Anterior Cervical Arthrodesis Research Articles

ARTRODESE CERVICAL VIA ANTERIOR: ENXERTO AUTÓLOGO OU SINTÉTICO?

ABSTRACT Objective: To compare patients who underwent anterior cervical arthrodesis with autologous iliac crest graft and those who used synthetic graft. Methods: Analysis of 38 patients aged between 18 and 100 years with anterior cervical spondylosis of 1 or 2 levels in a spine surgery service. Results: degenerative cervical spine changes associated with cervicalgia and cervicobrachialgia. Excluded: previous cervical spine surgeries, fractures, or surgery above two levels. Two groups were formed with 19 patients, one using autologous graft and the other using synthetic tricalcium phosphate - a questionnaire assessed satisfaction (Oswestry and VAS) pre- and postoperatively. Bone consolidation was evaluated by tomography at nine months. Results: Mean ODI (Group 1) was 68.5% ± 4.6% preoperatively and 27.2% ± 3.8% postoperatively, being statistically relevant (p<0.001). VAS performed to evaluate the cervical region, Group 1 pre and post-op was considered statistically relevant (p<0.001). No significant difference was observed when comparing the mean values found in the postoperative period between Group 1 and Group 2 (p=0.463). Only two patients complained of chronic pain, representing 10% of the total. In nine-month tomography, 100% of patients in Group 1 and 100% of Group 2 showed bone consolidation, with no statistically relevant difference (p=0.676) between the groups. Conclusion: Similar functional and osteointegration outcomes were observed in both types of grafts. Synthetic graft minimizes the risks and complications of using allografts. Level of Evidence III; Retrospective comparative study.

Long-term functional and radiological outcomes of cervical disc arthroplasty at a tertiary level spine center in India: A retrospective cohort analysis with minimum 2 years of follow-up.

Cervical disc arthroplasty (CDA) was developed for the treatment of cervical disc disease with the potential advantages of preservation of physiological motion at a discal level, thereby potentially reducing adjacent level stresses and degeneration, which were a known complication of anterior cervical arthrodesis. The objective of this study was the assessment of long-term functional and radiological outcomes overtime in all the patients who underwent CDA from 2011 to 2019 at our institute. Forty-eight patients who underwent CDA (2011-2019) with a minimum 2-year follow-up were retrospectively evaluated. The functional outcome included the Visual Analog Score (VAS) and Neck Disability Index (NDI). Radiographs were assessed for range of motion (ROM) at the index surgical level, presence of heterotopic ossification (HO), and adjacent segment degeneration. The mean follow-up was 5.79 ± 2.96 (2.16-11.75) years. Significant improvement (P < 0.05) was observed in the VAS (8.91 ± 2.52 [preoperative] to 0.89 ± 1.27 [follow-up]) and NDI (65.5% ±23.06% [preoperative] to 4.79 ± 3.87 [follow-up]) score. Motion at index level increased significantly from 5.53° preoperatively to 7.47°, and 92% of the implanted segments were still mobile (referring to the threshold of ROM > 3°). HOs are responsible for the fusion of 4/50 (8%) levels at the last follow-up. Distal and proximal adjacent disc degeneration occurred in 36% and 28% of patients, respectively. No migration of the implant was observed on the radiograph. Our study showed favorable clinical outcome of CDA with preservation of ROM at the index surgical level. CDA can be a promising alternative to anterior cervical arthrodesis when properly indicated.

Impact of COVID-19 on Spinal Diagnosis and Procedural Volume in the United States.

Retrospective analysis of a national database. COVID-19 resulted in the widespread shifting of hospital resources to handle surging COVID-19 cases resulting in the postponement of surgeries, including numerous spine procedures. This study aimed to quantify the impact that COVID-19 had on the number of treated spinal conditions and diagnoses during the pandemic. Using CPT and ICD-10 codes, TriNetX, a national database, was utilized to quantify spine procedures and diagnoses in patients >18years of age. The period of March 2020-May 2021 was compared to a reference pre-pandemic period of March 2018-May 2019. Each time period was then stratified into four seasons of the year, and the mean average number of procedures per healthcare organization was compared. In total, 524,394 patient encounters from 53 healthcare organizations were included in the analysis. There were significant decreases in spine procedures and diagnoses during March-May 2020 compared to pre-pandemic levels. Measurable differences were noted for spine procedures during the winter of 2020-2021, including a decrease in lumbar laminectomy and anterior cervical arthrodesis. Comparing the pandemic period to the pre-pandemic period showed significant reductions in most spine procedures and treated diagnoses; however, there was an increase in open repair of thoracic fractures during this period. COVID-19 resulted in a widespread decrease in spinal diagnosis and treated conditions. An inverse relationship was observed between new COVID-19 cases and spine procedural volume. Recent increases in procedural volume from pre-pandemic levels are promising signs that the spine surgery community has narrowed the gap in unmet care produced by the pandemic.

Over 20 years of declining Medicare reimbursement for spine surgeons: a temporal and geographic analysis from 2000 to 2021.

Procedural reimbursement for spine surgery has changed drastically over the past 20 years. A comprehensive understanding of these trends is important as major changes in reimbursement models of spine surgery continue to evolve within various spine specialties as well as broader national healthcare policy. In this study the authors evaluated the monetary trends in Medicare reimbursement rates for the 15 most common spinal surgery procedures from 2000 to 2021. The National Surgery Quality Improvement Project database (2019) was queried to determine the 15 most commonly performed spine surgery procedures. The Current Procedural Terminology (CPT) codes for each of these procedures were obtained from the Physician Fee Schedule Look-Up Tool from the Centers for Medicare and Medicaid Services, and comprehensive reimbursement data for each code were extracted. Changes in Medicare reimbursement rates were calculated and averaged for each procedure as both raw percent changes and percent changes adjusted for inflation to 2021 US dollars (USD) based on the consumer price index (CPI). The adjusted R2 value, the compound annual growth rate (CAGR), and both the average annual and the total percent change in reimbursement were calculated based on these adjusted trends for all included procedures. After adjustment for inflation, average reimbursement for all procedures decreased by 33.8% from 2000 to 2021. The greatest mean decrease was seen in anterior cervical arthrodesis (-38.7%), while the smallest mean decrease was in vertebral body excision (-17.1%). From 2000 to 2021, the adjusted reimbursement rate for all included procedures decreased by an average of 1.9% each year, with an average R2 value of 0.69. This is the first study to evaluate monetary trends in Medicare reimbursement for spine surgery procedures. After adjusting for inflation, Medicare reimbursement for the 15 most commonly performed spine procedures has steadily decreased from 2000 to 2021. Increased awareness of these trends and the forces driving them will be critical in the coming years as negotiations regarding reimbursement models continue to unfold. Greater understanding of spine surgery reimbursement among policy makers, hospitals, and surgeons will be important to ensure continued access to quality surgical spine care in the United States.

Outcomes of cervical arthroplasty versus anterior cervical arthrodesis: a systematic review and meta-analysis of randomized clinical trials with a minimum follow-up of 7-year.

Compare the outcomes of randomized clinical trials of cervical disc arthroplasty (CDA) versus anterior cervical discectomy with fusion (ACDF), with a minimum follow-up of 7years. Nine randomized clinical trials were selected. The clinical, radiological, and surgical outcomes were analyzed, including functional and pain scores, range of motion, adjacent segment degeneration, adverse events, and need for reoperation. 2664 patients were included in the study. Pooled results indicated that the CDA group had a significantly higher overall success rate (p < 0.001), a higher improvement in the neck disability index (NDI) (p = 0.002), less VAS arm pain (p = 0.01), and better health questionnaire SF-36 physical component (p = 0.01) than ACDF group. Likewise, the pooled results indicated a significantly higher motion rate (p < 0.001), less adjacent syndrome (p < 0.05), and a lower percentage of reoperation (p < 0.001) in the CDA group. There were no significant differences between the CDA and ACDF groups in the neck pain scale (p = 0.11), the health questionnaire SF-36 mental component (p = 0.10), and in adverse events (p = 0.42). In long-term follow-up, CDA showed a better overall success rate, better improvement in NDI, less VAS arm pain, better health questionnaire SF-36 physical component, a higher motion rate, less adjacent syndrome, and less reoperation rate than ACDF. No significant differences were found in the neck pain scale, SF-36 mental component, and in adverse events.

In Vivo Evidence of Early Instability and Late Stabilization in Motion Segments Immediately Superior to Anterior Cervical Arthrodesis.

Prospective cohort study. The aim was to identify patient factors that affect adjacent segment kinematics after anterior cervical discectomy and fusion (ACDF) as measured by biplane radiography. The etiology of adjacent segment disease (ASD) may be multifactorial. Previous studies have investigated associations between patient factors and ASD, although few attempted to link patient factors with mechanical changes in the spine that may explain ASD development. Previous studies manually measured intervertebral motion from static flexion/extension radiographs, however, manual measurements are unreliable, and those studies failed to measure intervertebral motion during rotation. Patients had continuous cervical spine flexion/extension and axial rotation movements captured at 30 images per second in a dynamic biplane radiography system preoperatively and 1 year after ACDF. Digitally reconstructed radiographs generated from subject-specific computed tomography scans were matched to the biplane radiographs using a validated tracking process. Dynamic kinematics and preoperative disc height were calculated from this tracking process. Preoperative magnetic resonance imagings were evaluated for disc bulge. Patient age, sex, body mass index, smoking status, diabetes, psychiatric history, presence of an inciting event, and length of symptoms were collected. Multivariate linear regression was performed to identify patient factors associated with 1-year postoperative changes in adjacent segment kinematics. Sixty-three patients completed preoperative and postoperative testing. Superior adjacent segment disc height and disc bulge predicted the change in superior adjacent segment range of motion after surgery. Inferior adjacent segment disc bulge, smoking history, and the use of psychiatric medications predicted the change in inferior adjacent segment flexion/extension range of motion after surgery. Preexisting adjacent segment disc degeneration, as indicated by disc height and disc bulge, was associated with reduced adjacent segment motion after ACDF, while lack of preexisting adjacent disc degeneration was associated with increased adjacent segment motion after ACDF. These findings provide in vivo evidence supporting early instability and late stabilization in the pathophysiology of disc degeneration.

In Vivo Changes in Dynamic Adjacent Segment Motion 1 Year After One and Two-Level Cervical Arthrodesis.

Biomechanical cadaver testing indicates adjacent segment motion increases after one-level anterior cervical spine arthrodesis, and two-level arthrodesis exacerbates these effects. There is little in vivo evidence to support those biomechanical studies. The purpose of this study was to assess the effects of one- and two-level cervical arthrodesis on adjacent segment motion. Fifty patients received either one-level C56 arthrodesis or two-level C456 or C567 arthrodesis and were tested preoperatively (PRE) and 1 year postoperatively (1YR-POST) along with 23 asymptomatic controls. A validated CT model-based tracking technique was used to measure 3D vertebral motion from biplane radiographs collected during dynamic flexion-extension and axial rotation of the cervical spine. Head and adjacent segment intervertebral end-range range of motion (ROM) and mid-range ROM were compared between one-level and two-level arthrodesis patients and controls. Small (2.3° or less) but non-significant increases in adjacent segment end-range ROM were observed from PRE to 1YR-POST. Mid-range flexion-extension ROM in the C67 motion segment inferior to the arthrodesis and mid-range axial rotation ROM in the C45 motion segment superior to the arthrodesis increased from PRE to 1YR-POST (all p < 0.022). This study provides in vivo evidence that contradicts long-held beliefs that adjacent segment end-range ROM increases appreciably after anterior cervical arthrodesis and that two-level arthrodesis exacerbates these effects. Mid-range ROM appears to be more useful than end-range ROM for detecting early changes in adjacent segment motion after cervical spine arthrodesis.

2-Level Anterior Cervical Arthrodesis With Integrated Spacer and Plate vs Traditional Anterior Spacer and Plate System.

Anterior cervical discectomy and fusion (ACDF) is a common surgery to treat cervical degenerative disc disease. Use of an anterior spacer and plate system (ASPS) results in increased disc height, higher fusion rate, lower subsidence rate, and lower complication rate than a spacer alone.1,2 However, anterior cervical plating is associated with complications, such as dysphagia, plate-screw dislodgment, soft tissue injury, neural injury, and esophageal perforation.3-9 To potentially reduce these drawbacks, integrated spacer and plate (ISP) systems have gained popularity. From November 2009 to October 2013, a total of 84 consecutive patients who underwent 2-level ACDF using ISP or ASPS were reviewed for clinical and radiographic outcomes. Patient-reported visual analog scale (VAS) and Neck Disability Index (NDI) scores, fusion rates, and hardware failure were determined at 1, 3, 6, 12, and 24 months after surgery. Forty-three patients received ISP and 41 patients received ASPS. There were no significant differences in patient demographics between the 2 groups. Perioperative characteristics were similar, except for operative time. Postoperatively, no significant differences in VAS or NDI scores or fusion status were found. At the proximal surgical level only, there was a trend toward an earlier observed radiographic fusion rate in ASPS vs ISP, but this finding was not statistically significant (P = 0.092). One case of long-term dysphagia was reported in each group. Neither group had implant failures up to 2 years. The ISP system for 2-level ACDF compared to traditional ASPS has comparable clinical and radiographic outcomes up to 2 years postoperatively. There may be a trend toward an earlier observed radiographic fusion in the ASPS group, but there was no difference in long-term dysphagia rate. Integrated spacer and traditional anterior spacer for 2-level ACDF has similar clinical and radiographical outcome.

Evaluation of the Use of Drain in Anterior Cervical Disc Fusion Procedures

<i>Introduction</i>: The worldwide tendency is to minimize surgical treatments, providing lesser incisions, length of hospitalization and complications. Anterior cervical arthrodesis (ACA) is a very common procedure realized daily in many services. One of its most dread complications it’s the cervical hematoma that in severe cases need urgent evacuation and can lead to higher morbidity and even death. Despite of this is not a consensus between surgeons to use or not a drain in ACA. We retrospectively analyzed the use of a drain in patients submitted to ACA and evaluate the results of minimizing cervical collections caused by the lowest symptomatology in the post-operative period. <i>Materials and Methods</i>: Fifty-four patients submitted to ACA in one or more segments were retrospectively evaluated, through the analysis of medical records, examinations, surgical descriptions, as well the output of each drain in the postoperative period, conditions of the surgical wound (presence or not of bulging) and postoperative symptomatology (swallowing and local pain). The data obtained were submitted to statistical analysis. <i>Results</i>: 54 patients underwent ACA. The overall mean volume of cervical drain was 28.56 mL (10 - 90 ml). A direct relationship was observed between the number of levels operated and the mean drain output: 1 level=12.86 ml; 2 levels=27.88 ml; and 3 levels=32.60 ml with statistical significance (p<0.0001). In all patients, minimal or no cervical bulging, nor dysphagia was observed. <i>Conclusion</i>: We conclude that the use of the drain in ACA reduces the cervical collections, regardless of the number of segments addressed, causing less postoperative symptomatology with consequent decrease in hospitalization time, and because independent of levels we observed significant accumulation of blood we recommend that every surgeon dealing with ACA must use routinely a drain.

Safety and efficacy of low-dose rhBMP-2 use for anterior cervical fusion.

The use of recombinant human bone morphogenetic protein 2 (rhBMP-2) in routine anterior cervical fusion (ACF) is controversial. Early reports described high complication rates. A variety of dosing regimens ranging from 0.6 to 2.1 mg per level fused have been reported. The authors hypothesized that the high amounts of rhBMP-2 used in these studies led to the high complication rates observed; therefore, they set out to evaluate the safety and efficacy of low-dose rhBMP-2 for use in ACFs. Patient inclusion criteria were 1) age 18 to 70 years; 2) initial stand-alone ACF construct; 3) fusion augmentation with rhBMP-2; and 4) at least 1 year of radiographic follow-up. A successful fusion was defined by either 1) lateral flexion-extension radiographs with less than 1 mm of movement across the fused spinous processes, or 2) bone bridging at least half of the fusion area originally achieved by surgery on fine-cut CT. Patient demographics, perioperative data, and postoperative complications were recorded. A total of 198 patients met the inclusion criteria and were included for analysis. Sixty-two patients (31%) were smokers. The median number of levels fused was 2 (IQR 1.25). The mean dose of rhBMP-2 was 0.50 ± 0.09 mg per level. Twenty-two (11%) patients experienced dysphagia. Eleven (6%) patients experienced cervical swelling. Two (1%) patients returned to the operating room (OR) for postoperative hematoma. One (0.5%) patient returned to the OR for seroma. Two (1%) patients experienced pseudarthrosis requiring a posterior fusion. Three (2%) patients experienced a new postoperative neurological deficit that had recovered by last the follow-up. Overall, 190 (96%) patients experienced solid arthrodesis over an average of 15 months of follow-up. There was no difference in fusion rates between patients who were either smokers or nonsmokers (p = 0.7073). The use of low-dose rhBMP-2 safely and effectively augmented anterior cervical arthrodesis. The low-dose protocol assessed in this study appeared to significantly reduce complications associated with rhBMP-2 use in ACF compared with the literature. The authors have determined that using low-dose rhBMP-2 in patients who are smokers, those with multilevel ACFs, or others at high risk of developing pseudarthrosis is recommended.

Surgery-related Factors Do Not Affect Short-term Adjacent Segment Kinematics After Anterior Cervical Arthrodesis.

Prospective cohort study. The aim of this study was to identify surgical factors that affect adjacent segment kinematics after anterior cervical discectomy and fusion (ACDF) as measured by biplane radiography. Previous studies investigated the effect of surgical factors on spine kinematics as a potential etiology for adjacent segment disease (ASD). Those studies used static flexion-extension radiographs to evaluate range of motion. However, measurements from static radiographs are known to be unreliable. Furthermore, those studies were unable to evaluate the effect of ACDF on adjacent segment axial rotation. Patients had continuous cervical spine flexion/exten- sion and axial rotation movements captured at 30 images per second in a dynamic biplane radiography system preoperatively and 1 year after ACDF. Digitally reconstructed radiographs generated from subject-specific CT scans were matched to biplane radiographs using a previously validated tracking process. Dynamic kinematics, postoperative segmental kyphosis, and disc distraction were calculated from this tracking process. Plate-to-disc distance was measured on postoperative radiographs. Graft type was collected from the medical record. Multivariate linear regression was performed to identify surgical factors associated with 1-year post-surgery changes in adjacent segment kinematics. A secondary analysis was also performed to compare adjacent segment kinematics between each of the surgical factors and previously defined thresholds believed to be associated with adjacent segment degeneration. Fifty-nine patients completed preoperative and postoperative testing. No association was found between any of the surgical factors and change in adjacent segment flexion/exten- sion or axial rotation range of motion (all P > 0.09). The secondary analysis also did not identify differences between adjacent segment kinematics and surgical factors (all P > 0.07). Following ACDF for cervical spondylosis, factors related to surgical technique were not associated with short-term changes in adjacent segment kinematics that reflect the hypermobility hypothesized to lead to the development of ASD.Level of Evidence: 2.

Comparison of adverse events between cervical disc arthroplasty and anterior cervical discectomy and fusion: a 10-year follow-up

BACKGROUND CONTEXTCervical disc arthroplasty (CDA) has been advocated as an alternative to anterior cervical discectomy and fusion (ACDF) with the added potential to reduce the risk of adjacent level disc degeneration and segmental instability. However, the long-term adverse events of arthroplasty have yet to be fully reported. PURPOSETo investigate the 10-year follow-up adverse events rates between CDA and ACDF. STUDY DESIGN/SETTINGThe study was a randomized, prospective, multicenter Investigational Device Exemption (IDE) trial and its continued follow-up as a postapproval study (PAS). Single level surgeries were performed for cervical disc pathologies between May 2002 and October 2004. PATIENT SAMPLEn=463 patients. OUTCOME MEASURESAdverse events comparison of CDA and ACDF from self-reported and physiologic measures. METHODSAt each evaluation time point, subjects were queried for adverse events since their last visit; and all adverse events were documented, regardless of whether or not they appeared related to the surgery or device. Adverse events were recorded, categorized, and assessed for severity and relationship to the study device and/or surgical procedure. The 10-year cumulative rates for each type of adverse events were summarized using a life-table method for the time-to-event analysis. A log-rank test was used to compare the two treatment groups. RESULTSA total of 242 patients received CDA and 221 patients received ACDF. At 10-year follow-up, 54% (130/242) of CDA patients and 47% (104/221) of the ACDF subjects were evaluated. At up to 10-year follow-up, 231 patients in the CDA group (cumulative rate 98.4%) and 199 patients in the ACDF group (cumulative rate 98.7%) had at least one adverse event. Overall, the difference in the cumulative rate of all adverse events over 10 years was not statistically different (p=0.166). The cumulative rates of the following adverse events were not different between the two groups for cancer, cardiovascular, death, dysphonia/dysphagia, gastrointestinal, infection, urogenital, respiratory, implant displacement/loosening, implant malposition, neck and arm pain, neurological, other pain, spinal events, and intraoperative vascular injury. However, there were more adverse events in the CDA group resulting from trauma (p=.012) and more spinal events at the index level (p=.006). The ACDF group had significantly more nonunion events (p=.019), and nonunion outcome pending (p=.034), adjacent level spinal events (p=.033), and events that fell into the “other” category (p=.015). CONCLUSIONSThe cumulative rates of patients who had any adverse events were not different between the artificial cervical disc and the anterior cervical arthrodesis groups. In addition, the cumulative rates were not different between the two groups for the majority of categories as well.

Comparison between repeat anterior and posterior decompression and fusion in the treatment of two-level symptomatic adjacent segment disease after anterior cervical arthrodesis

BackgroundTwo-level symptomatic adjacent segment disease (ASD) is rarely reported, but remains a challenge after anterior cervical arthrodesis. The purpose of this study was to compare the clinical and radiological outcomes of repeat anterior and posterior decompression and fusion procedures for two-level symptomatic ASD.MethodsThirty-two patients with two-level symptomatic ASD were retrospectively reviewed and underwent repeat anterior cervical discectomy and fusion (ACDF) or posterior decompression and fusion (PDF). Clinical outcomes (JOA, NDI, and VAS scores), perioperative parameters (blood loss, operation time, and length of hospital stay), radiological parameters (cervical lordosis and ROM), and complications were compared.ResultsEighteen patients underwent ACDF, and 14 patients underwent PDF. Patients who underwent PDF were older, more frequently presented with myelopathic deficits, and were fused at more levels. Patients who underwent ACDF experienced significantly shorter surgery time (p < 0.001), lower blood loss (p < 0.001), and reduced hospital stay (p = 0.002). Both groups exhibited significant increases in JOA scores and decreases in NDI and both neck pain and arm pain VAS scores (p < 0.05), but patients who underwent PDF had significantly higher NDI scores (p = 0.012), neck pain VAS scores (p = 0.019), loss of cervical lordosis (p < 0.001), and loss of ROM (p = 0.001). Three patients developed dysphagia in the ACDF group, and two patients had C5 root palsy and one had hematoma in the PDF group. Recurrent ASD after the second operation occurred in two patients in the ACDF group but no patients in the PDF group.ConclusionsFor patients with two-level symptomatic ASD, both anterior and posterior decompression and fusion were effective for improving the neurological function. For patients with radicular symptoms, ACDF had less surgical trauma, better restoration of lordosis, and less postoperative neck pain, but higher chance of recurrent ASD. PDF was an effective surgical option for older patients with myelopathy developing in adjacent segments.

Anterior Cervical Arthrodesis With Polyetheretherketone Spacers: What is the Role of the Grafting Material?

This was a retrospective study of 2 surgeons' use of a single polyetheretherketone (PEEK) device. Our objective was to investigate the fusion adjunct placed within PEEK devices to examine the likelihood of an arthrodesis, regardless of the PEEK interbody device itself. The effectiveness of PEEK interbody devices in anterior cervical arthrodesis has been questioned. The authors retrospectively reviewed the results of 121 patients with demineralized bone matrix (DBM) and 96 with local autograft bone placed within identical PEEK devices for anterior cervical arthrodesis (from 2011 to 2018); 1 surgeon used DBM and another local autograft bone. Arthrodesis was determined independently by a surgeon and 2 blinded neuroradiologists. For DBM versus autograft; mean age was 60 versus 61 years, smoking status 42.1% versus 31%, diabetes mellitus 18.2% versus 28%, mean body mass index 31 versus 30, and follow up averaged 17 months in both groups. For DBM versus autograft; a radiographic arthrodesis was observed in 22.3% versus 76% of patients. Refusion at the index level was required in 5.8% of the DBM and 0% of the autograft patients. A PEEK interbody device filled with local autograft resulted in a higher radiographic fusion rate and a lower need for reoperation at the index level than an identical device filled with DBM. Caution is warranted in assigning fusion failure to the PEEK device alone in anterior cervical discectomy and fusion surgery.

Minimally Invasive Posterior Cervical Fusion With Facet Cages to Augment High-Risk Anterior Cervical Arthrodesis: A Case Series.

Study Design:Retrospective case series.Objectives:To evaluate the efficacy and results of minimally invasive posterior cervical fusion with facet cages as an augment to high-risk patients and patients status post multilevel anterior cervical decompression and fusion.Methods:Thirty-five patients with symptomatic cervical stenosis with high risk for pseudoarthrosis underwent circumferential cervical decompression and fusion via staged anterior and posterior approach. Anterior cervical decompression and fusion was performed first by means of the standard anterior approach, with the patient supine on the operating table. The patients were subsequently flipped into a prone position and minimally invasive posterior cervical facet fusion with DTRAX was performed. The patients were then followed in the outpatient clinic for an average of 312.71 days. Postoperative patient satisfaction scores were obtained via the visual analogue scale (VAS). Preoperative VAS scores were compared with postoperative VAS scores in order to evaluate patient outcomes.Results:Of the 35 patients evaluated, minimum follow-up was 102 days, with a maximum follow-up of 839 days. Average preoperative and postoperative VAS scores were 7.6 and 2.8, respectively (P < .0001), with an average improvement of 4.86 points. This was an average improvement of 64.70% from preoperative to postoperative. Seventeen patients had excellent outcomes, with a postoperative VAS score ≤2. Seven patients achieved a postoperative VAS score of 0, with 100% improvement of preoperative pain and symptoms. Average blood loss was 70.38 mL. Average length of stay was 1.03 days.Conclusions:The results indicate that minimally invasive posterior cervical decompression and fusion with facet cages, when combined with standard anterior cervical decompression and fusion, is an effective means of obtaining circumferential cervical fusion while simultaneously improving patient outcomes.

P66. An analysis of Medicare reimbursement rates in spine surgery: 2000-2018

BACKGROUND CONTEXT Considering fluctuating policy, variance in proposed payment models, and the presence of ever-rising health care costs, there is noted financial uncertainty regarding health care in the US. Despite this, there has been relatively few studies regarding reimbursement models and trends in reimbursement rates. A comprehensive understanding of such trends is important as continued progress is made to advance agreeable reimbursement models in spine surgery. PURPOSE The purpose of this study was to evaluate monetary trends in Medicare reimbursement rates for the 15 most common spinal surgery procedures from 2000 to 2018. STUDY DESIGN/SETTING Analysis of a publicly-available, government-compiled reimbursement database. OUTCOME MEASURES Annual reimbursement rates across 15 commonly performed spine surgery procedures. METHODS The National Surgery Quality Improvement Project (NSQIP) database (2016) was queried to determine the 15 most performed spine surgery procedures. Next, the Physician Fee Schedule Look-Up Tool from the Centers for Medicare & Medicaid Services was queried for each of the top 15 most utilized CPT codes in spine surgery, and reimbursement data was extracted. All monetary data was adjusted for inflation to 2018 US dollars (USD) utilizing changes to the consumer price index (CPI). The R-squared and both average annual and the total percentage change in reimbursement were calculated based on these adjusted trends for all included procedures. RESULTS After adjusting for inflation, the average physician reimbursement for all procedures decreased by 25.8% from 2000 to 2018. The greatest mean decrease was seen in anterior cervical arthrodesis (-32.1%), while the smallest mean decrease was in vertebral body excision (-13.3%). From 2000 to 2018, the adjusted reimbursement rate for all included procedures decreased by an average of 1.7% each year, with an average R-squared value of 0.69. CONCLUSIONS This is the first study to evaluate trends in procedural Medicare reimbursement for spine surgery. When adjusted for inflation, Medicare reimbursement for included procedures has steadily decreased from 2000 to 2018. Increased awareness and consideration of these trends will be important for policy-makers, hospitals, and surgeons in order to assure continued access to meaningful surgical spine care in the United States. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

249. Traumatic subaxial cervical facet joint dislocation: predictors of spinal cord injury and surgical failure

BACKGROUND CONTEXT Approximately two thirds of cervical spine injuries affect the subaxial cervical spine, with fractures occurring most often at C6 and C7 and dislocations at C5-C6 and C6-C7. In the spectrum of these injuries, facet joint dislocation represents a severe injury, frequently associated with spinal cord injury (SCI). PURPOSE The purpose of this study was to analyze a cohort of surgically treated subaxial cervical spine dislocations and to identify factors associated with higher risk of SCI and predictors of surgical failure. METHODS All patients operated in a single institution during a 10-year period (2007-2016) for traumatic single-level cervical facet joint dislocation were retrospectively reviewed. Age, gender, injury characteristics (dislocation or subluxation, uni- or bilateral, level of injury and presence of associated facet fracture), mechanism of trauma, presence of SCI (determined by the American Spinal Injury Association Impairment Scale [ASIA]), surgical data and follow-up records were reviewed. All patients had a minimum follow-up of 2 years. RESULTS A total of 71 patients, 53 men and 18 women, with mean age of 57 ± 18 years (18-90) were identified. Motor-vehicle accidents were the most frequent trauma mechanism, followed by fall from height. Young adults were mostly represented among motor-vehicle accidents, whereas falls contributed to a majority of facet joint dislocations sustained by the elderly. The C6-C7 level was the most affected (37/71 cases). Forty-seven patients had unilateral and 24 bilateral dislocation, with 47 of these cases (66%) having associated facet fractures. Spinal cord injury was present in 37% of the cases. Rigid columns (p = 0.009) and bilateral dislocations (p = 0.004) were associated with the presence of spinal cord injury. Patients with bilateral dislocation were 4.7 times more likely to have a spinal cord injury (OR: 4.7, 95% CI = 1.6-13.8). The closed reduction with cranial traction was attempted in 51 cases, with a success rate of 86%. 59 cases were submitted to isolated anterior cervical arthrodesis and 7 to anterior cervical corpectomy. Five were submitted to combined anterior and posterior fixation (360°). There were 3 failures after the previous isolated fixation, which required revision surgery with 360 ° fusion. All cases of failure occurred after an isolated anterior fusion in the C7-T1 transition (p CONCLUSIONS Patients with rigid spines or with bilateral facet dislocations are at higher risk for SCI. After successful reduction, anterior discectomy and fusion, as a single procedure, offers an excellent surgical option in the management of many cervical facet fracture dislocations, has showed in this analysis. Failure occurred always at the C7-T1 level, suggesting that here; a 360 degree fusion may be needed. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Anterior Cervical Arthrodesis With Polyetheretherketone Spacers: What Is the Role of the Grafting Material?

Abstract INTRODUCTION In light of a recent award-winning publication questioning the effectiveness of polyetheretherketone (PEEK) interbody devices in anterior cervical arthrodesis when compared to allograft and our own published good experience with such devices, we were skeptical of the results reported. It was our hypothesis that it was the fusion adjunct placed within the PEEK device that resulted in widely disparate likelihood of an arthrodesis, rather than an intrinsic failure of the PEEK device. METHODS We retrospectively reviewed the results of 2 surgeons using an identical PEEK interbody device for anterior cervical arthrodesis, one using demineralized bone matrix (DBM) within the lumen of the device, and the other local autograft bone. Arthrodesis was determined independently by a surgeon and 2 blinded neuroradiologists. RESULTS We reviewed 122 patients with DBM and 97 with local autograft bone within the PEEK devices. Ages (mean 60 and 61 yr), smoking status (43% and 32%), diabetes mellitus (18% and 28%), mean body mass index (31 and 30), and immunosuppressive status were determined for all patients. Follow-up for each group averaged 19 and 18 mo. A radiographic arthrodesis was seen in 22% of the patients with DBM and 76% of the patients with local autograft. Refusion at the index level was required in 5% of the DBM and 0% of the autograft patients. CONCLUSION A PEEK interbody device filled with local autograft resulted in a higher radiographic fusion rate and a lower need for reoperation at the index level than an identical device filled with DBM. Caution is warranted in assigning fusion failure to the PEEK device alone in anterior cervical discectomy and fusion surgery.

Wednesday, September 26, 2018 3:35 PM – 5:05 PM Preserving Spinal Motion: 84. Ten-year adverse events after randomization to BRYAN cervical disc arthroplasty versus anterior cervical discectomy and fusion

BACKGROUND CONTEXT Cervical disc arthroplasty (CDA) has been advocated as an alternative to anterior cervical discectomy and fusion (ACDF) with the added potential benefit of an early return toward unrestricted activities. However, the long-term adverse of arthroplasty are yet to be fully reported. A 10-year experience with the BRYAN disc arthroplasty trial provides the opportunity to report adverse events. PURPOSE To investigate the adverse rates between BRYAN CDA and ACDF. STUDY DESIGN/SETTING Prospective, randomized multicenter IDE trial with surgeries performed between May 2002 and October 2004. PATIENT SAMPLE A total of 242 patients received BRYAN CDA (110=male, and 132=female) with a mean age 44.4 years; 221 patients received ACDF (113=male, and 108=female) with a mean age of 44.7 years. OUTCOME MEASURES Adverse that occurred up to 10 years after the initial surgery. METHODS A 10-year analysis of outcomes following FDA investigation of patients randomized to the BRYAN cervical disc arthroplasty versus fusion at a single level was performed. Patients were followed at regular intervals and adverse associated with CDA and ACDF were recorded. Adverse included: cancer, cardiovascular, carpal tunnel syndrome, death, dysphagia or dysphonia, gastrointestinal, infection, urogenital, respiratory, implant displacement/loosening, implant malposition, neck and arm pain, neurological, non-union, spinal events, other events, other pain and intraoperative vascular injury. Other events consisted of various that did not fit into another category, such as rash, depression, or hypertension. Each adverse event was compared between groups for the cumulative rate up to 10 years. Time to event analysis with a log-rank test was used for analysis. RESULTS At up to 10 years of follow-up, 231 patients in the CDA group (cumulative rate 98.4%) and 199 patients in the ACDF group (cumulative rate 98.7%) had at least one adverse event (p=0.166). The cumulative rates of the following adverse were not different between the two groups for cancer (p=.860), cardiovascular (p=.653), death (p=.507), dysphonia/dysphagia (p=.341), gastrointestinal (p=.389), infection (p=.669), urogenital (p=.873), respiratory (p=.984), implant displacement/loosening (p=.200), implant malposition (p=0.179), neck and arm pain (p=.411), neurological (p=.888), other pain (p=.147), spinal (p=.792), urogenital (p=0.873) and intraoperative vascular injury (p=.583). However, the cumulative rates were different between the CDA and ACDF groups for non-union (p=.019), other (p=0.015) and trauma (p=0.012). CONCLUSIONS The cumulative rates of patients who had any adverse were not different between BRYAN artificial cervical disc and the anterior cervical arthrodesis group. In addition, the cumulative rates were not different between the two groups for the majority of categories as well. FDA DEVICE/DRUG STATUS BRYAN cervical disc (Approved for this indication).

What is the most accurate radiographic criterion to determine anterior cervical fusion?

BACKGROUND CONTEXTThe accuracy of radiographic criteria for determining anterior cervical fusion remains controversial, and inconsistency in the literature makes a comparison of published clinical results problematic. The descriptions of bridging bone are still lacking and subjective, and the interpretation of images can be influenced by the type of graft or cage used. PURPOSETo assess and validate the diagnostic accuracies of four radiographic fusion criteria using the results of surgical exploration. STUDY DESIGNRetrospective, radiographic, and comparative study. PATIENT SAMPLEThis study included patients who required anterior or posterior exploration of a previous anterior cervical arthrodesis level(s) ranging from C3–C4 to C7–T1 for suspected pseudarthrosis or adjacent-segment pathologies. They underwent radiologic examinations to determine the four fusion criteria. We included patients whose images were taken at least 1 year after the index surgery, and 82 patients with 151 cervical segments were enrolled. OUTCOME MEASURESThe inter- and intra-rater reliabilities and validity that correlated with the results of surgical exploration for the four fusion criteria were assessed using data (fusion or not) that were collected by two raters. METHODSThe four published radiographic fusion criteria were interspinous motion (ISM) < 1 mm and superjacent ISM ≥ 4 mm, seen on dynamic radiographs; conventional bridging bone, as seen on computed tomography (CT) scans; and extra-graft bridging bone (ExGBB) and intragraft bridging bone (InGBB), observed on multi-axial reconstructed CT scans. The criteria were evaluated by two raters (spine surgeons with 5 and 7 years of experience). The raters evaluated each criterion twice at two different time points, 3 to 4 weeks apart. First, ISM and conventional bridging bone on CT scans were evaluated, followed by ExGBB and InGBB, with a time interval of 4 months. This Research was supported by the Chung-Ang University Research Grants (less than 5,000 US dollars) in 2016. RESULTSThe inter- and intra-rater reliability values of the ExGBB (0.887–0.933) criteria were the highest, followed by those for the ISM (0.860–0.906), bridging bone (0.755–0.907), and InGBB (0.656–0.695) criteria. The validity values that correlated with the exploration results were the highest for the ExGBB criteria (k=0.889), followed by the ISM (k=0.776), bridging bone (k=0.757), and InGBB (k=0.656) criteria and ExGBB showed the highest sensitivity (91.7%) and specificity (98.4%). Regarding the graft materials that were used, all criteria had the highest values in the auto-cortical group and lowest values in the cage group. Of note, sensitivity and specificity of ExGBB were 100% in autocortical group. In the cage group, the validity values for the ExGBB (k=0.663) and ISM (k=0.666) criteria were higher than those for the bridging bone (k=0.504) and InGBB (k=0.308) criteria CONCLUSIONThe presence of ExGBB (anterior, posterior, or lateral to the graft or cage) correlated the best with surgical exploration. The ISM criteria demonstrated a similar accuracy to that of conventional bridging bone criteria on CT scans. In arthrodesed segments with auto-cortical bone, criteria showed the highest validity values. In cage group, ISM and ExGBB had acceptable accuracy, but the conventional bridging bone and InGBB were worse than guessing. We recommend that ISM and ExGBB criteria should be used to increase accuracy in patients who undergo arthrodesis with cages.