaanalysis involved 9 randomized controlled clinical trials including the long-term outcomes of surgical treatment in 2,439 patients. A pooled analysis of the data showed that regression of neurological symptoms (p<0.00001), improvement in the quality of life of patients (Neck Disability Index), and lower pain severity (visual analogue scale for upper extremities) were significantly more often observed (p=0.02) in the group of TA patients. In addition, the TA technique was characterized by a statistically significantly lower rate of re-surgery (p<0.0005) and degeneration of the superjacent segment (p<0.0001), with the rate of adverse events being slightly increased (p=0.04). Compared to anterior cervical spinal fusion, TA of cervical intervertebral discs is characterized by significantly better clinical efficacy in patients with cervical degenerative disc disease in the long-term postoperative follow-up.

Комбинация тотальной артропластики и переднего шейного спондилодеза в хирургическом лечении двухуровневого дегенеративного заболевания шейных межпозвонковых дисков

Комбинация тотальной артропластики и переднего шейного спондилодеза в хирургическом лечении двухуровневого дегенеративного заболевания шейных межпозвонковых дисков

Complications Related to the Recombinant Human Bone Morphogenetic Protein 2 Use in Posterior Cervical Fusion.

A retrospective cohort study. To compare the complications between posterior cervical fusions with and without recombinant human bone morphogenetic protein 2 (rhBMP2). Use of rhBMP2 in anterior cervical spinal fusion procedures can lead to potential complications such as neck edema, resulting in airway complications or neurological compression. However, there are no data on the complications associated with the "off-label" use of rhBMP2 in upper and lower posterior cervical fusion approaches. Patients from the PearlDiver database who had a posterior cervical fusion between 2005 and 2011 were identified. We evaluated complications within 90 days after fusion and data was divided in 2 groups: (1) posterior cervical fusion including upper cervical spine O-C2 (upper group) and (2) posterior cervical fusion including lower cervical spine C3-C7 (lower group). Complications were divided into: any complication, neck-related complications, wound-related complications, and other complications. Of the 352 patients in the upper group, 73 patients (20.7%) received rhBMP2, and 279 patients (79.3%) did not. Likewise, in the lower group of 2372 patients, 378 patients (15.9%) had surgery with rhBMP2 and 1994 patients (84.1%) without. In the upper group, complications were observed in 7 patients (9.6%) with and 34 patients (12%) without rhBMP2. In the lower group, complications were observed in 42 patients (11%) with and 276 patients (14%) without rhBMP2. Furthermore, in the lower group the wound-related complications were significantly higher in the rhBMP2 group (23 patients, 6.1%) compared with the non-rhBMP2 group (75 patients, 3.8%). Our data showed that the use of rhBMP2 does not increase the risk of complications in upper cervical spine fusion procedures. However, in the lower cervical spine, rhBMP2 may elevate the risk of wound-related complications. Overall, there were no major complications associated with the use of rhBMP2 for posterior cervical fusion approaches. Level III.

Corticosteroid Administration to Prevent Complications of Anterior Cervical Spine Fusion: A Systematic Review.

Study Design:Systematic review.Objectives:Anterior cervical approach is associated with complications such as dysphagia and airway compromise. In this study, we aimed to systematically review the literature on the efficacy and safety of corticosteroid administration as a preventive measure of such complications in anterior cervical spine surgery with fusion.Methods:Following a systematic literature search of MEDLINE, Embase, and Cochrane databases in July 2016, all comparative human studies that evaluated the effect of steroids for prevention of complications in anterior cervical spine surgery with fusion were included, irrespective of number of levels and language. Risk of bias was assessed using MINORS (Methodological Index for Non-Randomized Studies) checklist and Cochrane Back and Neck group recommendations, for nonrandomized and randomized studies, respectively.Results:Our search yielded 556 articles, of which 9 studies (7 randomized controlled trials and 2 non–randomized controlled trials) were included in the final review. Dysphagia was the most commonly evaluated complication, and in most studies, its severity or incidence was significantly lower in the steroid group. Although prevertebral soft tissue swelling was less commonly assessed, the results were generally in favor of steroid use. The evidence for airway compromise and length of hospitalization was inconclusive. Steroid-related complications were rare, and in both studies that evaluated the fusion rate, it was comparable between steroid and control groups in long-term follow-up.Conclusions:Current literature supports the use of steroids for prevention of complications in anterior cervical spine surgery with fusion. However, evidence is limited by substantial risk of bias and small number of studies reporting key outcomes.