Anterior and Posterior Approaches for Cervical Myelopathy: Clinical and Radiographic Outcomes

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.

Degenerative Cervical Myelopathy: A Concept Review and Clinical Approach

STUDY DESIGN

Narrative review.

OBJECTIVE

To provide an overview of the evaluation and diagnosis of degenerative cervical myelopathy (DCM).

SUMMARY OF BACKGROUND DATA

DCM describes several etiologies of degenerative, nontraumatic spinal cord impairment. Early diagnosis and intervention can decrease neurological decline.

METHODS

An extensive literature review was conducted.

RESULTS

The incidence and prevalence of DCM are increasing worldwide. Asymptomatic spinal cord compression can progress to cervical myelopathy. Static and dynamic factors contribute to spinal cord compression. Patients frequently present with decreased manual dexterity, gait instability, and neck pain. On physical exam, patients frequently present with upper motor neuron signs, a Lhermitte sign, a failed Romberg test, global proprioceptive dysfunction, and decreased pain sensation. Anatomic variation may complicate physical exam interpretation. The modified Japanese Orthopaedic Association Scale and Nurick Classification, based on functional impairment, provide diagnostic utility. Magnetic Resonance Imaging imaging is useful in narrowing the differential diagnosis, evaluating the severity of neurological impairment, and predicting disease progression.

CONCLUSIONS

Understanding the pathophysiology of DCM and the diagnostic utility of the signs and symptoms of DCM is critical. The decision for anterior cervical discectomy and fusion (ACDF), laminoplasty, or combined ACDF and posterior cervical fusion is individualized for each patient.

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.

Factors Associated With the Rate of Recovery After Cervical Decompression Surgery for Degenerative Cervical Myelopathy: A Retrospective Analysis

Introduction Degenerative cervical myelopathy (DCM) is a debilitating spinal condition with a wide variety of symptoms that can differ greatly among individuals. Common symptoms include numbness, extremity weakness, loss of balance, and gait instability. Decompression surgeries are commonly indicated for the treatment of DCM with varying outcomes reported in the literature. However, there is little evidence on the rate of recovery defined as the time until improvement in symptoms such as numbness, balance, and strength after surgery for DCM. The purpose of this study was to determine the rate of neurological recovery after surgery for DCM and its subsequent association with various risk factors to guide clinicians while providing care and improve patient education. Methods This study was a retrospective case series (n=180 patients) examining patients who underwent cervical decompression surgery for DCM. All patients had a clinical presentation of DCM, were diagnosed with DCM, had radiographic degenerative changes and cervical stenosis, and received surgical management from 2010 to 2020 in a tertiary hospital system. Data recorded included age, smoking status, duration of pre-operative symptoms, preoperative and postoperative pain, and postoperative rate of recovery (days until improvement) in numbness, upper extremity strength, and balance. Results Patients (n=180) had an average age of 65.7 years (SD ±9.2 years, range 43-93 years). The mean ± standard deviation for the rate of recovery (days until improvement) in numbness, upper extremity strength, and balance was 84.5 ± 94.4 days, 50.6 ± 42.8 days, and 60.4 ± 69.9 days, respectively. There was only a marginally significant association between the rate of recovery for numbness after surgery and patient age (p=0.053). The average rate of recovery in numbness for patients older than 60 years was significantly longer than those younger than 60 years (99.3 versus 60.2 days). Preoperative smoking status was significantly associated with persistent moderate to severe pain (p=0.032) within the six-month postoperative period. No significant correlations were seen between the rate of recovery for balance or strength and patient age or preoperative duration of symptoms. Conclusion There was great variability in the rate of recovery for postoperative symptoms after surgery for DCM. A longer time for improvement in postoperative numbness was only marginally correlated with the increased patient age after surgery for DCM. There was no correlation found between strength or balance recovery times and patient age. Smoking status was associated with moderate to severe postoperative pain after surgery for DCM. Furthermore, the duration of preoperative symptoms was not associated with improvement in postoperative symptoms after surgery for DCM. More research is needed to determine factors impacting the rate of recovery after surgery for DCM.

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.

Perioperative Complications of Surgery for Degenerative Cervical Myelopathy: A Comparison Between 3 Procedures

STUDY DESIGN

Retrospective comparative study.

OBJECTIVES

To compare the perioperative complications of propensity score-matched cohorts of patients with degenerative cervical myelopathy (DCM), who were treated with anterior cervical discectomy and fusion (ACDF), posterior laminectomy with fusion, or laminoplasty.

METHODS

The Humana PearlDiver Patient Record Database was queried using the International Classification of Diseases (ICD-9 and ICD-10) and the Current Procedural Terminology (CPT) codes. Propensity score-matched analysis was done using multiple Chi-squared tests with Bonferroni correction of the significance level.

RESULTS

Cohorts of 11,790 patients who had ACDF, 2,257 patients who had posterior laminectomy with fusion, and 477 patients who had laminoplasty, were identified. After propensity score matching, all the 3 groups included 464 patients. The incidence of dysphagia increased significantly following ACDF compared to laminoplasty, P < 0.001, and in laminectomy with fusion compared to laminoplasty, P < 0.001. The incidence of new-onset cervicalgia was higher in ACDF compared to laminoplasty, P = 0.005, and in laminectomy with fusion compared to laminoplasty, P = 0.004. The incidence of limb paralysis increased significantly in laminectomy with fusion compared to ACDF, P = 0.002. The revision rate at 1 year increased significantly in laminectomy with fusion compared to laminoplasty, P < 0.001, and in ACDF compared to laminoplasty, P < 0.001.

CONCLUSIONS

The incidence of dysphagia following laminectomy with fusion was not different compared to ACDF. Postoperative new-onset cervicalgia and revisions were least common in laminoplasty. The highest rate of postoperative limb paralysis was noticed in laminectomy with fusion.

Determinants of quality of life in degenerative cervical myelopathy: a systematic review

BACKGROUND

Degenerative cervical myelopathy (DCM) is the most common cause of chronic, progressive spinal cord impairment worldwide. Patients experience substantial pain, functional neurological decline and disability. Health-related quality of life (HRQoL) appears to be particularly poor, even when compared to other chronic diseases. However, the determinants of HRQoL are poorly understood. The objective was to perform a systematic review of the determinants of quality of life of people with DCM.

METHODS

A systematic search was conducted in MEDLINE and Embase following PRISMA 2020 guidelines (PROSPERO CRD42018115675). Full-text papers in English, exclusively studying DCM, published before 26 March 2020 were eligible for inclusion and were assessed using the Newcastle-Ottawa Scale and the Cochrane Risk of Bias 2 (RoB 2) tool. Study sample characteristics, patient demographics, cohort type, HRQoL instrument utilised, HRQoL score, and relationships of HRQoL with other variables were qualitatively synthesised.

RESULTS

A total of 1176 papers were identified; 77 papers and 13,572 patients were included in the final analysis. A total of 96% of papers studied surgical cohorts and 86% utilised the 36-Item Short Form Survey (SF-36) as a measure of HRQoL. HRQoL determinants were grouped into nine themes. The most common determinant to be assessed was surgical technique (38/77, 49%) and patient satisfaction and experience of pain (10/77, 13%). HRQoL appeared to improve after surgery. Pain was a negative predictor of HRQoL.

CONCLUSION

Current data on the determinants of HRQoL in DCM are limited, contradictory and heterogeneous. Limitations of this systematic review include lack of distinction between DCM subtypes and heterogenous findings amongst the papers in which HRQoL is measured postoperatively or post-diagnosis. This highlights the need for greater standardisation in DCM research to allow further synthesis. Studies of greater precision are necessary to account for HRQoL being complex, multi-factorial and both time and context dependent.

Anterior and Posterior Approaches for 4-Level Degenerative Cervical Myelopathy: Low-Profile Cage Versus Cervical Pedicle Screws Fixation

(1) Background: The choice of surgical access for 4-level degenerative cervical myelopathy (DCM) remains controversial, and the clinical and radiological outcomes of anterior surgery using a low-profile cage (Low-P) versus posterior surgery using cervical pedicle screw fixation (CPS) have not been compared. (2) Methods: This is a retrospective controlled study conducted between January 2019 and June 2021 of 72 patients with 4-level DCM who underwent ACDF using a low-profile cage (n = 39) or laminectomy and instrument fusion using CPS (n = 33). The minimum follow-up time was 12 months. The outcomes were C2−7Cobb angle, C2−7sagittal vertical axis (SVA) fusion rate, the Japanese Orthopedic Association (JOA) score, pain visual analog scale (VAS), neck disability index (NDI), and complications. (3) Results: Both anterior and posterior procedures significantly improved the patients’ quality-of-life parameters. Anterior cervical convexity and SVA significantly increased in both groups, but the SVA was greater in the posterior group than in the anterior group (p < 0.001). The C2−7 Cobb angle significantly improved in both groups postoperatively, and at the final follow-up, there was a slight but nonsignificant reduction in cervical lordosis in both groups (p = 0.567). There was a longer operative time, less intraoperative blood loss, and reduced mean hospital stay in the anterior group compared to the posterior group, with two cases of postoperative hematoma requiring a second operation, two cases of axial pain (AP), five cases of dysphagia, two cases of c5 palsy in the anterior group, and four cases of axial pain, and three cases of c5 palsy in the posterior group. According to Bridwell fusion grade, anterior fusion reached grade I in 28 cases (71.8%) and grade II in 10 cases (25.6%) in the anterior group, and posterior fusion reached grade I in 25 cases (75.8%) and grade II in 8 cases (24.2%) in the posterior group. (4) Conclusions: There was no difference between the anterior and posterior surgical approaches for MDCM in terms of improvement in neurological function. Posterior surgery using CPS achieved similar recovery of cervical anterior convexity as anterior surgery with a shorter operative time but was more invasive and had a greater increase in SVA. The use of Low-P in anterior surgery reduced the incidence of dysphagia and cage subsidence and was less invasive, but with a longer operative time.

Comparison Between Sagittal Balance Outcomes After Corpectomy, Laminectomy, and Fusion for Cervical Spondylotic Myelopathy: A Matched Cohort Study

Cervical spondylotic myelopathy (CSM) can be successfully decompressed via either anterior cervical corpectomy and fusion (ACCF) or posterior laminectomy with fusion (LMF). However, few studies have compared the isolated effect of both techniques on cervical sagittal balance, a surrogate end point for clinical outcomes.We aimed to compare the sagittal balance radiological outcomes of ACCF against LMF. A case-matched controlled study of radiological cervical alignment parameters (C0-2, C2-3, index angles, T1 slope, and sagittal vertical axis (SVA)) in two groups of patients was performed by using pre- and postoperative neutral cervical X-rays.In total, 34 patients were enrolled (ACCF n = 17; LMF n = 17). The mean preoperative C2-7 angle was similar (11.58 ± 16.00° for ACCF; 13.36 ± 12.21° for LMF) in both cohorts. Both led to a loss of lordosis (-2.68 ± 13.8°, p = 0.43; -2.94 ± 11.5°, p = 0.31, respectively). At the C0-2, the two operations induced opposite variations (-0.9 ± 8.0°, p = 0.709 for ACCF; 3.5 ± 15.4°, p = 0.357 for LMF). ACCF led to a significant increase in SVA (7.1 ± 11.9 mm, p = 0.002). The C2-3 disk angle more pronouncedly increased with LMF.Both techniques show an equivalent kyphotic effect, with a greater disadvantage for ACCF. The negative impact on SVA changes is greater with ACCF. Both affect the C0-2 unit, with a tendency for kyphosis with ACCF and one for lordosis with LMF. When choosing the appropriate decompression and fusion technique, preoperative sagittal balance parameters should be included in the decision-making process.

Effect of different fixation methods on biomechanical property of cervical vertebral body replacement and fusion

BACKGROUND

The main purpose of this study was to examine the effect of different fixation methods (anterior fixation, self-stabilizing fixation and anterior-posterior fixation) on biomechanical property of vertebral body replacement and fusion.

METHODS

Three finite element models of cervical vertebral body replacement and fusion were established. The implanted models included artificial vertebral body and fixation system, and the loads imposed on the models included 75 N compression load and 1 Nm moment load.

FINDINGS

For anterior-posterior fixation, the cervical load was mainly transmitted by the posterior pedicle screw and rod (more than 50%), and the stress shielding problem was the most significant than the self-stabilizing and anterior fixation. Self-stabilizing fixation was more helpful to the fusion of implant and vertebrae, but the higher risk of vertebral body collapse was worthy of attention if the cervical spine with osteoporosis. The stress of bone was mainly concentrated around the screw hole. The maximum stress (20.03 MPa) was lower than the yield stress of cortical bone and the possibility of fracture around the fixation device of cervical spine was low. The anterior fixation could meet the requirement of vertebral body replacement and fusion, and the addition of posterior pedicle screws and rods might obtain better treatment in cases of severe spine injury or osteoporosis.

INTERPRETATION

The findings of this study may provide guidance on clinical treatments for choosing more appropriate fixation methods for different patients.

A comparison of in-hospital outcomes after elective anterior cervical discectomy and fusion in cases with and without Parkinson's Disease

Background

Following orthopedic surgery, patients with Parkinson's disease (PD) have been shown to have high rates of surgical complications, and some studies suggest that PD may be associated with greater risk for postoperative medical complications. As complication rates are critical to consider for elective surgery planning, the current study aimed to describe the association of PD with medical complications following anterior cervical discectomy and fusion (ACDF), the most commonly performed procedure to treat cervical degenerative pathology.

Methods

The 2008-2018 National Inpatient Sample database was queried for cases involving elective ACDF. Demographics and comorbidities were extracted using ICD codes. Cases were propensity matched based on demographic and comorbidity burden, and logistic regression was used to compare in-hospital complications between patients with and without PD.

Results

After weighting, a total of 1,273,437 elective ACDF cases were identified, of which 3948 (0.31%) involved cases with PD. After 1:1 propensity score matching by demographic and comorbidity variables, there were no differences between the PD and non-PD cohorts. Logistic regression models constructed for the matched and unmatched populations showed that PD cases have greater odds of in-hospital minor adverse events with no differences in odds of serious adverse events or mortality.

Conclusions

After matching for demographics and comorbidity burden, PD cases undergoing elective ACDF had slightly longer length of stay and greater risk for minor adverse events but had similar rates of serious adverse events and mortality. These findings are important for surgeons and patients to consider when making decisions about surgical intervention.

Determining the time frame of maximum clinical improvement in surgical decompression for cervical spondylotic myelopathy when stratified by preoperative myelopathy severity: a cervical Quality Outcomes Database study

OBJECTIVE

While surgical decompression is an important treatment modality for cervical spondylotic myelopathy (CSM), it remains unclear if the severity of preoperative myelopathy status affects potential benefit from surgical intervention and when maximum postoperative improvement is expected. This investigation sought to determine if retrospective analysis of prospectively collected patient-reported outcomes (PROs) following surgery for CSM differed when stratified by preoperative myelopathy status. Secondary objectives included assessment of the minimal clinically important difference (MCID).

METHODS

A total of 1151 patients with CSM were prospectively enrolled from the Quality Outcomes Database at 14 US hospitals. Baseline demographics and PROs at baseline and 3 and 12 months were measured. These included the modified Japanese Orthopaedic Association (mJOA) score, Neck Disability Index (NDI), quality-adjusted life-years (QALYs) from the EQ-5D, and visual analog scale from the EQ-5D (EQ-VAS). Patients were stratified by preoperative myelopathy severity using criteria established by the AO Spine study group: mild (mJOA score 15-17), moderate (mJOA score 12-14), or severe (mJOA score < 12). Univariate analysis was used to identify demographic variables that significantly varied between myelopathy groups. Then, multivariate linear regression and linear mixed regression were used to model the effect of severity and time on PROs, respectively.

RESULTS

For NDI, EQ-VAS, and QALY, patients in all myelopathy cohorts achieved significant, maximal improvement at 3 months without further improvement at 12 months. For mJOA, moderate and severe myelopathy groups demonstrated significant, maximal improvement at 3 months, without further improvement at 12 months. The mild myelopathy group did not demonstrate significant change in mJOA score but did maintain and achieve higher PRO scores overall when compared with more advanced myelopathy cohorts. The MCID threshold was reached in all myelopathy cohorts at 3 months for mJOA, NDI, EQ-VAS, and QALY, with the only exception being mild myelopathy QALY at 3 months.

CONCLUSIONS

As assessed by statistical regression and MCID analysis, patients with cervical myelopathy experience maximal improvement in their quality of life, neck disability, myelopathy score, and overall health by 3 months after surgical decompression, regardless of their baseline myelopathy severity. An exception was seen for the mJOA score in the mild myelopathy cohort, improvement of which may have been limited by ceiling effect. The data presented here will aid surgeons in patient selection, preoperative counseling, and expected postoperative time courses.

Comparison of anterior cervical discectomy and fusion versus artificial disc replacement for cervical spondylotic myelopathy: a meta-analysis

OBJECTIVE

Anterior cervical discectomy and fusion (ACDF) has long been regarded as a gold standard in the treatment of cervical myelopathy. Subsequently, cervical artificial disc replacement (c-ADR) was developed and provides the advantage of motion preservation at the level of the intervertebral disc surgical site, which may also reduce stress at adjacent levels. The goal of this study was to compare clinical and functional outcomes in patients undergoing ACDF with those in patients undergoing c-ADR for cervical spondylotic myelopathy (CSM).

METHODS

A systematic literature review and meta-analysis were performed using the Embase, PubMed, and Cochrane Central Register of Controlled Trials databases from database inception to November 21, 2021. The authors compared Neck Disability Index (NDI), SF-36, and Japanese Orthopaedic Association (JOA) scores; complication rates; and reoperation rates for these two surgical procedures in CSM patients. The Mantel-Haenszel method and variance-weighted means were used to analyze outcomes after identifying articles that met study inclusion criteria.

RESULTS

More surgical time was consumed in the c-ADR surgery (p = 0.04). Shorter hospital stays were noted in patients who had undergone c-ADR (p = 0.04). Patients who had undergone c-ADR tended to have better NDI scores (p = 0.02) and SF-36 scores (p = 0.001). Comparable outcomes in terms of JOA scores (p = 0.24) and neurological success rate (p = 0.12) were noted after the surgery. There was no significant between-group difference in the overall complication rates (c-ADR: 18% vs ACDF: 25%, p = 0.17). However, patients in the ACDF group had a higher reoperation rate than patients in the c-ADR group (4.6% vs 1.5%, p = 0.02).

CONCLUSIONS

At the midterm follow-up after treatment of CSM, better functional outcomes as reflected by NDI and SF-36 scores were noted in the c-ADR group than those in the ACDF group. c-ADR had the advantage of retaining range of motion at the level of the intervertebral disc surgical site without causing more complications. A large sample size with long-term follow-up studies may be required to confirm these findings in the future.

Visualized Analysis of Global Studies on Cervical Spondylosis Surgery: A Bibliometric Study Based on Web of Science Database and VOSviewer

PURPOSE

This study used multiple type of bibliometric analysis for identifying and summarizing the publications regarding cervical spondylosis surgery, for clarifying the history of this field, predicting the future hotspots of this field and improving communication among researchers.

METHODS

Publications from Web of Science database between 1900 and 2019 were downloaded and analyzed by Excel 2016 and VOSviewer. Bibliometric maps of co-citations and maps of co-occurrence of keywords are constructed by VOSviewer software.

RESULTS

A total of 2110 publications were searched from Web of Science. The total sum of times cited is 40448 with the average citation per publication of 19.17 times. USA published most papers (652, 30.9%). The most productive organizations is University of Toronto (96 publications). Spine (308 publications) published the most publications in this field. In co-citations of references analysis, four clusters of references are constructed by VOSviewer. In co-occurrence of keywords analysis, three clusters of keywords are constructed by VOSviewer. The latest keyword "degenerative cervical myelopathy" appeared in 2017 in 42 papers. Other relatively new keywords include "surgical outcomes", "association", "sagittal alignment", "prognostic-factors" that appeared in 2016 in 33, 31, 34 and 37 papers respectively.

CONCLUSION

USA dominates the research regarding cervical spondylosis surgery. University of Toronto is the most productive organization in this field. Spine, European Spine Journal and Journal of Neurosurgery Spine are the top three productive journals on publications of cervical spondylosis surgery. "Degenerative cervical myelopathy", "surgical outcomes", "association", "sagittal alignment" and "prognostic-factors" may be the new research hotspots in this field.

Use of a smartphone leveling application to optimize cervical thoracic alignment prior to posterior instrumentation

OBJECTIVE

Posterior cervical decompression and instrumentation (PCDI) is often associated with increase in sagittal balance and loss of lordosis. Here we propose a simple method of surgical positioning utilizing a readily available smartphone application to optimize cervical thoracic alignment in PCDI. The intent of this optimization is to minimize losses in lordosis and increases in sagittal balance.

METHODS

For patients since 2019, the position of the head was adjusted so that the occiput to thoracic spine was aligned and the chin brow angle was parallel to the rails of the surgical table utilizing a leveling smart application (RIDGID Level). Patients before 2019 who were not optimized were compared.

RESULTS

There were 13 patients in the nonoptimized cohort (NOC) and 20 in the optimized cohort (OC). In the NOC, the change in lordosis was -7° (p=0.016) and change in C2-SVA was 7 mm (p<0.001) from preoperative to postoperative values. In the OC, the change in lordosis was 2° (p=0.104) and change in C2-SVA was 2 mm (p=0.592) from preoperative to postoperative values. Between the NOC and OC cohorts, the changes in lordosis and sagittal balance between cohorts were significant (p=0.002 and p=0.001 respectively). There was no significant difference in clinical outcomes as measured by JOA or complication rates.

CONCLUSION

Positioning of the patient in preparation for PCDI can influence post-operative lordosis and sagittal balance. Using the leveling application on the smart phone (RIDGID Level), is a rapid and free alternative for the maintenance of lordosis and sagittal balance during instrumentation in the operating room.

Kinematics after cervical laminoplasty: risk factors for cervical kyphotic deformity after laminoplasty

BACKGROUND CONTEXT

Laminoplasty of the cervical spine is widely used as an effective surgical method to treat compressive myelopathy of the cervical spine; however, there is an adverse effect of kyphosis after surgery. The risk factors or predictors of kyphosis have not been sufficiently evaluated.

PURPOSE

To assess the risk factors for kyphosis following laminoplasty.

STUDY DESIGN

Retrospective study.

PATIENT SAMPLE

Patients diagnosed with cervical spondylotic myelopathy (CSM) or ossification of the posterior longitudinal ligament (OPLL) who underwent laminoplasty between May 2011 and October 2018 were enrolled.

OUTCOME MEASURES

Changes in lordosis and range of motion (ROM).

METHODS

Radiological imaging data were collected from simple neutral and flexion-extension radiographs at baseline and at 2-year follow-up. The ROM from the neutral position to complete flexion was defined as the flexion capacity, and the ROM from the neutral position to complete extension was defined as the extension capacity.

RESULTS

This study included 53 patients (mean age, 59.3 years). Multivariate linear regression analysis revealed that, the smaller the preoperative extension capacity, the greater was the decrease in lordosis (p=.025), while the larger the T1 slope, the greater was the decrease in lordosis following laminoplasty (p= .008). Correlation analysis revealed that C2-7 lordosis increased with increasing baseline T1 slope before surgery (p< .01). In patients with large preoperative C2-7 lordosis, the postoperative decrease in ROM tended to be greater (p= .028). However, the degree of lordosis and ROM reduction did not demonstrate a clear correlation with the clinical outcomes at 2 years after surgery.

CONCLUSIONS

Kyphotic changes in the cervical spine following laminoplasty were related to preoperative radiological parameters. The greater the preoperative extension capacity, the lower was the decrease in lordosis, and the greater the T1 slope, the greater was the decrease in lordosis.

The impact of postoperative neurologic complications on recovery kinetics in cervical deformity surgery

Objective:

The objective of the study is to investigate which neurologic complications affect clinical outcomes the most following cervical deformity (CD) surgery.

Methods:

CD patients (C2-C7 Cobb >10°, CL >10°, cSVA >4 cm or chin-brow vertical angle >25°) >18 years with follow-up surgical and health-related quality of life (HRQL) data were included. Descriptive analyses assessed demographics. Neurologic complications assessed were C5 motor deficit, central neurodeficit, nerve root motor deficits, nerve sensory deficits, radiculopathy, and spinal cord deficits. Neurologic complications were classified as major or minor, then: intraoperative, before discharge, before 30 days, before 90 days, and after 90 days. HRQL outcomes were assessed at 3 months, 6 months, and 1 year. Integrated health state (IHS) for the neck disability index (NDI), EQ5D, and modified Japanese Orthopaedic Association (mJOA) were assessed using all follow-up time points. A subanalysis assessed IHS outcomes for patients with 2Y follow-up.

Results:

153 operative CD patients were included. Baseline characteristics: 61 years old, 63% female, body mass index 29.7, operative time 531.6 ± 275.5, estimated blood loss 924.2 ± 729.5, 49% posterior approach, 18% anterior approach, 33% combined. 18% of patients experienced a total of 28 neurologic complications in the postoperative period (15 major). There were 7 radiculopathy, 6 motor deficits, 6 sensory deficits, 5 C5 motor deficits, 2 central neurodeficits, and 2 spinal cord deficits. 11.2% of patients experienced neurologic complications before 30 days (7 major) and 15% before 90 days (12 major). 12% of neurocomplication patients went on to have revision surgery within 6 months and 18% within 2 years. Neurologic complication patients had worse mJOA IHS scores at 1Y but no significant differences between NDI and EQ5D (0.003 vs. 0.873, 0.458). When assessing individual complications, central neurologic deficits and spinal cord deficit patients had the worst outcomes at 1Y (2.6 and 1.8 times worse NDI scores, P = 0.04, no improvement in EQ5D, 8% decrease in EQ5D). Patients with sensory deficits had the best NDI and EQ5D outcomes at 1Y (31% decrease in NDI, 8% increase in EQ5D). In a subanalysis, neurologic patients trended toward worse NDI and mJOA IHS outcomes (P = 0.263, 0.163).

Conclusions:

18% of patients undergoing CD surgery experienced a neurologic complication, with 15% within 3 months. Patients who experienced any neurologic complication had worse mJOA recovery kinetics by 1 year and trended toward worse recovery at 2 years. Of the neurologic complications, central neurologic deficits and spinal cord deficits were the most detrimental.

Surgical Options in Treating Ossification of the Posterior Longitudinal Ligament: Single-Center Experience

BACKGROUND

Ossified posterior longitudinal ligament (OPLL) of the cervical spine can lead to spinal stenosis and become clinically symptomatic. The optimal approach in addressing OPLL is a debated topic and dependent on factors such as preoperative lordosis and levels affected.

METHODS

In this study, we retrospectively identified patients undergoing operative management for OPLL. Demographics, operative details, radiographic parameters, outcome measurements, and complications were compared between the different approaches for OPLL treatment.

RESULTS

We identified a total of 44 patients with 16 undergoing laminoplasty (Plasty), 18 anterior corpectomy and diskectomy (Ant), and 10 laminectomy and instrumentation (Linst). Ant had least OPLL levels with median (range) 3 (2-5), compared with Plasty 4 (2-7) and Linst 4 (3-6). Plasty was associated with the shortest operative time and hospital stay. Ant showed significant correction in kyphosis from 0.5° (-13 to 16°) to 9.5° (-7 to 20°). There was loss in lordosis in Plasty and Linst. Sagittal balance significantly increased irrespective of surgical approach with the least increase in the Ant group. Complications were least in the Plasty group with similar overall improvement in outcome measurements.

CONCLUSIONS

All 3 approaches in the management of OPLL were associated with clinical improvement without 1 approach surpassing the others. Laminoplasty had the advantage of addressing more levels of stenosis than the anterior approach and was associated with a shorter operating time. Laminoplasty patients had a shorter hospital stay than those undergoing laminectomy and instrumentation and appeared to have fewer complications than the other approaches. Laminoplasty is the preferred approach in patients with preserved motion and lordosis, with the anterior approach effective in the correction of kyphosis.

DEGENERATIVE CERVICAL MYELOPATHY: A REVIEW OF CURRENT CONCEPTS

ABSTRACT Herbert von Luschka, a German anatomist, was the first to describe the developmental changes in the anatomical structures of the cervical spine. Degenerative cervical myelopathy (DCM) represents a collection of pathological entities that cause compression of the cervical spinal cord, resulting in a clinical syndrome typified by spasticity, hyperreflexia, pathologic reflexes, finger/hand clumsiness, gait disturbance and sphincter dysfunction. In the cervical spine, certain patients are more likely to have myelopathy due to a congenitally narrowed cervical spine canal. Degenerative changes are more common at C5 and C6 or C6 and C7 due to the increased motion at these levels. Additional contributors to canal narrowing are infolding of the ligamentum flavum, olisthesis, osteophytes, and facet hypertrophy. Myelopathy will develop in approximately 100% of patients with canal stenosis greater than 60% (less than 6 mm sagittal disc cord space). Classically it has an insidious onset, progressing in a stepwise manner with functional decline. Without treatment, patients may progress toward significant paralysis and loss of function. Treatment requires surgery with either anterior or posterior decompression of the area of narrowing, and probable fusion. Factors of a poor prognosis include symptoms lasting for more than 18 months, increased range of motion in the cervical spine, and female gender. In this study, we give an overview of the state-of-the-art in DCM, with a focus on the pathophysiology, clinical presentation, differential diagnosis, imaging evaluation, natural history, treatment options and complications. Level of evidence III; Review article.

Double crush syndrome: Epidemiology, diagnosis, and treatment results

BACKGROUND

Double Crush Syndrome (DCS) is a clinical condition that involves multiple compression sites along a single peripheral nerve. The present study aims to describe the epidemiology of DCS and surgical results.

METHODS

A retrospective observational analytic study included patients with clinical diagnosis of cervical radiculopathy and carpal tunnel syndrome who underwent surgery between January 2009 and January 2019. General demographic characteristics were noted, and 3 groups were distinguished: spinal surgery, carpal tunnel release, and bimodal decompression (BD); statistical differences were analyzed between them.

RESULTS

The sample comprised 32 patients. DCS prevalence was 10.29%. Mean age at presentation was 59.25±10.98 years. There was female predominance (75%). Paresthesia was the main symptom (65.6%). Post-surgical results of BD showed significant improvement in sensory nerve conduction velocity, motor nerve conduction velocity (both P=0.008), and disability on Douleur Neuropathique 4 questions, Neck Disability Index, and Boston Carpal Tunnel Questionnaire (P=0.001, 0.004, 0.008, respectively).

CONCLUSIONS

Diagnosis and management of DCS are a challenge. It is necessary to determine the site with maximal compression and risk of complications to decide on treatment. If first-line surgery is adequate, proximal and distal symptomatology can be improved. To maximize success, we recommend BD, according to the present results.

Impact of the Inclusion of C2 in Posterior Cervical Fusions for Cervical Myelopathy on Sagittal Cervical Alignment

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine the impact of including C2 in posterior fusions on radiographic parameters of cervical alignment in cervical spondylotic myelopathy.

SUMMARY OF BACKGROUND DATA

Despite the use of posterior instrumentation and arthrodesis after cervical laminectomy, loss of lordosis and the development of kyphosis are prevalent. Inadequate cervical lordosis and other measures of sagittal cervical alignment have been shown to correlate with disability, general health scores, and severity of myelopathy. The role of C2 in the posterior tension band, which maintains sagittal alignment, differs from the subaxial spine, as it is the insertion point for erector spinae muscles that play a critical role in maintaining posture.

PATIENTS AND METHODS

This study compares the radiographic outcomes of sagittal balance between 2 cohorts of patients who underwent posterior cervical decompression and fusion for cervical myelopathy over a 12-year period at a single institution. Demographic and surgical characteristics were collected using the electronic medical record of patients undergoing posterior cervical fusions (PCF) which included the axis [axial fusion (AF)] and those that were subaxial fusions (SAF). Radiographic measurements included preopertaive and postoperative C2-C7 lordosis (CL), C2-C7 sagittal vertical axis (SVA), and T1 slope (T1S).

RESULTS

After review of the electronic medical records, 229 patients were identified as having PCF and decompression for treatment of myelopathy. One hundred sixty-seven patients had AF, whereas 62 had SAF. PCF resulted in loss of CL in both cohorts. Although there was no statistical difference in postoperative CL, there was a significant increase in SVA (P<0.001) and T1S (P<0.001) with AF.

CONCLUSIONS

PCF often result in loss of lordosis. When compared with SAF, inclusion of C2 into the fusion construct may result in worsened sagittal balance, increasing the SVA and T1S.

Spinal alignment, surgery, and outcomes in cervical deformity: A practical guide to aid the spine surgeon

Compared to the thoracolumbar spine, the literature on cervical spine alignment is scarce. While a consistent number of articles have been published, few analyze the ideal surgical approaches for each type of deformity and the optimal amount of correction to achieve. This paper provides a comprehensive review of current literature on cervical spinal deformities (with or without myelopathy) and their surgical management; it is our goal to create a framework on which surgical planning can be made. A general assessment of the actually utilized parameters and correlation between the cervical and thoracolumbar spine alignment is presented. Moreover, we provide an analysis of cervical surgical approaches (anterior, posterior, or combined), techniques (laminoplasty, laminectomy and fusion, anterior cervical discectomy and fusion, corpectomy), and their indications. Finally, a complete evaluation of outcomes and postoperative health-related quality of life (HRQOL) measures based on questionnaires (NDI, VAS, SF-36, mJOA) is discussed. Several prospective studies would be useful in understanding how cervical alignment may be important in the assessment and treatment of cervical deformities with or without myelopathy. In particular, future works should concentrate on the correlation between cervical alignment parameters, disability scores, and myelopathy outcomes. We propose, via comprehensive literature review, a guide of practical key points on surgical techniques, cervical alignment, and symptom improvement goals surgeons should aim to achieve for each patient.

Development and Achievement of Cervical Laminoplasty and Related Studies on Cervical Myelopathy

Cervical laminoplasty (CL) is one of the surgical methods via the posterior approach for treating patients with multilevel affected cervical myelopathy (CM). The main purpose of CL is to decompress the cervical spinal cord by widening the narrowed spinal canal, combined with preserving the posterior anatomical structures to the degree possible and preserving the widened space stably. During the development and improvement of spine surgeries including CL, various studies on CM have progressed and useful achievements have been obtained: (1) posterior cervical spine fixation systems that can be used in combination with CL simultaneously have been developed; (2) various materials to stably maintain the enlarged spinal canal have been developed; (3) the main influential factors on the surgical results are the inner factors of the patients, such as the patient's age and the disease duration; (4) various surgical methods to preserve the function of the posterior cervical muscles have been tried to avoid postoperative kyphotic changes of the cervical spine; (5) postoperative complications, such as C5 palsy and axial pain, have been examined, and the countermeasures have been tried; (6) K-line on lateral X-ray films has been applied to evaluate the indication of CL in patients with CM due to ossification of the posterior longitudinal ligament (OPLL) preoperatively; and (7) the method and idea of CL have been adapted to surgeries at the thoracic and lumbar spine. However, some issues remain to be resolved, such as the deterioration of neurological findings, especially in patients with continuous or mixed-type OPLL, the postoperative kyphotic-directional alignment change of the cervical spine, C5 palsy, and axial pain.