Perioperative and safety outcomes following tissue-sparing posterior cervical fusion to revise a pseudarthrosis: A multicenter retrospective review of 150 cases.

Background: Posterior cervical fusion (PCF) with lateral mass screws is a favorable treatment option to revise a symptomatic pseudarthrosis due to reliable rates of arthrodesis; however, this technique introduces elevated risk for wound infection and hospital readmission. A tissue-sparing PCF approach involving facet fixation instrumentation reduces the rates of postoperative complications while stabilizing the symptomatic level to achieve arthrodesis; however, these outcomes have been limited to small study cohorts from individual surgeons commonly with mixed indications for treatment. Materials and Methods: One hundred and fifty cases were identified from a retrospective chart review performed by seven surgeons across six sites in the United States. All cases involved PCF revision for a pseudarthrosis at one or more levels from C3 to C7 following anterior cervical discectomy and fusion (ACDF). PCF was performed using a tissue-sparing technique with facet instrumentation. Cases involving additional supplemental fixation such as lateral mass screws, rods, wires, or other hardware were excluded. Demographics, operative notes, postoperative complications, hospital readmission, and subsequent surgical interventions were summarized as an entire cohort and according to the following risk factors: age, sex, number of levels revised, body mass index (BMI), and history of nicotine use. Results: The average age of patients at the time of PCF revision was 55 ± 11 years and 63% were female. The average BMI was 29 ± 6 kg/m2 and 19% reported a history of nicotine use. Postoperative follow-up visits were available with a median of 68 days (interquartile range = 41-209 days) from revision PCF. There were 91 1-level, 49 2-level, 8 3-level, and 2 4±-level PCF revision cases. The mean operative duration was 52 ± 3 min with an estimated blood loss of 14 ± 1.5cc. Participants were discharged an average of 1 ± 0.05 days following surgery. Multilevel treatment resulted in longer procedure times (single = 45 min, multi = 59 min, P = 0.01) but did not impact estimated blood loss (P = 0.94). Total nights in the hospital increased by 0.2 nights with multilevel treatment (P = 0.01). Sex, age, nicotine history, and BMI had no effect on recorded perioperative outcomes. There was one instance of rehospitalization due to deep-vein thrombosis, one instance of persistent pseudarthrosis at the revised level treated with ACDF, and four instances of adjacent segment disease. In patients initially treated with multilevel ACDF, revisions occurred most commonly on the caudal level (48% of revised levels), followed by the cranial (43%), and least often in the middle level (9%). Conclusions: This chart review of perioperative and safety outcomes provides evidence in support of tissue-sparing PCF with facet instrumentation as a treatment for symptomatic pseudarthrosis after ACDF. The most common locations requiring revision were the caudal and cranial levels. Operative duration and estimated blood loss were favorable when compared to open alternatives. There were no instances of postoperative wound infection, and the majority of patients were discharged the day following surgery.

A systematic review of risk factors and adverse outcomes associated with anterior cervical discectomy and fusion surgery over the past decade.

Background: Anterior cervical discectomy and fusion (ACDF) is one of the most frequently performed cervical surgeries in the world, yet there have been several reported complications. Objective: To determine the actual incidence of complications related to ACDF as well as any risk variables that may have been identified in earlier research. Methods: To evaluate the origin, presentation, natural history, and management of the risks and the complications, we conducted a thorough assessment of the pertinent literature. An evaluation of clinical trials and case studies of patients who experienced one or more complications following ACDF surgery was done using a PubMed, Cochrane Library, and Google Scholar search. Studies involving adult human subjects that were written in the English language and published between 2012 and 2022 were included in the search. The search yielded 79 studies meeting our criteria. Results: The overall rates of complications were as follows: Dysphagia 7.9%, psudarthrosis 5.8%, adjacent segment disease (ASD) 8.8%, esophageal perforations (EPs) 0.5%, graft or hardware failure 2.2%, infection 0.3%, recurrent laryngeal nerve palsy 1.7%, cerebrospinal fluid leak 0.8%, Horner syndrome 0.5%, hematoma 0.8%, and C5 palsy 1.9%. Conclusion: Results showed that dysphagia was a common postoperative sequelae with bone morphogenetic protein use and a higher number of surgical levels being the major risk factors. Pseudarthrosis rates varied depending on the factors such as asymptomatic radiographic graft sinking, neck pain, or radiculopathy necessitating revision surgery. The incidence of ASD indicated no data to support anterior cervical plating as more effective than standalone ACDF. EP was rare but frequently fatal, with no correlation found between patient age, sex, body mass index, operation time, or number of levels.

A Unique Presentation of Vertebral Body Osteochondroma of Sixth Cervical Spine Causing Myelopathic Symptoms: Management with En bloc Excision and Cervical Fusion.

Introduction: Vertebral body osteochondroma presenting with myelopathic symptoms is exceptionally rare entity of spinal osteochondroma which arises from the posterior surface of vertebral body and leading to spinal canal stenosis and cord compression. Early definitive diagnosis and subsequent successful treatment is necessary in such cases to prevent life threatening complications. Case Report: In this context, we report a case of a 20-years old female presented with mechanical neck pain, unsteady gait, giddiness with neurological deficit for the past 3 months. An MRI of the cervical spine revealed a mass growing from the posterior aspect of the C6 vertebral body and extending toward the vertebral canal, causing marked spinal cord compression. Conclusion: The following case report not only describes the rare presentations of vertebral body osteochondroma but also emphasizes on surgical management by en bloc resection of tumor and anterior cervical fusion, resulting in a favorable outcome without any recurrence.

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

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

Challenges and outcomes of upper cervical spinal tuberculosis surgery in pandemic-Case series study.

INTRODUCTION AND IMPORTANCE: Tuberculosis is a bacterial infection caused by Mycobacterium tuberculosis, primarily affecting the lungs. Conversely, the incidence of spinal tuberculosis (TB) was limited to a mere 6 % of cases of extrapulmonary tuberculosis. Upper cervical spinal TB is an exceptionally uncommon condition, with an incidence rate of approximately 0.3-1 % among all cases of spinal tuberculosis. CASE DESCRIPTION: Three patients diagnosed with upper cervical spinal tuberculosis who underwent Anterior Cervical Corpectomy Fusion (ACCF) or Occipitocervical fusion surgery were reviewed retrospectively. The data was obtained during the pandemic period in Indonesia. The patients were evaluated using pre-operative and post-operative Cobb's angles, Visual Analog Scale (VAS), Frankel scale, and Neck Pain and Disability (NPAD) scale. CLINICAL DISCUSSION: The ACCF surgery was more favourable when the compression was extended to the vertebral body; it showed good clinical and radiological outcomes. Multilevel ACCF and pathologies affecting bone quality seemed to be risk factors for material subsidence and instability. In this case, all the patients had performed ACCF surgery. The mean Cobb's angle pre-operative was 15.30, and Cobb's angle post-operative was 6.50. The mean pre-operative VAS value was 6.3, and the post-operative VAS value was 3. Compared to the post-operative scale, the pre-operative Frankel scale experienced an average increase of 2 levels. In contrast, the mean value of good post-operative NPAD is 29.3. CONCLUSION: Operative procedures on upper cervical spinal tuberculosis cases can improve patient's quality of life significantly, clinically and radiologically.

The Assessment of Airway Compression Due to Cervical Fusion in Klippel-Feil Syndrome Patients: A Report of Two Cases.

In general anesthesia for Klippel-Feil syndrome (KFS) patients, there is a potential risk of difficult intubation. However, airway assessment to predict difficult intubation for KFS patients is not known. In Patient 1, cervical spine computed tomography (CT) revealed airway compression due to cervical fusion. For airway assessment, bronchofiberscopy, three-dimensional (3-D) CT, and virtual bronchoscopic image (VBI) construction were performed. Based on these images, fiberoptic nasotracheal awake intubation was performed. In Patient 2, magnetic resonance imaging and bronchofiberscopy showed no airway compression due to cervical fusion; therefore, tracheal intubation was performed using a video laryngoscope after anesthetic administration. Airway compression due to cervical fusion is considered one of the risk factors for difficult intubation in KFS patients.

Bone morphogenetic protein in subaxial cervical arthrodesis: a meta-analysis of 5828 patients.

OBJECTIVE: Use of bone morphogenetic protein (BMP)-an osteoinductive agent commonly used in lumbar arthrodesis-is off-label for cervical arthrodesis. This study aimed to identify the effect of BMP use on clinical and radiological outcomes in instrumented cervical arthrodesis. METHODS: A comprehensive systematic review of the literature was performed to identify studies directly comparing outcomes between cervical arthrodeses with and without using BMP. Outcomes were analyzed separately for cases of anterior cervical discectomy and fusion (ACDF) and posterior cervical fusion (PCF). RESULTS: A total of 20 studies with 5828 patients (1948 with BMP and 3880 without BMP) were included. In the ACDF cases, BMP use was associated with higher fusion rates (98.9% vs 93.6%, risk difference [RD] 8%; risk ratio [RR] 1.12, p = 0.02), lower reoperation rates (2.2% vs 3.1%, RD 3%; RR 0.48, p = 0.04), and higher risk of dysphagia (24.7% vs 8.1%, RD 11%; RR 1.93, p = 0.02). No significant differences in the Neck Disability Index, neck pain, or arm pain scores were associated with the use of BMP. On subgroup meta-analysis of ACDF cases, older age (≥ 50 years) and higher BMP dose (≥ 0.9 mg/level) were associated with significantly higher fusion rates and relatively lower risk for dysphagia, whereas arthrodesis of fewer segments (< 2 levels) showed significantly higher dysphagia rates without a significant increase in fusion rates. In the PCF cases, the use of BMP was not associated with significant differences in fusion (p = 0.38) or reoperation (p = 0.61) rates but was associated with significantly higher blood loss during surgery (mean difference 146.7 ml, p ≤ 0.01). CONCLUSIONS: Use of BMP in ACDF offers higher rates of augmented fusion and lower rates of all-cause reoperation but with an increased risk of dysphagia. The benefit of fusion outweighs the risk of dysphagia with a higher BMP dose in older patients being operated on for < 2 levels. The use of BMP in PCF seems to have a less important effect on clinical and radiological outcomes.

Autologous rib graft for posterior cervical fusion in pediatric patients: efficacy and safety in the early postoperative period.

OBJECTIVE: The objective was to describe the indications, technique, and initial outcomes of autologous rib graft with recombinant human bone morphogenetic protein (rhBMP) in pediatric patients undergoing posterior cervical fusion. METHODS: A retrospective study was performed of all pediatric patients who underwent autologous rib grafting with extra-small rhBMP-2 for posterior craniocervical or cervical arthrodesis at a single institution between May 2020 and July 2023. Patients with less than 3 months of postoperative follow-up and no postoperative CT data were excluded. Primary outcomes included presence of fusion on CT, 30-day perioperative complications, and rib harvest complications. RESULTS: Twenty-eight sequential patients met inclusion criteria. Thirteen were male, 15 were female, and the average age was 9 years. There were no surgical site infections or instances of postoperative seroma or unplanned return to the operating room. All patients had solid fusion on postoperative CT at 3 months. The average follow-up was 14.5 months, with a range of 4 months to 3 years. There were no complications associated with the rib harvest, including no instances of harvest site pain, and all patient incisions healed well. CONCLUSIONS: The authors' preliminary results demonstrate that autologous rib graft with extra-small rhBMP-2 is an effective strategy to achieve a high rate of fusion in pediatric patients undergoing posterior instrumented craniocervical or cervical fusion. In this series, the authors found an acceptable safety profile, without seroma, surgical site infection, unplanned return to the operating room, or rib harvest complications.

Using Machine Learning Models to Identify Factors Associated With 30-Day Readmissions After Posterior Cervical Fusions: A Longitudinal Cohort Study.

OBJECTIVE: Readmission rates after posterior cervical fusion (PCF) significantly impact patients and healthcare, with complication rates at 15%-25% and up to 12% 90-day readmission rates. In this study, we aim to test whether machine learning (ML) models that capture interfactorial interactions outperform traditional logistic regression (LR) in identifying readmission-associated factors. METHODS: The Optum Clinformatics Data Mart database was used to identify patients who underwent PCF between 2004-2017. To determine factors associated with 30-day readmissions, 5 ML models were generated and evaluated, including a multivariate LR (MLR) model. Then, the best-performing model, Gradient Boosting Machine (GBM), was compared to the LACE (Length patient stay in the hospital, Acuity of admission of patient in the hospital, Comorbidity, and Emergency visit) index regarding potential cost savings from algorithm implementation. RESULTS: This study included 4,130 patients, 874 of which were readmitted within 30 days. When analyzed and scaled, we found that patient discharge status, comorbidities, and number of procedure codes were factors that influenced MLR, while patient discharge status, billed admission charge, and length of stay influenced the GBM model. The GBM model significantly outperformed MLR in predicting unplanned readmissions (mean area under the receiver operating characteristic curve, 0.846 vs. 0.829; p < 0.001), while also projecting an average cost savings of 50% more than the LACE index. CONCLUSION: Five models (GBM, XGBoost [extreme gradient boosting], RF [random forest], LASSO [least absolute shrinkage and selection operator], and MLR) were evaluated, among which, the GBM model exhibited superior predictive performance, robustness, and accuracy. Factors associated with readmissions impact LR and GBM models differently, suggesting that these models can be used complementarily. When analyzing PCF procedures, the GBM model resulted in greater predictive performance and was associated with higher theoretical cost savings for readmissions associated with PCF complications.

The effect of C2 screw type on perioperative outcomes and long-term stability after C2-T2 posterior cervical decompression and fusion.

PURPOSE: To determine if C2 pedicle versus pars screw type predicts change in fusion status, C2 screw loosening, cervical alignment, and patient-reported outcomes measures (PROMs) after C2-T2 posterior cervical decompression and fusion (PDCF). METHODS: All adult patients who underwent C2-T2 PCDF for myelopathy or myeloradiculopathy between 2013-2020 were retrospectively identified. Patients were dichotomized by C2 screw type into bilateral C2 pedicle and bilateral C2 pars screw groups. Preoperative and short- and long-term postoperative radiographic outcomes and PROMs were collected. Univariate and multivariate analysis compared patient factors, fusion status, radiographic measures, and PROMs across groups. RESULTS: A total of 159 patients met the inclusion/exclusion criteria (76 bilateral pedicle screws, 83 bilateral pars screws). Patients in the C2 pars relative to C2 pedicle screw group were on average more likely to have bone morphogenic protein (p = 0.001) and four-millimeter diameter rods utilized intraoperatively (p = 0.033). There were no significant differences in total construct and C2-3 fusion rate, C2 screw loosening, or complication and revision rates between C2 screw groups in univariate and regression analysis. Changes in C2 tilt, C2-3 segmental lordosis, C0-2 Cobb angle, proximal junctional kyphosis, atlanto-dens interval, C1 lamina-occiput distance, C2 sagittal vertical axis, C2-7 lordosis, and PROMs at all follow-up intervals did not vary significantly by C2 screw type. CONCLUSION: There were no significant differences in fusion status, hardware complications, and radiographic and clinical outcomes based on C2 screw type following C2-T2 PCDF. Accordingly, intraoperative usage criteria can be flexible based on patient vertebral artery positioning and surgeon comfort level.

Craniocervical instability in patients with Ehlers­Danlos syndromes: outcomes analysis following occipito­cervical fusion of published cases.

This critique provides a critical analysis of the outcomes following occipito-cervical fusion in patients with Ehlers-Danlos syndromes (EDS) and craniocervical instability. The study examines the efficacy of the surgical intervention and evaluates its impact on patient outcomes. While the article offers valuable insights into the management of EDS-related craniocervical instability, several limitations and areas for improvement are identified, including sample size constraints, the absence of a control group, and the need for long-term follow-up data. Future research efforts should focus on addressing these concerns to optimize treatment outcomes for individuals with EDS.

Factors associated with increased length of stay in degenerative cervical spine surgery: a cohort analysis from the Canadian Spine Outcomes and Research Network.

OBJECTIVE: Postoperative length of stay (LOS) significantly contributes to healthcare costs and resource utilization. The primary goal of this study was to identify patient, clinical, surgical, and institutional variables that influence LOS after elective surgery for degenerative conditions of the cervical spine. The secondary objectives were to examine the variability in LOS and institutional practices used to decrease LOS. METHODS: This was a multicenter observational retrospective cohort study of patients enrolled in the Canadian Spine Outcomes and Research Network (CSORN) between January 2015 and October 2020 who underwent elective anterior cervical discectomy and fusion (ACDF) (1-3 levels) or posterior cervical fusion (PCF) (between C2 and T2) with/without decompression for degenerative conditions of the cervical spine. Prolonged LOS was defined as LOS greater than the median for the ACDF and PCF populations. The principal investigators at each participating CSORN healthcare institution completed a survey to capture institutional practices implemented to reduce postoperative LOS. RESULTS: In total, 1228 patients were included (729 ACDF and 499 PCF patients). The median (IQR) LOS for ACDF and PCF were 1.0 (1.0) day and 5.0 (4.0) days, respectively. Predictors of prolonged LOS after ACDF were female sex, myelopathy diagnosis, lower baseline SF-12 mental component summary score, multilevel ACDF, and perioperative adverse events (AEs) (p < 0.05). Predictors of prolonged LOS after PCF were nonsmoking status, education less than high school, lower baseline numeric rating scale score for neck pain and EQ5D score, higher baseline Neck Disability Index score, and perioperative AEs (p < 0.05). Myelopathy did not significantly predict prolonged LOS within the PCF cohort after multivariate analysis. Of the 8 institutions (57.1%) with an enhanced recovery after surgery (ERAS) protocol or standardized protocol, only 3 reported using an ERAS protocol specific to patients undergoing ACDF or PCF. CONCLUSIONS: Patient and clinical factors predictive of prolonged LOS after ACDF and PCF are highly variable, warranting individual consideration for possible mitigation. Perioperative AEs remained a consistent independent predictor of prolonged LOS in both cohorts, highlighting the importance of preventing intra- and postoperative complications.

The Effect of Diabetes on Complications after Spinal Fusion: A Systematic Review and Meta-Analysis.

OBJECTIVE: Spinal fusion procedures are used to treat a wide variety of spinal pathologies. Diabetes mellitus (DM) has been shown to be a significant risk factor for several complications following these procedures in previous studies. To the authors' knowledge, this is the first systematic review and meta-analysis elucidating the relationship between DM and complications occurring after spinal fusion procedures. METHODS: Systematic literature searches of PubMed and EMBASE were performed from their inception to October 1, 2022, to identify studies that directly compared postfusion complications in patients with and without DM. Studies met the prespecified inclusion criteria if they reported the following data for patients with and without DM: (1) demographics; (2) postspinal fusion complication rates; and (3) postoperative clinical outcomes. The included studies were then pooled and analyzed. RESULTS: Twenty-eight studies, with a cumulative total of 18,853 patients (2695 diabetic patients), were identified that met the inclusion criteria. Analysis showed that diabetic patients had significantly higher rates of total number of postoperative complications (odds ratio [OR] = 1.33; 95% confidence interval [CI] = 1.12-1.58; P = 0.001), postoperative pulmonary complications (OR=2.01; 95%CI=1.31-3.08; P = 0.001), postoperative renal complications (OR=2.20; 95%CI=1.27-3.80; P = 0.005), surgical site infection (OR=2.65; 95%CI=2.19-3.20; P < 0.001), and prolonged hospital stay (OR=1.67; 95%CI=1.47-1.90; P < 0.001). CONCLUSIONS: Patients with DM had a significantly higher risk of developing complications after spinal fusion, particularly pulmonary and renal complications, in addition to surgical site infections and had a longer length of stay. These findings are important for informed discussions of surgical risks with patients and families before surgery.

Diagnostic and Management Challenges of Esophageal Rupture with Concomitant Cervical Abscess in Chronic High Cervical Tetraplegia.

A 65-year-old with a history of spinal cord injury and previous cervical surgery presented with persistent fever despite antibiotic treatment. MRI scans revealed an abscess in the neck extending from C3 to C6, with associated osteomyelitis. After an initial discharge following antibiotic therapy, the patient was readmitted due to recurrent systemic infection symptoms and another abscess. A subsequent endoscopy showed esophageal rupture with protruding cervical fusion metal. Due to operative risks, a percutaneous endoscopic gastrostomy was performed without further infection recurrence. The absence of typical imaging signs of esophageal rupture made diagnosis difficult. The infection spread through the cervical fascia from superficial to deep cervical areas. Esophageal rupture, a rare complication of cervical surgery, presents with varying symptoms depending on its location and was particularly challenging to diagnose in this patient due to high cervical tetraplegia, which masked typical pain responses. Therefore, this case highlights the need to consider esophageal rupture in differential diagnoses for chronic ACDF patients, even when typical symptoms are absent.

Biomechanical evaluation of the novel assembled internal fixed system in C2-C3 anterior cervical discectomy and fusion: a finite element analysis.

BACKGROUND: To analyze and compare the biomechanical characteristics of the new combined cervical fusion device (NCCFD) and the traditional cage-plate construct (CPC) to ascertain its effectiveness in anterior cervical discectomy and fusion (ACDF) using finite element analysis. METHODS: A finite element model of the cervical spine, inclusive of the occipital bone was created and validated. In the ACDF model, either CPC or NCCFD was implanted at the C2-C3 segment of the model. A pure moment of 1.0 Nm combined with a follower load of 50 N was directed onto the superior surfaces of the occipital bone to determine flexion, extension, lateral bending (left and right), and axial rotation (left and right). The range of motion (ROM), stress distribution at the bone-implant interface, and facet joint forces were investigated and compared between CPC and NCCFD systems. RESULT: The results showed that the ROMs of the fused levels in both models were nearly zero, and the motions of the unfused segments were similar. In addition, the maximum displacement exhibited nearly identical values for both models. The maximum stress of NCCFD screws in lateral bending and rotational conditions is significantly higher than that of the CPC, while the NCCFD model's maximum stress remains within an acceptable range. Comparing the maximum fusion stress, it was found that the CPC experiences much lower fusion stress in anterior flexion and extension than the NCCFD, with no significant difference between the two in lateral bending and rotational states. Stress on the cage was mainly concentrated on both sides of the wings. Comparing the maximum IDP in the CPC and NCCFD, it was observed that maximum stresses rise in extension and lateral bending for both models. Lastly, stress distributions of the facet joints were generally similar across the two devices. CONCLUSION: NCCFD not only provides the same level of biomechanical stability as CPC but also avoids postoperative complications associated with uneven force damage to the implant. The device offers a novel surgical alternative for ACDF in C2-C3 level.

Are There Advantages in Cervical Intrafacetal Fusion With Minimal Posterolateral Fusion (PLF) Compared to Conventional PLF in Posterior Cervical Fusion?

OBJECTIVE: We propose that cervical intrafacetal fusion (cIFF) using bone chip insertion into the facetal joint space additional to minimal PLF is a supplementary fusion method to conventional posterolateral fusion (PLF). METHODS: Patients who underwent posterior cervical fixation accompanied by cIFF with minimal PLF or conventional PLF for cervical myelopathy from 2012 to 2023 were investigated retrospectively. Radiological parameters including Cobb angle and C2-7 sagittal vertical axis (SVA) were compared between the 2 groups. In cIFF with minimal PLF group, cIFF location and PLF location were carefully divided, and the fusion rates of each location were analyzed by computed tomography scan. RESULTS: Among enrolled 46 patients, 31 patients were in cIFF group, 15 in PLF group. The postoperative change of Cobb angle in 1-year follow-up in cIFF with minimal PLF group and conventional PLF group were 0.1° ± 4.0° and -9.7° ± 8.4° respectively which was statistically lower in cIFF with minimal PLF group (p = 0.022). Regarding the fusion rate in cIFF with minimal PLF group in postoperative 6 months, the rates was achieved in 267 facets (98.1%) in cIFF location, and 244 facets (89.7%) in PLF location (p < 0.001). CONCLUSION: Postoperative sagittal alignment was more preserved in cIFF with minimal PLF group compared with conventional PLF group. Additionally, in cIFF with minimal PLF group, the bone fusion rate of cIFF location was higher than PLF location. Considering the concerns of bone chip migration onto the spinal cord and relatively low fusion rate in PLF method, applying cIFF method using minimized PLF might be a beneficial alternative for posterior cervical decompression and fixation.

Anatomical Brushite-Coated Mg-Nd-Zn-Zr Alloy Cage Promotes Cervical Fusion: One-Year Results in Goats.

In this study, an anatomical brushite-coated Mg-Nd-Zn-Zr alloy cage was fabricated for cervical fusion in goats. The purpose of this study was to investigate the cervical fusion effect and degradation characteristics of this cage in goats. The Mg-Nd-Zn-Zr alloy cage was fabricated based on anatomical studies, and brushite coating was prepared. Forty-five goats were divided into three groups, 15 in each group, and subjected to C2/3 anterior cervical decompression and fusion with tricortical bone graft, Mg-Nd-Zn-Zr alloy cage, or brushite-coated Mg-Nd-Zn-Zr alloy cage, respectively. Cervical radiographs and computed tomography (CT) were performed 3, 6, and 12 months postoperatively. Blood was collected for biocompatibility analysis and Mg2+ concentration tests. The cervical spine specimens were obtained at 3, 6, and 12 months postoperatively for biomechanical, micro-CT, scanning electron microscopy coupled with energy dispersive spectroscopy, laser ablation-inductively coupled plasma-time-of-flight mass spectrometry, and histological analysis. The liver and kidney tissues were obtained for hematoxylin and eosin staining 12 months after surgery for biosafety analysis. Imaging and histological analysis showed a gradual improvement in interbody fusion over time; the fusion effect of the brushite-coated Mg-Nd-Zn-Zr alloy cage was comparable to that of the tricortical bone graft, and both were superior to that of the Mg-Nd-Zn-Zr alloy cage. Biomechanical testing showed that the brushite-coated Mg-Nd-Zn-Zr alloy cage achieved better stability than the tricortical bone graft at 12 months postoperatively. Micro-CT showed that the brushite coating significantly decreases the corrosion rate of the Mg-Nd-Zn-Zr alloy cage. In vivo degradation analysis showed higher Ca and P deposition in the degradation products of the brushite-coated Mg-Nd-Zn-Zr alloy cage, and no hyperconcentration of Mg was detected. Biocompatibility analysis showed that both cages were safe for cervical fusion surgery in goats. To conclude, the anatomical brushite-coated Mg-Nd-Zn-Zr alloy cage can promote cervical fusion in goats, and the brushite-coated Mg-Nd-Zn-Zr alloy is a potential material for developing absorbable fusion cages.

Impact of the COVID-19 Pandemic on Outcomes and Perioperative Factors Associated with Posterior Cervical Fusion.

Introduction: While there is anecdotal evidence that the coronavirus disease 2019 (COVID-19) pandemic altered perioperative decision-making in patients requiring posterior cervical fusion (PCF), a national-level analysis to examine the significance of this hypothesis has not yet been conducted. This study aimed to determine the potential differences in perioperative variables and surgical outcomes of PCF performed before vs. during the COVID-19 pandemic. Methods: Adults who underwent PCF were identified in the 2019 (prepandemic) and 2020 (intrapandemic) NSQIP datasets. Differences in 30-day readmission, reoperation, and morbidity were evaluated using multivariate logistic regression. On the other hand, differences in operative time and relative value units (RVUs) were estimated using quantile regression. Furthermore, the odds ratios (OR) for length of stay (LOS) were estimated using negative binomial regression. Secondary outcomes included rates of nonhome discharge and outpatient surgery. Results: A total of 3,444 patients were included in this study (50.7% from 2020). Readmission, reoperation, morbidity, operative time, and RVUs per minute were similar between cohorts (p>0.05). The LOS (OR 1.086, p<0.001) and RVUs-per-case (coefficient +0.360, p=0.037) were significantly greater in 2020 compared to 2019. Operation year 2020 was also associated with lower rates of nonhome discharge (22.3% vs. 25.8%, p=0.017) and higher rates of outpatient surgery (4.8% vs. 3.0%, p=0.006). Conclusions: During the COVID-19 pandemic, a 28% decreased odds of nonhome discharge following PCF and a 72% increased odds of PCF being performed in an outpatient setting were observed. The readmission, reoperation, and morbidity rates remained unchanged during this period. This is notable given that patients in the 2020 group were more frail. This suggests that patients were shifted to outpatient centers possibly to make up for potentially reduced case volume, highlighting the potential to evaluate rehabilitation-discharge criteria. Further research should evaluate these findings in more detail and on a regional basis.

Effect of Furosemide on Prevertebral Soft Tissue Swelling after Anterior Cervical Fusion: A Comparative Study with Dexamethasone.

STUDY DESIGN: Retrospective cohort study. PURPOSE: This study aimed to investigate the effect of furosemide on prevertebral soft tissue swelling (PSTS) after anterior cervical fusion (ACF) and compare it with the effect of dexamethasone. OVERVIEW OF LITERATURE: Postoperative PSTS is a common complication of ACF. Dexamethasone has been used for its treatment; however, its efficacy remains controversial. Furosemide may reduce PSTS if it is soft tissue edema; however, no studies have demonstrated the effect of furosemide on PSTS after ACF. METHODS: The symptomatic PSTS group received intravenous (IV) administration of dexamethasone or furosemide. The asymptomatic PSTS group did not receive any medication. Patients were divided into the control (no medication, n=31), Dexa (IV dexamethasone, n=25), and Furo (IV furosemide, n=28) groups. PSTS was checked daily with simple radiographs and medication-induced reductions in PSTS from its peak or after medication. RESULTS: The peak time (postoperative days) of PSTS in the control (2.27±0.47, p<0.05) and Dexa (1.91±0.54, p<0.01) groups were significantly later than that in the Furo group (1.38±0.74). PSTS was significantly lower in the Furo group than in the Dexa group from postoperative days 4 to 7 (p<0.05). PSTS reduction after the peak was significantly greater in the Furo group than in the control (p<0.01) and Dexa (p<0.01) groups. After starting the medication therapy, the Furo group showed a significantly greater reduction in PSTS than the Dexa group (p<0.01). No difference was found in symptom improvement among the three groups. CONCLUSIONS: If furosemide is used to reduce PSTS after ACF, it can effectively reduce symptoms.

Are Patients With Segmental Cervical Kyphosis Appropriate Candidates for Cervical Disc Arthroplasty (CDA)? A Clinical and Radiographic Analysis Compared to Anterior Cervical Discectomy and Fusion (ACDF).

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To compare the clinical and radiographic outcomes of Anterior Cervical Discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA) in patients with preoperative segmental kyphosis. METHODS: Patients with segmental cervical kyphosis at the operative levels undergoing 1- or 2-level ACDF or CDA from 2017 to 2020 with 2 years of follow were identified. Patient demographics, perioperative data, complication rates, radiographic findings and reported outcomes were analyzed. RESULTS: A total of 48 patients met inclusion criteria and were included in our study (ACDF: n = 24, CDA: n = 24). Patient demographic data between the 2 cohorts was similar expect for proportion of males (ACDF: 62.5% vs CDA: 33.3%, P = .043). There was no statistical significance in the change of segmental lordosis (ACDF: +8.09° vs CDA: +5.88°, P = .075) between the preoperative and final postoperative period. Additionally, the change in cervical lordosis was similar between groups (ACDF:+ 9.86° vs CDA: +7.60°, P = .226). VAS scores were similar between the 2 groups at every follow-up interval. NDI scores were significantly different at the 6-month, 12 month and the final follow-up. Mean improvements between preoperative and final postoperative periods were statistically superior in the CDA cohort compared to the ACDF cohort (ACDF: 22.8 vs CDA: 24.1, P = .0375). CONCLUSION: CDA was superior to ACDF in regards to NDI scores following index procedure in patients with preoperative segmental cervical kyphosis. Those in the CDA cohort had similar complication rates, revision rates and radiographic outcomes as those who underwent ACDF.