Anterior approach versus posterior approach for the treatment of multilevel cervical spondylotic myelopathy: a systemic review and meta-analysis

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.

Comparison of Anterior Cervical Decompression and Fusion and Posterior Laminoplasty for Four-Segment Cervical Spondylotic Myelopathy: Clinical and Radiographic Outcomes

BACKGROUND

 Although anterior or posterior surgery for cervical spondylotic myelopathy (CSM) has been extensively studied, the choice of anterior or posterior approach in four-segment CSM remains poorly studied and controversial. We compared the clinical and radiographic outcomes of four-segment CSM by posterior laminoplasty (LAMP) and anterior cervical decompression fusion (ACDF) to further explore the merits and demerits of ACDF and LAMP for four-segment CSM in this study.

METHODS

 Patients with four-segment CSM who underwent ACDF or LAMP between January 2016 and June 2019 were retrospectively analyzed. We compared the preoperative and postoperative cervical Japanese Orthopaedic Association (JOA) scores, neck disability index (NDI), neck pain visual analog scale (VAS) score, sagittal vertical axis, cervical lordosis (CL), and range of motion.

RESULTS

 There were 47 and 79 patients in the ACDF and LAMP groups, respectively. Patients in the ACDF group had a significantly longer surgical time and lower estimated blood loss and length of stay than those in the LAMP group. There was no significant difference in the JOA, NDI, or neck pain VAS scores between the two groups preoperatively, but the NDI and neck pain VAS scores in the ACDF group were significantly lower than those in the LAMP group at the final follow-up. The preoperative C2-C7 Cobb angle of the ACDF group was significantly lower than that of the LAMP group but there was no significant difference between the two groups postoperatively. The improvement of C2-C7 Cobb angle (∆C2-C7 Cobb angle) in the ACDF group was significantly higher than that in the LAMP group. This indicated that ACDF can improve CL better than LAMP. The linear regression analysis revealed the ∆C2-C7 Cobb angle was negatively correlated with the final follow-up neck pain VAS scores and NDI. This indicated that patients with better improvement of CL may have a better prognosis.

CONCLUSIONS

 Although both ACDF and LAMP surgeries are effective for four-segment CSM, ACDF can better improve CL and neck pain. For patients with poor CL, we suggest ACDF when both approaches are feasible.

Outcomes Following Anterior Cervical Discectomy and Fusion in Patients With Ehlers-Danlos Syndrome

STUDY DESIGN

Retrospective database analysis.

OBJECTIVES

To study postoperative complication rates following anterior cervical discectomy and fusion (ACDF) in patients with Ehlers-Danlos syndrome (EDS) compared with patients without EDS.

METHODS

The Mariner database was utilized to identify patients with EDS undergoing one or two level anterior cervical discectomy and fusion (ACDF). Postoperative short-term outcomes assessed included medical complications, readmissions, and ED-visits within 90 days of surgery. Additionally, surgical complications including wound complications, surgical site infection, one- and two-year anterior revision along with posterior revision, pseudarthrosis, and hardware failure within 2 years were assessed. Multivariate logistic regression was used to adjust for demographic variables, comorbidities and number of levels operated on.

RESULTS

The present study identified 533 patients in the EDS group and 2634 patients in the matched control group. EDS patients undergoing ACDF are at an increased risk for 90-day major medical complications (OR 3.31; P < .001). EDS patients were also found to be associated with surgical complications including wound complications (OR 2.94; P < .001), surgical site infection (OR 8.60; P < .001) within 90 days, pseudarthrosis (OR 2.33; P < .001), instrument failure (OR 4.03; P < .001), anterior revision (OR 22.87; P < .001), and posterior revision (OR 3.17; P < .001) within 2 years.

CONCLUSIONS

EDS is associated with higher rates of both medical and surgical complications following ACDF. Spine surgeons should be cognizant of the increased risks in this population to provide appropriate preoperative counseling and enhanced perioperative medical management.

A Comparison of Clinical Outcomes Between Anterior Cervical Discectomy and Fusion Versus Posterior Cervical Laminoplasty for Multilevel Cervical Myelopathy

STUDY DESIGN

Retrospective Cohort.

OBJECTIVE

To compare patient-reported outcomes and surgical outcomes after anterior cervical discectomy and fusion (ACDF) versus cervical laminoplasty for multilevel cervical spondylotic myelopathy.

BACKGROUND

Treatment options for multilevel cervical spondylotic myelopathy include ACDF and cervical laminoplasty. Given that the literature has been mixed regarding the optimal approach, especially in patients without kyphosis, there is a need for additional studies investigating outcomes between ACDF and cervical laminoplasty.

METHODS

A retrospective review was conducted of adult patients undergoing 3 or 4-level surgery. Patients with preoperative kyphosis based on C2-C7 Cobb angles were excluded. The electronic medical record and institutional databases were reviewed for baseline characteristics, surgical outcomes, and patient-reported outcomes.

RESULTS

A total of 101 patients who underwent ACDF and 52 patients who underwent laminoplasty were included in the study. The laminoplasty cohort had a higher overall Charlson Comorbidity Index (3.10 ± 1.43 vs 2.39 ± 1.57, P = 0.011). Both groups had a comparable number of levels decompressed, C2-C7 lordosis, and diagnosis of myelopathy versus myeloradiculopathy. Patients who underwent laminoplasty had a longer length of stay (2.04 ± 1.15 vs 1.48 ± 0.70, P = 0.003) but readmission, complication, and revision rates were similar. Both groups had similar improvement in myelopathy scores (∆modified Japanese Orthopedic Association: 1.11 ± 3.09 vs 1.06 ± 3.37, P = 0.639). ACDF had greater improvement in Neck Disability Index (∆Neck Disability Index: -11.66 ± 19.2 vs -1.13 ± 11.2, P < 0.001), neck pain (∆Visual Analog Scale-neck: -2.69 ± 2.78 vs -0.83 ± 2.55, P = 0.003), and arm pain (∆Visual Analog Scale-arm: -2.47 ± 3.15 vs -0.48 ± 3.19, P = 0.010). These findings persisted in multivariate analysis except for Neck Disability Index.

CONCLUSION

ACDF and cervical laminoplasty appear equally efficacious at halting myelopathic progression. However, patients who underwent ACDF had greater improvements in arm pain at 1 year postoperatively. Longitudinal studies evaluating the efficacy of laminoplasty to mitigate adjacent segment disease are indicated to establish a robust risk-benefit assessment for these 2 procedures.

LEVEL OF EVIDENCE

III.

Correlation of imaging characteristics of degenerative cervical myelopathy and the surgical approach with improvement for postoperative neck pain and neural function: a retrospective cohort study

Background

Complex degenerative cervical spondylotic myelopathy (DCM) is characterized by a variety of complex imaging features. The surgical method for DCM remains controversial. This study aimed to examine the correlation between the imaging characteristics of DCM with varying degrees of complexity and the surgical approach and clinical outcome.

Methods

A retrospective cohort study involving retrospective data collection was performed. A total of 139 patients with DCM who underwent surgery between January 2015 and January 2018 in the Orthopedics Department of Shanxi Bethune Hospital were divided into 3 groups according to the complexity of imaging features: 18 patients in the mild group, 66 patients in the moderate group, and 55 patients in the severe group. The Visual Analog Scale (VAS) and Japanese Orthopaedic Association (JOA) scores were used to compare the effects of neck pain and neural function prior to surgery according to the rate of improvement as of the last follow-up. Routine X-ray films were obtained at the follow-up of 3-6 months. The necessity of computed tomography (CT) and magnetic resonance imaging (MRI) examinations was determined based on clinical findings and X-ray images. Analysis of variance (ANOVA) was used to compare groups, the least significant difference (LSD) test was used for multiple comparisons, and the Chi-square test was used to compare classification indicators (imaging manifestations, gender), with P<0.05 being statistically significant. Binary logistic regression analysis was performed to determine the primary influencing factors of the JOA recovery rate.

Results

In all three groups, JOA and VAS scores at the final follow-up were significantly higher than those before surgery (P<0.001). There were significant differences in the preoperative VAS and JOA scores between any two groups, as well as in the VAS and JOA scores and improvement rates at the last follow-up between the mild group and the moderate group and between the mild group and the severe group (P<0.001). Age, preoperative JOA scores, MRI intramedullary hyperintensity signal, and the degree of spinal cord compression were primarily related to the nervous system recovery rate (P<0.001).

Conclusions

Age, MRI intramedullary hyperintensity signal, degree of spinal cord compression, and other variables were associated with the improvement of neural function in patients with DCM. Therefore, in addition to the JOA improvement rate or VAS score, additional factors, such as the patient's condition, the improvement in quality of life, and the patient's financial capacity, should be considered in evaluating the improvement of postoperative neck pain and neural function.

The Radiological Characteristics of Degenerative Cervical Kyphosis with Cervical Spondylotic Myelopathy

Introduction

In this study, we aim to describe the radiological characteristics of degenerative cervical kyphosis (DCK) with cervical spondylotic myelopathy (CSM) and discuss the relationship between DCK and the pathogenesis of spinal cord dysfunction.

Methods

In total, 90 patients with CSM hospitalized in our center from September 2017 to August 2022 were retrospectively examined in this study; they were then divided into the kyphosis group and the nonkyphosis group. The patients' demographics, clinical features, and radiological data were obtained, including gender, age, duration of illness, cervical Japanese Orthopaedic Association (JOA) score, cervical lordosis (CL), height of intervertebral space, degree of wedging vertebral body, degree of osteophyte formation, degree of disc herniation, degree of spinal cord compression, and anteroposterior diameter of the spinal cord. In the kyphosis group, kyphotic segments, apex of kyphosis, and segmental kyphosis angle were recorded. Radiological characteristics between the two groups were also compared. Correlation analysis was performed for different spinal cord compression types.

Results

As per our findings, the patients in the kyphosis group showed more remarkable wedging of the vertebral body, more severe anterior compression of the spinal cord, and a higher degree of disc herniation, while the posterior compression of the spinal cord was relatively mild when compared with the nonkyphosis group. CL was related to the type of spinal cord compression, as cervical kyphosis is an independent risk factor for anterior spinal cord compression.

Conclusions

DCK might play a vital role in the pathogenesis of spinal cord dysfunction. In patients with DCK, it was determined that the anterior column is less supported, and more severe anterior spinal cord compression is present. The anterior approach is supposed to be preferred for CSM patients with DCK.

Deep Learning Prediction of Cervical Spine Surgery Revision Outcomes Using Standard Laboratory and Operative Variables

BACKGROUND

Cervical spine procedures represent a major proportion of all spine surgery. Mitigating the revision rate following cervical procedures requires careful patient selection. While complication risk has successfully been predicted, revision risk has proven more challenging. This is likely due to the absence of granular variables in claims databases. The objective of this study was to develop a state-of-the-art model of revision prediction of cervical spine surgery using laboratory and operative variables.

METHODS

Using the Stanford Research Repository, patients undergoing a cervical spine procedure between 2016 and 2022 were identified (N = 3151), and recent laboratory values were collected. Patients were classified into separate cohorts by revision outcome and time frame. Machine and deep learning models were trained to predict each revision outcome from laboratory and operative variables.

RESULTS

Red blood cell count, hemoglobin, hematocrit, mean corpuscular hemoglobin concentration, red blood cell distribution width, platelet count, carbon dioxide, anion gap, and calcium all were significantly associated with ≥1 revision cohorts. For the prediction of 3-month revision, the deep neural network achieved an area under the receiver operating characteristic curve of 0.833. The model demonstrated increased performance for anterior versus posterior and arthrodesis versus decompression procedures.

CONCLUSIONS

Our deep learning approach successfully predicted 3-month revision outcomes from demographic variables, standard laboratory values, and operative variables in a cervical spine surgery cohort. This work used standard laboratory values and operative codes as meaningful predictive variables for revision outcome prediction. The increased performance on certain procedures evidences the need for careful development and validation of one-size-fits-all risk scores for spine procedures.

Analysis of Complications in Multilevel Anterior Cervical Discectomy and Fusion Using Osteobiologics Other than Bone Morphogenetic Protein: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

The aim of this study is to analyze the complications related to multilevel anterior cervical discectomy and fusion (ACDF) using osteobiologics other than bone morphogenetic protein (BMP).

METHODS

A systematic review of the literature was conducted using PubMed, EMBASE, Cochrane Library, and ClinicalTrials.gov databases. The search to identify studies reporting complications in multilevel ACDF surgery using osteobiologics other than bone morphogenetic protein was performed in August 2020. The study was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA).

RESULTS

A total of 584 articles were found after searching the databases and removing duplicates. Next, screening was performed in a double reviewer process, and 153 eligible articles-with 4 retrospective studies-in full-text were selected; these met all inclusion criteria. A total of 197 patients received 3-level ACDF, while 72 patients received 4-level ACDF. Osteobiologics were used in all selected articles, allograft was used in 4 studies, autologous bone graft was utilized in 3 articles, and hydroxyapatite was used in 1 article. The main complications reported were dysphagia, adjacent segment disease, and pseudarthrosis.

CONCLUSIONS

Given the limited evidence, no conclusions on complications in multilevel ACDF using osteobiologics other than BMP could be made. However, descriptively, the most common complications found were dysphagia, adjacent segment disease, and pseudoarthrosis. Further prospective studies separately analyzing complications in multilevel ACDF by osteobiologics and a number of treated levels are needed.

Impact of Preoperative Frailty on Outcomes in Patients with Cervical Spondylotic Myelopathy Undergoing Anterior vs. Posterior Cervical Surgery

Introduction: Frailty has been shown to negatively influence patient outcomes across many disease processes, including in the cervical spondylotic myelopathy (CSM) population. The aim of this study was to assess the impact that frailty has on patients with CSM who undergo anterior cervical discectomy and fusion (ACDF) or posterior cervical decompression and fusion (PCDF). Materials and Methods: A retrospective cohort study was performed using the 2016-2019 national inpatient sample. Adult patients (≥18 years old) undergoing ACDF only or PCDF only for CSM were identified using ICD codes. The patients were categorized based on receipt of ACDF or PCDF and pre-operative frailty status using the 11-item modified frailty index (mFI-11): pre-Frail (mFI = 1), frail (mFI = 2), or severely frail (mFI ≥ 3). Patient demographics, comorbidities, operative characteristics, perioperative adverse events (AEs), and healthcare resource utilization were assessed. Multivariate logistic regression analyses were used to identify independent predictors of extended length of stay (LOS) and non-routine discharge (NRD). Results: A total of 37,990 patients were identified, of which 16,665 (43.9%) were in the pre-frail cohort, 12,985 (34.2%) were in the frail cohort, and 8340 (22.0%) were in the severely frail cohort. The prevalence of many comorbidities varied significantly between frailty cohorts. Across all three frailty cohorts, the incidence of AEs was greater in patients who underwent PCDF, with dysphagia being significantly more common in patients who underwent ACDF. Additionally, the rate of adverse events significantly increased between ACDF and PCDF with respect to increasing frailty (p < 0.001). Regarding healthcare resource utilization, LOS and rate of NRD were significantly greater in patients who underwent PCDF in all three frailty cohorts, with these metrics increasing with frailty in both ACDF and PCDF cohorts (LOS: p < 0.001); NRD: p < 0.001). On a multivariate analysis of patients who underwent ACDF, frailty and severe frailty were found to be independent predictors of extended LOS [(frail) OR: 1.39, p < 0.001; (severely frail) OR: 2.25, p < 0.001] and NRD [(frail) OR: 1.49, p < 0.001; (severely frail) OR: 2.22, p < 0.001]. Similarly, in patients who underwent PCDF, frailty and severe frailty were found to be independent predictors of extended LOS [(frail) OR: 1.58, p < 0.001; (severely frail) OR: 2.45, p < 0.001] and NRD [(frail) OR: 1.55, p < 0.001; (severely frail) OR: 1.63, p < 0.001]. Conclusions: Our study suggests that preoperative frailty may impact outcomes after surgical treatment for CSM, with more frail patients having greater health care utilization and a higher rate of adverse events. The patients undergoing PCDF ensued increased health care utilization, compared to ACDF, whereas severely frail patients undergoing PCDF tended to have the longest length of stay and highest rate of non-routine discharge. Additional prospective studies are necessary to directly compare ACDF and PCDF in frail patients with CSM.

Failure of Surgical Equipoise in Posterior Cord Syndrome Myelopathy

We suggest that a clinical diagnosis of posterior cord syndrome indicates primary posterior decompression in cervical spondylotic myelopathy cases. We present two unique cases of failed anterior decompression in neutrally aligned necks with compressive myelopathy and a literature review. Two recent cases of cervical spondylotic myelopathy that failed to respond after anterior surgical decompression and fusion surgery were observed at our institution. Both patients had motor strength preservation but were unable to stand and walk independently and had other clinical findings consistent with posterior cord syndrome rather than the more common anterior or central cord syndromes, and both responded well to staged posterior decompression. Posterior cervical decompression successfully relieved posterior cord syndrome symptoms after a failed anterior decompression in both of our cases. Posterior cord syndrome is a rare syndrome best diagnosed clinically and should be considered in cases of cervical spondylotic myelopathy in which motor strength testing is preserved.

Comparative study of preoperative sagittal alignment between patients with multisegment cervical ossification of the posterior longitudinal ligament and cervical spondylotic myelopathy

BACKGROUND CONTEXT

Preoperative sagittal alignment is of great significance in the development of spinal deformities, degenerative diseases, preoperative planning, postoperative clinical evaluation, and functional recovery. However, few reports have focused on the difference in preoperative sagittal alignment between patients with ossification of the posterior longitudinal ligament (OPLL) and patients with cervical spondylotic myelopathy (CSM).

PURPOSE

To compare preoperative sagittal alignment between patients with multisegment cervical OPLL and multilevel CSM.

STUDY DESIGN

Retrospective study.

PATIENT SAMPLE

A total of 243 patients were included in this study.

OUTCOME MEASURES

The outcome measures were the Japanese Orthopaedic Association (JOA) score, visual analog scale (VAS) score, number of hand actions in 10 seconds, hand-grip strength, C2 to C7 Cobb angle, C2 to C5 Cobb angle, C5 to C7 Cobb angle, C2 to C7 sagittal vertical axis, C7 slope, T1 slope, K-line, K-line tilt, and range of motion (ROM).

METHODS

The outcome measures were calculated in the OPLL group and CSM group and the data were analyzed using the unpaired t-test, χ² test, and one-way analysis of variance.

RESULTS

A total of 243 patients (136 men, 107 women; mean age, 59.1±10.6 years) underwent surgical treatment from September 2013 to December 2021. In total, 123 patients were diagnosed with multisegment cervical OPLL, including continuous type (n=39), segmental type (n=38), and mixed type (n=46). The remaining 120 patients had multisegment CSM. The disease course in the OPLL group was significantly shorter than that in the CSM group (p<.05). Among the above preoperative measurements, the JOA score, number of hand actions in 10 seconds, hand-grip strength, and VAS score were not significantly different between the two groups (p>.05). The C2 to C7 Cobb angle was significantly larger in the OPLL than CSM group (17.7°±9.2° and 14.9°±9.3°, respectively; p< .05), as was the C5 to C7 Cobb angle (10.0°±6.3° and 7.5°±6.1°, respectively; p<.05). The ROM was significantly smaller in the OPLL than CSM group (33.1°±8.1° and 40.1°±10.9°, respectively; p<.001). Within the OPLL group, the ROM was significantly smaller in the continuous type than in the segmental type (p<.05).

CONCLUSION

Patients with multisegment cervical OPLL have greater lordotic preoperative sagittal alignment and smaller preoperative ROM than patients with CSM.

Intraoperative Deterioration of Neurophysiological Potentials of the Spinal Tracts in Cervical Spine Surgery: Correlation With Patient-Related and Procedure-Related Variables

PURPOSE

To identify characteristics associated with higher incidence of intraoperative deterioration of neurophysiological potentials related to spinal tracts in cervical spine surgeries.

METHODS

Electrophysiological raw data and neurophysiological case reports of 1,611 patients from multiple medical centers, who underwent cervical spine surgery for decompression and/or fusion, were retrospectively reviewed. Patient-related and procedure-related variables were identified and analyzed for correlation with intraoperative neurophysiological event of the spinal tracts. The neurophysiological events were analyzed for identification of collective characteristics.

RESULTS

The study cohort presented consistent dominancy of male over female patients (67% vs. 33%). Intraoperative deterioration of spinal tract-derived potentials was noted in 10.5% of the total cases, which was not correlated with gender, age, or indication of the surgery. Higher incidence of neurophysiological events was noted in patients with impaired baseline of motor evoked potentials from the thenar muscle ( P = 0.01) or somatosensory evoked potentials of the posterior tibial nerve ( P = 0.0002). Procedures of circumferential approach or procedures that involved ≥3 spinal levels demonstrated higher incidence of neurophysiological events as well ( P = 0.0003 and 0.001, respectively).

CONCLUSIONS

Patients with deteriorated neurophysiological baseline and procedures of extensive intervention are at higher risk of intraoperative neurophysiological event in cervical spine surgery. Inclusion of intraoperative neurophysiological monitoring should be encouraged in complicated cases of cervical spine surgeries.

Association between Anterior Surgical Approach and Dysphagia Severity in Patients with Cervical Spinal Cord Injury

INTRODUCTION

Early detection and management of dysphagia are essential for preventing aspiration pneumonia and reducing mortality in patients with cervical spinal cord injury (C-SCI). In this study, we identified risk factors for dysphagia in patients with C-SCI by analyzing the correlation between the clinical factors and the severity of dysphagia, not the presence or absence of dysphagia. Combined with the analysis results of previous studies, we thought that this additional analysis method could more accurately reveal the risk factors for dysphagia in patients with C-SCI.

METHODS

The presence and severity of dysphagia in patients with C-SCI was evaluated using a modified videofluoroscopic dysphagia scale (mVDS) and penetration-aspiration scale (PAS). All included patients with C-SCI performed a video fluoroscopic swallowing study (VFSS). Clinical factors such as age, sex, the presence of tracheostomy, spinal cord independence measure (SCIM), pulmonary function test (PFT), including forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FVC/FEV1, maximal inspiratory pressure (MIP), and maximal expiratory pressure (MEP), American Spinal Cord Injury Association (ASIA) score, Berg Balance Scale (BBS), and operation method were investigated.

RESULTS

In the multivariate regression analysis, the anterior surgical approach was the only clinical factor that had a significant correlation in both mVDS and PAS, which represents the severity of dysphagia in C-SCI patients (p < 0.05).

CONCLUSION

The anterior surgical approach was correlated with the severity of dysphagia in patients with C-SCI. Considering this, as one of the risk factors affecting dysphagia in patients with C-SCI, surgical method may also need to be considered. Additionally, we recommend that clinicians should pay particular attention to the potential for development of dysphagia in patients who received anterior cervical surgery. However, further prospective studies with larger sample sizes are needed for more accurate generalization.

Nationwide sample data analysis of additional surgery rate after anterior or posterior cervical spinal surgery

Surgical outcomes of degenerative cervical spinal disease are dependent on the selection of surgical techniques. Although a standardized decision cannot be made in an actual clinical setting, continued education is provided to standardize the medical practice among surgeons. Therefore, it is necessary to supervise and regularly update overall surgical outcomes. This study aimed to compare the rate of additional surgery between anterior and posterior surgeries for degenerative cervical spinal disease using the National Health Insurance Service-National Sample Cohort (NHIS-NSC) nationwide patient database. The NHIS-NSC is a population-based cohort with about a million participants. This retrospective cohort study included 741 adult patients (> 18 years) who underwent their first cervical spinal surgery for degenerative cervical spinal disease. The median follow-up period was 7.3 years. An event was defined as the registration of any type of cervical spinal surgery during the follow-up period. Event-free survival analysis was used for outcome analysis, and the following factors were used as covariates for adjustment: location of disease, sex, age, type of insurance, disability, type of hospital, Charles comorbidity Index, and osteoporosis. Anterior cervical surgery was selected for 75.0% of the patients, and posterior cervical surgery for the remaining 25.0%. Cervical radiculopathy due to foraminal stenosis, hard disc, or soft disc was the primary diagnosis in 78.0% of the patients, and central spinal stenosis was the primary diagnosis in 22.0% of them. Additional surgery was performed for 5.0% of the patients after anterior cervical surgery and 6.5% of the patients after posterior cervical surgery (adjusted subhazard ratio, 0.83; 95% confidence interval, 0.40-1.74). The rates of additional surgery were not different between anterior and posterior cervical surgeries. The results would be helpful in evaluating current practice as a whole and adjusting the health insurance policy.

Patient-Reported Outcomes Following Anterior and Posterior Surgical Approaches for Multilevel Cervical Myelopathy

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

To compare health-related quality of life (HRQoL) outcomes between approach techniques for the treatment of multilevel degenerative cervical myelopathy (DCM).

SUMMARY OF BACKGROUND DATA

Both anterior and posterior approaches for the surgical treatment of cervical myelopathy are successful techniques in the treatment of myelopathy. However, the optimal treatment has yet to be determined, especially for multilevel disease, as the different approaches have separate complication profiles and potentially different impacts on HRQoL metrics.

MATERIALS AND METHODS

Retrospective review of a prospectively managed single institution database of patient-reported outcome measures after 3 and 4-level anterior cervical discectomy and fusion (ACDF) and posterior cervical decompression and fusion (PCDF) for DCM. The electronic medical record was reviewed for patient baseline characteristics and surgical outcomes whereas preoperative radiographs were analyzed for baseline cervical lordosis and sagittal balance. Bivariate and multivariate statistical analyses were performed to compare the two groups.

RESULTS

We identified 153 patients treated by ACDF and 43 patients treated by PCDF. Patients in the ACDF cohort were younger (60.1 ± 9.8 vs . 65.8 ± 6.9 yr; P < 0.001), had a lower overall comorbidity burden (Charlson Comorbidity Index: 2.25 ± 1.61 vs . 3.07 ± 1.64; P = 0.002), and were more likely to have a 3-level fusion (79.7% vs . 30.2%; P < 0.001), myeloradiculopathy (42.5% vs . 23.3%; P = 0.034), and cervical kyphosis (25.7% vs . 7.69%; P = 0.027). Patients undergoing an ACDF had significantly more improvement in their neck disability index after surgery (-14.28 vs . -3.02; P = 0.001), and this relationship was maintained on multivariate analysis with PCDF being independently associated with a worse neck disability index (+8.83; P = 0.025). Patients undergoing an ACDF also experienced more improvement in visual analog score neck pain after surgery (-2.94 vs . -1.47; P = 0.025) by bivariate analysis.

CONCLUSIONS

Our data suggest that patients undergoing an ACDF or PCDF for multilevel DCM have similar outcomes after surgery.

Update of the Natural History, Pathophysiology, and Treatment Strategies of Degenerative Cervical Myelopathy: A Narrative Review

Cervical myelopathy is a clinical syndrome resulting in symptoms of neurologic deficits due to prolonged spinal cord compression or ischemia in the cervical spine. Spinal cord compression can be caused by ossification of the posterior longitudinal ligament and hypertrophy of ligamentun flavum in addition to degenerative cervical spondylosis, degenerative disc disease, and progressive cervical kyphosis. Degenerative cervical myelopathy (DCM) is a series of disease entities caused by spinal cord compression by various nontraumatic and non-infectious causes. The pathophysiology of DCM includes spinal cord structure and function abnormalities caused by both static and dynamic factors. Surgical decompression for patients with moderate to severe cervical myelopathy not only inhibits the progression of neurological deterioration, but also improves functional status, pain, and quality of life. However, the role of nonsurgical treatment in patients with mild spinal cord compression is controversial. In general, patients with cervical myelopathies who do not undergo surgery have a poor prognosis. Appropriate surgical treatment is recommended when spinal cord compression is confirmed on image study in patients with reasonable symptoms of cervical myelopathy. The patient's overall health, degree of compression, presence of concurrent cervical radiculopathy, and cervical spine alignment, in addition to lesion location and etiology, should be considered when determining an appropriate surgical procedure. This review covers the updated issues, including pathophysiology, clinical manifestations, differential diagnosis, and available treatments for DCM.

Degenerative Cervical Myelopathy: Evaluation and Management

Degenerative cervical myelopathy is most commonly caused by cervical spondylosis, with a predominant elderly population, and is the most common cause of spinal cord impairment. Patients typically present with gait dysfunction, hand impairment, and/or the presence of long tract signs: clonus, Hoffman sign, Babinski sign, or inverted radial reflexes. One of the key surgical strategies is deciding an approach, which is based on patient characteristics and cause of pathologic condition. Without operative intervention, there is a high rate of neurological decline. Most surgeons recommended surgical treatment given the favorable outcomes and well understood natural history of disease.

Comparison of the Safety and Efficacy of Three-Dimensional Guiding Templates and Free Hand Technique for Cervical Pedicle Screw Fixation: A Retrospective Study

Aim. To compare the safety and efficacy of computed tomography (CT)-assisted three-dimensional guiding templates (3DGTs) and free-hand (FH) technique for posterior cervical pedicle screw fixation in cervical spondylotic myelopathy (CSM) treatment. Methods. Thirty-five patients (216 screws) with CSM and developmental cervical stenosis were randomly divided into groups A (FH) and B (3DGTs). All patients underwent modified posterior surgery with cervical pedicle screw insertion (C1-7). Preoperative, postoperative, and intergroup comparisons of efficacy were evaluated using the visual analog scale (VAS), Japanese Orthopaedic Association (JOA), and Short Form 12 (SF-12) scores and JOA score improvement rate. Incidence of intra- and postoperative complications was analyzed. Postoperative cervical spine CT was performed to evaluate (i) the pedicle screws’ deviation angle from the optimal path (sagittal deviation, α; coronal deviation angle, β), screw insertion point’s deviation distance (d), and screw accuracy and (ii) the deviation angle and distance of screw entrance point of pedicle screws from the optimal channel. Results. All patients successfully completed the procedures. Groups A and B did not significantly differ in age, sex ratio, body mass index, operative time, or intraoperative blood loss amount. Postoperative VAS, JOA, and SF-12 scores improved in both groups. VAS, JOA, or SF-12 scores did not significantly differ between the 2 groups. The α, β, and d scores were lower in group B, but accuracy was higher in group B. Conclusions. 3DGTs and FH technique show comparable outcomes with respect to neurological improvement and safety.

Treatment of three-level cervical spondylotic myelopathy using ACDF or a combination of ACDF and ACCF

Objectives

This study aims to compare the outcomes between two anterior decompression and fusion techniques to treat multilevel cervical spondylotic myelopathy (MCSM).

Methods

After the screening for eligibility, a total of 66 patients were admitted to this study. These participants underwent anterior surgeries due to MCSM in our hospital between June 2016 and July 2018. All participants underwent either the anterior cervical discectomy and fusion (ACDF) surgery (ACDF group) or the combination of ACDF and anterior cervical corpectomy and fusion (ACCF), which was the anterior cervical hybrid decompression and fusion (ACHDF) surgery group. All the patients were followed up ≥18 months, the average latest followed up time was 23.64 (±2.69) months. The length of hospitalization, operation time, blood loss, visual analog scale (VAS), Japanese Orthopaedic Association (JOA) score, improvement rate, Hounsfield units (HU) of C3–C7, cobb angle, and anterior column height of fusion levels pre and post operation were analyzed.

Results

There were no statistical differences between the ACDF and ACHDF groups regarding the length of hospitalization, operation time, blood loss, HU of C3–C7, VAS, JOA score, improvement rate, cobb angle, and anterior column height in fusion levels in pre-operation and 3 months after operation (all P > 0.05). However, compared with the ACHDF group, the ACDF group achieved significantly better improvement in the anterior column height of fusion levels in the final 18–29 months post-operatively (P < 0.05).

Conclusions

Both approaches of ACDF alone and a combination of ACDF and ACCF can achieve satisfactory outcomes in the treatment of MCSM, but ACDF has better outcomes in maintaining anterior column height of fusion levels.

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

STUDY DESIGN

Retrospective Cohort.

OBJECTIVE

To compare the short-term outcomes for Laminoplasty, Laminectomy/fusion, and ACDF.

METHODS

We utilized a prospectively-collected, multi-center national database with a propensity score matching algorithm to compare the short-term outcomes for laminoplasty, laminectomy/fusion, and multi-level (>3) ACDF (with and without corpectomy). Bivariate analyses involved both chi-square/fisher exact test and t-test/ANOVA on perioperative factors. Multivariate analyses were performed to determined independent risk factors for short term outcomes.

RESULTS

546 patients remained after propensity score matching, with 182 patients in each cohort. ACDF required the longest operative time 188 ± 79 versus laminectomy/fusion (169 ± 75, p = 0.017), and laminoplasty (167 ± 66, p = 0.004). ACDF required the shortest hospital stay (LOS ≥ 2: ACDF 56.6%, laminoplasty 89.6%, laminectomy/fusion 93.4%, p < 0.05). ACDF had lower overall complications (ACDF 3.9%, laminoplasty 7.7%, laminectomy/fusion 11.5%, p < 0.05), mortality (ACDF 0%, laminoplasty 0.55%, laminectomy/fusion 2.2%, p < 0.05), and unplanned readmissions (ACDF 4.4%, laminoplasty 4.4%, laminectomy/fusion 9.9%, p < 0.05). No significant differences were seen in the other outcomes including DVT/PT, acute renal failure, UTI, stroke, cardiac complications, or sepsis. In the multivariate analysis, laminectomy/fusion (OR 17, reference: ACDF) and laminoplasty (OR10, reference: ACDF) were strong independent risk factors for LOS ≥ 2 days. Laminectomy/fusion (OR 3.2, reference: ACDF) was an independent predictor for any adverse events 30-days after surgery.

CONCLUSIONS

Laminectomy/fusion carries the highest risk for morbidity, mortality, and unplanned readmissions in the short-term postoperative period. Laminoplasty and ACDF cases carry similar short-term complications risks. ACDF is significantly associated with the longest operative duration and shortest LOS without an increase in individual or overall complications, readmissions, or reoperations.

Biomechanical Analysis of the Reasonable Cervical Range of Motion to Prevent Non-Fusion Segmental Degeneration After Single-Level ACDF

The compensatory increase in intervertebral range of motion (ROM) after cervical fusion can increase facet joint force (FJF) and intradiscal pressure (IDP) in non-fusion segments. Guiding the post-ACDF patient cervical exercise within a specific ROM (defined as reasonable ROM) to offset the increase in FJF and IDP may help prevent segmental degeneration. This study aimed to determine the reasonable total C0–C7 ROM without an increase in FJF and IDP in non-fusion segments after anterior cervical discectomy and fusion (ACDF). A three-dimensional intact finite element model of C0–C7 generated healthy cervical conditions. This was modified to the ACDF model by simulating the actual surgery at C5–C6. A 1.0 Nm moment and 73.6 N follower load were applied to the intact model to determine the ROMs. A displacement load was applied to the ACDF model under the same follower load, resulting in a total C0–C7 ROM similar to that of the intact model. The reasonable ROMs in the ACDF model were calculated using the fitting function. The results indicated that the intervertebral ROM of all non-fusion levels was increased in the ACDF model in all motion directions. The compensatory increase in ROM in adjacent segments (C4/5 and C6/7) was more significant than that in non-adjacent segments, except for C3/4 during lateral bending. The intervertebral FJF and IDP of C0–C7 increased with increasing ROM. The reasonable ROMs in the ACDF model were 42.4°, 52.6°, 28.4°, and 42.25° in flexion, extension, lateral bending, and axial rotation, respectively, with a decreased ROM of 4.4–7.2%. The postoperative increase in FJF and IDP in non-fusion segments can be canceled out by reducing the intervertebral ROM within reasonable ROMs. This study provided a new method to estimate the reasonable ROMs after ACDF from a biomechanical perspective, and further in vitro and clinical studies are needed to confirm this.

Quality assessment of systematic reviews of surgical treatment of cervical spine degenerative diseases: an overview

Objective

To gather all systematic reviews of surgical treatment of degenerative cervical diseases and assess their quality, conclusions and outcomes.

Methods

A literature search for systematic reviews of surgical treatment of degenerative cervical diseases was conducted. Studies should have at least one surgical procedure as an intervention. Included studies were assessed for quality through Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) and Assessment of Multiple Systematic Reviews (AMSTAR) questionnaires. Quality of studies was rated accordingly to their final score as very poor (<30%), poor (30%-50%), fair (50%-70%), good (70%-90%), and excellent (>90%). If an article reported a conclusion addressing its primary objective with supportive statistical evidence for it, they were deemed to have an evidence-based conclusion.

Results

A total of 65 systematic reviews were included. According to AMSTAR and PRISMA, 1.5% to 6.2% of studies were rated as excellent, while good studies counted for 21.5% to 47.7%. According to AMSTAR, most studies were of fair quality (46.2%), and 6.2% of very poor quality. Mean PRISMA score was 70.2%, meaning studies of good quality. For both tools, performing a meta-analysis significantly increased studies scores and quality. Cervical spondylosis studies reached highest scores among diseases analyzed. Authors stated conclusions for interventions compared in 70.7% of studies, and only two of them were not supported by statistical evidence.

Conclusion

Systematic reviews of surgical treatment of cervical degenerative diseases present “fair” to “good” quality in their majority, and most of the reported conclusions are supported by statistical evidence. Including a meta-analysis significantly increases the quality of a systematic review.

Conversion Paralysis After Cervical Surgery: A Case Report and Literature Review

We report a case of conversion paralysis triggered by cervical surgery that was caused by cervical spondylotic myelopathy (CSM). A 67-year-old man underwent anterior cervical corpectomy decompression and fusion for CSM. Upon awakening from the anesthesia, he had incomplete paraplegia. Emergency surgery for hematoma evacuation was performed, but no obvious hematoma was found. After the second surgical procedure, he showed paraplegic. When the patient was informed that a third operation was needed, he recovered almost completely without any treatment. This case reminds us that spine surgeons should be aware of possible conversion paralysis, especially in patients who develop a new neurological deficit after spinal surgery.

Comparison of Anterior and Posterior Approaches for Acute Traumatic Central Spinal Cord Syndrome with Multilevel Cervical Canal Stenosis without Cervical Fracture or Dislocation

INTRODUCTION

This is a retrospective comparative study that aims to compare the benefits of different surgical approaches for patients with multilevel cervical canal stenosis (CCS) without cervical fracture or dislocation of acute traumatic central cord syndrome (ATCCS).

METHODS

From January 2015 to December 2018, 59 patients were included in the study. Among them, 35 patients (Group A) received anterior surgery and 24 patients (Group B) received posterior surgery. Primary outcome measures were American Spinal Cord Injury Association (Asia) grade, Japanese Orthopaedic Association (JOA) score, and recovery rate (RR). Secondary outcome measures included operation time, intraoperative blood loss, visual analogue scale (VAS) score, cervical sagittal parameters, and complications. Multivariate linear regression was used to analyze prognostic determinants.

RESULTS

Compared with Group B, Group A had longer operation time and more intraoperative blood loss (P < 0.05). However, the VAS score of Group B was higher than that of Group A at discharge (P < 0.05). There was no significant difference in cervical sagittal plane parameters between the two groups (P > 0.05). Postoperative complications were different in the two groups. During follow-up, the Asia grade, the JOA score, and RR of both groups improved (P < 0.05), but there were no significant differences between the two groups (P > 0.05). Younger age, earlier surgery, and better preoperative Asia grade were correlated with better prognosis.

CONCLUSIONS

For patients with multilevel CCS without cervical fracture or dislocation of ATCCS, both surgical approaches had good outcomes. Although no significant differences were found in the primary outcome measures between the two groups, there were different recommendations for the secondary outcome measures. Younger age, earlier surgery, and better preoperative Asia grade were protective factors for better prognosis.

ACDF and posterior spinal fusion revision for posterior nonunion with deformity, myelopathy, and osteoporosis in an 87-year-old: A case report and literature review

Introduction

Cervical spondylotic myelopathy (CSM) is a spinal degenerative disorder that can ultimately lead to compression of the vertebral column with neurological sequelae. Although CSM is the most common spine pathology in the elderly American population, it remains a challenging disorder to treat among older patients.

Case presentation

We report an 86 year old female patient with CSM with a history of posterior cervical fusion attempt on C3-C6 that progressed to C3-C6 nonunion with loose instrumentation. The patient had severe osteoporosis. With these indications, the patient underwent a combined anterior-posterior decompression and fusion (CAPDF) consisting of anterior cervical discectomy and fusion (ACDF) of the C3-C5, corpectomy of C6 and C7 with off FDA label use of polymethyl methacrylate augmentation (PMMA) fixation of T1 screws anteriorly for C3-T1 plate fixation and second stage instrumented posterior spinal fusion (PSF) of C3-T3. The patient had a successful fusion and reduction of her cervical spine pain with preservation of her neurological status.

Discussion

We report this case of multi-stage combined anterior and posterior fusion as a corrective measure for pseudarthrosis of a prior posterior cervical spinal fusion attempt.

Conclusion

In the event of posterior spinal fusion instrumentation failure in patients with severe osteoporosis, combined multi-stage anterior-posterior fusion is a viable corrective intervention in octogenarians. This case also illustrated the utility of using PMMA for anterior cervical plate and screw stabilization in osteoporotic bone. The authors are not aware of the prior use of PMMA for screw fixation augmentation in the anterior cervical spine.

•

Combined anterior-posterior cervical fusion for cervical spondylotic myelopathy and pseudarthrosis of prior intended fusion.

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Polymethylmethacrylate (PMMA) demonstrated as safe and effective for screw purchase augmentation in anterior cervical spine

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Multi stage spinal fusion to limit prolonged one-stage anesthesia identified to be safe and effective for this patient

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Management of cervical fusion pseudarthrosis in the setting of osteoporosis in the elderly

Anterior Controllable Antedisplacement and Fusion (ACAF) Technique for the Treatment of Multilevel Cervical Spondylotic Myelopathy With Spinal Stenosis (MCSMSS): A Retrospective Study of 54 Cases

STUDY DESIGN

Retrospective study.

OBJECTIVE

To investigate the clinical effect of anterior controllable antedisplacement and fusion (ACAF) technique for the treatment of multilevel cervical spondylotic myelopathy with spinal stenosis (MCSMSS), compared with hybrid decompression fixation (HDF).

SUMMARY OF BACKGROUND DATA

A retrospective analysis of 94 cases with MCSMSS was carried out. Fifty-four patients were treated with ACAF, whereas 40 patients were treated with HDF.

METHODS

The operation time, intraoperative blood loss, postoperative complications, Japanese Orthopedic Association score, Neck Disability Index score, parameters at axial computed tomography, cervical curvature and the Kang grade were compared between 2 groups.

RESULTS

The patients were followed up for 12-17 (15.6±1.6) months. Compared with HDF, ACAF group achieved better decompression according to computed tomography measurement and Kang grade (P<0.05), and recovered to a greater cervical Cobb angle (P<0.05). However, Japanese Orthopedic Association score and Neck Disability Index showed no significant difference 1 year after surgery (P>0.05). In addition, ACAF presented longer operation time (P<0.05) and similar intraoperative blood loss (P>0.05), compared with HDF. In terms of complications, ACAF produced less incidences of cerebrospinal fluid leakage, implant complication, epidural hematoma, and C5 palsy compared with HDF.

CONCLUSIONS

ACAF is an effective method for the treatment of MCSMSS. In comparison to HDF, ACAF has the advantages of more sufficient decompression, more satisfactory cervical curvature, and lower incidence rates of complications.

Comparison of Postoperative Complications and Reoperation Rates Following Surgical Management of Cervical Spondylotic Myelopathy in the Privately Insured Patient Population

STUDY DESIGN

This was a large database study.

OBJECTIVE

The objective of this study was to compare the incidence of complications and reoperation rates between the most common surgical treatments for cervical spondylotic myelopathy (CSM): anterior cervical discectomy and fusion (ACDF), anterior cervical corpectomy and fusion (ACCF), and posterior laminectomy and fusion (Lamifusion).

SUMMARY OF BACKGROUND DATA

CSM is a major contributor to disability and reduced quality of life worldwide.

METHODS

Humana insurance database was queried for CSM diagnoses between 2007 and 2016. The initial population was divided based on the surgical treatment and matched for age, sex, and Charlson Comorbidity index. Specific postoperative complications or revisions were analyzed at individual time points. Pearson χ2 analysis with Yate continuity correction was used.

RESULTS

Lamifusion had significantly higher rates of wound infection/disruption than ACDF or ACCF (5.03%, 2.19%, 2.29%; P=0.0008, 0.002, respectively) as well as iatrogenic deformity (4.75%, 2.19%, 2.10%; P=0.0036, 0.0013). Lamifusion also had a significantly higher rate of shock and same-day transfusion than ACDF (4.75%, 2.01%, P=0.0005), circulatory complications (2.01%, <1%, P=0.0183), and C5 palsy (4.84%, 1.74%, P≤0.0001). Compared with ACDF, Lamifusion had higher rates of hardware complication (3.29%, 2.01%, P=0.0468), and revision surgery (8.23% 5.85%, P=0.0395). Lamifusion had significantly lower rates of dysphagia than either ACDF (3.93% vs. 6.58%, P=0.0089) or ACCF (3.93% vs. 8.59%, P<0.0001). When comparing ACCF to ACDF, ACCF had significantly higher rates of circulatory complications (2.38%, <1%, P=0.0053), shock/same-day transfusion (3.2%, 2.0%, P=0.59), C5 palsy (3.47%, 1.74%, P=0.0108), and revision surgery (9.51%, 5.85%, P=0.0086).

CONCLUSIONS

The data shows that posterior Lamifusion has higher overall rate of complications compared with ACDF or ACCF. Furthermore, when comparing the anterior approaches, ACDF was associated with lower rate of complication and revision. ACCF had the highest overall rate of revision surgery.

The Rare Occurrence of Reoperation After Cervical Laminoplasty: A 14-Year Retrospective Review of Reoperative Rates at a Single Institution

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine the rate of recurrent or adjacent-level stenosis requiring reoperation after single-door cervical laminoplasty for spondylotic myelopathy at our institution.

SUMMARY OF BACKGROUND DATA

Adjacent-level stenosis requiring reoperation is a commonly evaluated condition for anterior or posterior arthrodesis, however, there are few studies that evaluate adjacent-level stenosis in the case of cervical laminoplasty.

METHODS

Retrospective review of adults undergoing cervical laminoplasty for spondylotic myelopathy between January 2005 and May 2018 at our institution. Demographics, symptom duration, stenotic levels, preoperative and postoperative Medical Research Council motor, American Spinal Injury Association, modified Japanese Orthopaedic Association scores, and Nurick grade were obtained. Postoperative data included presence of C5 palsy, infection rate, alleviation or persistence of symptoms, and rate of recurrent or adjacent-level stenosis.

RESULTS

A total of 102 patients underwent cervical laminoplasty; mean age was 56.7 years (±12.96). Most were men (n=76, 74.5%), with myelopathy (n=64, 63.4%), C4 (n=94, 93.1%), and C5 (n=92, 91.1%) cervical stenosis; mean symptom duration was 55 days (7 d to 2.8 y). Average follow-up was 6.4 months (±3.4). After surgery, there was statistically significant improvement in Nurick grade (3.1±2.2 vs. 2.7±2.4, P=0.002) and modified Japanese Orthopaedic Association score (11.4±3.7 vs. 13.9±3.6, P<0.001); American Spinal Injury Association scores also improved (P<0.001). Rate of postoperative C5 palsy was 7.8% (n=8); postoperative infection rate was 1.96% (n=2). Reoperation rate was 4.9% (n=5); reoperation for recurrent or adjacent-level stenosis was 1.96% (n=2).

CONCLUSIONS

Recurrent or adjacent-level stenosis requiring reoperation after cervical laminoplasty is rare. Longitudinal studies are needed to verify correlation between motion preservation and incidence of adjacent or recurrent stenosis.

LEVEL OF EVIDENCE

Level III-treatment benefits: nonrandomized controlled cohort/follow-up study.

Atypical Symptoms of Cervical Spondylosis: Is Anterior Cervical Discectomy and Fusion Useful? - An Institutional Experience

Background

A significant proportion of patients with cervical spondylosis can present with atypical symptoms like vertigo, tinnitus, nausea, vomiting, headache, blurred vison, palpitations and gastrointestinal (GI) discomfort. The role of ACDF in alleviating these atypical symptoms remains unexplored.

Objective

The current study attempts to investigate the role of anterior cervical discectomy and fusion (ACDF) in alleviating atypical symptoms associated with cervical spondylosis.

Materials and Methods

The patients with cervical spondylosis who underwent ACDF between January 2011 and December 2015 were contacted by phone. Data regarding the severity and frequency of atypical symptoms was collected by a structured questionnaire. Wilcoxon signed rank test was used to compare the severity and frequency of these symptoms before the surgery and at last follow up.

Results

A total of 467 patients underwent ACDF for cervical spondylosis between January 2011 and December 2015, of which 358 patients were interviewed telephonically. 99 of 358 (27.65%) patients who met the eligibility criteria were included in the final analysis. The severity and frequency of vertigo, headache, nausea, vomiting and GI discomfort significantly improved at last follow-up (P < 0.001) compared to pre-operative period. Significant improvement in hypertension was also seen (P = 0.001). Improvements in severity and frequency of tinnitus (P = 0.083), palpitation (P = 0.317) and blurring of vision (P = 1.00) were not significant.

Conclusions

ACDF might improve the atypical symptoms like vertigo, headache, nausea, vomiting and GI discomfort in patients with cervical spondylosis. Some patients also show improvement in hypertension following surgery.

Cervical laminoplasty with unilateral C4-5 foraminotomy: Technical note and case series

OBJECTIVE

The open-door laminoplasty technique is widely used in the treatment of multilevel cervical myelopathy. Despite the satisfactory functional and radiological results of this technique, postoperative C5 palsy is still a severe and disabling complication with a variable incidence in the literature. The objective of this article is to describe and demonstrate the surgical technique step by step with the addition of unilateral C4-5 foraminotomy and to evaluate the results obtained to date, with special emphasis on C5 palsy.

MATERIAL AND METHODS

Retrospective study of 20 patients operated on for cervical myelopathy using the "extended" laminoplasty technique, which is described step by step.

RESULTS

Between January 2013 and April 2019, 20 patients were operated on using the extended laminoplasty technique. Only one patient (5%) presented postoperative C5 palsy. The postoperative recovery rate of the modified JOA (Japanese Orthopaedic Association) score was 54.5%, similar to that observed in other series.

CONCLUSION

The extended cervical laminoplasty technique with unilateral C4-5 foraminotomy was developed and demonstrated for the prevention of C5 palsy. The results were analysed and an incidence of C5 palsy coinciding with the lowest percentage reported in the literature was obtained. A prospective randomised study would be useful to assess the role of preventive unilateral C4-5 foraminotomy.

A Clinicoradiological Assessment following Surgical Intervention in Patients of Cervical Spondylotic Myelopathy: An Institutional Experience

Introduction  To critically analyze the functional and radiological improvement in patients of cervical spondylotic myelopathy (CSM) who underwent surgical decompression by an anterior or posterior approach.

Materials and Methods  A retrospective study was conducted in a tertiary-level Armed Forces Hospital from June 2015 to December 2019. Preoperative assessment included a thorough clinical examination and functional and radiological assessment. The surgical decompression was done by an anterior or a posterior approach with instrumented fusion. Anterior approach was taken for single or two-level involvement and posterior approach for three or more cervical levels. The pre and postoperative neurological outcome was assessed by Nurick and modified Japanese Orthopaedic Association (mJOA) score along with measurement of canal diameter and cross-sectional area.

Results  A total of 120 patients of CSM who underwent surgical decompression were analyzed. Both the groups were comparable and had male predominance. A total of 59 patients underwent surgical decompression by an anterior approach and the remaining 61 patients by the posterior approach. Out of the 59 patients operated by the anterior approach, 30 (50.85%) underwent anterior cervical discectomy and fusion (ACDF); remaining 29 (49.15%) underwent anterior cervical corpectomy and fusion (ACCF). In the posterior group (n = 61), 26 (42.6%) patients underwent laminoplasty and the remaining 35 (57.4%) underwent laminectomy with or without instrument fusion. Sixteen patients out of these underwent lateral mass fixation and the remaining 19 underwent laminectomy. There was functional improvement (mJOA and Nurick grade) and radiological improvement in both subgroups, which were statistically significant (p < 0.0001).

Conclusion  A prompt surgical intervention in moderate-to-severe cases of CSM either by the anterior or the posterior approach is essential for good outcome.

Risk factors for rapid progressive neurological deterioration in patients with cervical spondylotic myelopathy

Background

The rapid progressive cervical spondylotic myelopathy (rp-CSM) which had a course of CSM less than 1 month and suffered rapidly progressive neurological deterioration had few reports. Therefore, it is important for us to recognize the pathophysiology of CSM especially the rp-CSM. The study aimed to investigate the risk factors for rapidly progressive (rp) neurological deterioration in patients with cervical spondylotic myelopathy (CSM).

Methods

A total of 159 patients were reviewed and divided into an rp-CSM group and a chronic-CSM (c-CSM) group. Various clinical indexes, including age, sex, Japanese Orthopaedic Association (JOA) score, intramedullary MR T2-hyperintensity, congenital/degenerative spinal stenosis, and local type of ossification of the posterior longitudinal ligament (OPLL), were analyzed, and independent risk factors were investigated.

Results

Thirty-four of 159 patients (21.4%) were diagnosed with rp-CSM. All patients were followed up for a mean of 68.56 ± 14.00 months in the rp-CSM group and 62.66 ± 19.95 months in the c-CSM group. No significant difference was found in sex, mean age, smoking and drinking status, diabetes mellitus (DM), hypertension, surgery time, blood loss, JOA score, degenerative spinal stenosis, or OPLL (local). Univariate analyses demonstrated that rp-CSM patients tended to have MR T2-hyperintensity, longer hospital stay, shorter waiting time for surgery, more congenital spinal stenosis, and worse neurological function and to prefer more posterior surgeries than c-CSM patients. A multiple logistic regression analysis showed that congenital spinal stenosis and MR T2-hyperintensity were independently related to the presence of rp-CSM.

Conclusions

MR T2-hyperintensity and congenital spinal stenosis were risk factors for rp-CSM. Although neurological function deteriorates rapidly, early surgical decompression is recommended and can achieve good neurological recovery after surgery, indicating that rp-CSM could be a reversible condition.

Cervical laminoplasty with unilateral C4-5 foraminotomy: Technical note and case series

OBJECTIVE

The open-door laminoplasty technique is widely used in the treatment of multilevel cervical myelopathy. Despite the satisfactory functional and radiological results of this technique, postoperative C5 palsy is still a severe and disabling complication with a variable incidence in the literature. The objective of this article is to describe and demonstrate the surgical technique step by step with the addition of unilateral C4-5 foraminotomy and to evaluate the results obtained to date, with special emphasis on C5 palsy.

MATERIAL AND METHODS

Retrospective study of 20 patients operated on for cervical myelopathy using the "extended" laminoplasty technique, which is described step by step.

RESULTS

Between January 2013 and April 2019, 20 patients were operated on using the extended laminoplasty technique. Only one patient (5%) presented postoperative C5 palsy. The postoperative recovery rate of the modified JOA (Japanese Orthopaedic Association) score was 54.5%, similar to that observed in other series.

CONCLUSION

The extended cervical laminoplasty technique with unilateral C4-5 foraminotomy was developed and demonstrated for the prevention of C5 palsy. The results were analysed and an incidence of C5 palsy coinciding with the lowest percentage reported in the literature was obtained. A prospective randomised study would be useful to assess the role of preventive unilateral C4-5 foraminotomy.

Comparison of the anterior and posterior approach in treating four-level cervical spondylotic myelopathy

BACKGROUND

The optimal surgical approach for four-level cervical spondylotic myelopathy remains controversial. The purpose of this study was to compare clinical and radiological outcomes and complications between the anterior and posterior approaches for four-level cervical spondylotic myelopathy.

METHODS

A total of 19 patients underwent anterior decompression and fusion and 25 patients underwent posterior laminoplasty and instrumentation in this study. Perioperative information, intraoperative blood loss, clinical and radiological outcomes, and complications were recorded. Japanese Orthopedic Association (JOA) score, 36-item short form survey (SF-36) score and cervical alignment were assessed.

RESULTS

There were no significant differences in JOA scores between the anterior and posterior group preoperatively (11.6 ± 1.6 vs. 12.1 ± 1.5), immediately postoperatively (14.4 ± 1.1 vs. 13.8 ± 1.3), or at the last follow-up (14.6 ± 1.0 vs. 14.2 ± 1.1) (P > 0.05). The JOA scores significantly improved immediately postoperatively and at the last follow-up in both groups compared with their preoperative values. The recovery rate was significantly higher in the anterior group both immediately postoperatively and at the last follow-up. The SF-36 score was significantly higher in the anterior group at the last follow-up compared with the preoperative value (69.4 vs. 61.7). Imaging revealed that there was no significant difference in the Cobb angle at C2-C7 between the two groups preoperatively (-2.0° ± 7.3° vs. -1.4° ± 7.5°). The Cobb angle significantly improved immediately postoperatively (12.3° ± 4.2° vs. 9.2° ± 3.6°) and at the last follow-up (12.4° ± 3.5° vs. 9.0° ± 2.6°) in both groups compared with their preoperative values (P = 0.00). Three patients had temporary dysphagia in the anterior group and four patients had persistent axial symptoms in the posterior group.

CONCLUSIONS

Both the anterior and posterior approaches were effective in treating four-level cervical spondylotic myelopathy in terms of neurological clinical outcomes and radiological features. However, the JOA score recovery rate and SF-36 score in the anterior group were significantly higher. Persistent axial pain could be a major concern when undertaking the posterior approach.

Multiple level anterior cervical discectomy and fusion versus posterior laminectomy for the management of multilevel cervical spondylotic myelopathy: clinical and radiological outcome

Background

Though both anterior and posterior approach are used for the management of multilevel cervical spondylotic myelopathy (CSM), the choice between both approaches remains to be of considerable debate.

Aim of the work

The aim of the study was to evaluate the clinical and radiographic outcomes of patients with multiple level CSM who underwent posterior laminectomy (PL) versus anterior cervical discectomy and fusion (ACDF).

Methods

This is a retrospective comparative study of 30 patients, with multiple level CSM managed by the authors, either by PL (n = 15) or ACDF (n = 15). Clinical outcome was assessed at 1, 3, 6, and 12 months postoperatively using the modified Japanese Orthopedic Association scale (mJOA) while the postoperative radiographic changes represented by the Cobb’s angle variation was recorded at 12 months postoperatively and compared with preoperative values. Also, the incidence of postoperative complications and neurological deterioration was recorded and studied between the two groups. Study duration was for 2 years from December 2014 to December 2016.

Results

Both the ACDF and PL groups showed an improvement in the mJOA score mean value at 1 year after surgery in comparison with the preoperative evaluation data; however, on comparing between both groups at 1 year postoperatively, the median percent of increase in mJOA score was significantly higher in the ACDF group compared with the PL group (33.3% vs 22.2% respectively). On the other hand, the Cobb’s angle percent of change 1 year after surgery showed a median percent of increase of 18.7% in the ACDF group in contrast to a median decrease of − 11.1% in the PL group which was statistically significant. Minimal complications were reported in both groups.

Conclusion

Both PL and ACDF are effective modalities for the surgical management of multilevel CSM showing good clinical outcome; however, when compared with the posterior approach, there was a statistical significant difference favoring ACDF regarding the median percent of increase in mJOA score and the postoperative Cobb’s angle improvement.

Trajectory of Improvement in Myelopathic Symptoms From 3 to 12 Months Following Surgery for Degenerative Cervical Myelopathy

BACKGROUND

Degenerative cervical myelopathy (DCM) is a progressive disease resulting from cervical cord compression. The modified Japanese Orthopaedic Association (mJOA) is commonly used to grade myelopathic symptoms, but its persistent postoperative improvement has not been previously explored.

OBJECTIVE

To utilize the Quality Outcomes Database (QOD) to evaluate the trajectory of outcomes in those operatively treated for DCM.

METHODS

This study is a retrospective analysis of prospectively collected data. The QOD was queried for patients undergoing elective surgery for DCM. Patients were divided into mild (≥14), moderate (9-13), or severe (<9) categories for their baseline severity of myelopathic symptoms (mJOA scores). A parsimonious multivariable logistic regression model was fitted with 2 points improvement on mJOA from 3- to 12-mo follow-up as the outcome of interest.

RESULTS

A total of 2156 patients who underwent elective surgery for DCM and had complete 3- and 12-mo follow-up were included in our analysis. Patients improved significantly from baseline to 3-mo on their mJOA scores, regardless of their baseline mJOA severity. After adjusting for the relevant preoperative characteristics, the baseline mJOA categories had significant impact on outcome of whether a patient keeps improving in mJOA score from 3 to 12 mo postsurgery. Patient with severe mJOA score at baseline had a higher likelihood of improvement in their myelopathic symptoms, compared to patients with mild mJOA score in.

CONCLUSION

Most patients achieve improvement on a shorter follow-up; however, patients with severe symptoms keep on improving until after a longer follow-up. Preoperative identification of such patients helps the clinician settling realistic expectations for each follow-up timepoint.

Clinical and radiological outcomes of multilevel cervical laminoplasty versus three-level anterior cervical discectomy and fusion in patients with cervical spondylotic myelopathy

Background

Cervical spondylotic myelopathy (CSM) is one of the most common causes of spinal cord impairment in elderly patients. However, a consensus has yet to be reached on the ideal method of surgical intervention. In this study, we investigated serial changes of radiological findings after three-level anterior cervical discectomy and fusion (ACDF) and multilevel laminoplasty and attempted to identify the radiological parameters affecting long-term clinical outcomes in CSM.

Methods

Of the 152 patients with multilevel CSM treated with three-level ACDF and multilevel laminoplasty, 42 had complete radiological parameters both before and 2 years after surgery (three-level ACDF, 22 patients; multilevel laminoplasty, 20 patients). Radiological parameters included spinal cord signal intensity (SI) changes on magnetic resonance imaging (MRI). Clinical outcomes including the Japanese Orthopaedic Association (JOA) score, neck disability index (NDI), Oswestry disability index (ODI), and 36-Item Short Form Health Survey score were measured.

Results

The ACDF group showed significant restoration of segmental lordosis postoperatively (preoperatively: 2.21°, 6 months: 8.37°, P=0.026), and segmental and cervical range of motion (ROM) was markedly reduced and well maintained until the final follow-up (preoperatively: 25.48°, 24 months: 4.35°, P<0.001; preoperatively: 41.71°, 24 months: 20.18°, P<0.001). The recovery rates of the JOA score were 42.85% and 57.40% in the ACDF and laminoplasty groups, respectively, although this difference was not statistically significant. Multivariate regression analysis demonstrated that signal change on MRI significantly affected the recovery rate (P=0.003). The visual analog scale (VAS) score and NDI decreased considerably only in the laminoplasty group, and device complications were confirmed only in the ACDF group (incidence rate =36.5%).

Conclusions

Multilevel laminoplasty showed better radiological and similar clinical outcomes. ACDF had more surgical complications. Spinal cord SI change on preoperative MRI was the independent risk factor for poor clinical outcomes. We recommend laminoplasty instead of three-level ACDF to treat multilevel CSM.

Degenerative Cervical Myelopathy: Pathophysiology and Current Treatment Strategies

Chronic compression or ischemia of the spinal cord in the cervical spine causes a clinical syndrome known as cervical myelopathy. Recently, a new term “degenerative cervical myelopathy (DCM)” was introduced. DCM encompasses spondylosis, intervertebral disk herniation, facet arthrosis, ligamentous hypertrophy, calcification, and ossification. The pathophysiology of DCM includes structural and functional abnormalities of the spinal cord caused by static and dynamic factors. In nonoperative patients, cervical myelopathy has a poor prognosis. Surgical treatments, such as anterior or posterior decompression accompanying arthrodesis, arthroplasty, or laminoplasty, should be considered for patients with chronic progressive cervical myelopathy. Surgical decompression can prevent the progression of myelopathy and improve the neurologic status, functional outcomes, and quality of life, irrespective of differences in medical systems and sociocultural determinants of health. The anterior surgical approach to the cervical spine has the advantage of removing or floating the intervertebral disk, osteophytes, and ossification of the posterior longitudinal ligament that compress the spinal cord directly. The posterior surgical approach to the cervical spine is mainly used for multisegment spinal cord compression in patients with cervical lordosis. In this review article, we addressed the pathophysiology, clinical manifestations, differential diagnosis, and treatment options for DCM.

State of the art review: Vertebral Osteotomies for the management of Spinal Deformity

Spinal deformity is a complex condition caused by various etiologies (degenerative, neuromuscular, congenital, developmental, traumatic, neoplastic, idiopathic) leading to clinical deformity, axial back pain, and neurologic deficits. Patients presenting with severe deformities require vertebral osteotomies to achieve the necessary curve correction for radiographic and clinical improvement. The three major vertebral osteotomy techniques commonly used at this time are the posterior column osteotomy (PCO), pedicle subtraction osteotomy (PSO), and vertebral column resection (VCR). The different vertebral osteotomies have unique merits and pitfalls that need to be addressed during preoperative planning to achieve maximum benefit while limiting or avoiding possible complications. The more difficult vertebral osteotomies have a steeper learning curve and requires extensive pre, intra and postoperative management of the patient. This review will aim to discuss the indications, surgical techniques, and clinical outcomes for each of these different vertebral osteotomy techniques with illustrative cases.

Anterior Reconstruction Techniques for Cervical Spine Deformity

Cervical spine deformity is an uncommon yet severely debilitating condition marked by its heterogeneity. Anterior reconstruction techniques represent a familiar approach with a range of invasiveness and correction potential-including global or focal realignment in the sagittal and coronal planes. Meticulous preoperative planning is required to improve or prevent neurologic deterioration and obtain satisfactory global spinal harmony. The ability to perform anterior only reconstruction requires mobility of the opposite column to achieve correction, unless a combined approach is planned. Anterior cervical discectomy and fusion has limited focal correction, but when applied over multiple levels there is a cumulative effect with a correction of approximately 6° per level. Partial or complete corpectomy has the ability to correct sagittal deformity as well as decompress the spinal canal when there is anterior compression behind the vertebral body. If pathoanatomy permits, a hybrid discectomy-corpectomy construct is favored over multilevel corpectomies. The anterior cervical osteotomy with bilateral complete uncinectomy may be necessary for angular correction of fixed cervical kyphosis, and is particularly useful in the midcervical spine. A detailed understanding of the patient's local anatomy, careful attention to positioning, and avoiding long periods of retraction time will help prevent complications and iatrogenic injury.

Predictors of poor outcome in cervical spondylotic myelopathy patients underwent anterior hybrid approach: focusing on change of local kyphosis

Objective

This study was a retrospective multivariable analysis for risk factors of poor outcome in patients who underwent anterior hybrid approach, and discussed the causes of worsening of postoperative local alignment.

Methods

A total of 86 patients with progressive spinal cord compression and local kyphosis underwent an anterior hybrid approach (ACDF+ACCF), between June 2011 and June 2017. We evaluated clinical outcome by the Japanese Orthopaedic Association (JOA) score and recovery rate. Patients were divided into two groups according to the worsening and improving of postoperative local alignment. Multivariate logistic regression analysis was applied to the evaluation of risk factors. Mann-Whitney U test, independent t test, and chi-squared test were performed for the comparison of local kyphosis between postoperative and last follow-up.

Results

There were twenty patients who had a recovery rate of less than 50%. Advance age, longer duration of symptoms, bigger T1 slope angle, and lower change of local kyphosis angle were significantly associated with a poor clinical outcome by multivariate logistic regression analysis. The cause of worsening of postoperative local alignment had T1 slope, C2–7 sagittal vertical axis (SVA), adjacent segment degeneration (ASD), and implant subsidence.

Conclusions

The change of local kyphosis was a predictor of clinical outcome after the hybrid approach. Furthermore, postoperative ASD, implant subsidence, T1 slope, and C2–7 Cobb were associated with recurrence of postoperative cervical kyphosis.

Spine Fixation Hardware: An Update

OBJECTIVE. The purpose of this article is to provide a review of the imaging of spine fixation hardware. CONCLUSION. As the prevalence of neck and back pain continues to increase, so does the number of surgical procedures used to treat such pain. Accordingly, new techniques and hardware designs are used, and the hardware will be seen on postoperative imaging. It is critical that radiologists understand the appropriate imaging modalities for the assessment of spine fixation hardware, recognize the normal imaging appearance of such hardware, and be able to detect hardware-related complications.

Cranial Kyphotic Change After Multilevel Anterior Cervical Corpectomy and Fusion May Lead to Myelopathy Recurrence

OBJECTIVE

To determine the characteristic alignment change in patients with myelopathy recurrence after multilevel anterior cervical corpectomy and fusion (m-ACCF).

METHODS

We analyzed 52 patients who underwent m-ACCF, including 20 who underwent revision surgeries for myelopathy recurrence (R group) and 32 postoperative asymptomatic patients (A group). Classic alignment parameters (cervical lordosis angle, cervical sagittal vertical axis, and fusion area angle and length) and original alignment parameters (α-β, β-bone graft [BG], BG-γ, and γ-δ angles) were measured preoperatively, postoperatively, and at follow-up or before revision surgery. The difference in the amount of change in parameters between groups was analyzed. The relationship between distribution of restenotic lesions and characteristic alignment change in the R group was evaluated.

RESULTS

Cervical lordosis angle, fusion area angle, and fusion area length in the R group significantly decreased postoperatively compared with the A group (P < 0.01, P < 0.01, and P = 0.04). Compared with the A group, α-β and β-BG angles in the R group significantly decreased (P < 0.01), indicating kyphotic change on the cranial side. BG-γ and γ-δ angles in the R group significantly increased (P < 0.01), indicating lordotic change in the caudal fused area. Restenotic lesions significantly increased on the cranial side in the R group (cranial side, 19 levels; caudal side, 5 levels; P < 0.01).

CONCLUSIONS

In patients with myelopathy recurrence after m-ACCF, the cranial side has significant kyphosis and the caudal side has lordosis. Moreover, 79.2% of the restenotic lesions were significantly maldistributed on the cranial side. Surgeons should pay close attention to cranial kyphosis inducing myelopathy recurrence after m-ACCF.

Is it necessary to place screws in the intervening vertebrae in two-level anterior cervical discectomy with fusion and plating?

OBJECTIVE

The clinical outcomes, radiological parameters, complication rate and the cost of implants in two-level ACDF with and without screws in the intervening segment were compared.

METHODS

A retrospective study of 68 patients who underwent 2-level ACDF from January 2014 to June 2016 was performed. The patients were divided into two groups: ACDF with screws in the intervening vertebra and those without screws in the intervening vertebra. Perioperative factors, clinical outcomes, postoperative complications, radiological parameters, and cost of the implants were evaluated in both groups.

RESULTS

No statistical differences in clinical outcomes, operative blood loss, hospital stay, restoration of cervical lordosis or segment height, postoperative complications, and fusion rate were found between the ACDF (middle vertebra with screw) and ACDF (middle vertebra without screw) groups (P > 0.05). But the operative time of added screw placement and cost of implants in the ACDF (middle vertebra without screw) group were significantly less than the ACDF (middle vertebra with screw) group (P < 0.05).

CONCLUSION

Two kinds of screw placement with ACDF were found to be similar in terms of clinical outcomes. However, ACDF (middle vertebra without screw) was found to be superior to ACDF (middle vertebra with screw) in terms of the screw placement time and cost of implants.

The value of dynamic MRI in the treatment of cervical spondylotic myelopathy: a protocol for a prospective randomized clinical trial

Background

Cervical spondylotic myelopathy (CSM) is the most severe type of cervical spondylosis and the most common cause of spinal cord dysfunction among adults over 55 years old. MRI plays an important role in the diagnosis and evaluation of CSM, which can directly demonstrate the correlation between disc, spinal cord, posterior structures and abnormal signal in spinal cord. Static MRI can only show the static and neutral position of spinal cord, which is not enough to understand the pathogenesis of CSM. Dynamic MRI demonstrating the extension and flexion position of spinal cord can be a better tool for the treatment of CSM, especially the surgical decision making.

Method

A total of 180 CSM patients who have indications for surgery will be recruited in outpatient of Peking University Third Hospital and assigned to three groups (Group A, B and C) based on their static MRI after consent. Group A (incomplete dura compression) means the signal of cerebral spinal fluid (CSF) is still visible. Group B (complete dura compression) means no CSF signal and no shape change of spinal cord. Group C (spinal cord compression) means shape change of spinal cord. Two surgical plans will be made for each participant by one professional surgeon according to the static MRI and dynamic MRI respectively and we will randomly choose one to perform via a random number system. Follow-up will be maintained at 3, 6, and 12 months after surgery through outpatient or telephone interview, including mJOA score, 10-s G&R (grip and release) and 10-s step test, SF-36 score, radiographic examination and complications. Finally, data collection and statistical analysis will be finished by researchers who are blinded to recruitment and treatment.

Discussion

This study will help us to explore the indication of dynamic MRI and the value of dynamic MRI in the treatment of CSM, especially the surgical decision making. Dynamic MRI can be a useful tool in the treatment of CSM patients.

Trial registration

ChiCTR1900023014. Registered on May 7th, 2019.

Analysis of adjacent-segment cervical kinematics: the role of construct length and the dorsal ligamentous complex

OBJECTIVE

Lateral mass fixation stabilizes the cervical spine while causing minimal morbidity and resulting in high fusion rates. Still, with 2 years of follow-up, approximately 6% of patients who have undergone posterior cervical fusion have worsening kyphosis or symptomatic adjacent-segment disease. Based on the length of the construct, the question of whether to extend the fixation system to undisrupted levels has not been answered for the cervical spine. The authors conducted a study to quantify the role of construct length and the terminal dorsal ligamentous complex in the adjacent-segment kinematics of the subaxial cervical spine.

METHODS

In vitro flexibility testing was performed using 6 human cadaveric specimens (C2-T8), with the upper thoracic rib cage and osseous and ligamentous integrity intact. An industrial robot was used to apply pure moments and to measure segmental motion at each level. The authors tested the intact state, followed by 9 postsurgical permutations of laminectomy and lateral mass fixation spanning C2 to C7.

RESULTS

Constructs spanning a single level exerted no significant effects on immediate adjacent-segment motion. The addition of a second immobilized segment, however, created significant changes in flexion-extension range of motion at the supradjacent level (+164%). Regardless of construct length, resection of the terminal dorsal ligaments did not greatly affect adjacent-level motion except at C2-3 and C7-T1 (increasing by +794% and +607%, respectively).

CONCLUSIONS

Dorsal ligamentous support was found to contribute significant stability to the C2-3 and C7-T1 segments only. Construct length was found to play a significant role when fixating two or more segments. The addition of a fused segment to support an undisrupted cervical level is not suggested by the present data, except potentially at C2-3 and C7-T1. The study findings emphasize the importance of the C2-3 segment and its dorsal support.

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

BACKGROUND

Cervical sagittal parameters were closely related with clinical outcomes after multi-level ACDF. Our purpose was to evaluate the clinical outcomes and cervical sagittal parameters in patients with MCSM after ACDF and to identify the risk factors of poor clinical outcomes.

MATERIAL AND METHODS

ACDF was performed in 89 patients with MCSM. Based on average JOA recovery rate, patients were divided good-outcome group (group GO) and poor-outcome group (group PO). The cervical sagittal parameters including Cobb angle, SVA, T1S, cranial tilt and cervical tilt were measured. Multivariate logistic regression was used to identify risk factors.

RESULTS

Fifty-four patients (60.67%) were divided into group GO, while 35 patients (39.33%) were divided into group PO. Cobb angle, SVA and T1S was corrected from preoperative average 11.80° ± 9.63°, 23.69 mm ± 11.69 mm and 24.43° ± 11.78° to postoperative average 15.08° ± 9.05°, 18.79 mm ± 10.78 mm and 26.92° ± 11.94° respectively (p < 0.001). △Cobb angle (p = 0.008) and △SVA (p = 0.009) showed significantly statistical differences between two groups. Longer symptom duration, lower preoperative JOA score, smaller △Cobb angle and larger △SVA were identified as risk factors of poor clinical outcomes.

CONCLUSION

Multi-level ACDF is an effective surgical method to treat patients with MCSM. However, long duration of preoperative symptoms, lower preoperative JOA score, smaller △Cobb angle and larger △SVA are risk factors for poor outcomes in patients with MCSM after ACDF. Sagittal parameters should be paid attention to in surgery.

Does an Uninstrumented Level Increase the Rate of Revision Surgery in a Multilevel Posterior Cervical Decompression and Fusion?

STUDY DESIGN

This was a retrospective cohort study.

OBJECTIVE

The goal of this study is to determine if skipping a single level affects the revision rate for patients undergoing multilevel posterior cervical decompression and fusion (PCDF).

SUMMARY OF BACKGROUND DATA

A multilevel PCDF is a common procedure for patients with cervical spondylotic myelopathy. With advanced pathology, it can be difficult to safely place screw instrumentation at every level increasing the risk of intraoperative and perioperative morbidity. It is unclear whether skipping a level during PCDF affects fusion and revision rates.

PATIENTS AND METHODS

A cervical spine surgeries database at a single institution was used to identify patients who underwent ≥3 levels of PCDF. Inclusion criteria consisted of patients who had screws placed at every level or if they had a single level without screws bilaterally. Patients were excluded if the surgery was performed for tumor, trauma, or infection, and age below 18 years, or if there was <1 year of follow-up.

RESULTS

A total of 157 patients met inclusion criteria, with 86 undergoing a PCDF with instrumentation at all levels and 71 that had a single uninstrumented level. Overall mean follow-up was 46.5±22.8 months. In patients with or without a skipped level, the revision rate was 25% and 26%, respectively (P<1.00). Univariate regression analysis demonstrated that proximal fixation level in the upper cervical region, having the fusion end at C7, prior surgery, and myelopathy were significant predictors of revision. Skipping a single level, however, was not predictive of revision.

CONCLUSIONS

When performing a multilevel PCDF, there is no increase in the rate of revision surgery if a single level is uninstrumented. Conversely, other surgical factors, including the cranial and caudal levels, affect revision rates. In contrast to other reports, the C2 sagittal vertical axis did not affect reoperation rates.

LEVEL OF EVIDENCE

Level IV.

Factors Associated With C5 Palsy Following Cervical Spine Surgery: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

C5 palsy (C5P) is a not uncommon and disabling postoperative complication with a reported incidence varying between 0% and 30%. Among others, one explanation for its occurrence includes foraminal nerve root tethering. Although different risk factors have been reported, controversy about its causation and prevention persists. Inconsistent study findings contribute to the persistent ambiguity leading to an assumption of a multifactorial nature of the underlying C5P pathophysiology. Here, we report the results of a systematic review on C5P with narrow inclusion criteria in the hope of elucidating risk factors for C5P due to a common pathophysiological mechanism.

METHODS

Electronic databases from inception to March 9, 2019 and references of articles were searched. Narrow inclusion criteria were applied to identify studies investigating demographic, clinical, surgical, and radiographic factors associated with postoperative C5P.

RESULTS

Sixteen studies were included after initial screening of 122 studies. Eighty-four risk factors were analyzed; 27 in ≥2 studies and 57 in single studies. The pooled prevalence of C5P was 6.0% (range: 4.2%-24.1%) with no consistent evidence that C5P was associated with demographic, clinical, or specific surgical factors. Of the radiographic factors assessed, specifically decreased foraminal diameter and preoperative cord rotation were identified as risk factors for C5P.

CONCLUSION

Although risk factors for C5P have been reported, ambiguity remains due to potentially multifactorial pathophysiology and study heterogeneity. We found foraminal diameter and cord rotation to be associated with postoperative C5P occurrence in our meta-analysis. These findings support the notion that factors contributing to, and acting synergistically with foraminal stenosis increase the risk of postoperative C5P.

Reoperation Rates after Laminoplasty for Cervical Disorders: A 26-Year Period Survival Function Method Analysis

Introduction

Laminoplasty is a common surgery for cervical myelopathy. Previous studies have analyzed the reoperation rates in posterior decompression surgeries of the cervical spine. However, few studies have solely focused on midline-splitting laminoplasty (MSL) using a large number of patients. This aims to analyze the reoperation rates after MSL using the survival function method.

Methods

Between 1988 and 2013, 4,208 MSLs were performed as a primary operation for cervical myelopathy and enrolled in our spinal surgery registration system. The Kaplan-Meier survival function method was used to analyze the rates of reoperation.

Results

Of 4,208 patients with primary MSL, 40 underwent reoperation for neurological complications. The overall reoperation rate was 0.26%, 0.64%, 0.83%, 0.93%, and 0.95% at 1, 5, 10, 20, and >20 years, respectively. The causes of reoperation were postoperative cervical radiculopathy in 10 patients, stenosis at an adjacent level in 8, stenosis due to failed “open-door” lamina in 6, instability of the cervical spine in 4, cervical disc herniation in 3, elongation of ossification of the posterior longitudinal ligament in 3, spinal cord injury in 1, fracture of the cervical spine in 1, postoperative scar formation in 1, ossification of anterior longitudinal ligament in 1, and unknown in 2. The number of patients with surgical site infection (SSI) who needed surgical debridement was 34 (0.81%).

Conclusions

Excluding reoperations for SSI, the reoperation rate of MSL was approximately 1.0% at the maximum of 26 years after surgery. MSL was determined to be a reliable surgical procedure regarding postoperative complications requiring additional surgeries.