Risk Factors for and Clinical Outcomes of Dysphagia After Anterior Cervical Surgery for Degenerative Cervical Myelopathy: Results from the AOSpine International and North America Studies

Development and Validation of a Predictive Model to Evaluate the Risk of Dysphagia Following Anterior Cervical Discectomy and Fusion

STUDY DESIGN

A retrospective study.

OBJECTIVE

To investigate the potential risk factors of dysphagia after anterior cervical discectomy and fusion (ACDF) and to establish and validate a prediction model.

METHODS

The clinical data of 252 patients who underwent anterior cervical discectomy and fusion in our hospital from January 2018 to October 2020 were retrospectively analyzed and divided into the dysphagia group and the non-dysphagia group according to whether dysphagia occurred after surgery. Age, gender, body mass index, smoking and drinking history, hypertension history, diabetes history, disease duration, placement of Hemovac negative pressure drain, number of segments involved in surgery, whether C4-5/C5-6 segment surgery, incision length, incision position, level of preoperative EAT-10 score, whether preoperative tracheal exercise, and changes in cervical curvature before and after surgery were recorded in both groups. Risk factors for postoperative dysphagia were identified and nomogram prediction models were developed.

RESULTS

A total of 252 patients were included in the study, 115 of whom presented with dysphagia within 1 week after anterior cervical fusion. The results of multivariate logistic regression analysis indicated that male gender (OR = .045, 95% CI .223-.889) and whether preoperative tracheal exercise (OR = .260, 95% CI .107-.633) were independent risk factors associated with reduced incidence of postoperative dysphagia.

CONCLUSION

The incidence of dysphagia symptoms after anterior cervical decompression and fusion gradually decreased with the extension of follow-up time, and preoperative tracheal exercise and shortening the operation time may help to reduce the occurrence of postoperative dysphagia.

Efficacy and safety of microendoscopic anterior cervical decompression and fusion. Compared with conventional open surgery

STUDY DESIGN

Retrospective observational study of consecutive patients.

OBJECTIVE

This study aimed to (1) develop a new surgical procedure using microendoscopy in anterior cervical decompression and fusion (ACDF), (2) compare the complications and postoperative courses in patients with the new microendoscopic and conventional ACDFs, and (3) confirm the efficacy and safety of the microendoscopic ACDF.

SUMMARY OF BACKGROUND DATA

ACDF is an excellent procedure that is minimally invasive to the muscle tissue and can improve alignment. However, it poses significant risks of complications such as postoperative acute airway obstruction. Retraction manipulation during surgery is considered the cause. Hence, we introduced microendoscopic surgery, which minimizes retraction manipulation. This study aimed to verify the safety and efficacy of microendoscopic ACDF.

METHODS

We compared the anteroposterior thickness of the prevertebral soft tissue on the radiographs preoperatively and 1, 2, and 7 days postoperatively in 15 patients who underwent conventional ACDF with 8 patients undergoing microendoscopic ACDF. Additionally, we assessed the perioperative complications and postoperative course.

RESULTS

Microendoscopic ACDF significantly reduced prevertebral soft tissue swelling 2 and 7 days postoperatively. No significant differences in surgical data, complications, or rates of symptom improvement were found between the two groups.

CONCLUSIONS

Microendoscopic ACDF reduces postoperative prevertebral soft tissue swelling. Surgical data and efficacy are comparable to those of conventional techniques, indicating the safety and effectiveness of the procedure.

Perioperative Dysphagia Considerations for Patients With Severe Cervical Spondylotic Myelopathy

STUDY DESIGN

Cohort study with consecutive cases.

OBJECTIVES

Dysphagia after anterior cervical spine surgery is a well-known complication. The aim of this study is to identify risk factors for dysphagia in patients with cervical myelopathy requiring surgery.

METHODS

We conducted a prospective analysis of 92 consecutive patients with cervical spondylotic myelopathy (CSM) who underwent anterior cervical spine surgery. All patients underwent a pre- and postoperative swallowing evaluation using the Eating Assessment Tool (EAT-10) and the Hyodo-Komagane (H‒K) score, an endoscopic scoring method used by an examining otolaryngologist to assess dysphagia.

RESULTS

None of the patients had dysphagia when assessed using EAT-10; however, 15.2% of patients had H‒K scores indicative of dysphagia. Preoperative latent dysphagia was highly correlated with postoperative dysphagia (r = 0.51, P < 0.0001). No significant difference was found for the presence of dysphagia due to a history of smoking, dialysis, diabetes, asthma, and restrictive and/or obstructive ventilation disorder. The 10-s grip and release test (P < 0.0001) and the upper extremity function (P = 0.004) and bladder function (P = 0.0008) items from the Japanese Orthopaedic Association scores significantly correlated with H‒K scores.

CONCLUSION

This study suggests that advanced age and severe preoperative upper limb and bladder dysfunction are risk factors for dysphagia in patients with cervical myelopathy requiring surgery.

Stand-Alone Anchored Spacer vs Anterior Plate Construct in the Management of Adjacent Segment Disease after Anterior Cervical Discectomy and Fusion: A Systematic Review and Meta-Analysis of Comparative Studies

STUDY DESIGN

Systematic Review and Meta-Analysis.

OBJECTIVES

This study aimed to evaluate the clinical and radiological outcomes of surgically treated adjacent segment disease (ASDis) following ACDF with either anterior plate construct (APC) or stand-alone anchored spacers (SAAS).

METHOD

Multiple databases were searched until December 2022 for pertinent studies. The primary outcome was health-related quality of life outcomes [JOA, NDI, and VAS], whereas, the secondary outcomes included operative characteristics [estimated blood loss (EBL) and operative time (OT)], radiological outcomes [C2-C7 Cobb angle, disc height index (DHI) changes, fusion rate], and complications.

RESULTS

A total of 5 studies were included, comprising 210 patients who had been surgically treated for cervical ASDis. Among them, 113 received APC, and 97 received SAAS. Postoperative dysphagia was significantly higher in the APC group [47% vs 11%, OR = 7.7, 95% CI = 3.1-18.9, P < .05]. Similarly, operative time and blood loss were higher in the APC group compared to the SAAS group; [MD = 16.96, 95% CI = 7.87-26.06, P < .05] and [MD = 5.22, 95% CI = .35 - 10.09, P < .05], respectively. However, there was no difference in the rate of prolonged dysphagia and clinical outcomes in terms of JOA, NDI, and VAS. Furthermore, there was no difference in the radiological parameters including the C2-7 Cobb angle and DHI as well as the fusion rate.

CONCLUSION

Our meta-analysis demonstrated that both surgical techniques (APC and SAAS) are effective in treating ASDis. However, with low certainty of the evidence, considering patients are at high risk of dysphagia following revision cervical spine surgery SAAS may be the preferred choice.

The significance of metabolic disease in degenerative cervical myelopathy: a systematic review

Introduction

Degenerative cervical myelopathy (DCM) is a form of chronic spinal cord injury, with a natural history of potential for progression over time. Whilst driven by mechanical stress on the spinal cord from degenerative and congenital pathology, the neurological phenotype of DCM is likely to be modified by multiple systemic factors. The role of metabolic factors is therefore of interest, particularly given that ischaemia is considered a key pathological mechanism of spinal cord injury. The objective was therefore to synthesise current evidence on the effect of metabolism on DCM susceptibility, severity, and surgical outcomes.

Methods

A systematic review in MEDLINE and Embase was conducted following PRISMA guidelines. Full-text papers in English, with a focus on DCM and metabolism, including diabetes, cardiovascular disease, anaemia, and lipid profile, were eligible for inclusion. Risk of methodological bias was assessed using the Joanna Briggs Institute (JBI) critical assessment tools. Quality assessments were performed using the GRADE assessment tool. Patient demographics, metabolic factors and the relationships between metabolism and spinal cord disease, spinal column disease and post-operative outcomes were assessed.

Results

In total, 8,523 papers were identified, of which 57 met criteria for inclusion in the final analysis. A total of 91% (52/57) of included papers assessed the effects of diabetes in relation to DCM, of which 85% (44/52) reported an association with poor surgical outcomes; 42% of papers (24/57) discussed the association between cardiovascular health and DCM, of which 88% (21/24) reported a significant association. Overall, DCM patients with diabetes or cardiovascular disease experienced greater perioperative morbidity and poorer neurological recovery. They were also more likely to have comorbidities such as obesity and hyperlipidaemia.

Conclusion

Metabolic factors appear to be associated with surgical outcomes in DCM. However, evidence for a more specific role in DCM susceptibility and severity is uncertain. The pathophysiology and natural history of DCM are critical research priorities; the role of metabolism is therefore a key area for future research focus.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42021268814.

Comparison between 3-level and 4level anterior cervical discectomy and fusion in the treatment of cervical spondylotic myelopathy: A meta-analysis

OBJECTIVE

Our objective is to estimate the clinical effectiveness of 3-level and 4-level anterior cervical discectomy and fusion (ACDF) in the management of cervical spondylotic myelopathy (CSM).

METHODS

We conducted a thorough search in English databases. We gathered the data on surgical variables and complications to contrast the clinical effectiveness between 3-level and 4-level. We utilized RevMan 5.3 and STATA 12.0 to analyze the data.

RESULTS

Finally, eight studies met inclusion criteria of this study. Our findings indicated that operation time [p for heterogeneity = 0.23, I2 = 32 %, p＜0.00001, OR = -24.93, 95%CI (-32.39,-17.49)], blood loss [p for heterogeneity = 0.33, I2 = 10 %, p＜0.00001, OR = -60.87, 95%CI (-85.43,-36.32)] and the total number of complications [p for heterogeneity = 0.36, I2 = 0 %, p = 0.004, OR = 0.37, 95%CI (0.18,0.72)] in 3-level ACDF were significantly less than in 4-level ACDF. No marked difference was found in hospital stay, revision rate, fusion rate, the number of readmissions, infection, hematoma, or pseudarthrosis between 3-level and 4-level ACDF.

CONCLUSIONS

It is easy to understand that performing 4-level needs more operation time and blood loss. No obvious discrepancy was found with regard to the subgroups of complications between the two procedures, yet 4-level procedures had a more number of complications.

Cervical alignment and clinical outcome of anterior cervical discectomy and fusion vs. anterior cervical corpectomy and fusion in local kyphotic cervical spondylotic myelopathy

Background

Cervical local kyphosis (CLK) is a common degenerative disorder with a potentially debilitating and intractable condition. Currently, there is still debate on the optimal treatment of local kyphotic cervical spondylotic myelopathy (LKCSM) via different anterior approaches.

Objective

The objective of this study was to evaluate the surgical efficacy of anterior cervical discectomy and fusion (ACDF) vs. anterior cervical corpectomy and fusion (ACCF) for the treatment of LKCSM. In addition, the cervical sagittal alignment parameters and axial symptoms (AS) severity after CLK correction were analyzed.

Materials and methods

From January 2016 and December 2020, 104 patients who suffered LKCSM were retrospectively reviewed. These patients underwent ACDF (n = 53) and ACCF (n = 51). Pre- and postoperatively, cervical sagittal alignment parameters were measured on the lateral X-rays, including local kyphotic angles (LKA), C2-7 Cobb angle, T1 slope, and C2-7 sagittal vertical axis (C2-7 SVA). The neurological recovery rate was calculated according to the Japanese Orthopedic Association (JOA) score. The AS severity was evaluated using Neck Disability Index (NDI).

Results

Significant differences (P < 0.05) were demonstrated between ACDF and ACCF groups regarding LKA, LKA correction, C2-7 Cobb angle, T1 slope, C2-7 SVA, NDI, NDI recovery and NDI ranking system. However, no significant differences (P > 0.05) existed in JOA score, recovery rate, and neurological recovery rate grade. In both groups, significant differences (P < 0.05) were demonstrated between pre- and postoperative LKA, T1 slope, C2-7 Cobb angle, C2-7 SVA, JOA score, and NDI. LKA correction showed the positive correlations with the recovery rate (r = 0.48, P < 0.001), and with the NDI recovery in ACDF group (r = 0.49, P < 0.001) and in ACCF group (r = 0.55, P < 0.001).

Conclusions

LKCSM with ≤3 segments of spinal cord compression can be improved with either ACDF or ACCF, resulting in satisfactory neurological outcomes. CLK correction can significantly improve the neurological function and AS, and increase the T1 slope and C2-7 SVA. However, ACDF was more favorable than ACCF in the CLK correction.

Comparison of Surgical Outcomes of Anterior and Posterior Fusion Surgeries for K-line (-) Cervical Ossification of the Posterior Longitudinal Ligament: A Prospective Multicenter Study

STUDY DESIGN

A prospective multicenter study.

OBJECTIVE

The objective of this study is to compare the surgical outcomes of anterior and posterior fusion surgeries in patients with K-line (-) cervical ossification of the posterior longitudinal ligament (OPLL).

SUMMARY OF BACKGROUND DATA

Although laminoplasty is effective for patients with K-line (+) OPLL, fusion surgery is recommended for those with K-line (-) OPLL. However, whether the anterior or posterior approach is preferable for this pathology has not been effectively determined.

MATERIALS AND METHODS

A total of 478 patients with myelopathy due to cervical OPLL from 28 institutions were prospectively registered from 2014 to 2017 and followed up for two years. Of the 478 patients, 45 and 46 with K-line (-) underwent anterior and posterior fusion surgeries, respectively. After adjusting for confounders in baseline characteristics using a propensity score-matched analysis, 54 patients in both the anterior and posterior groups (27 patients each) were evaluated. Clinical outcomes were assessed using the cervical Japanese Orthopaedic Association and the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire.

RESULTS

Both approaches showed comparable neurological and functional recovery. The cervical range of motion was significantly restricted in the posterior group because of the large number of fused vertebrae compared with the anterior group. The incidence of surgical complications was comparable between the cohorts, but the posterior group demonstrated a higher frequency of segmental motor paralysis, whereas the anterior group more frequently reported postoperative dysphagia.

CONCLUSIONS

Clinical improvement was comparable between anterior and posterior fusion surgeries for patients with K-line (-) OPLL. The ideal surgical approach should be informed based on the balance between the surgeon's technical preference and the risk of complications.

Dysphagia after cervical spine surgery: a review of risk factors and preventative measures

Dysphagia is a regular occurrence after cervical spine surgery, and the development of dysphagia postoperatively is associated with worsened quality of life for patients. Despite the frequency and negative implications of this adverse outcome, there is no clear consensus for defining dysphagia within the spinal literature. Numerous patient-reported outcomes questionnaires are currently used to elucidate the presence and severity of postoperative dysphagia, several of which are not validated instruments. This variability in reporting creates difficulty when trying to determine the prevalence of dysphagia and any potential mitigating factors. In the current review, the authors discuss the causes of postoperative dysphagia after cervical spine surgery, metrics for evaluating postoperative dysphagia, risk factors for the development of this adverse outcome, and strategies for preventing its development. Readers will be able to use this information to improve patient outcomes after cervical spine surgery.

Cervical alignment and clinical outcome of anterior decompression with fusion vs. posterior decompression with fixation in kyphotic cervical spondylotic myelopathy

Background context

Cervical kyphosis is a common but potentially debilitating and challenging condition. There is controversy on the optimal surgical strategy for the treatment of kyphotic cervical spondylotic myelopathy (KCSM) using either anterior approach or posterior approach.

Introduction

The purpose of this study was to investigate the surgical efficacy of anterior decompression with fusion (ADF) vs. posterior decompression with fixation (PDF) for the treatment of KCSM, and to further analyze the changes of cervical spinal alignment parameters and axial symptoms (AS) severity after kyphotic correction.

Materials and methods

We retrospectively reviewed 117 patients with KCSM who had undergone ADF (58 patients) and PDF (59 patients) between January 2016 and December 2020. Cervical spinal alignment parameters, including curvature index (CI) and C2-7 Cobb angle, were measured on the PreOP and PostOP lateral radiographs. Recovery rate was calculated based on the Japanese Orthopedic Association (JOA) score. AS severity was quantified by Neck Disability Index (NDI). A P-value less than 0.05 was considered to be significant.

Results

The patient mean age, gender, presenting symptoms and follow-up time were similar between the two groups (P > 0.05). However, there were statistically significant differences (P < 0.001) between the two groups regarding the operation levels, operating time and intraoperative blood loss. Analysis of PostOP follow-up data showed significant differences (P < 0.001) in CI, correction of CI, C2-7 Cobb angle, and NDI between the two groups, whereas no significant differences in JOA score (P = 0.16) and recovery rate (P = 0.14). There were significant differences (P < 0.001) in CI, C2-7 Cobb angle, JOA score, and NDI between PreOP and PostOP follow-up in each group. Correction of CI showed positive correlation with recovery of NDI in Group ADF (r = 0.51, P < 0.001), and in Group PDF (r = 0.45, P < 0.001).

Conclusion

Satisfied neurological improvement was obtained by ADF and PDF for patients with KCSM. Cervical kyphotic correction caused significant improvement of AS, and was more favorable with ADF than with PDF. Surgeons should pay full consideration of the merits and shortcomings of each approach when deciding on a surgical plan.

Ossification of the Posterior Longitudinal Ligament: Pathophysiology, Diagnosis, and Management

Ossification of the posterior longitudinal ligament (OPLL) occurs as heterotopic bone forms in the posterior longitudinal ligament, resulting in neural compression, myelopathy, and radiculopathy. OPLL is most commonly observed in East Asian populations, with prevalence rates of 1.9% to 4.3% reported in Japan. OPLL rates are lower in North American and European patients, with reported prevalence of 0.1% to 1.7%. Patients typically develop symptoms due to OPLL in their cervical spines. The etiology of OPLL is multifactorial, including genetic, metabolic, and anatomic factors. Asymptomatic or symptomatic patients with OPLL can be managed nonsurgically, whereas patients with neurologic symptoms may require surgical decompression from an anterior, posterior, or combined approach. Surgical treatment can provide notable improvement in neurologic function. Surgical decision making accounts for multiple factors, including patient comorbidities, neurologic status, disease morphology, radiographic findings, and procedure complication profiles. In this study, we review OPLL epidemiology and pathophysiology, clinical features, radiographic evaluation, management, and complications.

Intraoperative Use of Topical Retropharyngeal Steroids for Dysphagia after Anterior Cervical Fusion: A Systematic Review and Meta-Analysis

Purpose

The anterior cervical approach is commonly used clinically for cervical spondylosis, but it also results in frequent postoperative dysphagia, which can increase the risk of complications and poor treatment satisfaction in severe cases. Intraoperative local application of retropharyngeal steroids has an impact on reducing the occurrence and severity of dysphagia; however, the results of current studies vary. The meta-analysis of this randomized trial was to evaluate the effectiveness and safety of intraoperative topical retropharyngeal steroids for the control of dysphagia after anterior cervical spine surgery.

Methods

Two authors searched electronic databases such as PubMed, MEDLINE, EMBASE, Cochrane Library, and Google Scholar, respectively. The search terms were “Dysphagia,” “Steroids,” “Anterior Cervical Discectomy and Fusion,” etc. A random effects model was used to conduct a meta-analysis based on deviance information criteria.

Results

A total of 8 studies were included in this meta-analysis after screening of 792 studies. Bazaz scores were not significantly different in the steroid group at one day postoperatively (P = 0.38), and dysphagia was significantly improved at 14 days postoperatively (95% CI: 0.15 to 0.64; P = 0.002). PSTSI was significantly improved one day (P = 0.03) and 14 days after surgery (P < 0.0001). VAS scores were all lower versus controls (P < 0.001).

Conclusion

Perioperative local retropharyngeal steroid administration as an adjunct to anterior cervical spine surgery reduces the incidence and severity of dysphagia compared with placebo control. However, future high-quality randomized controlled studies could incorporate nonsubjective dysphagia measures and long-term follow-up on the occurrence of associated complications or other side effects.

Comparison of Anterior Cervical Discectomy and Fusion with Cervical Laminectomy and Fusion in the Treatment of 4-Level Cervical Spondylotic Myelopathy

Objective

To assess and compare the therapeutic effects of Anterior Cervical Discectomy and Fusion (ACDF) and Cervical Laminectomy and Fusion (CLF) in the treatment of 4‐level cervical.

Methods

We performed a retrospective review on 39 patients with 4‐level CSM who underwent ACDF or CLF in the Third Hospital of Hebei Medical University from January 2010 to December 2018. The patients were divided into ACDF group and CLF group according to the treatment. The operative index was evaluated based on intraoperative blood loss and operation time. The functional outcomes including Japanese Orthopedic Association (JOA) score and visual analogue scale (VAS) of axial pain were compared. The Cobb angle, Cobb angle improvement rate, range of motion (ROM) and ROM loss ratio were measured for radiographic evaluation.

Results

No major complications or deaths occurred. The average age at baseline was 55 years. There was no significant difference between the ACDF and CLF group in follow‐up time (26.29 months, 25.39 months, P > 0.05). The intraoperative blood loss was higher in the CLF group than in the ACDF group (692.67 ± 38.68 vs 392.14 ± 128.06, P < 0.05). The operation time was longer in the CLF group than in the ACDF group (206.60 ± 49.37 vs 172.64 ± 31.96, P < 0.05). Significant improvements in the VAS and JOA scores were observed in both groups (P < 0.05). No significant difference in VAS was found between the ACDF and CLF groups (P < 0.05). There was a significantly larger improvement rate of JOA score in the ACDF group than in the CLF group (60.9% ± 9.57% vs 31.5% ± 15.70%, P < 0.05). There were two (9.6%) cases with complications In the ACDF group, including one (4.8%) case of dysphagia and one (4.8%) case of pharyngodynia. In the CLF group, two patients (11.1%) developed C₅ palsy. No significant difference in the incidence of complications, ROM loss ratio and Cobb angle improvement rate was found between group ACDF and group CLF (all P < 0.05).

Conclusion

Both ACDF and CLF were effective in the treatment of multi‐level cervical spondylosis and ACDF is more suitable for patients with 4‐level CSM.

The effect of local steroid application on bony fusion in a rat posterolateral spinal arthrodesis model

INTRODUCTION

Local steroid administration during anterior cervical spine surgery has been shown to improve postoperative dysphagia. However, concerns over potential complications remain. This study aims to evaluate the effect of local steroid administration on bone regeneration and spine fusion in a preclinical model, as well as the impact on osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBM-MSCs) in a 3D culture system.

MATERIALS AND METHODS

Forty-five rats underwent bilateral L4-L5 posterolateral lumbar fusion (PLF) utilizing local delivery of low-dose recombinant human bone morphogenetic protein-2 (rhBMP-2; 0.5 μg/implant). Rats were divided into three groups: no steroid (control), low dose (0.5 mg/kg), and high dose (2.5 mg/kg) of triamcinolone. Bone growth and fusion were assessed using radiography, blinded manual palpation, and micro-CT analysis and were visualized by histology. The impact of triamcinolone exposure on osteogenic differentiation of hBM-MSCs was evaluated by gene expression analysis, alkaline phosphatase activity assay, and alizarin red staining.

RESULTS

No significant differences in fusion scores or rates were seen in the low- or high-dose steroid treatment groups relative to untreated controls. Quantification of new bone formation via micro-CT imaging revealed no significant between-group differences in the volume of newly regenerated bone. Triamcinolone also had no negative impact on pro-osteogenic gene transcript levels, and ALP activity was enhanced in the presence of triamcinolone. Mineral deposition appeared comparable in cultures grown with and without triamcinolone.

CONCLUSIONS

Local steroid application does not seem to inhibit rhBMP-2-mediated spine fusion in rats, though our study may not be adequately powered to detect differences in fusion as measured by manual palpation or bone volume as measured by micro-CT. These findings suggest that local triamcinolone may not increase pseudarthrosis in spine fusion procedures. Further large animal and clinical studies to verify its safety and efficacy are warranted.

Risk factors for postoperative dysphagia and dysphonia following anterior cervical spine surgery: a comprehensive study utilizing the hospital for special surgery dysphagia and dysphonia inventory (HSS-DDI)

BACKGROUND CONTEXT

Postoperative dysphagia and dysphonia (PDD) are prevalent complications after anterior cervical discectomy and fusion (ACDF). Identification of risk factors for these complications is necessary for effective prevention. Recently, patient reported outcome measures (PROM) have been used to determine PDD after ACDF. The Hospital for Special Surgery Dysphagia and Dysphonia Inventory (HSS-DDI) is a validated PROM that specifically assesses dysphagia and dysphonia after anterior cervical spine surgery.

PURPOSE

To identify the perioperative risk factors for PDD utilizing the HSS-DDI.

STUDY DESIGN/SETTING

Observational study of prospectively collected data at a single academic institution.

PATIENT SAMPLE

Patients undergoing anterior cervical discectomy and fusion from 2015 to 2019 who enrolled in the prospective data collection.

OUTCOME MEASURE

The HSS-DDI administered 4 weeks, 8 weeks, and 4-6 months after surgery.

METHODS

As potential risk factors, the data on demographic factors, analgesic medications, history of psychiatric illness, preoperative sagittal alignment, surgical factors, preoperative diagnoses, and preoperative Neck Disability Index (NDI) scores were collected. Bivariate and multivariable regression analyses utilizing the Tobit model were conducted.

RESULTS

291 patients were included in the final analysis. The median HSS-DDI at 4-weeks, 8 weeks, and 4-6 months postoperatively, were 80.7, 92.7, and 98.4, respectively. Multivariable analysis demonstrated that current smoking, previous cervical spine surgery, preoperative C2-7 angle, upper level surgery, multilevel surgery, opioid use, and a high preoperative NDI score, were independent contributing factors to a low HSS-DDI score at 4-weeks follow-up. Intraoperative topical steroid use was an independent protective factor for a low HSS-DDI score. Opioid use and high NDI score remained independent factors at 4-6 months. Sub-domain analysis demonstrated that prior cervical surgery, preoperative C2-7 angle, multilevel surgery, and intraoperative topical steroid use were significant for dysphagia only. Current smoking was significant for dysphonia only.

CONCLUSIONS

Our results showed that preoperative opioid use and a high preoperative NDI score are novel independent risk factors for postoperative dysphagia and dysphonia in addition to other known factors.

Comparison of Zero-profile Anchored Spacer Versus Plate-and-Cage After 1-Level ACDF With Complete Uncinate Process Resection: A 3-Year Assessment of Radiographic and Clinical Outcomes

STUDY DESIGN

This is a retrospective study.

OBJECTIVE

The purpose of this study is to compare the zero-profile anchored spacer device (Zero-p) and traditional plate-and-cage implant (plate-and-cage) in anterior cervical discectomy and fusion (ACDF) with complete uncinate process resection (UPR) to treat 1-level cervical degenerative disk disease.

SUMMARY OF BACKGROUND DATA

We retrospectively surveyed the data from all patients who underwent single-level ACDF with complete UPR between 2009 and 2013.

PATIENTS AND METHODS

In total, 80 patients participated in 3 years of follow-up. Among them, Zero-p (38 patients) and plate-and-cage (42 patients) approaches were used in ACDF with complete UPR. Clinical outcomes and radiographic results were compared between 2 groups and they were followed for 39.1±2.2 months.

RESULTS

Duration of operation, intraoperative blood loss, and length of hospitalization were significantly lower in the Zero-p group than the plate-and-cage group (P<0.001). The clinical outcomes of visual analog scale, neck disability index, and the Odom criteria were improved after operation in both groups. The fusion rates, C2-C7 lordosis, T1 slope, C2-C7 sagittal vertical axis, sellar turcica-C7 sagittal vertical axis, and spinocranial angle after single-level ACDF were not significantly different between the 2 groups. Subsidence occurred in 5 cases (13%) in the Zero-p group and 10 cases (37%) in the plate-and-cage group (P<0.05). The horizontal length of the Zero-p implant was longer than that of allograft bone. Fusion occurred in 37 cases (95%) of the Zero-p group and 40 cases (94%) in the plate-and-cage group.

CONCLUSIONS

The Zero-p and plate-and-cage are effective when single-level ACDF with complete UPR was performed. Both groups showed good clinical outcomes, but Zero-p has more benefits than plate-and-cage such as lower duration of operation, intraoperative blood loss, length of hospitalization, and rate of subsidence compared with plate-and-cage. Surgeons should be aware of these results so that postoperative complications such as subsidence can be avoided.

Comparison of Bazaz scale, Dysphagia Short Questionnaire, and Hospital for Special Surgery-Dysphagia and Dysphonia Inventory for Assessing Dysphagia Symptoms After Anterior Cervical Spine Surgery in Chinese Population

Dysphagia is one of the most common complaints after anterior cervical spine surgery. The Bazaz scale, the Dysphagia Short Questionnaire (DSQ), and the Hospital for Special Surgery-Dysphagia and Dysphonia Inventory (HSS-DDI) were patient-reported outcome measures assessing the patients' perceptions of their swallowing functions after surgery. This prospective diagnostic test study aimed to compare these surveys' psychometric properties in the Chinese population. We evaluated 150 consecutive patients after anterior cervical spine surgery with the Bazaz scale, DSQ, HSS-DDI, and M.D. Anderson Dysphagia Inventory (MDADI). The reliability and validity of the Bazaz scale, DSQ, and HSS-DDI were compared. Receiver operating characteristic (ROC) curves of the DSQ, Bazaz scale, and HSS-DDI were constructed using the MDADI as a reference criterion. Their areas under the curve (AUCs) were further analyzed. In total, 132 participants completed all of the surveys. The results showed that all surveys were significantly correlated with each other. The HSS-DDI and HSS-Dysphagia subscale showed near-perfect reliability (Cronbach α = 0.969 and 0.957, respectively). ROC curves showed both HSS-DDI and HSS-Dysphagia subscale had greater accuracy (AUCs > 0.9) in detecting mild dysphagia and moderate/severe dysphagia. The HSS-Dysphagia subscale achieved higher accuracy in assessing the dysphagia symptoms after anterior cervical spine surgery. The Bazaz scale was considered less accurate than other scales. Our results provided guidance for selecting the appropriate measuring tool during clinical and research practices.

Does Obesity Affect Outcomes of Multilevel ACDF as a Treatment for Multilevel Cervical Spondylosis?: A Retrospective Study

STUDY DESIGN

This was a retrospective study of the clinical and radiologic outcomes of multilevel anterior cervical discectomy and fusion (ACDF) surgery for multilevel cervical spondylosis patients.

OBJECTIVE

In this retrospective study, we intended to determine the relationship of neck circumference, neck length, and body mass index (BMI) with the outcomes of multilevel ACDF surgeries for patients with multilevel cervical spondylosis.

SUMMARY OF BACKGROUND DATA

Obesity has become a worldwide epidemic problem since the beginning of the 21st century. However, no study has focused on how local or whole-body obesity indexes (neck circumference, length of neck, and BMI) are related to the outcome of anterior cervical surgery.

METHODS

A total of 156 consecutive patients with multilevel cervical spondylosis who underwent anterior cervical surgery in our department from 2010 to 2016 were enrolled in our study. Preoperative parameters of patients such as the neck circumference, length of neck, height and weight were measured, and the BMI was also calculated. Neck circumference and length of neck in neutral position ratio was determined as an index for evaluated the neck situation. Preoperative and postoperative neurological functions were evaluated using the neck disability index (NDI) and Japan Orthopedic Association (JOA) scores. Postoperative complications during the follow-up period were also recorded. Correlations between the obesity indexes and the various factors were analyzed.

RESULTS

The mean follow-up duration was 3.9±1.4 years (2.0-7.3 y). Compared with the preoperative score, the NDI and JOA score had significantly improved. There were 46 patients (29.49%) developed complications after surgery. Patients in the obese group had the highest rate of complications. Neck circumference and length of neck in neutral position ratio, BMI, and number of operation levels were significant risk factors for the occurrence of dysphagia after multilevel ACDF.

CONCLUSIONS

Patients with a higher BMI, larger neck circumference, and shorter neck length may have a longer operation duration, more blood loss, and more postoperative complications. The authors recommended that the presence of obesity and neck circumference and length should be carefully considered in the perioperative risk assessment for a multilevel ACDF surgery.

Locking stand-alone cage versus anterior plate construct in anterior cervical discectomy and fusion: a systematic review and meta-analysis based on randomized controlled trials

PURPOSE

To evaluate the efficacy of locking stand-alone cage (LSC) compared with anterior plate construct (APC) in anterior cervical discectomy and fusion (ACDF).

METHODS

A comprehensive literature search was carried out in PubMed, Embase, Web of Science, and Cochrane Library to screen randomized controlled trials (RCTs) that directly compared LSC with APC in ACDF. The Cochrane Collaboration's tool was used for assessment of study quality. Data were analyzed with the Review Manager 5.3 software.

RESULTS

A total of seven RCTs were included. The results revealed no significant differences between LSC and APC in ACDF regarding the fusion rate, Japanese Orthopaedic Association score, visual analogue scale score, neck disability index score, hospital stay, subsidence rate, cervical lordosis, segmental Cobb angle, and disc height. However, LSC was associated with a significantly shorter operation time, less blood loss, lower overall incidence of dysphagia, and lower adjacent-level ossification (ALO) rate compared with APC.

CONCLUSION

In summary, LSC is not only a safe and effective device for ACDF but also has the advantages of significantly reduced operation time, blood loss, overall incidence of dysphagia, and ALO rate over APC. Therefore, LSC is a better alternative than APC for the patients undergoing ACDF procedures.

Risk Factors and Assessment Using an Endoscopic Scoring System for Postoperative Respiratory Complications after Anterior Cervical Decompression and Fusion Surgery

Introduction

Postoperative respiratory complications (PRC) are one of the most serious complications. Potentially life-threatening accidents can occur after an anterior cervical discectomy and fusion (ADF), such as airway obstruction and aspiration pneumonia. Despite numerous studies, preoperative predictive and preventive methodology has yet to be established.

As reported in our previous study, the evaluation of preoperative dysphagia using the eating assessment tool (EAT-10) and a flexible endoscopic evaluation of swallowing (FEES) is useful for predicting the incidence and risk factors of dysphagia after ADF.

Methods

This prospective study comprised 60 consecutive patients who underwent ADF. An otolaryngologist and a speech-language-hearing therapist preoperatively and 1 week postoperatively evaluated dysphagia using EAT-10 and Hyodo-Komagane (H-K) scores during FEES. Patient demographics, comorbidities, and pre- and postoperative dysphagia were compared between patients with and without PRC.

Results

Seven of 60 (11.6%) patients had preoperative dysphagia diagnosed using the H-K score. A significant positive correlation existed between the pre- and postoperative H-K scores. Of all 60 cases, eight (13.3%) had PRC. Among them, two required reintubation due to airway obstruction and six had aspiration pneumonia. The PRC(+) group was significantly older and more prone to diabetes and asthma. The preoperative H-K score of the PRC(+) group was significantly higher than that of the PRC(−) group. Postoperatively, but not preoperatively, EAT-10 was significantly higher in the PRC(+) group.

Conclusions

Preoperative dysphagia may potentially exacerbate postoperative dysphagia after ADF. A preoperative evaluation of dysphagia using the H-K score during FEES is a useful method for predicting and reducing the risk of PRC.

Level of Evidence: 3

Ossification of the Posterior Longitudinal Ligament: Surgical Approaches and Associated Complications

Ossification of the posterior longitudinal ligament (OPLL) is a rare but potentially devastating cause of degenerative cervical myelopathy (DCM). Decompressive surgery is the standard of care for OPLL and can be achieved through anterior, posterior, or combined approaches to the cervical spine. Surgical correction of OPLL via any approach is associated with higher rates of complications and the presence of OPLL is considered a significant risk factor for perioperative complications in DCM surgeries. Potential complications include dural tear (DT) and subsequent cerebrospinal fluid leak, C5 palsy, hematoma, hardware failure, surgical site infections, and other neurological deficits. Anterior approaches are technically more demanding and associated with higher rates of DT but offer greater access to ventral OPLL pathology. Posterior approaches are associated with lower rates of complications but may allow for continued disease progression. Therefore, the decision to pursue either an anterior or posterior approach to surgical decompression may be critically influenced by complications associated with each procedure. The authors critically review anterior and posterior approaches to surgical decompression of OPLL with particular focus on the complications associated with each approach. We also review the recent work in developing new surgical treatments for OPLL that aim to reduce complication incidence.

Risk Factors for Dysphagia Following a Cervical Fusion in a Trauma Population

Background

Dysphagia following a cervical fusion is a known complication; however, this has not been examined in the trauma population. We sought to identify risk factors that can be optimized in this population.

Methods

We performed a retrospective chart review on consecutive trauma patients who underwent a cervical fusion from 2014 to 2017 at a single institution with multiple surgeons. We included patients more than 18-years-old who were admitted through the emergency department with a diagnosis of acute cervical injury and underwent a cervical fusion during the same admission. We excluded patients who remained intubated postoperatively or underwent a tracheostomy. The primary outcome was dysphagia as evaluated by a bedside swallow test on postoperative day one by the nursing staff. This was followed by a standardized assessment performed by a speech therapist on postoperative day two in some cases. Variables of interest included sex, age, mechanism of injury, surgical approach, cervical levels, and Charlson comorbidity index. Univariate analysis was also utilized.

Results

Sixty patients met the study criteria. Nineteen patients (31.7%) developed dysphagia postoperatively. Mechanical falls were the most common injury mechanism (80%) and most surgical procedures were performed on the subaxial cervical spine (68.3%). Comparing the dysphagia groups, there was no significant difference among the confounding variables. Patients with dysphagia had an increased length of stay (10.6 ± 6.7 vs. 7.4 ± 3.1, p = 0.056) and were more likely to have had an anterior vs. posterior cervical fusion (63.2% vs. 34.1%, p = 0.056).

Conclusions

We found no statistically significant risk factors leading to postoperative dysphagia. The objective of this pilot is to find the baseline dysphagia rate and the potential modifiable factors in this unique patient population undergoing cervical fusion procedures.

The Effect of Local Versus Intravenous Corticosteroids on the Likelihood of Dysphagia and Dysphonia Following Anterior Cervical Discectomy and Fusion: A Single-Blinded, Prospective, Randomized Controlled Trial

BACKGROUND

Dysphagia and dysphonia are the most common postoperative complications following anterior cervical discectomy and fusion (ACDF). Although most postoperative dysphagia is mild and transient, severe dysphagia can have profound effects on overall patient health and on surgical outcomes. The purpose of this study was to compare the efficacy of local to intravenous (IV) steroid administration during ACDF on postoperative dysphagia and dysphonia.

METHODS

This was a single-blinded, prospective, randomized clinical trial. Seventy-five patients undergoing ACDF with cervical plating were randomized into 3 groups: control (no steroid), IV steroid (10 mg of IV dexamethasone at the time of closure), or local steroid (40 mg of local triamcinolone). Patient-reported outcome measures (PROMs) were collected for dysphagia, dysphonia, and neck pain postoperatively for 1 year.

RESULTS

Patient demographics were similar. Postoperative day 1 PROMs showed significantly lower scores for dysphonia (p = 0.015) and neck pain (p = 0.034) in the local steroid group. At 2 weeks postoperatively, the local steroid cohort showed significantly decreased prevalence of severe dysphagia (Eating Assessment Tool-10 [EAT-10], severe dysphagia, p = 0.027) compared with the control and IV steroid groups. Both steroid groups had significantly less severe dysphagia when compared with the control group at the 6-week and 3-month time points. At 1 year postoperatively, both steroid groups had significantly reduced dysphagia rates (p = 0.014) compared with the control group.

CONCLUSIONS

Both local and IV steroid administration after cervical plating in ACDF yielded better PROMs for dysphagia compared with a control group. This finding is particularly evident in the reduced number of patients who reported severe dysphagia symptoms following ACDF with local steroid application within the first 2 postoperative weeks. Future studies should attempt to stratify dysphagia severity when reporting outcomes related to anterior cervical spine surgery.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Quality of Life After Combined Endonasal Endoscopic Odontoidectomy and Posterior Suboccipital Decompression and Fusion

BACKGROUND

Basilar invagination can result from systemic diseases that can weaken structural integrity of the craniocervical junction. Definitive treatment often requires ventral decompression and posterior decompression and fusion. Endonasal odontoidectomy is a relatively new minimal access procedure; quality of life (QOL) after this procedure has not been reported.

METHODS

We reviewed a consecutive database of endonasal odontoidectomy cases and identified patients having posterior decompression and fusion. Two QOL questionnaires were administered postoperatively: Sino-Nasal Outcome Test and 36-Item Short Form Survey. Comparisons with other endonasal or Chiari procedures were performed.

RESULTS

The study comprised 14 patients; 79% had Chiari malformation in addition to basilar invagination. Mean follow-up was 17.2 months. Symptomatic improvement occurred in 78.6% after surgery. Average postoperative Sino-Nasal Outcome Test scores were 39.2 ± 17.93, with worst scores in areas related to fatigue and sleep patterns but not nasal function. 36-Item Short Form Survey scores were lower in areas of physical function and general health but better for emotional health and pain. Compared with patients undergoing Chiari malformation surgery without endonasal odontoid resection or fusion, patients undergoing odontoidectomy had higher QOL in areas of role emotional, emotional well-being, and pain but worse QOL in general health and role physical.

CONCLUSIONS

Patients undergoing posterior decompression and fusion with endonasal odontoidectomy do well after surgery with respect to nasal function and emotional health. Patients who also have severe basilar invagination associated with systemic diseases demonstrate reduced QOL after surgery in areas of physical function and sleep leading to fatigue, irritability, and concentration difficulty, likely related to their systemic disease.

HSS Dysphagia and Dysphonia Inventory (HSS-DDI) Following Anterior Cervical Fusion: Patient-Derived, Validated, Condition-Specific Patient-Reported Outcome Measure Outperforms Existing Indices

BACKGROUND

Dysphagia and dysphonia are common complications after anterior cervical spine surgery; however, reported prevalences vary greatly due to a lack of reliable clinical standards for measuring postoperative swallowing and speech dysfunction. The Hospital for Special Surgery Dysphagia and Dysphonia Inventory (HSS-DDI) was developed as a patient-derived, patient-reported instrument to measure dysphagia and dysphonia more accurately after anterior cervical spine surgery than existing indices.

METHODS

This multiphase survey-development study implemented a mixed-methods approach. Phase 1 involved qualitative assessment of postoperative patient-reported swallowing or speaking deficiencies to assemble a draft survey. Phase 2 established test-retest reliability and finalized the 31-item HSS-DDI. Phase 3 compared the HSS-DDI with the Swallowing-Quality of Life (SWAL-QOL) questionnaire and the M.D. Anderson Dysphagia Inventory (MDADI) for validity and responsiveness.

RESULTS

Phase 1, performed to formulate the draft survey, included 25 patients who were asked about speech and swallowing dysfunction after anterior cervical spine surgery involving at least 3 vertebral levels. Phase 2 included 49 patients who completed the draft survey twice. The mean scores (and standard deviation) for each administration of the HSS-DDI were 67 ± 24 and 75 ± 22, the Cronbach alpha coefficients were both 0.97, and the intraclass correlation coefficient was 0.80. The 31-item HSS-DDI was finalized with all but 2 items having weighted kappa values of ≥0.40. Phase 3 included 127 patients and established external validity, with most correlation coefficients between the HSS-DDI and the SWAL-QOL and MDADI ranging from 0.5 to 0.7. Internal validity was established by identifying worsening HSS-DDI scores with increases in the number of vertebral levels involved (p = 0.02) and in the Surgical Invasiveness Index (p = 0.006). HSS-DDI responsiveness ascertained by effect size (0.73) was better than that of the SWAL-QOL and MDADI. The average administration time for the HSS-DDI was 2 minutes and 25 seconds.

CONCLUSIONS

The HSS-DDI is efficient, valid, and more responsive to change after anterior cervical spine surgery than existing surveys.

CLINICAL RELEVANCE

The HSS-DDI fills a gap in postoperative assessment by providing a reliable, more clinically sensitive, patient and condition-specific evaluation of dysphagia and dysphonia prospectively and longitudinally.