Efficacy and safety of surgical decompression in patients with cervical spondylotic myelopathy: results of the AOSpine North America prospective multi-center study

Are There Differences in 2-Year Outcomes Between Two-Level Anterior Cervical Diskectomy and Fusion Versus Single-Level Anterior Cervical Corpectomy and Fusion to Treat Cervical Myelopathy? A Quality Outcomes Database Study

BACKGROUND AND OBJECTIVES

There has been limited assessment between anterior cervical diskectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF) on patient-reported outcome measures (PROMs) in the treatment of cervical spondylotic myelopathy. We sought to compare PROMs from two-level ACDF with single-level ACCF procedures. We evaluate these results in the context of minimum clinically important difference (MCID) thresholds, which have not been performed previously.

METHODS

This retrospective analysis of prospectively collected data from the Quality Outcomes Database Spine Collaborative Research Study Group compared two-level ACDF and single-level ACCF at 3-, 12-, and 24 months postoperatively. PROMs included arm pain Numeric Rating Scale, neck pain Numeric Rating Scale, Neck Disability Index, and North American Spine Society Patient Satisfaction Index. Multivariate logistic regression was used to determine differences in perioperative outcomes, as well as the impact of two-level ACDF vs one-level ACCF on PROMs. MCID thresholds were based off previously established limits.

RESULTS

Three hundred and thirty patients were included (236 ACDF, 94 ACCF), and the follow-up rate was 82% at 2 years. There was a significantly higher baseline age, American Society of Anesthesiologists grade, proportion of diabetes, osteoarthritis, ambulation dependence, and myelopathy severity in the ACCF cohort. On multivariable analysis, the ACCF group had greater average length of stay and estimated blood loss. There were no significant differences between reoperation rates or nonroutine discharge. There were similar rates of MCID achievement for PROMs at all time points.

CONCLUSION

This study suggests that both ACDF and ACCF procedures for cervical spondylotic myelopathy are able to achieve similar, clinically meaningful improvements in PROMs by 2 years. Patients undergoing single-level ACCF have more estimated blood loss and longer length of stay, as well as worse baseline myelopathy. Both procedures have efficacious, durable outcomes. It is reasonable that other factors, such as radiographic characteristics and patient symptoms, may influence patient selection for ACDF vs ACCF.

Spinal Cord Status Assessment and Early Interventional Personalized Rehabilitation after Endoscopic Surgery for Cervical Compressive Myelopathy: A Randomized Trial

BACKGROUND CONTEXT

Cervical compressive myelopathy (CCM), frequently arising from spinal degeneration, results in significant motor and sensory deficits. Currently, there is a lack of precise prognostic evaluation methods following decompression surgery for CCM, which hinders the optimization of personalized rehabilitation therapy. However, the combination of intraoperative endoscopic visualization of dural sac compression morphology and electrophysiological functional assessment holds promise in addressing this gap.

PURPOSE

To determine whether a personalized rehabilitation strategy, informed by intraoperative endoscopic and electrophysiological assessments, enhances postoperative functional outcomes in CCM patients compared to traditional rehabilitation after canal decompression surgery.

STUDY DESIGN/SETTING

PROSPECTIVE SINGLE-CENTER RANDOMIZED CONTROLLED STUDY, TRIAL REGISTRATION: ChiCTR2400081458.

PATIENT SAMPLE

78 patients underwent spinal decompression surgery at The Sixth Medical Center of Chinese PLA General Hospital. The inclusion criteria included a diagnosis of CCM due to spondylosis or ossification of the longitudinal ligament. Participants were excluded if they had prior spinal surgeries or comorbidities unrelated to CCM.

OUTCOME MEASURES

The primary outcome was the Japanese Orthopaedic Association (JOA) score, assessing spinal function. Secondary outcomes included the Neck Disability Index (NDI), Visual Analogue Scale (VAS) for pain, and three-dimensional gait analysis.

METHODS

This study was a double-blind randomized controlled trial comparing two postoperative rehabilitation strategies for patients with CCM following endoscopic spinal decompression surgery. After surgery, patients were randomly assigned to two groups. The experimental group received personalized rehabilitation based on real-time intraoperative spinal cord status assessments, using a combination of endoscopic visualization and electrophysiological grading. Interventions included lower limb exoskeleton-assisted walking and targeted motor function training. The control group received conventional standard rehabilitation treatment. Both groups were assessed using the JOA, NDI, and VAS scores before rehabilitation, 1 month, 3 months, and 12 months after the start of rehabilitation. Additionally, gait analysis (including stride frequency, gait velocity, and stride length) was performed before and 3 months after the start of rehabilitation to evaluate the clinical rehabilitation outcomes in both groups.

RESULTS

Both groups showed significant improvements in JOA, NDI, VAS scores, and gait tests during the postoperative rehabilitation process. The experimental group demonstrated a more substantial increase in the primary outcome measure, the JOA score (12MO: 4.79±0.74 vs 3.53±0.93, P < 0.05). Additionally, the experimental group exhibited notable improvements in both stride frequency and gait velocity (3MO: Stride frequency (3.76±0.23 vs 1.05±0.07) and Gait velocity (4.53±0.63 vs 4.21±0.43), P < 0.05).

CONCLUSIONS

The spinal cord status assessment methods based on spinal endoscopy and electrophysiological techniques can effectively evaluate the condition of the spinal cord. When combined with personalized rehabilitation strategies tailored to these assessments, they can significantly enhance the postoperative spinal cord function recovery in CCM patients, providing superior clinical rehabilitation outcomes compared to traditional rehabilitation methods.

Role of Neck Pain in Defining Clinical Trajectories of Outcomes in Patients With Degenerative Cervical Myelopathy: Results of a Novel Machine Learning Algorithm

Study DesignRetrospective analysis of prospective data.ObjectivesNeck pain represents a crucial factor underscoring a patient's decision to receive surgical intervention for degenerative cervical myelopathy (DCM). However, postoperative pain trajectories are poorly defined. This study aimed to employ machine learning-based trajectory modeling to identify patient subpopulations with distinct pain trajectories after surgery.MethodsWe pooled subjects from three major clinical studies on DCM. Group-based multivariate trajectory (GBMT) modeling was used to classify patients into distinct trajectories based on their neck pain score over one year. Outcome differences were examined with univariate analyses. Predictors of group membership were revealed with multinomial logistic regression.ResultsThree distinct trajectories of neck pain were identified from a total of 968 patients with DCM: "slow pain improvement" (n = 239; 25%), "no pain improvement" (n = 537; 55%), and "fast pain improvement" (n = 192; 20%) groups. Each trajectory exhibited a unique baseline pain profile. The "fast pain improvement" group, comprised of patients experiencing profound neck pain, had the best overall outcomes for pain, NDI, SF-36 PCS, and SF-36 MSC postoperatively. On the other hand, the "no pain improvement" group, consisting of patients with pain and multimodal impairment of moderate severity, had residual pain that remained constant and was least likely to experience functional outcome and quality of life improvement after one year.ConclusionsUnsupervised learning on neck pain identified unique pain recovery trajectories that consist of distinct patient phenotypes. Trajectory grouping offers an important framework to both identify novel DCM subpopulations and predict patterns of pain over time.Clinical Trials Included(1) Assessment of Surgical Techniques for Treating Cervical Spondylotic Myelopathy (CSM); https://clinicaltrials.gov/study/NCT00285337; ClinicalTrials.gov ID NCT00285337. (2) Surgical Treatment of Cervical Spondylotic Myelopathy; https://clinicaltrials.gov/study/NCT00565734; ClinicalTrals.gov ID NCT00565734. (3) Efficacy of Riluzole in Surgical Treatment for Cervical Spondylotic Myelopathy (CSM-Protect) (CSM-Protect); https://clinicaltrials.gov/study/NCT01257828; ClinicalTrials.gov ID NCT01257828.

Conservative and newer drug treatment for degenerative cervical myelopathy

Degenerative cervical myelopathy (DCM) is the most common cause of non-traumatic spinal cord dysfunction in adults worldwide. Conservative treatments, such as physical therapy, activity modification, cervical traction, and the use of cervical collars, have been employed primarily for symptomatic relief in mild cases or for patients deemed unfit for surgery. Advances in our understanding of the molecular pathways involved in neuroinflammation and neuronal injury in DCM have spurred the development of newer pharmacological treatments aimed at neuroprotection and inflammation control. We found limited evidence that conservative treatment enhances functional recovery in patients with DCM. Patients with mild DCM who opt for conservative therapy should be aware of likely neurological deterioration and higher spinal cord injury risk following neck trauma. Nonoperative management could benefit patients with mild DCM who presented early (at least less than a year), have soft disc herniation as the cause of the myelopathy, have one level of myelopathic compression, and whose MRI does not show circumferential compression of the spinal cord. Riluzole did not replicate its promising animal results in human trials, using the modified Japanese Orthopaedic Association (mJOA) score as an outcome measure. Cerebrolysin is promising but needs more RCTs to define its role in the management algorithm. Limaprost Alfadex provided inconclusive evidence, however, is in an ongoing phase III trial. Erythropoietin showed benefit in animal and human trials but concerns over side effects may limit use. G-CSF demonstrated evidence of preserved neurological function in mice but needs human studies. Steroids did not show benefit and are likely deleterious to tissue healing and can increase infection risk. Anti-Fas ligand antibody has not been studied in humans but demonstrated benefit in animal models. Research should focus on large-scale RCTs for these drugs with careful attention to long-term effects, side effects, and finding the most effective doses.

Outcomes for Degenerative Cervical Myelopathy Following Implementation of the AO Spine International Guidelines: A Single-Centre Service Evaluation

IntroductionDegenerative cervical myelopathy (DCM) is a syndrome of symptomatic cervical spinal cord compression due to degenerative spinal changes. Until recently there was no formal consensus on exactly which patients are suitable for surgical or conservative management. The AO Spine international guidelines were introduced to address this issue, based on the best available current evidence. However, their implementation into routine clinical practice has not yet been reported. The objective was to evaluate surgical outcomes following the implementation of the AO Spine guidelines at our spinal neurosurgical centre.MethodsA service evaluation was conducted using data collected from electronic healthcare records for 259 patients, with outcomes of interest including change in mJOA score and complications. Data from 193 patients were included in the final analysis.ResultsThere was a mean improvement of the mJOA score by 1.53 points, 1.44 point and 1.92 points at post-operative intervals of 3 months (P < .001), 6 months (P < .001) and 12 months (P < .001). The percentage (number) of patients whose increase in mJOA score was greater than or equal to the minimal clinically importance difference (MCID) was 41% (44/107), 34% (33/96) and 43% (49/114) at these respective time intervals. Intraoperative complications occurred in 28 patients (11.7%). No association was found between BMI and postoperative change in mJOA score.ConclusionOur results are comparable to those from best practice data and suggest adherence to international guidelines provides a service that promotes meaningful recovery for patients with DCM. Therefore, our results offer support for implementation of the AO Spine international guidelines in clinical practice.

Duration of symptoms before diagnosis in degenerative cervical myelopathy: A systematic review and meta-analysis

Introduction

Degenerative cervical myelopathy (DCM), the commonest cause of spinal cord injury, can lead to progressive disability. Due to overlapping symptoms with other conditions and low awareness among healthcare professionals, many patients experience delayed diagnosis.

Research question

What is the typical duration of symptoms of DCM before diagnosis?

Materials and methods

We searched multiple databases for primary studies reporting duration of symptoms in people with confirmed diagnosis of DCM. Two independent reviewers screened titles, abstracts, full-text articles, extracted data and appraised study quality. We performed random-effects meta-analyses to pool duration of symptoms to presentation, diagnosis, and intervention.

Results

We identified 78 studies from 18 countries, with 12,450 participants. Time from symptom onset to first clinical presentation (two studies, n = 232 participants) was 3.3 (95 % confidence interval, -0.3-6.8) months. Time from symptom onset to diagnosis (five studies, n = 897) was 15.0 (5.0-25.0) months. In 29 studies (n = 3052) that measured from symptom onset to surgery/pre-operative assessment the duration was 14.5 (12.1-17.0) months. Thirty-seven studies had an undefined endpoint, in which when pooled, duration of symptoms was 15.2 (12.4-18.0) months. Most studies did not define the symptoms at onset, however when onset was defined as first occurrence of myelopathic (upper motor neurone) symptoms (five studies, n = 1006), time to surgery was 10.7 (2.3-18.5) months.

Discussion and conclusion

Most people with DCM experience symptoms for more than one year before diagnosis. These data may be useful to inform initiatives to promote early diagnosis. Standardised methodology would improve further research in this area.

Validation of a novel scoring system (Cervical Surgical Score) for the management of degenerative cervical myelopathy

Background

Degenerative Cervical Myelopathy (DCM) is the leading cause of spinal cord dysfunction globally. Surgical intervention is often recommended for moderate to severe cases, but the optimal surgical approach remains debated.

Objective

This study aims to validate the novel Cervical Surgical Score (CSS) for managing DCM, aiding surgical decision-making.

Methods

A prospective study was conducted in Carlo Besta institute (Milan) from a consecutive series, enrolling 113 patients undergoing surgery for DCM from January 2022 to February 2023. This cohort was compared with 106 patients from a retrospective cohort treated between 2019 and 2021.

Results

A total 219 patients (113 prospective, 106 retrospective) were included. The prospective group had an average age of 59.6 years (61 % males), and the retrospective group, 60.7 years (69 % males). The mean CSS score (calculated based on age, level of cervical pathologies, level of myelopathy, extension, site and type of compression, cervical alignment and mJOA) was 12.3 for prospective and 13.18 for retrospective groups. Most prospective cases used an anterior approach compared to retrospective group (88,5 % vs 48.1 %). At two years, neurological recovery (last follow-up mJOA-preoperative mJOA)/(18-preoperative mJOA × 100) was higher in prospective group (68 % vs. 54 %). CSS concordance linked to better recovery rates at one and two years (45 % and 66 % vs. 29 % and 47 %; p < 0,001). High-expertise surgeons (defined based on case-load evaluation scale) achieved higher CSS concordance (64 %) than medium (31 %) and low-expertise surgeons (0 %).

Conclusion

The CSS is a reliable tool for optimizing surgical strategies for DCM, enhancing decision-making, and improving patient outcomes.

Spinal Cord Tract Integrity in Degenerative Cervical Myelopathy

BACKGROUND AND OBJECTIVES

Degenerative cervical myelopathy (DCM) is the most common cause of spinal dysfunction globally. Despite surgical intervention, motor dysfunction may persist in many patients. The purpose of this study was to comprehensively examine specific spinal cord tract changes in patients with DCM, to better understand potential substrates for compensatory recovery of function.

METHODS

Cervical spinal cord MRI scans with diffusion tensor imaging were performed in patients with DCM and in healthy volunteers. Spinal Cord Toolbox was used to register the PAM50 template, which includes a probabilistic atlas of the white matter tracts of the spinal cord, to the imaging data. Fractional anisotropy (FA) was extracted for each tract at C3 above the level of maximal compression and compared between patients with DCM and healthy volunteers and between patients with mild vs moderate to severe DCM.

RESULTS

We included 25 patients with DCM (13 mild and 12 moderate to severe) and 6 healthy volunteers. FA was significantly reduced in DCM subjects relative to healthy volunteers for the lateral corticospinal tract (mild DCM vs healthy ∆ = -0.13, P = .018; moderate to severe DCM vs healthy ∆ = -0.11, P = .047), fasciculus gracilis (mild DCM vs healthy ∆ = -0.16, P = .010; moderate to severe DCM vs healthy ∆ = -0.13, P = .039), and fasciculus cuneatus (mild DCM vs healthy ∆ = -0.16, P = .007; moderate to severe DCM vs healthy ∆ = -0.15, P = .012). There were no differences in FA for all tracts between mild and moderate-to-severe DCM subjects.

CONCLUSION

Patients with DCM had altered diffusion tensor imaging signal in their lateral corticospinal tract, fasciculus gracilis, and fasciculus cuneatus in comparison with healthy volunteers. These findings indicate that DCM is characterized by injury to these structures, which suggests that other tracts within the cord could potentially act as substrates for compensatory motor recovery.

An in vivo 3-dimensional kinematics study of the cervical vertebrae under physiological loads in patients with cervical spondylosis

BACKGROUND CONTEXT

Studies of in vivo kinematic differences between healthy individuals and those with cervical spondylosis (CS) have been reported, but only movements under nonphysiological loads have been investigated. Differences in the in vivo, cervical kinematics between healthy individuals and those with CS are unknown.

PURPOSE

To investigate the in vivo, cervical kinematics of patients with CS under physiological loads.

STUDY DESIGN

This was a retrospective, case-controlled study that used three-dimensional (3D) to 3D registration techniques combined with conical beam computed tomography (CBCT) to investigate the cervical kinematics of patients with CS.

PATIENT SAMPLE

Twenty individuals diagnosed with CS were selected for study participation and matched with 20 participants who did not have CS and were in good health.

OUTCOME MEASURES

Pfirrmann grading, intervertebral range of motion (ROM), kinematics and cross-sectional area of posterior neck muscles (CAPNM).

METHODS

All study participants underwent seven CBCT scans of their cervical vertebrae. The 3D segmental motion features of the vertebra in vivo were calculated using 3D-to-3D volume registration to overlay images of the vertebra at each functional position. The 3D range of motion (ROM) of each cervical segment was expressed with six degrees of freedom using Euler angles and translated onto a coordinate system. A kinematic subgroup analysis was conducted based on the severity of symptoms within the CS group, and differences in muscle volume between the CS and control groups were also evaluated. Project supported by the National Natural Science Foundation of China (Grant No. 81960408,82260445), Key Project of Jiangxi Provincial Natural Science Foundation (Grant No. 20242BAB26125), Clinical Cultivation Project of The First Affiliated Hospital of Nanchang University (Grant No. YFYLCYJPY 20220203).The authors declare no conflict of interest in preparing this article.

RESULTS

The CS group exhibited noticeable reductions in the primary rotational ROMs of left-right rotation at C4-C5, C5-C6, C6-C7, C4-C7, and C1-C7 compared to the controls. During left-right bending, there were no significant differences in the primary ROMs, coupled translations, or rotations between the two groups. However, compared to controls, the CS group had significantly lower primary ROMs for C4-C7, C1-C7 and C5-C6 during flexion-extension. During left-right rotation, the primary rotations and coupled lateral bending at C6-C7 were significantly increased in the mild CS group compared to the moderate CS group. In the mild CS group, the primary ROM of the C4-C5 and C5-C6 during flexion-extension was significantly greater than that of the moderate CS group.

CONCLUSIONS

For the first time, the in vivo 3D kinematics of the cervical spine during head movement under physiological load in CS individuals have been adequately described and compared with healthy cervical vertebrae, which can be used as a reference point for future studies. The application of CBCT helps to obtain accurate and precise movement information of CS patients and effectively enhance the evaluation results obtained from imaging information.

Comparison of outcomes after anterior versus posterior surgery for degenerative cervical myelopathy: a pooled analysis of individual patient data

BACKGROUND CONTEXT

Uncertainty exists regarding the optimal surgical approach to treat patients with degenerative cervical myelopathy (DCM). This uncertainty is particularly marked for patients with mild DCM who may be more sensitive to different management techniques.

PURPOSE

To determine the effect of surgical approach on one-year outcomes for DCM.

STUDY DESIGN/SETTING

Individual patient data meta-analysis of 3 independent, prospective, multicentre clinical trials (ie, CSM-North America, CSM-International, CSM-Protect) that enrolled patients between 2005 and 2018 in academic hospitals, with 1 yr follow up. Statistical analysis was performed from September 13, 2023 to April 2, 2024.

PATIENT SAMPLE

From a total of 1047 adult subjects with DCM, 980 met the eligibility criteria who were surgical candidates with symptomatic and radiologically-evidenced DCM with no prior cervical surgery.

OUTCOMES MEASURES

The primary endpoint was change in 36-Item Short Form Health Survey Physical Component Summary score (SF36-PCS; minimum clinically important difference [MCID]=4) at 1 yr compared to preoperatively. Secondary endpoints were change in modified Japanese Orthopedic Association (mJOA; MCID=2) score, Neck Disability Index (NDI; MCID=15) score, SF36 Mental Component Summary (SF36-MCS; MCID=4) score, and postoperative complications.

METHODS

Two comparison cohorts were created: i) anterior surgery and ii) posterior surgery. Mean differences (MD) of outcomes with 95% confidence intervals (CI) were estimated using one-stage covariate-adjusted hierarchical mixed-effects meta-analyses with study and treatment exposure as random effects. A priori subgroup analysis in mild DCM patients (mJOA=15-17) was conducted.

RESULTS

The mean patient age was 56.9 years (SD=11.4), with 38.7% that identified as female. 560 patients (57.1%) received anterior cervical decompressive surgery for DCM. Patients who had anterior decompressive surgery experienced greater improvements in quality of life and disability at 1 yr follow-up than those who underwent posterior decompressive surgery in SF36-PCS (MD=1.57 [95% CI 0.11-3.03], p=.0348) and NDI (MD=3.32 [95% CI 0.58-6.05], p=.017). Dysphagia was more likely after anterior surgery. Pseudoarthrosis and wound infections were more likely after posterior surgery. In a subgroup of patients with mild DCM, patients who underwent anterior decompressive surgery experienced even greater improvements in SF36-PCS (MD=5.45 [95% CI 1.73-9.18], p=.0042), NDI (MD=10.37 [95%CI 3.43-17.31], p=.0035), and mJOA (MD=0.95 [95% CI 0.12-1.77], p=.0238; MCID=1) than posterior surgery patients.

CONCLUSION

Anterior surgical decompression for DCM is associated with greater improvements in 1 yr patient-reported quality of life and disability than posterior surgical decompression. These results may assist clinicians in driving complex management decisions.

A stacking ensemble machine learning model for predicting postoperative axial pain intensity in patients with degenerative cervical myelopathy

Machine learning (ML) has been extensively utilized to predict complications associated with various diseases. This study aimed to develop ML-based classifiers employing a stacking ensemble strategy to forecast the intensity of postoperative axial pain (PAP) in patients diagnosed with degenerative cervical myelopathy (DCM). A total of 711 consecutive postoperative DCM patients were included between 2016 and 2024, and after excluding patients who did not meet the inclusion criteria and those who met the exclusion criteria, a total of 484 patients were ultimately included in this study. The intensity of PAP was assessed using a standardized Numerical Rating Scale (NRS) score one year following surgery. Participants were randomly allocated into training and testing sub-datasets in a ratio of 8:2. 91 initial ML classifiers were developed, from which the top three highest-performing classifiers were subsequently integrated into an ensemble model utilizing 13 different machine learning models. The area under the curve (AUC) served as the primary metric for evaluating the predictive performance of all classifiers. The classifiers EmbeddingLR-RF (AUC = 0.81), EmbeddingRF-MLP (AUC = 0.81), and RFE-SVM (AUC = 0.80) were recognized as the leading three models. By implementing an ensemble learning approach such as stacking, an enhancement in performance for the ML classifier was observed after amalgamating these three models, with SVM ensemble classifier performed the best (AUC = 0.91). Decision curve analysis underscored the advantages conferred by these ensemble classifiers; notably, prediction curves for PAP intensity among DCM patients exhibited significant variability across the top three initial classifiers. The ensemble classifiers effectively predicted PAP intensity in DCM patients, showcasing substantial potential to aid clinicians in managing DCM cases while optimizing medical resource utilization.

Automated detection of cervical spondylotic myelopathy: harnessing the power of natural language processing

Background

The objective of this study was to develop machine learning (ML) algorithms utilizing natural language processing (NLP) techniques for the automated detection of cervical spondylotic myelopathy (CSM) through the analysis of positive symptoms in free-text admission notes. This approach enables the timely identification and management of CSM, leading to optimal outcomes.

Methods

The dataset consisted of 1,214 patients diagnosed with cervical diseases as their primary condition between June 2013 and June 2020. A random ratio of 7:3 was employed to partition the dataset into training and testing subsets. Two machine learning models, Extreme Gradient Boosting (XGBoost) and Bidirectional Long Short Term Memory Network (LSTM), were developed. The performance of these models was assessed using various metrics, including the Receiver Operating Characteristic (ROC) curve, Area Under the Curve (AUC), accuracy, precision, recall, and F1 score.

Results

In the testing set, the LSTM achieved an AUC of 0.9025, an accuracy of 0.8740, a recall of 0.9560, an F1 score of 0.9122, and a precision of 0.8723. The LSTM model demonstrated superior clinical applicability compared to the XGBoost model, as evidenced by calibration curves and decision curve analysis.

Conclusions

The timely identification of suspected CSM allows for prompt confirmation of diagnosis and treatment. The utilization of NLP algorithm demonstrated excellent discriminatory capabilities in identifying CSM based on positive symptoms in free-text admission notes complaint data. This study showcases the potential of a pre-diagnosis system in the field of spine.

Biomechanical Evaluation of Cervical Interbody Fusion Cages for Anterior Cervical Discectomy and Fusion With Variations in Morphology: A Finite Element Analysis

The spinal diseases commonly faced by people in the 19th century included intervertebral disc degeneration, tuberculosis and congenital defects that resulted in neurological impairment and global disability. To address these issues, cervical spine surgery was performed. Modern techniques currently used in spine surgery include interbody devices, pedicle screws, artificial discs and bone grafts. The postoperative complications clinically reported during follow-up include nonunion and implant subsidence, which remain significant drawbacks. The objective of this study is to develop a 3-dimensional finite element model of the C2-C7 cervical spine and validate it against existing experimental studies. The loading conditions considered for this study include a compressive preload of 50 N and a 1 Nm moment applied to the C2 vertebra, with the C7 vertebra fixed at the bottom. In this study, the biomechanical alterations of 4 different cage morphologies were analysed using finite element analysis. Valeo cages with 4 distinct designs were implanted at the C5-C6 level, and physiological motion at the surgical site was studied. Cage subsidence and migration, which can lead to adjacent segment disc degeneration, were also examined. Subsidence was primarily attributed to higher stress encountered in the cage, so stress distribution within the cages was evaluated. Additionally, stress distribution in the anterior plate and screws was analysed. The study concludes that introducing anterior plate and screw fixation helps prevent cage subsidence. Physiological motion at the surgical level was reduced compared to the intact model. Adjacent disc stress was also evaluated and found to be lower than in the intact model.

Predicting postoperative neurological outcomes of degenerative cervical myelopathy based on machine learning

Introduction

This study aimed to develop machine learning models to predict neurological outcomes in patients with degenerative cervical myelopathy (DCM) after surgical decompression and identify key factors that contribute to a better outcome, providing a reference for patient consultation and surgical decision-making.

Methods

This retrospective study reviewed 1,895 patients who underwent cervical decompression surgery for DCM at Peking University Third Hospital from 2011 to 2020, with 672 patients included in the final analysis. Five machine learning methods, namely, linear regression (LR), support vector machines (SVM), random forest (RF), XGBoost, and Light Gradient Boosting Machine (LightGBM), were used to predict whether patients achieved the minimal clinically important difference (MCID) in the improvement in the Japanese Orthopedic Association (JOA) score, which was based on basic information, symptoms, physical examination signs, intramedullary high signals on T2-weighted (T2WI) magnetic resonance imaging (MRI), and various scale scores. After training and optimizing multiple ML algorithms, we generated a model with the highest area under the receiver operating characteristic curve (AUROC) to predict short-term outcomes following DCM surgery. We evaluated the importance of the features and created a feature-reduced model. The model's performance was assessed using an external dataset.

Results

The LightGBM algorithm performed the best in predicting short-term neurological outcomes in the testing dataset, achieving an AUROC value of 0.745 and an area under the precision-recall curve (AUPRC) value of 0.810. The important features influencing performance in the short-term model included the preoperative JOA score, age, SF-36-GH, SF-36-BP, and SF-36-PF. The feature-reduced LightGBM model, which achieved an AUROC value of 0.734, also showed favorable performance. Moreover, the feature-reduced model showed an AUROC value of 0.785 for predicting the MCID of postoperative JOA in the external dataset, which included 58 patients from other hospitals.

Conclusion

We developed models based on machine learning to predict postoperative neurological outcomes. The LightGBM model presented the best predictive power regarding the surgical outcomes of DCM patients. Feature importance analysis revealed that variables, including age, preoperative JOA score, SF-36-PF, SF-36-GH, and SF-36-BP, were essential factors in the model. The feature-reduced LightGBM model, designed for ease of application, achieved nearly the same predictive power with fewer variables.

Recovery Trajectories of Patient-reported Outcomes After Surgery for Degenerative Cervical Myelopathy: A Bayesian Latent Class Modeling Approach

STUDY DESIGN

Retrospective study.

OBJECTIVE

The aim of this study was to identify recovery trajectory clusters after surgery for degenerative cervical myelopathy (DCM), as well as to determine clinical and imaging characteristics associated with functional recovery trajectories.

BACKGROUND

Accurate prediction of postsurgical neurological recovery for the individual patient with DCM is challenging due to varying patterns of functional recovery. Latent class Bayesian models can model individual patient patterns and identify groups of patients with similar phenotypes for personalized prognostication.

METHODS

A prospective single-center study of 70 consecutive patients with DCM undergoing elective cervical spine decompression for DCM between 2010 and 2017 was performed. Outcomes were recorded using the modified Japanese Orthopedic Association (mJOA), Neck Disability Index (NDI), and the Short Form-36 Physical Component Score (SF-36 PCS) at 3, 6, 12, and 24 months. Recovery trajectories were constructed based on unsupervised Bayesian latent class modeling. Clinical and imaging predictors of recovery trajectories were also determined.

RESULTS

Recovery after surgery for DCM showed 3 distinct recovery trajectory clusters for each outcome. The commonest recovery trajectory was sustained improvement for the mJOA (41.1%), stagnation for the NDI (60.3%), and stability for the SF-36 PCS (46.6%). Age, duration of symptoms, and baseline disability were the strongest predictors of each recovery trajectory. Degree of cord compression, neck pain, and intramedullary T2-hyperintensity were predictive of NDI and SF-36 PCS but not mJOA recovery trajectory. Sex was associated with the NDI recovery trajectory but not SF-36 PCS and mJOA recovery trajectories.

CONCLUSION

Using prospective data and a data-driven approach, we identified 3 distinct recovery trajectory clusters and associated factors for mJOA, NDI, and SF-36 PCS in the first 24 months after surgery for DCM. Our results can enhance personalized clinical prognostication and guide patient expectations at different time points after surgery for DCM.

Risk of Post-Traumatic Spinal Cord Injury in Patients with Stenosis of the Cervical Spine: A Systematic Review and Meta-Analysis

BACKGROUND

Cervical stenosis (CS) is the pathologic narrowing of the central canal of the cervical spine. It is often incidentally discovered. It is unclear whether pre-existing CS can lead to worse outcomes and higher incidences of post-traumatic spinal cord injury (SCI).

METHODS

We conducted a systematic review and meta-analysis of studies collected using the keywords "cervical stenosis" AND ("trauma" OR "injury"). About 381 articles were collected from PubMed, Embase, and Cochrane, and 2675 patients from 7 studies were included in the final analyses. Neo-Bayesian statistics were used to estimate a number needed to treat.

RESULTS

In a meta-analysis of studies with internal controls, patients with pre-existing CS are not at a higher risk of post-traumatic SCI (odds ratio 2.73, 95% confidence interval [CI] 0.78-9.50). However, CS patients have a greater incidence of SCI (0.41, 95% CI 0.26-0.56) compared to patients without CS (0.18, 95% CI 0.14-0.22). Patients with CS were also over-represented in the population of SCI patients (0.46, 95% CI 0.27; 0.65). Using neo-Bayesian statistics, we estimate that 70 patients with CS must be treated to prevent one SCI. In patients who participate in higher-risk physical activities, the number needed to treat may be lower.

CONCLUSIONS

Though patients with pre-existing CS do not have higher odds of SCI in studies with internal controls, we find that patients with CS do have higher incidences of SCI and are over-represented in the population of SCI patients. In select CS patients with active lifestyles, close follow-up and consideration of various treatment options may be indicated.

Evaluation of Financial Support Workshops for Patients Under State Pension Age With Degenerative Cervical Myelopathy: Survey Study

Background

Degenerative cervical myelopathy (DCM), a form of slow-motion and progressive spinal cord injury caused by spinal cord compression secondary to degenerative pathology, leads to high levels of disability and dependence, and may reduce quality of life. Myelopathy.org is the first global scientific and clinical charity for DCM, providing an accessible platform freely disseminating information relevant to the DCM diagnosis and its treatment. Significant transient and long-term change to earnings do occur and can thrust individuals into poverty. People with DCM face many challenges accessing state financial assistance. This can have a cumulative negative financial effect due to the association between DCM and low socioeconomic index. Financial support available to patients under pension age include Universal Credit (UC), a payment that helps with living costs, and Personal Independence Payment (PIP), which helps with extra living costs if someone has both a long-term health condition or disability and difficulty doing certain everyday tasks.

Objective

This study aimed to assess if delivering workshops centered around access to financial support could assist people with DCM living in the United Kingdom.

Methods

A series of 2 internet-based workshops was targeted at accessing financial support for English patients under the state pension age, with an anonymized survey delivered to participants after each session. The first session was on UC and the second on PIP. The survey consisted of a mixture of Likert scales, free text and yes or no answers. Survey responses were analyzed using descriptive statistics and free text answers underwent inductive thematic analysis.

Results

The average rating on the use of UC was 9.00/10. Presession self-rated confidence levels were 5.11/10 rising to 8.00/10. The mean score of wanting further similar sessions was 8.67/10 with 56% (5/9) of participants wanting one-to-one sessions. For PIP, the average session use rating was 10/10. Presession self-rated confidence levels were 4.43/10 rising to 9.57/10. The mean score of wanting further similar sessions was 8.71/10, with 43% (3/7) of participants wanting one-to-one sessions . Following inductive thematic analysis, themes regarding the usefulness of such sessions and the challenges to accessing financial support emerged. One participant gave negative feedback, which included the length of the session and perceived problems around confidentiality and data protection.

Conclusions

The pilot series was largely perceived as a success, with participants finding them useful and increasing their self-rated confidence in navigating the UK financial support system. Given the small sample size, it is hard to predict the success of future sessions. Finally, given that the hurdles in accessing financial support extend beyond DCM, such workshops may be relevant to other organizations.

The Prevalence of Congenital Cervical Stenosis Differs based on Race

BACKGROUND

Congenital cervical stenosis (CCS) is a rare condition involving a narrowed spinal canal due to developmental anomalies. CCS heightens the risk of neurologic deficits and acute spinal cord injury post-trauma, influencing return-to-play decisions for contact athletes. Additionally, CCS patients are prone to cervical myelopathy as degenerative changes progress with age. Limited evidence-based literature exists addressing the epidemiology of CCS, including the effects of race.

PURPOSE

To investigate the anatomical differences and prevalence of CCS as it pertains to race and ethnicity.

STUDY DESIGN

Single center retrospective cross-sectional study.

PATIENT SAMPLE

A total of 343 patients with cervicalgia between the years of 1999-2023.

OUTCOME MEASURES

Radiographic measurements of anatomical parameters were collected and CCS was defined as a sagittal canal diameter (SCD) of less than 10 mm at 2 or more vertebral levels (C3-7) at the pedicle.

METHODS

We screened 5395 cervical MRIs from a single institution. Exclusion criteria included patients under 18 and over 50 years, prior cervical spine surgery, congenital fusions, spinal malignancy, or active smoking history. For each patient, axial measurements were taken at each level, including coronal vertebral body length, anteroposterior vertebral body length, pedicle width, pedicle length, laminar length, anteroposterior lateral mass length, posterior canal distance, apex-to-vertebral body, lamina-disc angle (LDA), lamina-pedicle angle, and anteroposterior spinal cord diameter.

RESULTS

CCS prevalence varied significantly among ethnic groups; Black (39.3%), Asian (33.6%), and Hispanic (22%) patients demonstrated significantly higher CCS rates than White patients (7.5%) [x2 (3, N=343) = 30.04, p <0.05)]. Blacks and Asians showed consistently smaller SCDs at all pedicle levels compared to Whites, who had the largest SCDs overall (p<0.001). Average SCDs were 11.4 mm (White), 10.4 mm (Black), 10.5 mm (Asian), and 11 mm (Hispanic). Additionally, LDAs were larger in Asians, Blacks, and Hispanics compared to Whites, leading to a significantly decreased cross-sectional canal area (p<0.001).

CONCLUSIONS

Our study indicates a statistically significant correlation between race/ethnicity and CCS prevalence. Black and Asian patients had the highest CCS rates, smallest SCDs, and largest LDAs. These anatomical differences may predispose these subjects to the development of cervical myelopathy compared to those with normal spinal canal diameters. Increased knowledge base of the epidemiology of this condition may lead to personalized clinical management and possibly early intervention to prevent spinal cord injuries in these patients.

Who gets better after surgery for degenerative cervical myelopathy? A responder analysis from the multicenter Canadian Spine Outcomes and Research Network

BACKGROUND CONTEXT

Degenerative cervical myelopathy (DCM) is the most common cause of acquired nontraumatic spinal cord injury worldwide. Surgery is a common treatment for DCM; however, outcomes often vary across patients.

PURPOSE

To inform preoperative education and counseling, we performed a responder analysis to identify factors associated with treatment response.

STUDY DESIGN/SETTING

An observational cohort study was conducted utilizing prospectively collected data from the Canadian Spine Outcomes Research Network (CSORN) registry collected between 2015-2022.

PATIENT SAMPLE

We included all surgically treated DCM patients with complete 12-month follow-up and patient-reported outcomes (PROs) available at 1-year.

OUTCOME MEASURES

Treatment response was measured using the minimal clinically important difference (MCID) in PROs including the Neck Disability Index (NDI) and EuroQol-5D (EQ-5D) at 12 months postsurgery.

METHODS

A Least Absolute Shrinkage and Selection Operator (LASSO) machine learning model was used to identify significant associations between 14 preoperative patient factors and likelihood of treatment response measured by achievement of the MCID in NDI, and EQ-5D. Variable importance was measured using standardized coefficients. To test robustness of findings we trained a separate XGBOOST model, with variable importance measured using SHAP values.

RESULTS

Among the 554 DCM patients included, 229 (41.3%) and 330 (59.6%) patients responded to treatment by meeting or surpassing MCID thresholds for NDI and EQ-5D at 1-year, respectively. LASSO regression for likelihood of treatment response measured through NDI found the variable importance rank order to be baseline NDI (OR 1.06 per 1 point increase; 95% CI 1.04-1.07), then symptom duration (OR 0.65; 95% CI 0.44-0.97). For EQ-5D, the variable importance rank order was baseline EQ-5D (OR 0.16 per 0.1-point increase; 95% CI 0.03-0.78), living independently (OR 2.17; 95% CI 1.22-3.85), symptom duration (OR 0.62; 95% CI 0.40-0.97), then number of levels affected (OR 0.80 per additional level; 95% CI 0.67-0.96). A separate XGBoost model of treatment response measured through NDI, corroborated findings that patients with higher baseline NDI, and shorter symptom duration were more likely to respond to treatment, and additionally found older patients, and those with kyphosis on baseline upright X-ray were less likely to respond. Similarly, an XGBoost model for treatment response measured through EQ-5D corroborated findings that patients with higher baseline EQ-5D, shorter symptom duration, living independently, with fewer affected levels were more likely to respond to treatment, and additionally found older patients were less likely to respond.

CONCLUSIONS

Our findings suggest patients with shorter symptom duration, higher baseline patient NDI, lower EQ-5D, younger age, living independently, without kyphosis on preoperative X-ray, and fewer affected levels are more likely to respond to treatment. Timing of surgery with respect to patient symptoms is underscored as a crucial and modifiable patient factor associated with improved surgical outcomes in DCM.

Open-Door Cervical Laminoplasty Using Instrumentation of Every Level Versus Alternate Levels: A Multicenter, Randomized Controlled Trial

BACKGROUND

In the setting of cervical open-door laminoplasty, the question of whether or not every opened laminar level should be instrumented has not been sufficiently investigated. We postulated that the surgical outcomes of open-door laminoplasty with instrumentation of every second opened level (skip-fixation) might not be inferior to those of laminoplasty with instrumentation of every opened level (all-fixation). The purpose of the present study was to test the noninferiority of laminoplasty with skip-fixation in improving myelopathy at 2 years postoperatively compared with all-fixation. Additionally, we compared radiographic and surgical outcomes between the 2 types of procedures.

METHODS

This prospective, multicenter, unblinded randomized controlled trial included patients ≥60 years of age who underwent C3 to C6 open-door cervical laminoplasty for the treatment of degenerative cervical myelopathy. Patients were allocated to the skip-fixation group (n = 80) or the all-fixation group (n = 75) using a permuted block method. The primary outcome was the between-group difference in the Japanese Orthopaedic Association (JOA) score at 2 years postoperatively. Secondary outcomes included surgical data, complications, 2-year change in the JOA score, Neck Disability Index (NDI), EQ-5D-5L (EuroQol 5-dimension 5-level instrument) score, visual analog scale (VAS) score for neck pain, and radiographic outcomes.

RESULTS

One hundred and thirty patients (including 66 in the skip-fixation group and 64 in the all-fixation group) completed the trial at 2 years (follow-up rate, 83.9%). The difference in the JOA score at 2 years was 0.0298 (95% confidence interval [CI], -0.706 to 0.766), which was within the noninferiority margin (p < 0.0001; noninferiority test). In the secondary analyses, laminoplasty with skip-fixation demonstrated a significantly shorter surgical time (p = 0.010; Mann-Whitney U test) and greater improvement in the VAS score for neck pain, NDI, and EQ-5D-5L score (p = 0.006, p = 0.047, p = 0.037, respectively; mixed-effect model) compared with all-fixation. There were no significant between-group differences in radiographic outcomes, including the hinge union rate.

CONCLUSIONS

Skip-fixation may be sufficient to achieve noninferior 2-year postoperative improvement in myelopathy. Additionally, laminoplasty with skip-fixation potentially can lead to improvements in terms of neck pain, neck disability, and quality of life compared with all-fixation.

LEVEL OF EVIDENCE

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

Surgical Management of Thoracic Dorsal Arachnoid Webs: A 10-Year Single-Institution Experience

OBJECTIVE

Thoracic dorsal arachnoid webs are intradural membranes that may cause obstruction of cerebrospinal fluid flow and spinal cord compression. Although well recognized, they are rare and there is a paucity of long-term data on their natural history and prognosis. We reviewed radiographic features, surgical indications, and pathologic specimens of patients diagnosed with focal thoracic dorsal arachnoid webs.

METHODS

A radiology database and surgical case logs were queried for thoracic arachnoid webs at a single hospital system for a 10-year period. A retrospective chart review was performed on identified cases.

RESULTS

We identified 127 patients with dorsal thoracic arachnoid webs. Arachnoid webs were radiographically classified into 3 morphologic types: type 1 (54%) causing spinal cord deformity only, type 2 (32%) producing cord deformity with myelomalacia, and type 3 (14%) with cord deformity, myelomalacia, and syringomyelia. These arachnoid webs were commonly centered at the upper thoracic T4 segmental level. Forty-one cases (32%) required surgery, generally for thoracic myelopathy with gait instability (46%) and lower extremity numbness and pain (39%). In patients who underwent surgery, 79% experienced symptomatic improvement and 21% remained stable, after an average of 21 months follow-up evaluation. Surgical pathology revealed fibrous connective tissue (100%) with calcifications (26%) or inflammation (7%).

CONCLUSIONS

Most patients in a large series of patients with dorsal arachnoid webs did not undergo surgical intervention, but those with myelomalacia and syrinx experienced radiographic and clinical deterioration without surgery. Surgery to treat symptomatic arachnoid webs results in significant clinical improvement with low surgical morbidity.

Tract-specific magnetization transfer ratio provides insights into the severity of degenerative cervical myelopathy

STUDY DESIGN

Cross-sectional study.

OBJECTIVES

This study's goal is to report whether Magnetization Transfer Ratio (MTR) can evaluate the severity of white matter (WM) injury in degenerative cervical myelopathy (DCM).

SETTING

Laureate Institute of Brain Research, USA; Department of Neurosurgery, University of Oklahoma Health Sciences Center, USA.

METHODS

27 DCM patients were aged-matched with 20 healthy controls (HC) and categorized into treatment groups based on modified Japanese Orthopedic Association (mJOA) severity (11 mild and 16 moderate/severe). Regional and tract MTRs were extracted from the two vertebral levels containing maximum compression within magnetization transfer images. MTR differences between groups were assessed using a one-way ANOVA or Kruskal-Wallis test. The association between MTR and mJOA measures was evaluated using Spearman's correlation.

RESULTS

Significant decreases in MTR were found between HC and moderate/severe groups in the overall (p = 0.0065) and ventral (p = 0.0009) WM regions; and ventral corticospinal (p = 0.0101), ventral reticulospinal (p = 0.0084), spinal lemniscus (p = 0.0079), and fasciculus cuneatus (p = 0.0219) tracts. The spinal lemniscus MTR also significantly decreased between HC and mild groups (p = 0.038). Ventral reticulospinal tract MTR correlated with upper (r = 0.439; p = 0.022) and lower (r = 0.386; p = 0.047) limb motor mJOA scores.

CONCLUSIONS

Significant tract-based MTR changes and correlations align with known DCM symptoms, are demonstrated to be lost at the regional level, and display the inhomogeneous compressive damage occurring within DCM spinal cords.

Feasibility of Using Intraoperative Neurophysiological Monitoring for Detecting Bone Layer of Cervical Spine Surgery

STUDY DESIGN

Intraoperative neurophysiological monitoring (IONM) as a guide to bone layer estimation was examined during posterior cervical spine lamina grinding.

OBJECTIVE

To explore the feasibility of IONM to estimate bone layer thickness.

SUMMARY OF BACKGROUND DATA

Cervical laminoplasty is a classic operation for cervical spondylosis. To increase safety and accuracy, surgery-assistant robots are currently being studied. It combines the advantages of various program awareness methods to form a feasible security strategy. In the field of spinal surgery, robots have been successfully used to help place pedicle screws. IONM is used to monitor intraoperative nerve conditions in spinal surgery. This study was designed to explore the feasibility of adding IONM to robot safety strategies.

METHODS

Chinese miniature pig model was used. Electrodes were placed on the lamina, and the minimum stimulation threshold of DNEP for each lamina was measured (Intact lamina, IL). The laminae were ground to measure the DNEP threshold after incomplete grinding (Inner cortical bone preserved, ICP) and complete grinding (Inner cortical bone grinded, ICG). Subsequently, the lateral cervical mass screw canal drilling was performed, and the t-EMG threshold of the intact and perforated screw canals was measured and compared.

RESULT

The threshold was significantly lower than that of the recommended threshold of DENP via percutaneous cervical laminae measurement. The DNEP threshold decreases with the process of laminae grinding. The DNEP threshold of the IL group was significantly higher than ICP and ICG group, while there was no significant difference between the ICP group and the ICG group. There was no significant relationship between the integrity of the cervical spine lateral mass screw path and t-EMG threshold.

CONCLUSIONS

It is feasible to use DENP threshold to estimate lamina thickness. Cervical lateral mass screw canals by t-EMG showed no help to evaluate the integrity.

Degenerative Cervical Myelopathy: History, Physical Examination, and Diagnosis

Background: Degenerative cervical myelopathy is a progressive neurological disorder that is commonly encountered in clinical practice and its incidence is expected to increase alongside the aging population. Given the importance of early and accurate diagnosis in this patient population, this narrative review aims to provide a repository of up-to-date information regarding pertinent patient history, physical exam findings, and potential alternate diagnoses. Methods: The PubMed database was queried for publications from 1 January 2019 to 19 March 2024. The search terms utilized are as follows: cervical myelopathy", "cervical spondylotic myelopathy", "degenerative cervical myelopathy", "epidemiology", "prevalence", "incidence", "etiology", "diagnosis", "differential", "symptoms", "clinical presentation", and "atypical symptoms". The resultant articles were reviewed for relevance and redundancy and are presented within the following categories: Natural History, Epidemiology, Clinical Presentation, Diagnosis, and Management. Results: Myelopathy patients often present with subtle and non-specific symptoms such as sleep disturbances, increased falls, and difficulty driving, which can lead to underdiagnosis and misdiagnosis. Failing to diagnose degenerative cervical myelopathy in a timely manner can result in progressive and irreparable neurological damage. Although many nonoperative treatment modalities are available, surgical decompression is ultimately recommended in most cases to limit further deterioration in neurological function and optimize long-term patient outcomes. Conclusions: A thorough clinical history and physical examination remain the most important diagnostic tools to avoid misdiagnosis and implement early treatment in this patient population.

Cervical Open-Door Laminoplasty for Myelopathy Caused by Ossification of the Posterior Longitudinal Ligament: Correlation Between Spinal Canal Expansion and Clinical Outcomes

Background/Objectives: This study investigated the relationship between spinal canal expansion and clinical outcomes in patients with myelopathy due to ossification of the posterior longitudinal ligament (OPLL) who underwent cervical open-door laminoplasty. Methods: A retrospective study was conducted on 36 OPLL patients who underwent open-door laminoplasty between 2009 and 2021. Preoperative and two-year postoperative radiologic parameters, including bony canal area (BCA) and spinal canal area (SCA), were measured. Clinical outcomes were assessed using the Numerical Rating Scale (NRS) for neck pain and radicular pain, the Neck Disability Index (NDI), and Japanese Orthopaedic Association (JOA) scores. Results: The mean expansion of BCA was 112.1 mm2 (47%) and SCA was 100.5 mm2 (64%). All clinical outcomes improved after surgery, although not statistically significant. JOA scores improved significantly in the severe group, while NDI and NRS-neck scores improved in the mild to moderate group. Significant correlations were found between improvements in NRS-neck and expansions of BCA (r = 0.533, p = 0.001) and SCA (r = 0.537, p = 0.001). NDI improvement was also associated with BCA expansion. No significant correlations were found between canal expansion and NRS-R, NRS-L, or JOA scores. Conclusions: Cervical open-door laminoplasty effectively increased the bony and spinal canal areas in patients with OPLL and myelopathy. In addition to improving myelopathy symptoms, this procedure may also improve neck pain and disability. Further research is needed to assess the long-term outcomes and to better understand these clinical improvements.

Current Status and Trends of Research on Cervical Spondylotic Myelopathy from the Perspective of Bibliometrics

This review was performed to analyze the research on cervical spondylotic myelopathy published during the past 25 years, summarize the developments in existing research, and predict future hotspots in the field. The goal is to provide a comprehensive overview and exploration of developments in this research area. A bibliometric analysis was performed using CiteSpace and VOSviewer to quantitatively and visually analyze relevant literature from Web of Science between 1998 and 2023. Co-occurrence analysis and co-citation analysis were conducted to evaluate papers, authors, journals, countries, and keywords. In total, 1886 papers were included. The overall publication output in this field increased throughout the review period. Stable author collaboration groups were formed, with the most influential author being Fehlings M.G. Japan and the United States contributed the highest number of publications. The predicted future research hotspots include risk factor analysis, outcome prediction, and machine learning. This study provides both an overview of the research trajectory in the field of cervical spondylotic myelopathy for scholars interested in this area, as well as offering insights and references for future research directions in the field.

The preservation of cervical flexibility helps maintain cervical sagittal alignment after laminoplasty

BACKGROUND CONTEXT

Cervical spine range of motion (ROM) is a critical factor in changes in cervical sagittal alignment (CSA) and clinical outcomes after cervical laminoplasty (LMP). However, the impact of postoperative cervical ROM on CSA after cervical LMP is still unclear.

PURPOSE

Evaluating the imaging and symptomatic data from patients with cervical spondylotic myelopathy (CSM) to identify the influence of postoperative cervical ROM on post-LMP CSA and surgical outcomes.

STUDY DESIGN

Retrospective study.

PATIENT SAMPLE

Eighty-six patients undergoing LMP due to multilevel CSM.

OUTCOME MEASURES

Radiographic parameters were measured before surgery and at follow-up: cervical lordosis (CL), T1 slope (T1S), cervical sagittal vertical axis (cSVA), CL in flexion (Flex CL), CL in extension (Ext CL), total cervical spine range of motion (ROM), cervical spine range of flexion (Flex ROM), and cervical spine range of extension (Ext ROM). Japanese Orthopedic Association (JOA) and visual analog score (VAS) were used to assessed clinical outcomes. Other parameters included age, gender, body mass index (BMI), follow-up time, number of surgical segments, proximal level, distalis level, and collar wear time.

METHODS

We divided patients according to the changes in CSA (loss of cervical lordosis (LCL)>10°, or ≤10°; an increase in cervical sagittal vertical axis (I-cSVA) >10mm, or ≤10mm). A receiver-operating characteristic curve (ROC) analysis was constructed to identify the optimal cut-off value to discriminate the patients with and without postoperative deterioration of CSA.

RESULTS

The postoperative total and Flex ROM were significantly lower in the LCL>10° and I-cSVA>10mm groups. Multivariate logistic regression analysis showed that low post-Flex ROM was significant risk factor for postoperative deterioration of CSA. ROC showed that the cut-off value for postoperative Flex ROM was 15.60°. Improvements in JOA recovery rate and neck pain were more significant in the flexibility group (post-Flex ROM ≥15.6°) after surgery. Patients in the stiffness group (post-Flex ROM <15.6°) wore a collar longer.

CONCLUSIONS

The preservation of cervical flexibility can maintain CSA after cervical LMP. Postoperative cervical stiffness is related to poor surgical outcomes because significant cervical kyphotic change and sagittal imbalance are likely to occur after surgery. Prolonged wearing of cervical collar is correlated with cervical stiffness following cervical LMP.

Nonoperative Care Versus Surgery for Degenerative Cervical Myelopathy: An Application of a Health Economic Technique to Simulate Head-to-Head Comparisons

Background

Degenerative cervical myelopathy (DCM) occurs when spondylotic changes compress the spinal cord and cause neurologic dysfunction. Because of a lack of comparative data on nonoperative care versus surgery for DCM, it has been difficult to support patients through the shared decision-making process regarding treatment options. Our objective was to synthesize the best available data in a manner that helps clinicians and patients to weigh the differences between nonoperative care and surgery at different ages and disease severity. The 2 patient-centered questions we sought to answer were (1) "am I more likely to experience worsening myelopathy with nonoperative care, or need more surgery if I have my myelopathy treated operatively?" and (2) "how much better will my quality of life be with nonoperative care versus surgery?"

Methods

We used a health economic technique, microsimulation, to model head-to-head comparisons of nonoperative care versus surgery for DCM. We incorporated the best available data, modeled patients over a lifetime horizon, used direct comparators, and incorporated uncertainty in both natural history and treatment effect.

Results

Patients with mild DCM at baseline who were ≥75 years of age were less likely to neurologically decline under nonoperative care than to undergo a second surgery if the index surgery was an anterior cervical discectomy and fusion (ACDF), cervical disc arthroplasty (ADR), or posterior cervical decompression and instrumented fusion (PDIF). Using quality-adjusted life-years (QALYs), our results suggest that surgery for DCM may be superior to nonoperative care. However, for all patients except those with severe DCM who are of middle age or younger (depending on the procedure, ≤50 to ≤60 years of age), the lower bound of the 95% confidence interval for the estimated difference in QALYs was <0.

Conclusions

In most patient groups, neurologic progression with nonoperative management is more likely than the need for additional cervical surgery following operative management, with the exception of patients 75 to 80 years of age and older with mild DCM. Furthermore, on average, surgery for DCM tends to improve quality of life. However, patients with DCM who are older than middle age should be aware that the estimates of the quality-of-life benefit are highly uncertain, with a lower bound of <0.

Level of Evidence

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

Dynamic Functional Network Connectivity in Acute Incomplete Cervical Cord Injury Patients and Its Associations With Sensorimotor Dysfunction Measures

BACKGROUND

Dynamic functional network connectivity (dFNC) captures temporal variations in functional connectivity during magnetic resonance imaging acquisition. However, the neural mechanisms driving dFNC alterations in the brain networks of patients with acute incomplete cervical cord injury (AICCI) remain unclear.

METHODS

This study included 16 AICCI patients and 16 healthy controls. Initially, independent component analysis was employed to extract whole-brain independent components from resting-state functional magnetic resonance imaging data. Subsequently, a sliding time window approach, combined with k-means clustering, was used to estimate dFNC states for each participant. Finally, a correlation analysis was conducted to examine the association between sensorimotor dysfunction scores in AICCI patients and the temporal characteristics of dFNC.

RESULTS

Independent component analysis was employed to extract 26 whole-brain independent components. Subsequent dynamic analysis identified 4 distinct connectivity states across the entire cohort. Notably, AICCI patients demonstrated a significant preference for State 3 compared to healthy controls, as evidenced by a higher frequency and longer duration spent in this state. Conversely, State 4 exhibited a reduced frequency and shorter dwell time in AICCI patients. Moreover, correlation analysis revealed a positive association between sensorimotor dysfunction and both the mean dwell time and the fraction of time spent in State 3.

CONCLUSIONS

Patients with AICCI demonstrate abnormal connectivity within dFNC states, and the temporal characteristics of dFNC are associated with sensorimotor dysfunction scores. These findings highlight the potential of dFNC as a sensitive biomarker for detecting network functional changes in AICCI patients, providing valuable insights into the dynamic alterations in brain connectivity related to sensorimotor dysfunction in this population.

Machine-learning-based prediction by stacking ensemble strategy for surgical outcomes in patients with degenerative cervical myelopathy

BACKGROUND

Machine learning (ML) is extensively employed for forecasting the outcome of various illnesses. The objective of the study was to develop ML based classifiers using a stacking ensemble strategy to predict the Japanese Orthopedic Association (JOA) recovery rate for patients with degenerative cervical myelopathy (DCM).

METHODS

A total of 672 patients with DCM were included in the study and labeled with JOA recovery rate by 1-year follow-up. All data were collected during 2012-2023 and were randomly divided into training and testing (8:2) sub-datasets. A total of 91 initial ML classifiers were developed, and the top 3 initial classifiers with the best performance were further stacked into an ensemble classifier with a supported vector machine (SVM) classifier. The area under the curve (AUC) was the main indicator to assess the prediction performance of all classifiers. The primary predicted outcome was the JOA recovery rate.

RESULTS

By applying an ensemble learning strategy (e.g., stacking), the accuracy of the ML classifier improved following combining three widely used ML models (e.g., RFE-SVM, EmbeddingLR-LR, and RFE-AdaBoost). Decision curve analysis showed the merits of the ensemble classifiers, as the curves of the top 3 initial classifiers varied a lot in predicting JOA recovery rate in DCM patients.

CONCLUSIONS

The ensemble classifiers successfully predict the JOA recovery rate in DCM patients, which showed a high potential for assisting physicians in managing DCM patients and making full use of medical resources.

Preoperative expectations of patients with degenerative cervical myelopathy: an observational study from the Canadian Spine Outcomes and Research Network

BACKGROUND

Despite an abundance of literature on degenerative cervical myelopathy (DCM), little is known about preoperative expectations of these patients.

PURPOSE

The primary objective was to describe patient preoperative expectations. Secondary objectives included identifying patient characteristics associated with high preoperative expectations and to determine if expectations varied depending on myelopathy severity.

STUDY DESIGN

This was a retrospective study of a prospective multicenter, observational cohort of patients with DCM.

PATIENT SAMPLE

Patients who consented to undergo surgical treatment between January 2019 and September 2022 were included.

OUTCOMES MEASURES

An 11-domain expectation questionnaire was completed preoperatively whereby patients quantified the expected change in each domain.

METHODS

The most important expected change was captured. A standardized expectation score was calculated as the sum of each expectation divided by the maximal possible score. The high expectation group was defined by patients who had an expectation score above the 75th percentile. Predictors of patients with high expectations were determined using multivariable logistic regression models.

RESULTS

There were 262 patients included. The most important patient expectation was preventing neurological worsening (40.8%) followed by improving balance when standing or walking (14.5%), improving independence in everyday activities (10.3%), and relieving arm tingling, burning and numbness (10%). Patients with mild myelopathy were more likely to select no worsening as the most important expected change compared to patients with severe myelopathy (p<.01). Predictors of high patient expectations were: having fewer comorbidities (OR -0.30 for every added comorbidity, 95% CI -0.59 to -0.10, p=.01), a shorter duration of symptoms (OR 0.92, 95% CI 0.35-1.19, p=.02), no contribution from "failure of other treatments" on the decision to undergo surgery (OR 1.49, 95% CI 0.56-2.71, p=.02) and more severe neck pain (OR 0.19 for 1 point increase, 95% CI 0.05-0.37, p=.01).

CONCLUSIONS

Most patients undergoing surgery for DCM expect prevention of neurological decline, better functional status, and improvement in their myelopathic symptoms. Stopping neurological deterioration is the most important expected outcomes by patients.

Does Ending a Posterior Construct Proximally at C2 Versus C3 Impact Patient Reported Outcomes in Degenerative Cervical Myelopathy Patients up to 24 months After the Surgery?

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The primary objective was to evaluate the impact of the upper instrumented level (UIV) being at C2 vs C3 in posterior cervical construct on patient reported outcomes (PROs) up to 24 months after surgery for cervical degenerative myelopathy (DCM). Secondary objectives were to compare operative time, intra-operative blood loss (IOBL), length of stay (LOS), adverse events (AEs) and re-operation.

METHODS

Patients who underwent a posterior cervical instrumented fusion (3 and + levels) with a C2 or C3 UIV, with 24 months follow-up were analyzed. PROs (NDI, EQ5D, SF-12 PCS/MCS, NRS arm/neck pain) were compared using ANCOVA. Operative duration, IOBL, AEs, and re-operation were compared. Subgroup analysis was performed on patient presenting with pre-operative malalignment (cervical sagittal vertical axis ≥40 mm and/or T1slope- cervical lordosis >15°).

RESULTS

173 patients were included, of which 41 (24%) had a C2 UIV and 132 (76%) a C3 UIV. There was no statistically significant difference between the groups for the changes in PROs up to 24 months. Subgroup analysis of patients with pre-operative malalignment showed a trend towards greater improvement in the NDI at 12 months with a C2 UIV (P = .054). Operative time, IOBL and peri-operative AEs were more in C2 group (P < .05). There was no significant difference in LOS and re-operation (P > .05).

CONCLUSION

In this observational study, up to 24 months after surgery for posterior cervical fusion in DCM greater than 3 levels, PROs appear to evolve similarly.

Monocentric Retrospective Analysis of Clinical Outcomes, Complications, and Adjacent Segment Disease in 507 Patients Undergoing Anterior Cervical Discectomy and Fusion for Degenerative Cervical Myelopathy

BACKGROUND

Degenerative cervical myelopathy (DCM) is a leading cause of nontraumatic spinal cord injury. Surgery aims to arrest neurological decline and improve conditions, but controversies surround risks and benefits in elderly patients, outcomes in mild myelopathy, and the risk of adjacent segment disease (ASD).

METHODS

Retrospective data of patients who underwent anterior cervical discectomy and fusion for DCM in our hospital were collected. Patients were stratified by preoperative modified Japanese Orthopaedic Association (mJOA) (mild, moderate, severe) and age (under 70, over 70). Clinical outcomes, complications, and ASD rate were analyzed. We evaluated the relationship between mJOA recovery rate and the risk of complications and various preoperative parameters.

RESULTS

Five hundred seven consecutive patients were included in the study, with a mean follow-up of 43.52 months (12-71). Improvement in all outcome variables was observed in mild, moderate, and severe myelopathy categories, with elderly patients showing a lower improvement. Except for age, no other variable correlated with mJOA recovery rate. We observed 45 complications (11.1% of patients), with 14 in the U70 group and 31 in the O70 group (P value < 0.001). Age, Charlson comorbidity index, and ASA score were found to be predictors of complications. Fourteen patients (2.8% of total), mean age 54.2, developed radiological and clinical ASD. Most had cranial-level ASD with Pfirmann grade ≥ 2 before index surgery.

CONCLUSIONS

Most myelopathic patients improve after anterior cervical discectomy and fusion. Elderly patients show a lower improvement and higher complication rates than their younger counterparts. ASD rates are low, and younger patients with preexisting cranial level alterations are more susceptible.

Degenerative Cervical Myelopathy Awareness in Primary Care: UK National Cross-Sectional Survey of General Practitioners

BACKGROUND

Degenerative cervical myelopathy (DCM) is a progressive neurological condition, characterized by spinal cord injury secondary to degenerative changes in the spine. Misdiagnosis in primary care forms part of a complex picture leading to an average diagnostic delay of 2 years. This leads to potentially preventable and permanent disability. A lack of awareness secondary to deficits in postgraduate education may contribute to these delays.

OBJECTIVE

This study aims to assess the awareness of DCM in the setting of general practice.

METHODS

General practitioners completed a quantitative web-based cross-sectional questionnaire. The 17-item questionnaire captured data regarding demographics, subjective awareness, and objective knowledge. The questionnaire was disseminated via professional networks, including via practice managers and senior practice partners. Incentivization was provided via a bespoke DCM fact sheet for those that completed the survey.

RESULTS

A total of 54 general practitioners representing all 4 UK nations responded to the survey. General practitioners most commonly self-assessed that they had "limited awareness" of DCM (n=24, 51%). General practitioners felt most commonly "moderately able" to recognize a case of DCM (n=21, 46%). In total, 13% (n=6) of respondents reported that they would not be at all able to recognize a patient with DCM. Respondents most commonly reported that they were "moderately confident" in their ability to triage a patient with DCM (n=19, 41%). A quarter of respondents reported no prior introduction to DCM throughout their medical training (n=13, 25%). The mean score for knowledge-based questions was 42.6% (SD 3.96%) with the lowest performance observed in patient demographic and clinical recognition items.

CONCLUSIONS

General practitioners lack confidence in the recognition and management of DCM. These findings are consistent with the diagnostic delays previously described in the literature at the primary care level. Further work to develop and implement educational interventions to general practitioner practices is a crucial step to improving patient outcomes in DCM.

Identifying and exploring the favorable factors that help to slow the progression of disease in patients with mild cervical spondylotic myelopathy

To explore the favorable factors that help slow the progression of disease in patients with mild Cervical Spondylotic Myelopathy (CSM). A retrospective analysis was conducted, involving the enrollment of 115 CSM patients. The categorization of patients into two groups was based on the duration of symptoms, assessments using the mJOA scale and Health Transition (HT) scores: mild-slow group and severe-rapid group. We found that the patients in both groups had similar degrees of spinal cord compression, but mild-slow group were older and had smaller C2-C7 cobb angle (Flexion) (CL(F)), C2-C7 cobb angle (Range of motion) (CL(ROM)), Transverse area (TA), Normal-TA, Compressive spinal canal area (CSCA), Normal-Spinal canal area (Normal-SCA) and lower Spinal cord increased signal intensity (ISI) Grade than the severe-rapid group. A binary logistic regression analysis showed that CL(ROM) and Normal-TA are favorable factors to help slow the progression of disease patients with mild CSM. Through ROC curves, we found that when CL(ROM) < 39.1° and Normal-TA < 80.5mm2, the progression of disease in CSM patients may be slower. Meanwhile, we obtained a prediction formula by introducing joint prediction factor: L = CL(ROM) + 2.175 * Normal-TA. And found that when L < 213.0, the disease progression of patients may be slower which was superior to calculate CL(ROM) and Normal-TA separately.

Machine learning-based cluster analysis identifies four unique phenotypes of patients with degenerative cervical myelopathy with distinct clinical profiles and long-term functional and neurological outcomes

BACKGROUND

Degenerative cervical myelopathy (DCM), the predominant cause of spinal cord dysfunction among adults, exhibits diverse interrelated symptoms and significant heterogeneity in clinical presentation. This study sought to use machine learning-based clustering algorithms to identify distinct patient clinical profiles and functional trajectories following surgical intervention.

METHODS

In this study, we applied k-means and latent profile analysis (LPA) to identify patient phenotypes, using aggregated data from three major DCM trials. The combination of Nurick score, NDI (neck disability index), neck pain, as well as motor and sensory scores facilitated clustering. Goodness-of-fit indices were used to determine the optimal cluster number. ANOVA and post hoc Tukey's test assessed outcome differences, while multinomial logistic regression identified significant predictors of group membership.

FINDINGS

A total of 1047 patients with DCM (mean [SD] age: 56.80 [11.39] years, 411 [39%] females) had complete one year outcome assessment post-surgery. Latent profile analysis identified four DCM phenotypes: "severe multimodal impairment" (n = 286), "minimal impairment" (n = 116), "motor-dominant" (n = 88) and "pain-dominant" (n = 557) groups. Each phenotype exhibited a unique symptom profile and distinct functional recovery trajectories. The "severe multimodal impairment group", comprising frail elderly patients, demonstrated the worst overall outcomes at one year (SF-36 PCS mean [SD]: 40.01 [9.75]; SF-36 MCS mean [SD], 46.08 [11.50]) but experienced substantial neurological recovery post-surgery (ΔmJOA mean [SD]: 3.83 [2.98]). Applying the k-means algorithm yielded a similar four-class solution. A higher frailty score and positive smoking status predicted membership in the "severe multimodal impairment" group (OR 1.47 [95% CI 1.07-2.02] and 1.58 [95% CI 1.25-1.99, respectively]), while undergoing anterior surgery and a longer symptom duration were associated with the "pain-dominant" group (OR 2.0 [95% CI 1.06-3.80] and 3.1 [95% CI 1.38-6.89], respectively).

INTERPRETATION

Unsupervised learning on multiple clinical metrics predicted distinct patient phenotypes. Symptom clustering offers a valuable framework to identify DCM subpopulations, surpassing single patient reported outcome measures like the mJOA.

FUNDING

No funding was received for the present work. The original studies were funded by AO Spine North America.

Trends in Indications and Contraindications for Cervical Disk Arthroplasty from 2009 to 2019

STUDY DESIGN

Cross-sectional study.

OBJECTIVE

Assess trends of indications and contraindications for the use of Cervical Disk Arthroplasty (CDA).

SUMMARY OF BACKGROUND DATA

As spine surgeons become more familiar with CDA, there have been expansions in indications.

METHODS

The Medicare Provider Analysis and Review Limited Data Sets for 2009, 2014, and 2019 were utilized. Patients undergoing elective CDA were included. Diagnosis for index surgery and "contraindications" as defined by original CDA Investigative Device Exemption (IDE) criteria were assessed. Variables were identified by the International Classification of Diseases (ICD)-9 or ICD-10 diagnosis and procedural codes.

RESULTS

A total of 1067 elective CDA patients were included. There were 230 patients in 2009, 300 patients in 2014, and 537 patients in 2019. The proportion of patients aged >65 increased from 35% to 51% ( P <0.001). Incidence of CDA for radiculopathy increased from 57% to 69% ( P <0.001), myelopathy increased from 23% to 78% ( P <0.001), and spondylosis without radiculopathy or myelopathy decreased from 19% to 3% ( P <0.001). There were increased incidences of ankylosing spondylitis (0.4% to 2.8%, P =0.007), long-term steroid use (1% to 2%, P =0.039), morbid obesity (2% to 6%, P =0.019), and osteoporosis (1% to 5%, P =0.014). The incidence of hybrid CDA and anterior cervical discectomy and fusion (ACDF) decreased from 28% to 23% ( P =0.007).

CONCLUSION

From 2009 to 2019, the number of CDA performed in older patients increased. An increase in the use of CDA for the treatment of myelopathy and radiculopathy and a decrease in the treatment of isolated cervical spondylosis was observed. The proportion of CDA performed in patients with original IDE trial "contraindications" increased. Further research into the efficacy of CDA for patients with contraindications is warranted.

Clinical Effectiveness of Anterior Cervical Discectomy and Fusion Using Tritanium C Anterior Cervical Cage vs. PEEK Cage

Introduction

Anterior cervical discectomy and fusion (ACDF) has proven to be a clinically efficient and cost-effective method for treating patients with degenerative cervical spine conditions. New intervertebral implant products are being developed to improve fusion and stability while decreasing complications. This study assesses the effectiveness of Tritanium C (Tri-C) Anterior Cervical Cage (Stryker) in the treatment of degenerative disk disease (DDD) of the cervical spine compared with polyetheretherketone (PEEK) cages.

Methods

A retrospective cohort analysis was conducted using data prospectively collected from two institutions. Patients who underwent ACDFs for DDD using either the Tri-C cage or PEEK cage were identified. The patients' demographics, comorbidities, operative variables, and baseline patient-reported outcomes (PROs) were collected. PROs included the Neck Disability Index (NDI) and numeric rating scale (NRS) for neck and arm pain. The primary outcomes included 3- and 12-month PROs as well as the rates of 90-day readmission, 90-day reoperation, and perioperative complication. The radiographic outcomes included rates of subsidence, cage movement, and successful fusion within 12 months. Multivariate linear regression models were run to identify variables predictive of 12-month PROs.

Results

A total of 275 patients who underwent ACDF were included in this study and were divided into two groups: PEEK (n=213) and Tri-C (n=62). Both groups showed improvement in neck and arm pain and NDI postoperatively. When Tri-C and PEEK were compared, no significant differences were observed in the 3- or 12-month changes in neck or arm pain or NDI. Furthermore, there were no differences in the rates of 90-day readmission, 90-day reoperation, and perioperative complication. Regression analysis revealed that Tri-C vs. PEEK was not a significant predictor of any outcome.

Conclusions

Our results indicate that the use of porous titanium Tri-C cage during ACDFs is an effective method for managing cervical DDD in terms of PROs, perioperative morbidity, and radiologic parameters. No significant difference was observed in any clinical outcome between patients undergoing ACDF using the Tri-C cage and those in whom the PEEK cage was used.

Level of Evidence

III.

Preliminarily exploring the intraoperative ultrasonography characteristics of patients with degenerative cervical myelopathy

BACKGROUND

How to quickly read and interpret intraoperative ultrasound (IOUS) images of patients with degenerative cervical myelopathy (DCM) to obtain meaningful information? Few studies have systematically explored this topic.

PURPOSE

To systematically and comprehensively explore the IOUS characteristics of patients with DCM.

MATERIALS AND METHODS

This single-center study retrospectively included patients with DCM who underwent French-door laminoplasty (FDL) with IOUS guidance from October 2019 to March 2022. One-way ANOVA and Pearson's /Spearman's correlation analysis were used to analyze the correlations between the cross-sectional area of the spinal cord (SC) and individual characteristics; the relationships between the morphology, echogenicity, pulsation, decompression statuses, compression types of SC, location of the spinal cord central echo complex (SCCEC) and the disease severity (the preoperative Japanese Orthopedic Association score, preJOA score); the difference of the spinal cord pulsation amplitude(SCPA) and the SCCEC forward movement rate (FMR) between the compressed areas(CAs) and the non-compressed areas (NCAs).

RESULTS

A total of 38 patients were successfully enrolled (30 males and 8 females), and the mean age was 57.05 ± 10.29 (27-75) years. The cross-sectional area of the SC was negatively correlated with age (r = - 0.441, p = 0.006). The preJOA score was significantly lower in the heterogeneous group than in the homogeneous group (P < 0.05, p = 0.005). The hyperechoic area (HEA) was negatively while the SCCEC FMR was positively correlated with the preJOA score (r = - 0.334, p = 0.020; r = 0.286, p = 0.041). The SCCEC FMR and SCPA in CAs were significantly greater than those in NCAs (p < 0.05, p = 0.007; P < 0.001, P = 0.000).

CONCLUSION

The cross-sectional area of the SC decreases with age in adults. More changes in intramedullary echogenicity and less moving forward of the SCCEC often indicate poor SC status, and the SCCEC FMR and SCPA are more pronounced in CAs.

Association between grip strength and walking pace with incidence of degenerative cervical myelopathy: a UK biobank observational study

PURPOSE

This study investigates the association between handgrip strength, walking pace, and the incidence of degenerative cervical myelopathy (DCM) using the UK Biobank dataset.

METHODS

We analyzed data from 364,716 UK Biobank participants without prior neurological conditions. Handgrip strength was measured with a dynamometer, and walking pace was self-reported. Cox proportional hazards models assessed hazard ratios (HRs) and 95% confidence intervals (CIs) for DCM development.

RESULTS

The cohort, with an average age of 56.2 years (SD, 8.1) and 47.4% male, was followed for a median of 12.6 years. During this period, 3,993 participants (1.1%) developed DCM. A significant inverse correlation was found between handgrip strength and DCM incidence (P for trend < 0.001), with decreasing HRs for DCM across quartiles of increasing grip strength: HRs were 0.70 (95% CI: 0.64-0.76), 0.62 (95% CI: 0.57-0.68), and 0.59 (95% CI: 0.54-0.66) for the second, third, and fourth quartiles, respectively. Participants with average or brisk walking paces had a lower DCM risk (HR, 0.55; 95% CI: 0.50-0.61 and HR, 0.48; 95% CI: 0.43-0.54) compared to slow walkers. The greatest risk reduction was in those with both higher handgrip strength and faster pace (HR, 0.39; 95% CI: 0.34-0.44).

CONCLUSIONS

Handgrip strength and walking pace are inversely associated with DCM incidence, suggesting their potential as cost-effective screening tools for identifying individuals at risk for DCM.

Flipping the mJOA: Clinical utility of the modified Japanese Orthopaedic Association score as a tool for detecting degenerative cervical myelopathy

Introduction

People with Degenerative Cervical Myelopathy (DCM) often experience diagnostic delay. This could lead to poorer outcomes, including disability.

Research question

Does the modified Japanese Orthopaedic Association scale (mJOA) have clinical utility as an early detection tool for possible DCM?

Materials and methods

This is a prospective study of consecutive adult patients, referred to a National Neurosurgical Centre with a neck problem. Assessing clinicians undertook standard clinical examination and calculated the mJOA score. A consultant radiologist independently reported radiological findings, after which the assessing clinician determined the diagnosis. The sensitivity and specificity of mJOA for DCM at various cut-points was statistically analysed using Receiver Operating Characteristics (ROC) curves.

Results

Of 201 patients (98 male, mean age 52.6 ± 13y) assessed over 13 months, 21 were diagnosed with DCM (prevalence 10.4%). Fifteen (71.4%) had a mJOA score classifying disease severity as mild, 4/21 (19%) had moderate disease and two (9.5%) had severe disease. A mJOA score ≤17 (cutpoint ≥1) showed sensitivity of 95% and specificity of 71% for the clinical diagnosis of DCM. mJOA score ≤16 (cutpoint ≥2) had sensitivity of 62% and specificity of 90%. The ROC area under the curve was 0.885 (95% confidence interval: 0.82 to 0.95). 87% of patients were correctly classified.

Discussion and conclusion

mJOA score ≤16 is 90% specific for a subsequent diagnosis of DCM in people with neck problems and has potential to be used as an early detection tool. Further research is needed to replicate these findings and establish feasibility and acceptability in primary care.

Change of cervical flexion range of motion influences postoperative sagittal alignment of the cervical spine after laminoplasty

OBJECTIVE

The relationships between preoperative cervical spine range of motion (ROM) and postoperative cervical sagittal alignment (CSA), and clinical outcomes after laminoplasty (LMP) have been widely studied. However, the impact of ROM changes on postoperative CSA and clinical outcomes after LMP remains unclear. Herein, patients with cervical spondylotic myelopathy (CSM) were retrospectively analyzed to explore the association between postoperative cervical ROM changes and CSA and surgical outcomes.

METHODS

Patients who underwent cervical LMP at our hospital between January 2019 to June 2022 were retrospectively reviewed. CSA parameters were measured before the surgery and at the final follow-up. Loss of cervical lordosis (LCL) was defined as preoperative cervical lordosis (CL) - postoperative CL. An increase in the cervical sagittal vertical axis (I-cSVA) was defined as postoperative cervical sagittal vertical axis (cSVA) - preoperative cSVA. We defined the changes in cervical flexion range of motion (△Flex ROM, preoperative Flex ROM minus postoperative Flex ROM) > 10° as L- Flex ROM group, and △Flex ROM ≤ 10° as S- Flex ROM group. Japanese Orthopedic Association (JOA) score and visual analog score (VAS) were used to assess the surgical outcomes.

RESULTS

The study comprised 74 patients and the average follow-up period was 31.83 months. CL, total ROM, and Flex ROM decreased and cSVA increased after cervical LMP. LCL and I-cSVA were positively correlated with △Flex. Multiple linear regression analysis showed that a decrease in the Flex ROM was a risk factor for LCL and I-cSVA after LMP. LCL and I-cSVA were higher in the L-Flex ROM group than in the S-Flex ROM group. Postoperative JOA and the JOA recovery rate were worse in the L-Flex ROM group than in the S-Flex ROM group.

CONCLUSIONS

Cervical total and Flex ROM decreased after cervical LMP. The reduction of Flex ROM was associated with LCL and I-cSVA after surgery. The preservation of cervical Flex ROM helps maintain CSA after LMP. Therefore, more attention should be paid to maintaining cervical ROM to obtain good CSA and surgical effects after cervical LMP.

Neurodegeneration within the rostral spinal cord is associated with brain gray matter volume atrophy in the early stage of cervical spondylotic myelopathy

STUDY DESIGN

Case-control study.

OBJECTIVES

Investigating the association between neurodegeneration within rostral spinal cord and brain gray matter volume (GMV) and assessing the relationship between remote neurodegenerative changes and clinical outcomes at the early phase of Cervical Spondylotic Myelopathy (CSM).

SETTING

University/hospital.

METHODS

Using Spinal Cord Toolbox, spinal cord morphometrics (cross-sectional area [CSA], gray matter area [GMA], white matter area [WMA]) of 40 patients with CSM and 28 healthy controls (HCs) were computed and compared using two-sample t test. Brain GMV of the two groups was analyzed using voxel-based morphometry approach. Pearson's correlation between spinal cord morphometrics and altered brain GMV and Spearman's relationship between remote neurodegenerations and clinical outcomes were conducted in CSM group.

RESULTS

Compared to HCs, CSA and WMA at C2/3 and GMV in right postcentral gyrus (PoCG.R) and left supplementary motor area (SMA.L) were significantly decreased in patients with CSM. CSA and WMA at C2/3 were associated with GMV in SMA.L and MCG.R in patients with CSM. CSA at C2/3 and GMV in PoCG.R were related to modified Japanese Orthopedic Association score in patients with CSM.

CONCLUSIONS

The associations between CSA and WMA at C2/3 and GMV in SMA.L and MCG.R suggest a concordant change pattern and adaptive mechanisms for neuronal plasticity underlying remote neurodegeneration in early CSM. The atrophy of CSA at C2/3 and GMV loss in PoCG.R can serve as potential neuroimaging biomarkers of early structural changes within spinal cord and brain preceding marked clinical disabilities in patients with CSM.

The Effect of Cervical and Lumbar Decompression Surgery for Spinal Stenosis on Erectile Dysfunction

STUDY DESIGN

Observational study.

OBJECTIVES

To evaluate the prevalence of erectile dysfunction and evaluate the effects of decompressive surgery on erectile dysfunction in cervical spinal stenosis and lumbar canal stenosis patients.

METHODS

This observational, prospective analysis enrolled patients aged 18-80 with cervical spinal stenosis and/or lumbar canal stenosis that underwent respective decompressive surgery. The IIEF-5 questionnaire was administered preoperatively, and at 6- and 12-months postoperatively to assess erectile dysfunction severity. The EPIC database was queried to determine any postoperative complications and document prominent erectile dysfunction risk factors.

RESULTS

Of 79 patients included in the analysis, 42 (53.2%) completed the IIEF-5 at 6 months, and 62 (78.5%) completed it at 12 months. Eighteen had cervical stenosis only, 54 had lumbar stenosis only, and 7 had both. 72% (18/25) of cervical stenosis patients and 83.6% (51/61) of lumbar stenosis patients had erectile dysfunction preoperatively according to IIEF-5 responses. The average preoperative IIEF-5 score indicated significant presence of erectile dysfunction for both the cervical and lumbar stenosis groups. No significant differences were identified in IIEF-5 score deltas from pre- to both postoperative periods. The presence of erectile dysfunction in both the cervical and lumbar stenosis groups was not significantly associated with the presence of any documented risk factors.

CONCLUSIONS

Our results suggest no significant improvement in overall erectile function postoperatively for patients with preoperative erectile dysfunction. This is important to address during patient counseling for decompression surgery candidates with cervical spinal stenosis and/or lumbar canal stenosis to manage expectations.

Patients with cervical spondylotic myelopathy and dependency in activities of daily living during hospitalization-descriptive and correlational study

Background and Aim

Cervical spondylotic myelopathy (CSM) causes progressive spinal cord compression and consequent functional decline. Surgical decompression is considered effective in halting disease progression, producing improvements in neurological prognosis. During hospitalization, several conditions may alter these patients' dependency levels. This study aimed to describe patients with CSM and their evolution regarding dependence in activities of daily living (ADL), from hospital admission to discharge.

Methods and Materials

Descriptive and correlational study based on document analysis.

Results

Included 96 files of patients with CSM who were admitted to Neurosurgery Department. The sample was 58.3% men, with a mean age of 64.4 years. Of the participants, 96.9% had surgery, mainly an anterior cervical approach. Hygiene was the ADL involving most dependence, both at admission (39.6%) and at discharge (71.9%). Worsening of dependence levels in ADLs was found at the midterm evaluation (mean 13.34; SD 5.59) and at discharge (mean 11.59; SD 5.28) in relation to the functional condition at admission (mean 9.77; SD 6.06). Gender was not associated with any differences, but age and days of hospitalization were associated with variations in participants' dependency levels (P<.05).

Conclusion

The level of dependence on ADLs increased during the hospitalization of patients with CSM.

Predictive value of intraoperative contrast-enhanced ultrasound in functional recovery of non-traumatic cervical spinal cord injury

OBJECTIVES

To evaluate the ability of intraoperative CEUS to predict neurological recovery in patients with degenerative cervical myelopathy (DCM).

METHODS

Twenty-six patients with DCM who underwent laminoplasty and intraoperative ultrasound (IOUS) were included in this prospective study. The modified Japanese Orthopaedic Association (mJOA) scores and MRI were assessed before surgery and 12 months postoperatively. The anteroposterior diameter (APD), maximum spinal cord compression (MSCC), and area of signal changes in the cord at the compressed and normal levels were measured and compared using MRI and IOUS. Conventional blood flow and CEUS indices (time to peak, ascending slope, peak intensity (PI), and area under the curve (AUC)) at different levels during IOUS were calculated and analysed. Correlations between all indicators and the neurological recovery rate were evaluated.

RESULTS

All patients underwent IOUS and intraoperative CEUS, and the total recovery rate was 50.7 ± 33.3%. APD and MSCC improved significantly (p < 0.01). The recovery rate of the hyperechoic lesion group was significantly worse than that of the isoechoic group (p = 0.016). 22 patients were analysed by contrast analysis software. PI was higher in the compressed zone than in the normal zone (24.58 ± 3.19 versus 22.43 ± 2.39, p = 0.019). ΔPI compress-normal and ΔAUC compress-normal of the hyperechoic lesion group were significantly higher than those of the isoechoic group (median 2.19 versus 0.55, p = 0.017; 135.7 versus 21.54, p = 0.014, respectively), and both indices were moderately negatively correlated with the recovery rate (r =  - 0.463, p = 0.030; r =  - 0.466, p = 0.029).

CONCLUSIONS

Signal changes and microvascular perfusion evaluated using CEUS during surgery are valuable predictors of cervical myelopathy prognosis.

CLINICAL RELEVANCE STATEMENT

In the spinal cord compression area of degenerative cervical myelopathy, especially in the hyperechoic lesions, intraoperative CEUS showed more significant contrast agent perfusion than in the normal area, and the degree was negatively correlated with the neurological prognosis.

KEY POINTS

• Recovery rates in patients with hyperechoic findings were lower than those of patients without lesions detected during intraoperative ultrasound. • The peak intensity of CEUS was higher in compressed zones than in the normal parts of the spinal cord. • Quantitative CEUS comparisons of the peak intensity and area under the curve at the compressed and normal levels of the spinal cord revealed differences that were inversely correlated to the recovery rate.

Preoperative Cervical Range of Motion in Flexion as a Risk Factor for Postoperative Cervical Sagittal Imbalance After Laminoplasty

STUDY DESIGN

Retrospective study.

OBJECTIVE

To investigate factors associated with cervical sagittal imbalance (CSI) after cervical laminoplasty (LMP).

SUMMARY OF BACKGROUND DATA

Preoperative dynamic cervical sagittal alignment is an important predictor for changes in cervical sagittal alignment and clinical outcomes after LMP. However, the impact of preoperative dynamic cervical sagittal alignment on postoperative changes in the cervical sagittal vertical axis (cSVA) after LMP remains unclear. We hypothesized that preoperative cervical flexion and extension function are associated with the changes in cSVA and clinical outcomes and found potential risk factors for post-LMP CSI.

PATIENTS AND METHODS

Patients undergoing LMP at a single institution between January 2019 and December 2021 were retrospectively reviewed. The average follow-up period was 19 months. The parameters were collected before the surgery and at the final follow-up. We defined the changes in cSVA (△cSVA) ≤ -10 mm as the improvement group, -10 mm < △cSVA ≤ 10 mm as the stable group, and △cSVA > 10 mm as the deterioration group. Multivariate logistic regression was used to evaluate factors associated with postoperative CSI. The χ 2 test was used to compare categorical data between groups. T tests, analysis of variance, Kruskal-Wallis tests, and Mann-Whitney Wilcoxon tests were used to assess the differences between radiographic and clinical parameters among groups. A receiver operating characteristic curve analysis was used to identify optimal cutoff values.

RESULTS

The study comprised 102 patients with cervical spondylotic myelopathy. The Japanese Orthopedic Association recovery rate was better in the improvement group and a significant aggravation in neck pain was observed in the deterioration group after surgery. Cervical Flex range of motion (ROM; spine range of flexion) was significantly higher in the deterioration group. The multivariate logistic regression model suggested that greater Flex ROM and starting LMP at C3 were significant risk factors for postoperative deterioration of cervical sagittal balance. Receiver operating characteristic curves showed that the cutoff value for preoperative Flex ROM was 34.10°.

CONCLUSION

Preoperative dynamic cervical sagittal alignment influences postoperative cervical sagittal balance after LMP. Cervical LMP should be carefully considered for patients with a preoperative high Flex ROM, as CSI is likely to occur after surgery.

LEVEL OF EVIDENCE

Level 3.

Prevalence of Neck Pain in Patients with Degenerative Cervical Myelopathy and Short-Term Response After Operative Treatment: A Cohort Study of 664 Patients From 26 Global Sites

STUDY DESIGN

Ambispective cohort study.

OBJECTIVES

1) To define the prevalence of neck pain in patients with degenerative cervical myelopathy (DCM). 2) To identify associated factors of preoperative neck pain in patients with DCM. 3) To assess the neck pain response to surgical intervention.

METHODS

757 patients with DCM were enrolled at 26 global sites from 2005 to 2011. A total of 664 patients had complete neck pain scores preoperatively (Neck Disability Index, NDI). The prevalence and severity of neck pain preoperatively and at the 6-months follow-up was summarized. Functional assessments of individuals with and without pain were compared. Associations of preoperative neck pain and related factors were evaluated.

RESULTS

Preoperatively, 79.2% of patients reported neck pain while 20.8% had no neck pain. Of individuals with neck pain, 20.2% rated their pain as very mild, 27.9% as moderate, 19.6% as fairly severe, 9.6% as very severe and 1.9% as the worst imaginable. Functional status (mJOA), number of stenotic levels, age, and duration of symptoms did not significantly differ in patients with and without pain. Factors associated with the presence of neck pain were female gender, BMI ≥27 kg/m2, rheumatologic and gastrointestinal comorbidities, and age <57 years. Neck pain improved significantly from the preoperative examination to the 6-months postoperative follow-up (P < .0001).

CONCLUSION

Here, we demonstrate a high prevalence of neck pain in patients with DCM as well as a link between gender, body weight, comorbidity and age. We highlight a significant reduction in neck pain 6 months after surgery.

Residual Paresthesia After Surgery for Degenerative Cervical Myelopathy: Incidence and Impact on Clinical Outcomes and Satisfaction

STUDY DESIGN

Multicenter, prospective cohort study.

OBJECTIVE

The current study aimed to identify the incidence of residual paresthesias after surgery for degenerative cervical myelopathy (DCM), and to demonstrate the impact of these symptoms on clinical outcomes and patient satisfaction.

SUMMARY OF BACKGROUND DATA

Surgery for DCM aims to improve and/or prevent further deterioration of physical function and quality-of-life (QOL) in the setting of DCM. However, patients are often not satisfied with their treatment for myelopathy when they have severe residual paresthesias, even when physical function and QOL are improved after surgery.

MATERIALS AND METHODS

The authors included 187 patients who underwent laminoplasty for DCM. All patients were divided into two groups based on their visual analog scale score for paresthesia of the upper extremities at one year postoperatively (>40 vs. ≤40 mm). Preoperative factors, changes in clinical scores and radiographic factors, and satisfaction scales at one year postoperatively were compared between groups. The authors used mixed-effect linear and logistic regression modeling to adjust for confounders.

RESULTS

Overall, 86 of 187 patients had severe residual paresthesia at one year postoperatively. Preoperative patient-oriented pain scale scores were significantly associated with postoperative residual paresthesia ( P =0.032). A mixed-effect model demonstrated that patients with severe postoperative residual paresthesia showed significantly smaller improvements in QOL ( P =0.046) and myelopathy ( P =0.037) than patients with no/mild residual paresthesia. Logistic regression analysis identified that residual paresthesia was significantly associated with lower treatment satisfaction, independent of improvements in myelopathy and QOL (adjusted odds ratio: 2.5, P =0.010).

CONCLUSION

In total, 45% of patients with DCM demonstrated severe residual paresthesia at one year postoperatively. These patients showed significantly worse treatment satisfaction, even after accounting for improvements in myelopathy and QOL. As such, in patients who experience higher preoperative pain, multidisciplinary approaches for residual paresthesia, including medications for neuropathic pain, might lead to greater clinical satisfaction.

LEVEL OF EVIDENCE

3.

Predictors of Outcome After Surgical Decompression for mild degenerative Cervical Myelopathy -A Systematic Review

STUDY DESIGN

Systematic Reviews.

OBJECTIVES

To investigate predictors of surgical outcomes for mild Degenerative Cervical Myelopathy (DCM) by reviewing all related studies conducted at this point.

METHODS

An electronic search was carried out in PubMed, EMBASE, Scopus, and Web of Science until June 23, 2021. Full-text articles reporting surgical outcome predictors of mild DCM cases were eligible. We included studies with mild DCM which was defined as a modified Japanese Orthopaedic Association score of 15 to 17 or a Japanese Orthopaedic Association score of 13 to 16. Independent reviewers screened all the records, and discrepancies between the reviewers were solved in a session with the senior author. For risk of bias assessment, RoB 2 tool was used for randomized clinical trials and ROBINS-I for non-randomized studies.

RESULTS

After screening 6 087 manuscripts, only 8 studies met the inclusion criteria. Lower pre-operative mJOA scores and quality-of-life measurement scores were reported by multiple studies to predict better surgical outcomes compared to other groups. High-intensity pre-operative T2 magnetic resonance imaging (MRI) was also reported to predict poor outcomes. Neck pain before intervention resulted in improved patient-reported outcomes. Two studies also reported motor symptoms prior to surgery as outcome predictors.

CONCLUSION

Lower quality of life before surgery, neck pain, lower pre-operative mJOA scores, motor symptoms before surgery, female gender, gastrointestinal comorbidities, surgical procedure and surgeon's experience with specific techniques, and high signal intensity of cord in T2 MRI were the surgical outcome predictors reported in the literature. Lower Quality of Life (QoL) score and neck prior to surgery were reported as predictors of the more improved outcome, but high cord signal intensity in T2 MRI was reported as an unfavorable outcome predictor.