Multilevel ACDF Research Articles

Anterior cervical discectomy and fusion versus cervical disc arthroplasty: an epidemiological review of 433,660 surgical patients from 2011 to 2021

Background ContextAnterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA) are commonly performed operations to address cervical radiculopathy and myelopathy. Trends in utilization and revision surgery rates warrant investigation. PurposeTo explore the epidemiology, postoperative complications, and reoperation rates of ACDF and CDA. DESIGNRetrospective cohort study. Patient SampleA total of 433,660 patients who underwent ACDF or CDA between 2011 and 2021 were included in this study. Outcome MeasuresThe following data were observed for all cases: patient demographics, complications, and revisions. MethodsThe PearlDiver database was queried to identify patients who underwent ACDF and CDA between 2011 and 2021. Epidemiological analyses were performed to examine trends in cervical procedure utilization by age group and year. After matching by age, sex, Charlson Comorbidity Index (CCI), levels of operation, and reason for surgery, the early postoperative (2-week), short-term (2-year), and long-term (5-year) complications of both cervical procedures were examined. ResultsIn total, 404,195 ACDF and 29,465 CDA patients were included. ACDF utilization rose by 25.25% between 2011 and 2014 while CDA utilization rose by 654.24% between 2011-2019 followed by relative plateauing in both procedures. Mann-Kendall trend test confirmed a significant but small rise in ACDF and large rise in CDA procedures from 2011 to 2021 (p<.001). After matching, ACDF and CDA had an overall complication rate of 12.20% and 8.77%, respectively, with the most common complications being subsequent anterior revision (4.96% and 3.35%) and dysphagia (3.70% and 2.98%). The ACDF cohort, especially multilevel ACDF patients, generally had more complications and higher revision rates than the CDA cohort (p<.05). ConclusionsWhile ACDF utilization has plateaued since 2014, CDA rates have risen by a staggering 654.24% over the past decade. ACDF and CDA complication and revision rates were relatively low in comparison to previously published values, with significantly lower rates in CDA. Although a lack of radiographic data in this study limits its power to recommend either procedure for individual patients with cervical radiculopathy or myelopathy, CDA may be associated with minor improvement in the complication and revision profile.

P122. Early outcomes of multilevel ACDF with segmental plate fixation

P122. Early outcomes of multilevel ACDF with segmental plate fixation

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

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

A real-world analysis of hybrid CDA and ACDF compared to multilevel ACDF

BackgroundMultilevel anterior cervical discectomy and fusion (mACDF) is the gold standard for multilevel spinal disease; although safe and effective, mACDF can limit regular spinal motion and contribute to adjacent segment disease (ASD). Hybrid surgery, composed of ACDF and cervical disc arthroplasty, has the potential to reduce ASD by retaining spinal mobility. This study examined the safety of hybrid surgery by utilizing administrative claims data to compare real-world rates of subsequent surgery and post-procedural hospitalization within populations of patients undergoing hybrid surgery versus mACDF for multilevel spinal disease.MethodsThis observational, retrospective analysis used the MarketScan Commercial and Medicare Database from July 2013 through June 2020. Propensity score matched cohorts of patients who received hybrid surgery or mACDF were established based on the presence of spinal surgery procedure codes in the claims data and followed over a variable post-period. Rates of subsequent surgery and post-procedural hospitalization (30- and 90-day) were compared between hybrid surgery and mACDF cohorts.ResultsA total of 430 hybrid surgery patients and 2,136 mACDF patients qualified for the study; average follow-up was approximately 2 years. Similar rates of subsequent surgery (Hybrid: 1.9 surgeries/100 patient-years; mACDF: 1.8 surgeries/100 patient-years) were observed for the two cohorts. Hospitalization rates were also similar across cohorts at 30 days post-procedure (Hybrid: 0.67% hospitalized/patient-year; mACDF: 0.87% hospitalized/patient-year). At 90 days post-procedure, hybrid surgery patients had slightly lower rates of hospitalization compared to mACDF patients (0.23% versus 0.42% hospitalized/patient-year; p < 0.05).ConclusionsFindings of this real-world, retrospective cohort study confirm prior reports indicating that hybrid surgery is a safe and effective intervention for multilevel spinal disease which demonstrates non-inferiority in relation to the current gold standard mACDF. The use of administrative claims data in this analysis provides a unique perspective allowing the inclusion of a larger, more generalizable population has historically been reported on in small cohort studies.

Anterior Cervical Discectomy and Fusion Surgery: Results with Zero-Profile Spacer/Cage

Objective: Study provides proof to support the promised benefits of employing stand-alone zero-profile cages in multilevel ACDF procedures, as the stand-alone zero-profile device has proven safety and a reduction of the risk of dysphagia in single-level ACDF surgeries.&#x0D; Materials and Methods: This is a retrospective descriptive study, conducted at the Punjab Institute of Neurosciences, Lahore, Pakistan. Data of 36 patients evaluated for post-operative dysphagia and fusion, who had multi-level ACDF surgery employing stand-alone zero-profile cages.&#x0D; Results: Total of 36 patients underwent ACDF surgeries. 86.1% (31/36) patients operated for 2 levels and 13.9% (5/36) patients operated for 3 levels. Dysphagia developed postoperatively in 2 (5.6%) patients in which zero-profile stand-alone cages were used. Fusion was achieved in 94.4% (34/36) patients.&#x0D; Conclusion: Stand-alone zero-profile cages in multi-level ACDF surgeries have a good outcome in terms of post-operative less dysphagia and higher fusion rates.&#x0D; Keywords: Anterior Cervical Discectomy (Decompression) And Fusion (ACDF), Zero-Profile Cages, Cervical Spondylotic Myelopathy.

80. Cellular bone matrix in multilevel ACDF: A prospective evaluation of 1-year fusion rates and patient reported outcomes

<h3>BACKGROUND CONTEXT</h3> Multilevel ACDF has an increased risk of pseudarthrosis compared to single-level fusion. Most current graft options carry some degree of morbidity or downside. Cellular bone matrix (CBM) is an off the shelf product containing allograft bone, mesenchymal stem cells and demineralized bone matrix. It possesses osteoinductive, osteoconductive and osteogenic properties. Early studies have shown high fusion rates, good patient reported outcomes (PROs), and low morbidity. <h3>PURPOSE</h3> To assess 12-month PROs and fusion rates in patients undergoing multilevel ACDF using CBM. <h3>STUDY DESIGN/SETTING</h3> Prospective, single center case series performed in a large private hospital system. <h3>PATIENT SAMPLE</h3> Patients >18 indicated for a 2-4 level ACDF between C2 and T1. Exclusion criteria included 1) BMI over 40 2) diagnosis of metabolic bone disease, 3) active infection, open wounds or lack of appropriate skin coverage, 4) history of previous cervical surgery, 5) known metal sensitivity or allergy to any components of CBM, 6) immunocompromised state, 7) history of substance abuse, 8) workman's comp for neck pain, 9) Prisoners, pregnant mothers or those planning to become pregnant. <h3>OUTCOME MEASURES</h3> Primary outcome measure was the NDI, using an MCID of 17.3%. Secondary measures were Bridwell grade I or II fusion at 12 months and statistically significant improvement on VAS and SF-36. <h3>METHODS</h3> ACDF was performed at each pathologic level. The graft was prepared by removing the cancellous center of an allograft spacer and filling the void with CBM. Operative levels were fixed with a standard titanium plate.NDI, VAS and SF-36 as well as AP and lateral X-rays were completed preoperatively and at 3, 6 and 12 months. CT was obtained at 12 months. Fusion was determined by the presence of bridging bone on 12-month CT. X-rays were graded by the senior author using the Bridwell anterior fusion grading system. Changes in NDI, VAS and SF-36 were calculated using a 1 sample t-test with Bonferroni correction. p<0.05 was used for significance. <h3>RESULTS</h3> NDI improved from 51.7% ± 8.8 to 31.2% ± 13.4 by 3 months and 29.1 ± 13.8 at final follow-up (p <0.001). SF-36 PCS improved from 40.7 ± 6.2 to 51 ± 9.1 at final follow-up (p<0.005). SF-36 MCS improved from 48.4 ± 8.3 to 52.8 ± 7.5 at final follow-up, which fell short of statistical significance (p=0.200). VAS improved from 78.9mm ± 15.3 to 14.8mm ± 19.4 by 3 months and 12.3mm ± 18 at final follow-up (p<0.001). Grade I or II fusion was present in 31/33 levels (93.9%) and 11/13 patients (84.6%) at 6 months. One level demonstrated grade IV resorption and collapse at 6 months. By 12 months there was grade I or II fusion at 33/33 levels. CT scan demonstrated bridging bone within or behind the allograft spacer in 33/33 levels. There were no major adverse events. <h3>CONCLUSIONS</h3> CBM used in multilevel ACDF resulted in high patient satisfaction, high fusion rate, and low morbidity. NDI at final follow-up showed a mean improvement of 23%, surpassing the MCID of 17.3%. We also saw significant improvements in the VAS and SF-36 PCS at 3,6 and 12 months, as well the SF-36 MCS at 6 months. At 6 months there was 93.9% fusion by level, and 84.6% by patient. By 12 months 100% of patients were fused. To our knowledge this represents the first prospectively collected, nonindustry funded study of its kind which adds to a small yet growing body of research in support of CBM in the cervical spine. <h3>FDA DEVICE/DRUG STATUS</h3> ViVigen Cellular Bone Matrix (Approved for this indication)

Safety profile of outpatient vs inpatient ACDF: An analysis of 33,807 outpatient ACDFs

IntroductionAnterior cervical discectomy and fusion (ACDF) is commonly performed to treat symptomatic cervical spondylolysis. Recently, many spine surgeons have begun performing ACDF in the outpatient setting. However, as this is a relatively new trend, many studies are either outdated or have small sample populations. The aim of this study was to evaluate outcomes following elective outpatient ACDF in comparison to those performed in the inpatient setting. MethodsPatients in Mariner Claims Database (2011–2017) undergoing outpatient elective ACDF were propensity score matched using age, gender and comorbidity burden. Chronic and peri-operative complications were assigned based on medical claims codes. All outcomes of interest were analyzed using multivariate logistic regression and compared to those undergoing inpatient ACDF. Significance was defined as p < 0.05 and adjusted with Bonferroni correction. ResultsOutpatient surgery had significantly lower risk of dysphagia within 24 h in both single (OR 0.44, p < 0.001) and multilevel ACDF (OR 0.48, p < 0.001). Patients undergoing outpatient procedures also have lower risk of 90-day minor (Single OR 0.64, p < 0.001; Multilevel OR 0.52, p < 0.001) and major (Single OR 0.48, p < 0.001; Multilevel OR 0.57, p < 0.001) medical complications. Outpatient procedures were also associated with decreased hospital resource utilization with a noted lower risk of subsequent hospital readmission (Single OR 0.71, p < 0.001; Multilevel OR 0.60, p < 0.001) and ER visits (Single OR 0.84, p < 0.001; Multilevel OR 0.87, p < 0.001). ConclusionOutpatient single and multilevel ACDF may be performed safely in properly selected patients. Since there are relatively low rates of readmission and significant complications within the days following outpatient ACDF, many surgeons should consider transitioning carefully selected patients to an outpatient setting.

Anterior Plate-Screws and Lower Postoperative T1 Slope Affect Cervical Allospacer Failures in Multi-Level ACDF Surgery: Anterior Versus Posterior Fixation.

Prospective observational study. In ACDF, graft failure and subsidence are common complications of surgery. Depending on the cervical fixation, different biomechanical characteristics are applied on the grafts. This aims to describe the incidence of cervical spacer failure in patients with cervical degenerative condition according to the cervical fixation method and sagittal balance. From November 2011 to December 2015, 262 patients who underwent cervical spine surgery were enrolled prospectively. Patients were divided into 3 groups based on fixation method: anterior plate/screw (APS), posterior lateral mass screw (LMS), pedicle screw (PPS) groups. Serial X-rays and CT scans were utilized to evaluate radiologic outcomes. Mean patient ages were 56.1 years in the APS group, 61.5 years in the LMS group, and 57.6 years in the PPS group (P = 0.002). Allospacer failure was most common in the APS group, compared to the LMS and PPS groups (chi-square, P = 0.038). Longer fusion level was associated with greater allospacer failure (Baseline 2 level surgery; Odds ratio (OR) 3.4 in 3 level, 15.2 in 4 level, P = 0.036,0.013). Higher T1 slope was correlated with less allospacer failure (OR 0.875, P = 0.001). ORs of allospacer failure in the LMS and PPS groups were 0.04 and 0.02, respectively, (P = 0.01, 0.01), compared with the APS group. This study was able to show that allospacer failure in multi-level ACDF surgery is more common with a longer fusion length, less postoperative T1 slope, and an anterior plate-screws technique. Pedicle screws provided the best biomechanical stability among the 3 constructs.

Cage-screw and anterior plating combination reduces the risk of micromotion and subsidence in multilevel anterior cervical discectomy and fusion—a finite element study

BACKGROUND CONTEXTAnterior cervical discectomy and fusion (ACDF) is widely used to treat patients with spinal disorders, where the cage is a critical component to achieve satisfactory fusion results. However, it is still not clear whether a cage with screws or without screws will be the best choice for long-term fusion as the micromotion (sliding distance) and subsidence (penetration) of the cage still take place repeatedly. PURPOSEThis study aims to examine the effect of cage-screws on the biomechanical characteristics of the human spine, implanted cage, and associate hardware by comparing the micromotion and subsidence. STUDY DESIGNA finite element (FE) analysis study. METHODSA FE model of a C3-C5 cervical spine with ACDF was developed. The spinal segment was modeled with the removal of the anterior longitudinal ligament (ALL), posterior longitudinal ligament (PLL), and discectomy was then implanted with a cage-screw system. Three models were analyzed: the first was the original spine (S1 model), the second, S2, was implanted with cages and anterior plating, and the third, S3, was implanted with a cage-screw system in addition to the anterior plate. All investigations were under 1 N•m in flexion, extension, lateral bending, and axial rotation situations. RESULTSFinite element analysis (FEA) demonstrated that range of motion (ROM) at C3-C4 in the S2 model was significantly reduced more than that in the S3 model, while the ROM at both C4-C5 in the S3 model was reduced more than that in the S2 model in all simulations. The ROM at C3-C5 in the S1 model was reduced by over 5° in the S2 and S3 models in all loading conditions. The micromotion and subsidence at all contacts of C3-C5 in the S3 model were lower than that in the S2 model in all flexion, extension, bending, and axial simulations. The subsidence and micromotion could be seen in the barrier area of the S2 model, while they occurred near the edge of the screw in the S3 model. CONCLUSIONSThese results showed that the cage-screw and anterior plating combination has promising potential to reduce the risk of micromotion and subsidence of implanted cages in two or more level ACDFs. CLINICAL SIGNIFICANCEThe use of double segmental fixation with cage-screw anterior plating combination constructs may increase the stiffness of the construct and reduce the incidence of clinical and radiographic pseudarthrosis following multilevel ACDF, which in turn, could decrease the need for revision surgeries or supplemental posterior fixation.

A Comparison of Various Surgical Treatments for Degenerative Cervical Myelopathy: A Propensity Score Matched Analysis.

Study Design:Retrospective Cohort.Objective:To compare the short-term outcomes for Laminoplasty, Laminectomy/fusion, and ACDF.Methods:We utilized a prospectively-collected, multi-center national database with a propensity score matching algorithm to compare the short-term outcomes for laminoplasty, laminectomy/fusion, and multi-level (>3) ACDF (with and without corpectomy). Bivariate analyses involved both chi-square/fisher exact test and t-test/ANOVA on perioperative factors. Multivariate analyses were performed to determined independent risk factors for short term outcomes.Results:546 patients remained after propensity score matching, with 182 patients in each cohort. ACDF required the longest operative time 188 ± 79 versus laminectomy/fusion (169 ± 75, p = 0.017), and laminoplasty (167 ± 66, p = 0.004). ACDF required the shortest hospital stay (LOS ≥ 2: ACDF 56.6%, laminoplasty 89.6%, laminectomy/fusion 93.4%, p < 0.05). ACDF had lower overall complications (ACDF 3.9%, laminoplasty 7.7%, laminectomy/fusion 11.5%, p < 0.05), mortality (ACDF 0%, laminoplasty 0.55%, laminectomy/fusion 2.2%, p < 0.05), and unplanned readmissions (ACDF 4.4%, laminoplasty 4.4%, laminectomy/fusion 9.9%, p < 0.05). No significant differences were seen in the other outcomes including DVT/PT, acute renal failure, UTI, stroke, cardiac complications, or sepsis. In the multivariate analysis, laminectomy/fusion (OR 17, reference: ACDF) and laminoplasty (OR10, reference: ACDF) were strong independent risk factors for LOS ≥ 2 days. Laminectomy/fusion (OR 3.2, reference: ACDF) was an independent predictor for any adverse events 30-days after surgery.Conclusions:Laminectomy/fusion carries the highest risk for morbidity, mortality, and unplanned readmissions in the short-term postoperative period. Laminoplasty and ACDF cases carry similar short-term complications risks. ACDF is significantly associated with the longest operative duration and shortest LOS without an increase in individual or overall complications, readmissions, or reoperations

Characterizing the fusion order and level-specific rates of arthrodesis in 3-level anterior cervical discectomy and fusion: A radiographic study

Pseudarthrosis is a well-recognized complication following multi-level ACDF. We aim to characterize the fusion order and level-specific rates of arthrodesis across four time points following 3-level ACDF. Patients who underwent 3-level ACDF by three UCSF spine surgeons from August 2012 to December 2019 were identified. Fusion status at each level was determined by measuring the interspinous motion on flexion and extension radiographs and assessing for evidence of bridging bone. Measurements were performed post-operatively at 6 weeks, 6 months, 12 months, and 18–24 months. A total of 77 patients with 3-level ACDF were identified and included in this study. Specific ACDF levels include C3-C6 (17 patients), C4-C7 (57 patients), and C5-T1 (3 patients). At 6 months, the cranial, middle, and caudal level fusion rates were 17.0%, 34.0%, and 3.8%, respectively. By 24 months, fusion rates were 61.1%, 88.9%, and 27.8% at the cranial, middle, and caudal level, respectively. PEEK cages were associated with lower odds of multi-level arthrodesis. Arthrodesis occurred the quickest at the middle level with an 88.9% fusion rate by 24 months after surgery. The caudal level had the slowest rate of arthrodesis with only a 27.8% fusion rate at 24 months, likely due to increased biomechanical stress at the most caudal level. Allograft was associated with higher odds of multi-level arthrodesis compared to PEEK cages.

A single-center retrospective analysis of 3- or 4-level anterior cervical discectomy and fusion: surgical outcomes in 66 patients.

Anterior cervical discectomy and fusion (ACDF) is a safe and effective intervention to treat cervical spine pathology. Although these were originally performed as single-level procedures, multilevel ACDF has been performed for patients with extensive degenerative disc disease. To date, there is a paucity of data regarding outcomes related to ACDFs of 3 or more levels. The purpose of this study was to compare surgical outcomes of 3- and 4-level ACDF procedures. The authors performed a retrospective chart review of patients who underwent 3- and 4-level ACDF at the University of Virginia Health System between January 2010 and December 2017. In patients meeting the inclusion/exclusion criteria, demographics, fusion rates, time to fusion, and reoperation rates were evaluated. Fusion was determined by < 1 mm of change in interspinous distance between individual fused vertebrae on lateral flexion/extension radiographs and lack of radiolucency between the grafts and vertebral bodies. Any procedure requiring a surgical revision was considered a failure. Sixty-six patients (47 with 3-level and 19 with 4-level ACDFs) met the inclusion/exclusion criteria of having at least one lateral flexion/extension radiograph series ≥ 12 months after surgery. Seventy percent of 3-level patients and 68% of 4-level patients had ≥ 24 months of follow-up. Ninety-four percent of 3-level patients and 100% of 4-level patients achieved radiographic fusion for at least 1 surgical level. Eighty-eight percent and 82% of 3- and 4-level patients achieved fusion at C3-4; 85% and 89% of 3- and 4-level patients achieved fusion at C4-5; 68% and 89% of 3- and 4-level patients achieved fusion at C5-6; 44% and 42% of 3- and 4-level patients achieved fusion at C6-7; and no patients achieved fusion at C7-T1. Time to fusion was not significantly different between levels. Revision was required in 6.4% of patients with 3-level and in 16% of patients with 4-level ACDF. The mean time to revision was 46.2 and 45.4 months for 3- and 4-level ACDF, respectively. The most common reason for revision was worsening of initial symptoms. The authors' experience with long-segment anterior cervical fusions shows their fusion rates exceeding most of the reported fusion rates for similar procedures in the literature, with rates similar to those reported for short-segment ACDFs. Three-level and 4-level ACDF procedures are viable options for cervical spine pathology, and the authors' analysis demonstrates an equivalent rate of fusion and time to fusion between 3- and 4-level surgeries.

79. Secondary surgery rate and five-year outcomes of hybrid TDR/ACDF vs multilevel ACDF

BACKGROUND CONTEXT Cervical total disc replacement, TDR, is increasingly accepted as a surgical treatment option for patients who have failed conservative care of single-level conditions. However, coverage for multilevel disease, which is more common, is usually restricted to fusion surgery. Multilevel conditions are more challenging as some levels have soft disc conditions favoring TDR and other levels have bony stenosis and facet overgrowth favoring fusion (ACDF). The purpose of this study was to compare off-label hybrid TDR/ACDF to multilevel ACDF for multilevel cervical disease. PURPOSE Comparison of off-label hybrid TDR/ACDF to multilevel ACDF for multilevel cervical degenerative conditions. STUDY DESIGN/SETTING Two cohort prospective study. PATIENT SAMPLE Consecutive patients who had cervical hybrid procedure with minimum 5-yr follow-up. Historical prospectively analyzed multilevel ACDF control cohort that could have had hybrid if insurance would have approved. OUTCOME MEASURES Neck and arm pain VAS, Pain Drawing, disability outcomes, self-report of success. METHODS Consecutive Hybrid TDR/ACDF patients, n=83, who had minimum of 5 years follow-up were compared to controls. The Hybrid group had the TDR placed at the level were the primary condition was (soft) disc-related whereas the ACDF was performed at the level(s) where the primary condition was bony stenosis or spondylotic. The control group was evaluated prospectively and those with central stenosis were eliminated as they were not satisfactory hybrid candidates. Secondary surgeries were also analyzed for all cohorts. Within the hybrid cohort, 2/3 had a hybrid construct at their index surgery and 1/3 had TDR adjacent to a prior ACDF. RESULTS There were no demographical differences between the two cohorts. Both hybrid TDR/ACDF and multilevel ACDF groups had similar preoperative pain and disability and, within both cohorts, had significantly improved outcomes after surgery. Between groups, there were no differences in outcomes for any of the measures over the 5+ year follow-up. Narcotic medication usage decreased; from 75% preop in the hybrid group to 19% at 3-5 years postop. Secondary surgeries found that over 5 years, adjacent level surgery was in 6 (7%) and 11(14%) patients in the Hybrid and the multilevel ACDF groups respectively. Pseudarthrosis repair was 6% vs 7% in the hybrid and multilevel ACDF cohorts respectively. The study appears valid in that our single-level TDR vs ACDF results were similar to that reported in multiple prior studies and found slightly better outcomes for single-level cervical TDR relative to ACDF. CONCLUSIONS Hybrid TDR/ACDF, used off-label, gives comparable outcomes to multilevel ACDF patients at medium-term follow-up. Secondary surgeries due to adjacent segment disease were half as frequent in the Hybrid cohort. A hybrid procedure is a viable treatment option for patients with multilevel cervical disease. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

The change of cervical sagittal parameters plays an important role in clinical outcomes of cervical spondylotic myelopathy after multi-level anterior cervical discectomy and fusion

BackgroundCervical sagittal parameters were closely related with clinical outcomes after multi-level ACDF. Our purpose was to evaluate the clinical outcomes and cervical sagittal parameters in patients with MCSM after ACDF and to identify the risk factors of poor clinical outcomes.Material and methodsACDF was performed in 89 patients with MCSM. Based on average JOA recovery rate, patients were divided good-outcome group (group GO) and poor-outcome group (group PO). The cervical sagittal parameters including Cobb angle, SVA, T1S, cranial tilt and cervical tilt were measured. Multivariate logistic regression was used to identify risk factors.ResultsFifty-four patients (60.67%) were divided into group GO, while 35 patients (39.33%) were divided into group PO. Cobb angle, SVA and T1S was corrected from preoperative average 11.80° ± 9.63°, 23.69 mm ± 11.69 mm and 24.43° ± 11.78° to postoperative average 15.08° ± 9.05°, 18.79 mm ± 10.78 mm and 26.92° ± 11.94° respectively (p < 0.001). △Cobb angle (p = 0.008) and △SVA (p = 0.009) showed significantly statistical differences between two groups. Longer symptom duration, lower preoperative JOA score, smaller △Cobb angle and larger △SVA were identified as risk factors of poor clinical outcomes.ConclusionMulti-level ACDF is an effective surgical method to treat patients with MCSM. However, long duration of preoperative symptoms, lower preoperative JOA score, smaller △Cobb angle and larger △SVA are risk factors for poor outcomes in patients with MCSM after ACDF. Sagittal parameters should be paid attention to in surgery.

Comparison of the Inpatient Complications and Health Care Costs of Anterior versus Posterior Cervical Decompression and Fusion in Patients with Multilevel Degenerative Cervical Myelopathy: A Retrospective Propensity Score–Matched Analysis

The optimal surgical approach for multilevel degenerative cervical myelopathy (DCM) is unclear, and there is significant variation in practice patterns. We sought to compare inpatient complications and costs of anterior (ACDF) versus posterior cervical decompression and fusion (PCDF). Patients who underwent multilevel ACDF or PCDF for DCM were identified from the National Inpatient Sample for 2004-2014 using ICD-9-CM codes. Propensity score matching was performed with age, sex, comorbidities, hospital bed size, and use of intraoperative monitoring as covariates. Hospitalization charges/costs, length of stay (LOS), discharge disposition, and inpatient morbidity/mortality were compared between matched ACDF and PCDF groups. Propensity score matching generated a cohort of 13,884 patients (n= 6,942 ACDF; n= 6,942 PCDF). PCDF was associated with greater LOS (mean difference [MD]+1.7 days, P < 0.001) and less frequent routine discharge home (odds ratio [OR] 0.26, P < 0.01). With regard to complications, PCDF had a higher rate of myocardial infarction (OR 1.6, P= 0.007), pulmonary embolism (OR 2.6, P= 0.009), deep vein thrombosis (OR 3.7, P < 0.001), neurological complications (OR 1.7, P= 0.037), hardware-related complications (OR 2.7, P < 0.001), wound infection/breakdown (OR 6.8, P < 0.001), and cerebrospinal fluid leak (OR 1.7, P= 0.011). By contrast, rates of postoperative hematoma (OR 0.61, P= 0.007), hoarseness (OR 0.13, P < 0.001), and dysphagia (OR 0.20, P < 0.001) were higher after ACDF. Mortality was comparable. Hospital charges (MD+$26,259, P < 0.001) and costs (MD+$7,728, P < 0.001) were significantly higher for PCDF. At a national level, for multilevel DCM, we found PCDF to be associated with greater LOS, in-hospital costs, and general medical and surgical complications. ACDF carried higher risk of postoperative hematoma, hoarseness, and dysphagia.

37. Effect of topical steroid on swallowing following ACDF: results of a prospective randomized double blind control trial

BACKGROUND CONTEXT Dysphagia is a common complication in the setting of ACDF surgery. There is controversy in the literature regarding the effectiveness of Local Intraoperative Corticosteroids (LIC) in reducing postoperative dysphagia. This study aims to evaluate the effectiveness of LIC in decreasing the severity of swallowing difficulty following ACDF. PURPOSE To determine if the application of local intraoperative corticosteroids (LIC) during multilevels ACDF surgery impacts early postoperative dysphagia severity STUDY DESIGN/SETTING Double blinded randomized clinical trial early postoperative results. PATIENT SAMPLE A total of 106 adult patients undergoing primary multilevel ACDF (2-4 levels) at a single institution. OUTCOME MEASURES SWAL-QOL, Eat-10 (standard and modified). METHODS Patients who sustained a multilevel ACDF were enrolled and randomized in a double blinded fashion. Arm S (steroid) received 1ml (40mg) of methylprednisolone delivered with an absorbable hemostatic matrix (vehicle) to the retro-esophageal space prior to closure. The control arm (C) only received the vehicle prior to closure. Dysphagia specific instruments (EAT-10 and the SWAL-QOL) were collected preoperatively, and at day 1 (POD1), day 2 (POD2), and 1 month (M1) postoperatively. Potential randomization biases were assessed by comparing the preoperative characteristics and surgical treatment of the 2 arms. A Friedman test was used to investigate change over time in patient-reported outcomes (PRO); a Mann-Whitney U test was performed to compare the median PRO scores (S vs C) at each time points. RESULTS Out of the 106 enrolled patients, 95 (90%) had complete dataset and were included in the analysis. The overall mean age was 57.6 year-old, for a BMI of 29.4kg/m2, and 48.4% of female patients. The most common diagnoses were cervical spondylosis (63.2%), radiculopathy (48.4%), myeloradiculopathy (30.5%) and myelopathy (24.2%). The comparison of the C arm (n=47) and S arm (n=48) revealed no significant difference in demographics, diagnosis, or surgical information in terms of number of levels fused (1.5±0.6 vs 1.4±0.6, p = 0.521), Op time (150min±37 vs 136min±33 p = 0.065), or EBL (100cc±43 vs 91cc±52 p = 0.358). Preoperatively, there was also no significant difference in PRO, with the exception of the Eat-Desire domain (p=0.049, but similar median, 25th and 75th percentile). Overall and for each randomized arm, significant change in dysphagia scores were observed from pre- to postop. The comparison of postoperative PRO across the study arms revealed that the S arm had significantly better dysphagia scores than the control arm. At POD1, the S arm had better SWALL-QOL in ood selection (p=0.049, 87.5 [50-100] vs 75 [37.5-100]), and Fear (p=0.027, 100 [89-100] vs 93.7 [75-100]); at POD2 the S arm had better dysphagia scores in Burden (p=0.02), Eat Duration (p=0.008), Fear (p = 0.017), Fatigue (p=0.047), and modified Eat-10 (p=0.013). Finally, better dysphagia scores were maintained at M1 in terms of Eat Desire (p = 0.015), East duration (p=0.046), Fear Swallow (p=0.016), and Fatigue (p=0.003) CONCLUSIONS Both arms demonstrated similar preoperative characteristics and underwent similar surgical procedure. Our study demonstrated the benefit of LIC with this delivery method to prophylactically reduce dysphagia following ACDFs. Early postop results were superior for treatment group, especially postop days 2, and maintained at 1 month. FDA DEVICE/DRUG STATUS Unavailable from authors at time of publication.

There is no increased risk of adjacent segment disease at the cervicothoracic junction following an anterior cervical discectomy and fusion to C7

Background ContextAnterior cervical discectomy and fusion (ACDF) is a very common operative intervention for the treatment of cervical spine degenerative disease in those who have failed non-operative measures. However, studies examining long-term follow-up on patients who underwent ACDF reveal evidence of radiographic and clinical degenerative disc disease at the levels adjacent to the fusion construct. Consistent with other junctional regions of the spine, the cervicothoracic junction (CTJ) has significant morphologic variations. As a result, the CTJ undergoes significant static and dynamic stress. Given these findings, there has been some thought that ACDF down to C7 may experience additional risks for adjacent segment degeneration/disease (ASD) when compared with ASDFs that are cephalad to C7. PurposeThe goal of this study is to evaluate the rate of radiographic and clinical ASD in patients who have undergone single- or multilevel ACDF, down to C7. Study DesignThis is a retrospective cohort study. Patient SampleThe sample included consecutive patients from a single orthopedic surgeon at one quaternary referral medical center who underwent an ACDF between January 2008 and November 2014. Indications for surgery included radiculopathy, myelopathy, or myeloradiculopathy in the setting of failed conservative treatments. Patients were excluded if they had an ACDF of which the caudal level was cephalad to C7 or if they had undergone a previous cervical fusion. Outcome MeasuresRadiographic diagnosis of ASD was determined by the presence of disc space narrowing >50%, new or enlarged osteophytes, end plate sclerosis, or increased calcification of the anterior longitudinal ligament (ALL). Postoperatively, data were collected on the presence of new radicular or myelopathic symptoms indicative of pathology at C7–T1, indicating a diagnosis of clinical ASD. MethodsDemographic information was collected for all patients, which included age, sex, body mass index, smoking status, and Charleston Comorbidity Index (CCI). Several radiographic parameters were measured preoperatively, immediately postoperatively, and at the last follow-up: C2–C7 lordosis, sagittal vertical axis (SVA), thoracic inlet angle (TIA), and T1 slope C2–C7 lordosis were measured using the Cobb angle between the inferior end plate of C2 to the inferior end plate of C7. Radiographic and clinical factors associated with ASD were analyzed postoperatively. ResultsFour patients (4.8%) presented with clinical evidence of ASD, all of whom also showed signs of radiographic ASD and improved with conservative measures. No patients underwent reoperation for ASD at the C7–T1 junction. Thirty patients (36.1%) presented radiographic evidence of ASD. These were generally older (54.4 vs. 48.4 years; p=.014). There were neither significant differences in radiographic parameters nor between single- versus multilevel ACDFs and the development of ASD. ConclusionsThe cervicothoracic junction may present with vulnerability to ASD given the junctional biomechanics. However, this study provides evidence that an ACDF with the caudal level of C7 does not incur additional risk of ASD, showing similar outcomes to ACDFs at other levels.

Radiographic Analysis of Cervical and Spinal Alignment in Multilevel ACDF with Lordotic Interbody Device.

Restoration and maintenance of cervical lordosis is an important clinical parameter in spine surgery. The purpose of this study was to determine the extent to which a multilevel anterior cervical discectomy and fusion (ACDF: greater than 3 levels) procedure restores cervical lordosis and the affect of increasing lordosis on sagittal vertical axis. We performed a retrospective radiographic analysis of 69 patients who underwent multilevel ACDF by 2 surgeons between 2013 and 2014. We measured the global and segmental sagittal alignment of the cervical spine using the cobb method at 4 time intervals (preop, post op 4wks, 10wks and 6 months) as well as the sagittal vertical axis (SVA) using both a C1-S1 and C7-S1 plumb line methods at 2 time intervals (preop and post op 4wks). Radiographs were measured by three reviewers. Interrater reliability was good to excellent for all measurements. Cervical lordosis significantly increased from preop 10.26° to 4 weeks postop 19.44° and was maintained up to 6 months 19.34 (p<0.0005). Segmental cervical lordosis was also significantly increased from preop 8.22° to post op at 4 weeks (20.26°) and was maintained at post op 10weeks 20.30° and post op 6 months 19.56° (p<0.0005). C7-S1 SVA and C1-S1 SVA also significantly increased from 12.04mm preop to 27.49mm post op 4 wks (p<0.0005) and -1.93mm preop to 8.67mm post op (p<0.0005) respectively. A change in C2-C7 lordosis positively correlated with a change in C7-SVA and C1-SVA (r=0.37, P<0.005, and r=0.312, p<0.05 respectively). Multilevel ACDF significantly increases and maintains both segmental and global cervical lordosis up to 6 months after surgery. Increasing C2-C7 global lordosis is correlated with increasing positive sagittal vertical axis. Level of evidence: IV.

Multi-channel motor evoked potential monitoring during anterior cervical discectomy and fusion

ObjectivesAnterior cervical discectomy and fusion (ACDF) surgery is the most common surgical procedure for the cervical spine with low complication rate. Despite the potential prognostic benefit, intraoperative neurophysiological monitoring (IONM), a method for detecting impending neurological compromise, is not routinely used in ACDF surgery. The present study aimed to identify the potential benefits of monitoring multi-channel motor evoked potentials (MEPs) during ACDF surgery. MethodsWe retrospectively reviewed 200 consecutive patients who received IONM with multi-channel MEPs and somatosensory evoked potentials (SSEPs). On average, 9.2 muscles per patient were evaluated under MEP monitoring. ResultsThe rate of MEP change during surgery in the multi-level ACDF group was significantly higher than the single-level group. Two patients from the single-level ACDF group (1.7%) and four patients from the multi-level ACDF group (4.9%) experienced post-operative motor deficits. Multi-channel MEPs monitoring during single and multi-level ACDF surgery demonstrated higher sensitivity, specificity, positive predictive and negative predictive value than SSEP monitoring. ConclusionsMulti-channel MEP monitoring might be beneficial for the detection of segmental injury as well as long tract injury during single- and multi-level ACDF surgery. SignificanceThis is first large scale study to identify the usefulness of multi-channel MEPs in monitoring ACDF surgery.

142 - Multilevel ACDF with Ultra Low Dose BMP-2 versus Posterior Approach in Multilevel Fusions to the Cervicothoracic Junction

142 - Multilevel ACDF with Ultra Low Dose BMP-2 versus Posterior Approach in Multilevel Fusions to the Cervicothoracic Junction