Pathophysiology and natural history of cervical spondylotic myelopathy

Peripheral blood RNA biomarkers can predict lesion severity in degenerative cervical myelopathy

JOURNAL/nrgr/04.03/01300535-202506000-00027/figure1/v/2024-08-05T133530Z/r/image-tiff Degenerative cervical myelopathy is a common cause of spinal cord injury, with longer symptom duration and higher myelopathy severity indicating a worse prognosis. While numerous studies have investigated serological biomarkers for acute spinal cord injury, few studies have explored such biomarkers for diagnosing degenerative cervical myelopathy. This study involved 30 patients with degenerative cervical myelopathy (51.3 ± 7.3 years old, 12 women and 18 men), seven healthy controls (25.7 ± 1.7 years old, one woman and six men), and nine patients with cervical spondylotic radiculopathy (51.9 ± 8.6 years old, three women and six men). Analysis of blood samples from the three groups showed clear differences in transcriptomic characteristics. Enrichment analysis identified 128 differentially expressed genes that were enriched in patients with neurological disabilities. Using least absolute shrinkage and selection operator analysis, we constructed a five-gene model (TBCD, TPM2, PNKD, EIF4G2, and AP5Z1) to diagnose degenerative cervical myelopathy with an accuracy of 93.5%. One-gene models (TCAP and SDHA) identified mild and severe degenerative cervical myelopathy with accuracies of 83.3% and 76.7%, respectively. Signatures of two immune cell types (memory B cells and memory-activated CD4+ T cells) predicted levels of lesions in degenerative cervical myelopathy with 80% accuracy. Our results suggest that peripheral blood RNA biomarkers could be used to predict lesion severity in degenerative cervical myelopathy.

Comparison of anterior and posterior approaches for functional improvement in cervical myelopathy: A systematic review and meta-analysis of 33,025 patients

Background

Cervical myelopathy is caused by pressure on the spinal cord in the neck, leading to pain, numbness, and balance issues. Surgery aims to decompress the spinal cord, with different approaches; anterior, posterior, or both depending on specifies. This systematic review and meta-analysis aimed to compare the risks and benefits of anterior and posterior surgical techniques.

Methods

Adhering to the PRISMA guidelines, we conducted a systematic search across the databases including PubMed, Scopus, and Web of Science for studies comparing anterior and posterior surgical approaches for cervical myelopathy. Studies that met our predefined inclusion criteria were selected by 2 independent reviewers. The methodological quality of the selected studies was assessed using NOS and Rob-2 tools and analysis was done using the Review Manager tool. One RCT and 22 cohort studies including 33,025 patients were included in the analysis.

Results

The anterior approach was associated with better neurological recovery and a greater improvement in Cobb's angle with MD of 4.18 (95%CI: 0.38, 7.91, p=.03), and 6.91 (95%CI: 1.85, 11.97, p=.007), respectively. The anterior approach showed a statistically significant decrease in VAS, and NDI scales with MD of -0.44 (95%CI: -0.75, -0.12, p=.007), and -1.91 (95%CI: -3.74, -0.09, p=.04), respectively as compared to posterior approach.

Conclusions

Studies suggest that an anterior approach for cervical myelopathy may improve nerve function, correct spinal curvature more effectively, and lead to fewer complications, less pain, reduced blood loss, and a shorter hospital stay compared to a posterior approach.

Deciphering the Role of Glial Cell-Specific Metabolites as Biomarkers in Early Cervical Myelopathy- Insights from in vivo MRS study

BACKGROUND

Early degenerative cervical myelopathy (DCM) presents a diagnostic dilemma due to its variability in presentation, overlap with other clinical conditions, and lack of specific clinical tests. Although magnetic resonance imaging (MRI) is the preferred imaging modality, its ability to detect early cervical myelopathy remains uncertain due to its inability to detect microstructural changes at an early spondylotic stage. Magnetic Resonance Spectroscopy (MRS) is a novel, non-invasive spinal imaging technique that provides metabolic and biochemical information regarding spinal cord function.

PURPOSE

This study aims to determine the diagnostic role of MRS and Diffusion Tensor Imaging (DTI) in patients with DCM. Additionally, we intend to explore the role of MRS metabolites/ratio as molecular biomarkers for the early detection of DCM.

STUDY DESIGN

Prospective observational study PATIENT SAMPLE: The study includes a sample size of 89 subjects (20 asymptomatic volunteers and 69 patients with different grades of DCM.

OUTCOME MEASURES

Predictability of MRS and DTI in identifying early DCM. The severity of myelopathy was assessed using the modified Japanese Orthopaedic Association (mJOA) score.

METHODS

The study populations were classified according to their mJOA scores: Group 1 included asymptomatic volunteers with no clinical features of cervical myelopathy. Group 2 included patients with a score of 15 to 17 (mJOA "mild") presenting with early symptoms of myelopathy, like arm pain, hand numbness and clumsiness with/ without the symptoms of radiculopathy. Group 3 included patients with mJOA "moderate" myelopathy score of 12 to 14, presenting with symptoms like gait instability and a decrease in hand dexterity. Group 4 included patients with mJOA "severe" score of less than or equal to 11, presenting with advanced symptoms like walker/wheelchair-dependence, loss of hand dexterity, and bladder disturbances. We then looked at MR Imaging in these symptomatic patients to evaluate stenosis. Single voxel MRS was placed at the C2 level, and DTI parameters were measured at the site of maximum compression. MRI parameters like the compression level, presence of signal hyperintensity, grading of stenosis, and compression ratio were also analysed in T2W MRI images.

RESULTS

Among the 89-study population, 20 asymptomatic volunteers in group 1 and 23 patients each in groups 2, 3 and 4 were included. Among the various parameters, there was a statistically significant difference between the groups for various MRS metabolite ratios, namely NAA/Cr (P= 0.008), Cho/Cr (P=0.025), Cho/NAA (P<0.001), Cr/NAA (P <0.001) and MIn/NAA (P=0.003) as well as DTI parameters namely FA (P= 0.010) and ADC (P=0.011). A significant linear correlation was observed between the severity of myelopathy (mJOA score) and the following parameters: Cho/NAA (R2=0.510, P=0.000), MIn/NAA (R2=0.393, P=0.002), Cr/NAA (R2=0.354, P=0.007), FA (R2= -0.331, P=0.012), ADC (R2=0.321, P=0.015), Cho/Cr (R2=0.289, P=0.029) and NAA (R2= -0.288, P=0.030). Among the various metabolites, we observed that the glial cell-specific metabolites (Cho, Cr and MIn) with respect to the neuron-specific metabolite, NAA, had good correlation in early identification of DCM patients presenting with mild to moderate disease severity. ROC analysis showed that glial cell-specific metabolites ratio(Cho/NAA, Cr/NAA, MIn/NAA) had good AUC for identifying both mild (0.725, 0.770, 0.765) and moderate (0.825, 0.736, 0.760) myelopathy.

CONCLUSION

Our study highlights that MRS-based Glial cell-specific metabolites ratio (Cho/NAA, Cr/NAA, and MIn/NAA) can be reliable molecular biomarkers for identifying early degenerative cervical myelopathy.

Is cervical disc arthroplasty an effective treatment option for patients with cervical spondylotic myelopathy? A matched cohort analysis compared to anterior cervical discectomy and fusion

BACKGROUND CONTEXT

Cervical spondylotic myelopathy (CSM) is a progressive condition characterized by spinal cord compression secondary to disc degeneration. While anterior cervical discectomy and fusion (ACDF) has long been considered the standard surgical treatment for CSM, loss of motion segments after this procedure may lead to sequelae, including adjacent segment disease (ASD), further propagating loss of function and the potential requirement for revision procedures. More recently, cervical disc arthroplasty (CDA) has been introduced as a motion-preserving alternative to ACDF in CSM.

PURPOSE

This study compares ACDF to CDA in patients with preoperative CSM.

STUDY DESIGN/SETTING

A matched cohort retrospective study.

PATIENT SAMPLE

About 110 patients were included in the final analysis; 55 underwent ACDF, and 55 underwent CDA.

OUTCOME MEASURES

Complication rates, myelopathic severity measured by the Nurick scale, and patient-reported outcomes measured by VAS-neck, VAS-arm, and NDI scores.

METHODS

We examined patients who underwent either one or two-level ACDF or CDA with a minimum follow-up of 2 years. Patients were matched for age, sex, comorbid conditions, preoperative myelopathy severity, and the number of indicated operative levels. Demographics, perioperative data, and complication rates were compared between the two cohorts of patients. Patient-reported outcome measures were assessed at multiple follow-up intervals.

RESULTS

No significant differences were observed in demographics or perioperative data. Overall complication rates were similar between the two cohorts (p=.167). Rates of dysphagia (p=1.00), dysphonia (p=.157), infection (p=1.00), construct failure (p=.154), heterotopic ossification (p=.132), and ASD (p=.315) were similar between the two groups. Furthermore, revision rates were similar between the two groups (p=.315). No significant differences were observed in median postoperative Nurick scores between the two cohorts (p=1.00). NDI improvements were greater in the CDA cohort (p=.040).

CONCLUSIONS

ACDF and CDA had statistically similar complication rates and improvements in myelopathic symptoms. However, patients who underwent CDA had superior PROMs to those who had undergone ACDF.

Long-Term Outcomes of One-Stage Combined Posteroanterior Procedure and Laminoplasty-Alone for Multilevel Degenerative Cervical Myelopathy With Concomitant Anterior and Posterior Compression: A Propensity Score Matching Analysis of 8-year Follow-Up

Study DesignRetrospective cohort study.ObjectiveThis study aimed to investigate the long-term outcomes of laminoplasty-alone (LP) and combined procedure (CP), consisting of laminoplasty and single-level anterior cervical discectomy and fusion, in comparable patients who had multilevel degenerative cervical myelopathy (MDCM) with concomitant anterior and posterior compression (CAPC).MethodsConsecutive MDCM patients with CAPC underwent LP or CP between 2012 and 2015 from a same surgical group were enrolled and followed up for a minimum of 8 years. Preoperative demographic, radiological, and clinical variables were collected. Propensity score matching (PSM) analysis was performed to match patients with comparable conditions. The outcomes were evaluated by postoperative Japanese Orthopedic Association (JOA) score improvement, JOA recovery rate (JOARR) and complications.ResultsA total of 230 patients were included, of whom 146 underwent LP and 84 underwent CP. After PSM, 84 pairs of comparable patients were matched. The matched groups presented fair comparability in preoperative conditions. The CP group had significantly prolonged surgery time and greater blood loss. At the final follow-up, the postoperative JOA scores of LP and CP groups were 14.51 ± 1.79 and 15.47 ± 1.81 (P < 0.001) and the JOARR were 42.5% ± 53.3% and 68.5% ± 35.4%, respectively (P < 0.001). Three (3.6%) patients in the LP group underwent reoperations because of recurrent symptoms (P = 0.081).ConclusionBoth LP and CP demonstrated considerable long-term neurological recovery in patients with CAPC. The CP showed a significantly higher JOA improvement and JOARR. The combined decompression might be a safe and effective alternative in treating MDCM with CAPC in experienced hands.

Clinical signs and symptoms for degenerative cervical myelopathy: a scoping review of case-control studies to facilitate early diagnosis among healthcare professionals with stakeholder engagement

STUDY DESIGN

Scoping Review.

OBJECTIVE

Degenerative cervical myelopathy (DCM) is a leading cause of chronic spinal cord dysfunction, with diverse clinical presentations that complicate diagnosis. Therefore, it is important to identify the signs and symptoms of DCM that demonstrate high diagnostic accuracy. This review aims to evaluate the sensitivity and specificity of signs and symptoms in diagnosing DCM.

METHODS

Articles up to June 2024 were retrieved from PubMed, EMBASE, and Cochrane databases using search terms like "degenerative cervical myelopathy", "cervical spondylotic myelopathy", "sensitivity", "specificity", and related signs and symptoms. Studies were screened based on selection criteria assessing the sensitivity and specificity of signs or symptoms using an appropriate control group.

RESULTS

Sixteen studies were included. The most sensitive signs were Tromner sign (93-97%) and hyperreflexia (15-85%). Specific signs included the Babinski sign (93-100%), Tromner sign (79-100%), clonus (96-99%), and inverted supinator sign (78-99%). Neck pain had a sensitivity of 76-94% and specificity of 11-73%. Hand incoordination showed 52% sensitivity and 92% specificity. Altered hand sensation had 76% sensitivity and 90% specificity. Upper extremity weakness had 51-75% sensitivity and 18-95% specificity. Gait imbalance exhibited 56-63% sensitivity and 52-95% specificity.

CONCLUSION

Sensitive signs like the Tromner sign and hyperreflexia are useful for screening, while specific signs such as Babinski, clonus, and the inverted supinator sign aid in confirmation of DCM. Symptoms like neck pain, hand incoordination, and altered hand sensation should heighten suspicion and guide differential diagnosis. Early and accurate diagnosis using these indicators can improve patient outcomes and reduce diagnostic delays.

Cervical spondylotic myelopathy and radiculopathy: a stepwise approach and comparative analysis of surgical outcomes: a narrative review of recent literature

Selecting the optimal surgical treatment for multilevel cervical spondylotic myelopathy and radiculopathy significantly affects symptom improvement, postoperative prognosis, and quality of life. Proper patient selection and precise surgical execution are crucial for achieving successful outcomes, considering the favorable natural course of cervical radiculopathy. Several factors must be considered, including the number of affected segments, spinal alignment, kyphosis degree, stiffness, and surgeon expertise, when determining the surgical approach for cervical spondylotic myelopathy. An anterior approach is commonly used in cases that involve fewer than three segments with mild kyphosis, whereas posterior laminoplasty or anterior cervical discectomy and fusion (ACDF) are effective for cases with more than three segments with maintained lordosis. Both the degree of stiffness and spinal cord compression need to be considered for cases with kyphotic deformity. ACDF may be suitable when anterior structures are the primary source of compression and mild kyphosis is present. The decision between laminoplasty or laminectomy and fusion depends on the kyphosis degree for multilevel compression with kyphosis. An evaluation of cervical rigidity is required for severe kyphosis, and posterior laminectomy and fusion may be effective for flexible kyphosis, whereas a staged posterior-anterior-posterior approach may be required for rigid kyphosis to address both deformity and neural compression. This review summarizes recent research and presents illustrative cases of optimal surgical decision-making for various cervical spondylotic radiculopathy and myelopathy presentations.

Preoperative Cervical Epidural Steroid Injections: Utilization and Postoperative Complications in ACDF, PCDF, and Decompression

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Identify factors associated with cervical epidural steroid injection (CESI) receipt before anterior cervical discectomy and fusion (ACDF), posterior cervical decompression and fusion (PCDF), or decompression; evaluate the association between CESI receipt and 90-day postoperative complications; and determine characteristics of CESI associated with complications.

SUMMARY OF BACKGROUND DATA

Previous literature has suggested that a preoperative CESI may increase the risk of postoperative complications. However, these studies were limited in the procedures and complications they evaluated.

METHODS

The IBM MarketScan database was queried for patients aged 18 years or older who underwent ACDF, PCDF, or cervical decompression for disc herniation, stenosis, radiculopathy, myelopathy, and/or spondylosis without myelopathy between January 1, 2014 and September 30, 2020. CESI receipt within 12 months preoperatively, injection characteristics, and postoperative complications were extracted. Multivariable logistic regression models were used to investigate associations between patient characteristics and receipt of CESI, receipt of a CESI and each 90-day postoperative complication, and CESI characteristics and each 90-day complication.

RESULTS

Among the unique patients who underwent each procedure, 20,371 ACDF patients (30.93%), 1259 (22.24%) PCDF patients, and 3349 (36.30%) decompression patients received a preoperative CESI. In all 3 cohorts, increasing age, increasing comorbidity burden, smoker status, and diagnosis of myelopathy were associated with decreased odds of preoperative CESI receipt, while female sex and diagnosis of radiculopathy and spondylosis without myelopathy were associated with increased odds. There were no meaningful between-group comparisons or significant associations between preoperative CESI receipt and any 90-day postoperative complications in multivariable models (all P >0.05).

CONCLUSIONS

This study elucidated the main determinants of CESI receipt and found no differences in the odds of developing 90-day postoperative complications, but did identify differential outcomes with regard to some injection characteristics.

LEVEL OF EVIDENCE

Level III.

Does snake-eye appearance affect the clinical outcome of ACDF in treating cervical myelopathy

PURPOSE

To explore the impact of the snake-eye appearance (SEA) on the efficacy of anterior cervical discectomy and fusion (ACDF) in treating Degenerative Cervical Myelopathy (DCM).

METHODS

A total of 316 Patients were divided into three groups, those with SEA were in the SEA group, and those with the absence of SEA were in the non-SEA group. Meanwhile, in the non-SEA group, patients with grade 1 or 2 increased signal intensity (ISI) on T2-weighted MRI were in the ISI group, and the remaining patients without ISI were in the non-ISI group. The modified Japanese Orthopaedic Association scale (mJOA) and the neurologic functional improvement rate (IR) were measured. The number of patients who achieved upper-limb motor weakness improvement was recorded and compared. Propensity score matching (PSM) was used among the three groups.

RESULTS

The postoperative JOA and IR were similar in the SEA and non-SEA group; however, they were significantly lower than in the non-ISI group after PSM(P < 0.05). Besides, only 32.1% of patients in the SEA obtained an improvement of upper-limb motor weakness, which was the lowest in three groups after PSM (60.7% in the non-SEA group and 78.6% in the non-ISI group, P < 0.05).

CONCLUSIONS

We suggested that patients with SEA tend to achieve an inadequate neurological recovery after ACDF. Besides, a SEA may be an unfavorable prognostic factor for upper extremity motor function recovery.

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.

Impact of congenital spinal stenosis on the outcome of three-level anterior cervical discectomy and fusion in patients with cervical spondylotic myelopathy: a retrospective study

PURPOSE

To investigate whether congenital cervical spinal stenosis (CCSS) affects the outcome of three-level anterior cervical discectomy and fusion (ACDF) in patients with cervical spondylotic myelopathy (CSM).

METHODS

One hundred seventeen patients with CSM who underwent three-level ACDF between January 2019 and January 2023 were retrospectively examined. Patients were grouped according to presence of CCSS, which was defined as Pavlov ratio ≤ 0.75. The CCSS and no CCSS groups comprised 68 (58.1%) and 49 (41.9%) patients, respectively.

RESULTS

The Japanese Orthopaedic Association (JOA) score did not significantly differ between the two groups at any postoperative time point (p > 0.05). The JOA improvement rate was lower in the CCSS group 1 month after surgery (41.7% vs. 45.5%, p < 0.05), but showed no difference at any follow-up time point after one month. Multivariate logistic regression identified preoperative age (OR = 10.639), JOA score (OR = 0.370), increased signal intensity (ISI) in the spinal cord on T2-weighted MRI (T2-WI) (Grade 1: OR = 6.135; Grade 2: OR = 29.892), and degree of spinal cord compression (30-60%: OR = 17.919; ≥60%: OR = 46.624) as independent predictors of a poor one year outcome (JOA recovery rate < 50%).

CONCLUSION

Although early JOA improvement is slower in the CCSS group, it does not affect the final neurological improvement at 1 year. Therefore, CCSS should not be considered a contraindication for three-level ACDF in patients with CSM. The main factors influencing one year outcome were preoperative age, JOA score, ISI grade, and degree of spinal cord compression.

Neuromonitoring Signal Changes in Degenerative Cervical Myelopathy: An Analysis of Risk Factors for Signal Drops During Posterior Cervical Decompression

OBJECTIVE

To analyze intraoperative neuromonitoring data of patients with degenerative cervical myelopathy undergoing cervical laminectomy and assess the incidence of signal drops and their risk factors.

METHODS

This retrospective observational study included patients with degenerative cervical myelopathy who underwent cervical laminectomy with intraoperative neuromonitoring between July 2018 and March 2023. We analyzed the signal changes for any correlation with the type of pathology (ossified posterior longitudinal ligament vs. cervical spondylotic myelopathy [CSM]) and clinical (severity of myelopathy, duration of symptoms) and radiological (length of cord signal changes and K-line) parameters.

RESULTS

Of 100 degenerative cervical myelopathy cases, 55 were diagnosed as OPLL and 45 as CSM. Signal drops were recorded in 26 patients-14 persistent drops and 12 transient drops. True positive drops were seen in 4 patients (2 OPLL and 2 CSM), 3 of whom had sustained bimodal drops (both somatosensory evoked potentials and motor evoked potentials). Signal drops were significantly more frequent with OPLL compared with CSM (P < 0.01). Ten of 14 persistent signal drops and 9 of 12 transient drops were seen in patients in OPLL. Continuous OPLL, negative K-line, hill type OPLL, severity of myelopathy, and longer duration of symptoms were risk factors for signal drops.

CONCLUSIONS

Patients with cervical OPLL have a higher incidence of false positive and transient signal drops after decompression compared with patients with CSM. Longer duration of symptoms, high-grade myelopathy, continuous OPLL, hill type OPLL, and negative K-line were risk factors for signal drops.

Severity of lumbar spinal stenosis does not impact responsiveness to exercise-based rehabilitation

Spine pain is a prevalent and costly condition affecting up to 85% of individuals throughout their lifetime, and spinal stenosis is one of the most debilitating sources of spine pain. Although conservative management is the first line of treatment for spinal stenosis, severe cases often are directly referred to surgical intervention due to the belief that conservative strategies delay necessary treatment. However, there are no studies supporting the premise that individuals with more severe stenosis respond poorly to conservative management. The purpose of this study was to compare improvements in pain, disability, strength, medication usage, and patient goals in response to an exercise-based physical therapy program across 1,806 individuals with mild, moderate, or severe lumbar spine stenosis. Participants demonstrated significant improvements in all variables of interest (p<0.001), and 11.5% of participants reported cessation of narcotic use with treatment. There were no significant differences in treatment response across mild, moderate, or severe stenosis groups for any outcome (p>0.546). Exercise-based rehabilitation is as beneficial in the short term for individuals presenting for nonoperative care with severe stenosis compared to their milder counterparts. Future research is needed to evaluate long term durability and cost effectiveness of rehabilitation in this patient population.

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.

Resource Utilization Following Anterior Versus Posterior Cervical Decompression and Fusion for Acute Central Cord Syndrome

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The purpose of this study is to compare the impact of anterior cervical decompression and fusion (ACDF) versus posterior cervical decompression and fusion (PCDF) for the treatment of acute traumatic central cord syndrome (CCS) on hospital episodes of care in terms of (1) cost, (2) length of hospital stay, and (3) discharge destination.

SUMMARY OF BACKGROUND DATA

Acute traumatic CCS is the most common form of spinal cord injury in the United States. CCS is commonly treated with surgical decompression and fusion. Hospital resource utilization based on surgical approach remains unclear.

METHODS

Patients undergoing ACDF and PCDF for acute traumatic CCS were identified using the 2019 Medicare Provider Analysis and Review Limited Data Set and Centers for Medicare and Medicaid Services 2019 Impact File. Multivariate models for hospital cost of care, length of stay, and discharge destination were performed, controlling for confounders. Subanalysis of accommodation and revenue center cost drivers was performed.

RESULTS

There were 1474 cases that met inclusion criteria: 673 ACDF (45.7%) and 801 PCDF (54.3%). ACDF was independently associated with a decreased cost of $9802 ( P <0.001) and a 59.2% decreased risk of discharge to nonhome destinations (adjusted odds ratio: 0.408, P <0.001). The difference in length of stay was not statistically significant. On subanalysis of cost drivers, ACDF was associated with decreased charges ($55,736, P <0.001) compared with PCDF, the largest drivers being the intensive care unit ($15,873, 28% of total charges, P <0.001) and medical/surgical supply charges ($19,651, 35% of total charges, P <0.001).

CONCLUSIONS

For treatment of acute traumatic CCS, ACDF was associated with almost $10,000 less expensive cost of care and a 60% decreased risk of discharge to nonhome destination compared with PCDF. The largest cost drivers appear to be ICU and medical/surgical-related. These findings may inform value-based decisions regarding the treatment of acute traumatic CCS. However, injury and patient clinical factors should always be prioritized in surgical decision-making, and increased granularity in reimbursement policies is needed to prevent financial disincentives in the treatment of patients with CCS better addressed with posterior approach-surgery.

Cervical kyphosis after posterior cervical laminectomy with and without fusion

BACKGROUND

Cervical posterior instrumentation and fusion is often performed to avoid post-laminectomy kyphosis. However, larger comparative analyses of cervical laminectomy with or without fusion are sparse.

METHODS

A retrospective, two-center, comparative cohort study included patients after stand-alone dorsal laminectomy with (n = 91) or without (n = 46) additional fusion for degenerative cervical myelopathy with a median follow-up of 59 (interquartile range (IQR) 52) months. The primary outcome was the C2-7 Cobb angle and secondary outcomes were Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA) scale, revision rates, T1 slope and C2-7 sagittal vertical axis (C2-7 SVA) at final follow-up. Logistic regression analysis adjusted for potential confounders (i.e. age, operated levels, and follow-up).

RESULTS

Preoperative C2-7 Cobb angle and T1 slope were higher in the laminectomy group, while the C2-7 SVA was similar. The decrease in C2-7 Cobb angle from pre- to postoperatively was more pronounced in the laminectomy group (- 6° (IQR 20) versus -1° (IQR 7), p = 0.002). When adjusting for confounders, the decrease in C2-7 Cobb angle remained higher in the laminectomy group (coefficient - 12 (95% confidence interval (CI) -18 to -5), p = 0.001). However, there were no adjusted differences for postoperative NDI (- 11 (- 23 to 2), p = 0.10), mJOA, revision rates, T1 slope and C2-7 SVA.

CONCLUSION

Posterior cervical laminectomy without fusion is associated with mild loss of cervical lordosis of around 6° in the mid-term after approximately five years, however without any clinical relevance regarding NDI or mJOA in well-selected patients (particularly in shorter segment laminectomies of < 3 levels).

Elective Single-Level Primary Anterior Cervical Decompression and Fusion for Degenerative Spondylotic Cervical Myelopathy Is Associated With Decreased Resource Utilization Versus Posterior Cervical Decompression and Fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To compare elective single-level anterior cervical discectomy and fusion (ACDF) versus posterior cervical decompression and fusion (PCDF) for degenerative cervical myelopathy (DCM) in terms of (1) cost, (2) length of hospital stay, and (3) discharge destination in Medicare patients. A sub-analysis of potential cost drivers was also performed.

BACKGROUND

In the era of value-based medicine, there is substantial interest in reducing the cost of care. Both ACDF and PCDF are used to treat DCM but carry different morbidity and risk profiles that can impact hospital resource utilization. However, this has not been assessed on a national level.

METHODS

Patients undergoing single-level elective ACDF and PCDF surgery were identified using the 2019 Medicare Provider Analysis and Review (MedPAR) Limited Data Set (LDS) and Centers for Medicare and Medicaid Services (CMS) 2019 Impact File. Multivariate models of hospital cost of care, length of stay, and discharge destination were performed, controlling for confounders. A univariate sub-analysis of 9 revenue centers was performed.

RESULTS

In all, 3942 patients met the inclusion criteria. The mean cost of elective single-level cervical fusion for myelopathy was $18,084±10,783, and the mean length of stay was 2.45±2.95 d. On multivariate analysis, ACDF was independently associated with decreased cost of $5,814 ( P <0.001), shorter length of stay by 1.1 days ( P <0.001), and decreased risk of nonhome discharge destination by 58% (adjusted odds ratio: 0.422, P <0.001).On sub-analysis of 9 revenue centers, medical/surgical supply ($10,497, 44%), operating room charges ($5401, 23%), and accommodations ($3999, 17%) were the largest drivers of charge differences.

CONCLUSIONS

Single-level elective primary ACDF for DCM was independently associated with decreased cost, decreased hospital length of stay, and a lower rate of nonhome discharge compared with PCDF. Medical and surgical supply, operating room, and accommodation differences between ACDF and PCDF are potential areas for intervention. Increased granularity in reimbursement structures is warranted to prevent the creation of disincentives to the treatment of patients with DCM with pathology that is better addressed with PCDF.

LEVEL OF EVIDENCE

Level-III Retrospective Cohort Study.

A novel minimally invasive and versatile kyphoplasty balloon-based model of porcine spinal cord injury

Introduction

Spinal cord injury (SCI) animal models often utilize an open surgical laminectomy, which results in animal morbidity and also leads to changes in spinal canal diameter, spinal cord perfusion, cerebrospinal fluid flow dynamics, and spinal stability which may confound SCI research. Moreover, the use of open surgical laminectomy for injury creation lacks realism when considering human SCI scenarios.

Methods

We developed a novel, image-guided, minimally invasive, large animal model of SCI which utilizes a kyphoplasty balloon inserted into the epidural space via an interlaminar approach without the need for open surgery.

Results

The model was validated in 5 Yucatán pigs with imaging, neurofunctional, histologic, and electrophysiologic findings consistent with a mild compression injury.

Discussion

Few large animal models exist that have the potential to reproduce the mechanisms of spinal cord injury (SCI) commonly seen in humans, which in turn limits the relevance and applicability of SCI translational research. SCI research relies heavily on animal models, which typically involve an open surgical, dorsal laminectomy which is inherently invasive and may have untoward consequences on animal morbidity and spinal physiology that limit translational impact. We developed a minimally invasive, large animal model of spinal cord injury which utilizes a kyphoplasty balloon inserted percutaneously into the spinal epidural space. Balloon inflation results in a targeted, compressive spinal cord injury with histological and electrophysiological features directly relevant to human spinal cord injury cases without the need for invasive surgery. Balloon inflation pressure, length of time that balloon remains inflated, and speed of inflation may be modified to achieve variations in injury severity and subtype.

Sex-specific alterations in functional connectivity and network topology in patients with degenerative cervical myelopathy

Patients with degenerative cervical myelopathy (DCM) experience structural and functional brain reorganization. However, few studies have investigated the influence of sex on cerebral alterations. The present study investigates the role of sex on brain functional connectivity (FC) and global network topology in DCM and healthy controls (HCs). The resting-state functional MRI data was acquired for 100 patients (58 males vs. 42 females). ROI-to-ROI FC and network topological features were characterized for each patient and HC. Group differences in FC and network topological features were examined. Compared to healthy counterparts, DCM males exhibited higher FC between vision-related brain regions, and cerebellum, brainstem, and thalamus, but lower FC between the intracalcarine cortex and frontal and somatosensory cortices, while DCM females demonstrated higher FC between the thalamus and cerebellar and sensorimotor regions, but lower FC between sensorimotor and visual regions. DCM males displayed higher FC within the cerebellum and between the posterior cingulate cortex (PCC) and vision-related regions, while DCM females displayed higher FC between frontal regions and the PCC, cerebellum, and visual regions. Additionally, DCM males displayed significantly greater intra-network connectivity and efficiency compared to healthy counterparts. Results from the present study imply sex-specific supraspinal functional alterations occur in patients with DCM.

Potential thresholds of critically increased cardiac-related spinal cord motion in degenerative cervical myelopathy

Introduction

New diagnostic techniques are a substantial research focus in degenerative cervical myelopathy (DCM). This cross-sectional study determined the significance of cardiac-related spinal cord motion and the extent of spinal stenosis as indicators of mechanical strain on the cord.

Methods

Eighty-four DCM patients underwent MRI/clinical assessments and were classified as MRI+ [T2-weighted (T2w) hyperintense lesion in MRI] or MRI- (no T2w-hyperintense lesion). Cord motion (displacement assessed by phase-contrast MRI) and spinal stenosis [adapted spinal canal occupation ratio (aSCOR)] were related to neurological (sensory/motor) and neurophysiological readouts [contact heat evoked potentials (CHEPs)] by receiver operating characteristic (ROC) analysis.

Results

MRI+ patients (N = 31; 36.9%) were more impaired compared to MRI- patients (N = 53; 63.1%) based on the modified Japanese Orthopedic Association (mJOA) subscores for upper {MRI+ [median (Interquartile range)]: 4 (4-5); MRI-: 5 (5-5); p < 0.01} and lower extremity [MRI+: 6 (6-7); MRI-: 7 (6-7); p = 0.03] motor dysfunction and the monofilament score [MRI+: 21 (18-23); MRI-: 24 (22-24); p < 0.01]. Both patient groups showed similar extent of cord motion and stenosis. Only in the MRI- group displacement identified patients with pathologic assessments [trunk/lower extremity pin prick score (T/LEPP): AUC = 0.67, p = 0.03; CHEPs: AUC = 0.73, p = 0.01]. Cord motion thresholds: T/LEPP: 1.67 mm (sensitivity 84.6%, specificity 52.5%); CHEPs: 1.96 mm (sensitivity 83.3%, specificity 65.6%). The aSCOR failed to show any relation to the clinical assessments.

Discussion

These findings affirm cord motion measurements as a promising additional biomarker to improve the clinical workup and to enable timely surgical treatment particularly in MRI- DCM patients.

Clinical trial registration

www.clinicaltrials.gov, NCT02170155.

Would the one-stage combined approach lead to better long-term neurological outcomes than the posterior approach alone in multilevel degenerative cervical myelopathy patients with T2-Weighted increased signal intensity? An 8-year follow-up results and propensity score matching analysis

BACKGROUND

T2-weighted increased signal intensity (ISI) is commonly recognized as a sign of more severe spinal cord lesions, usually accompanied by worse neurological deficits and possibly worse postoperative neurological recovery. The combined approach could achieve better decompression and better neurological recovery for multilevel degenerative cervical myelopathy (MDCM). The choice of surgical approach for MDCM with intramedullary T2-weighted ISI remains disputed. This study aimed to compare the neurological outcomes of posterior and one-stage combined posteroanterior approaches for MDCM with T2-weighted ISI.

METHODS

A total of 83 consecutive MDCM patients with confirmed ISI with at least three intervertebral segments operated between 2012 and 2014 were retrospectively enrolled. Preoperative demographic, radiological and clinical condition variables were collected, and neurological conditions were evaluated by the Japanese Orthopedic Assessment score (JOA) and Neck Disability Index (NDI). Propensity score matching analysis was conducted to produce pairs of patients with comparable preoperative conditions from the posterior-alone and combined groups. Both short-term and mid-term surgical outcomes were evaluated, including the JOA recovery rate (JOARR), NDI improvements, complications, and reoperations.

RESULTS

A total of 83 patients were enrolled, of which 38 and 45 patients underwent posterior surgery alone and one-stage posteroanterior surgery, respectively. After propensity score matching, 38 pairs of comparable patients from the posterior and combined groups were matched. The matched groups presented similar preoperative clinical and radiological features and the mean follow-up duration were 111.6 ± 8.9 months. The preoperative JOA scores of the posterior and combined groups were 11.5 ± 2.2 and 11.1 ± 2.3, respectively (p = 0.613). The combined group presented with prolonged surgery duration(108.8 ± 28.0 and 186.1 ± 47.3 min, p = 0.028) and greater blood loss(276.3 ± 139.1 and 382.1 ± 283.1 ml, p<0.001). At short-term follow-up, the combined group presented a higher JOARR than the posterior group (posterior group: 50.7%±46.6%, combined group: 70.4%±20.3%, p = 0.024), while no significant difference in JOARR was observed between the groups at long-term follow-up (posterior group: 49.2%±48.5%, combined group: 59.6%±47.6%, p = 0.136). No significant difference was found in the overall complication and reoperation rates.

CONCLUSIONS

For MDCM patients with ISI, both posterior and one-stage posteroanterior approaches could achieve considerable neurological alleviations in short-term and long-term follow-up. With greater surgical trauma, the combined group presented better short-term JOARR but did not show higher efficacy in long-term neurological function preservation in patients with comparable preoperative conditions.

Pharmacological Treatment of Degenerative Cervical Myelopathy: A Critical Review of Current Evidence

Degenerative cervical myelopathy (DCM) is the leading cause of spinal cord dysfunction in adults, representing substantial morbidity and significant financial and resource burdens. Typically, patients with progressive DCM will eventually receive surgical treatment. Nonetheless, despite advancements in pharmacotherapeutics, evidence for pharmacological therapy remains limited. Health professionals from various fields would find interest in pharmacological agents that could benefit patients with mild DCM or enhance surgical outcomes. This review aims to consolidate all clinical and experimental evidence on the pharmacological treatment of DCM. We conducted a comprehensive narrative review that presents all pharmacological agents that have been investigated for DCM treatment in both humans and animal models. Riluzole exhibits effectiveness solely in rat models, but not in treating mild DCM in humans. Cerebrolysin emerges as a potential neuroprotective agent for myelopathy in animals but had contradictory results in clinical trials. Limaprost alfadex demonstrates motor function improvement in animal models and exhibits promising outcomes in a small clinical trial. Glucocorticoids not only fail to provide clinical benefits but may also lead to adverse events. Cilostazol, anti-Fas ligand antibody, and Jingshu Keli display promise in animal studies, while erythropoietin, granulocyte colony-stimulating factor and limaprost alfadex exhibit potential in both animal and human research. Existing evidence mainly rests on weak clinical data and animal experimentation. Current pharmacological efforts target ion channels, stem cell differentiation, inflammatory, vascular, and apoptotic pathways. The inherent nature and pathogenesis of DCM offer substantial prospects for developing neurodegenerative or neuroprotective therapies capable of altering disease progression, potentially delaying surgical intervention, and optimizing outcomes for those undergoing surgical decompression.

The role of comprehensive rehabilitation in the care of degenerative cervical myelopathy

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To find out if comprehensive rehabilitation itself can improve daily performance in persons with DCM.

SETTING

The spinal department of a rehabilitation hospital.

METHODS

Data from 116 DCM inpatients who underwent comprehensive rehabilitation after spinal surgery were retrospectively analyzed. The definitions of the calculated outcome variables made possible analyses that distinguished the effect of rehabilitation from that of spinal surgery. Paired t-tests were used to compare admission with discharge outcomes and functional gains. Spearman's correlations were used to assess relationships between performance gain during rehabilitation and between time from surgery to rehabilitation.

RESULTS

The Spinal Cord Injury Ability Realization Measurement Index (SCI-ARMI) increased during rehabilitation from 57 (24) to 78 (19) (p < 0.001). The Spinal Cord Independence Measure 3rd version (SCIM III) gain attributed to neurological improvement (dSCIM-IIIn) was 6.3 (9.2), and that attributed to rehabilitation (dSCIM-IIIr) 16 (18.5) (p < 0.001). dSCIM-IIIr showed a rather weak negative correlation with time from spinal surgery to rehabilitation (r = -0.42, p < 0.001).

CONCLUSIONS

The study showed, for the first time, that comprehensive rehabilitation can achieve considerable functional improvement for persons with DCM of any degree, beyond that of spinal surgery. Combined with previously published evidence, this indicates that comprehensive rehabilitation can be considered for persons with DCM of any functional degree, before surgery.

A Comparison of Short-Term Outcomes after Surgical Treatment of Multilevel Degenerative Cervical Myelopathy in the Geriatric Patient Population: An Analysis of the National Surgical Quality Improvement Program Database 2010-2020

STUDY DESIGN

Retrospective review of the American College of Surgeons-National Surgical Quality Improvement Program database from 2010 to 2020.

PURPOSE

To compare the short-term complication rates of anterior cervical decompression and fusion (ACDF), posterior cervical laminoplasty (LP), and posterior cervical laminectomy and fusion (PCF) in a geriatric population.

OVERVIEW OF LITERATURE

The geriatric population in the United States has increased significantly. Degenerative cervical myelopathy (DCM) is caused by cervical spinal stenosis, and its prevalence increases with age. Therefore, the incidence of multilevel DCM requiring surgical intervention is likely to increase. ACDF, LP, and PCF are the most commonly used surgical techniques for treating multilevel DCM. However, there is uncertainty regarding the optimal surgical technique for the decompression of DCM in geriatric patients.

METHODS

Patients aged 65 years who had undergone either multilevel ACDF, LP, or PCF for the treatment of DCM were analyzed. Additional analysis was performed by standardizing the data for the American Society of Anesthesiologists classification scores and preoperative functional status.

RESULTS

A total of 23,129 patients were identified. Patients with ACDF were younger, more often female, and preoperatively healthier than those in the other two groups. The estimated postoperative mortality and morbidity, mean operation time, and length of hospital stay were the lowest for ACDF, second lowest for LP, and highest for PCF. The readmission and reoperation rates were comparable between ACDF and LP; however, both were significantly lower than PCF.

CONCLUSIONS

PCF is associated with the highest risk of mortality, morbidity, unplanned reoperation, and unplanned readmission in the short-term postoperative period in patients aged 65 years. In contrast, ACDF carries the lowest risk. However, some disease-specific factors may require posterior treatment. For these cases, LP should be included in the preoperative discussion when determining the ideal surgical approach for geriatric patients.

An independent agreement study of modified Pfirrmann grading system for cervical inter-vertebral disc degeneration in cervical spondylotic myelopathy

OBJECTIVE

Neck pain, sensory disturbance and motor dysfunction in most patients suffered cervical spondylotic myelopathy (CSM). For CSM surgery, it is necessary to evaluate preoperative inter-vertebral disc degeneration (IDD) which determines whether to adopt fusion strategy, and postoperative IDD which is one of the main reasons for reoperation. Modified Pfirrmann grading system is commonly used to evaluate IDD. The objective of this study is to evaluate its reliability and reproducibility on cervical IDD in CSM patients, and to explore its clinical application value.

METHODS

All 165 patients with CSM were enrolled. 6 physicians (3 spine surgeons and 3 radiologists) who have certain clinical experience were selected. They graded cervical inter-vertebral disc according to modified Pfirrmann grading system, we used intra-class correlation coefficient (ICC) and weighted kappa (wκ) to assess the inter- and intra-observer agreement. After 12 weeks, we repeated the analysis.

RESULTS

The inter-observer reliability of modified Pfirrmann grading system was excellent with an ICC value of 0.76 and near perfect with wκ value of 0.82. The intra-observer reproducibility of modified Pfirrmann grading system was excellent with ICC values ranging from 0.80 to 0.91, and near perfect with wκ values ranging from 0.83-0.92.

CONCLUSION

Modified Pfirrmann grading system has excellent inter-observer reliability and intra-observer reproducibility on cervical IDD in CSM. In addition, it indicates a good appliance among spine surgeons and radiologists, clinical and radiological studies applying it should be deemed accurate. Thus, modified Pfirrmann grading system can be widely used as an appropriate instrument in clinical care.

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.

A Pilot Study of a Finger Kinematic Parameter-Based Tool for Evaluating Degenerative Cervical Myelopathy

STUDY DESIGN

This is a cross-sectional study.

OBJECTIVE

To evaluate the effectiveness of a novel finger Kinematic Parameter-Based Tool in the grip and release (G&R) test for assessing degenerative cervical myelopathy (DCM).

SUMMARY OF BACKGROUND DATA

The development and progression of DCM symptoms are gradual and obscure. Although previous studies have objectively evaluated hand movements specific to myelopathy using the G&R test, virtual reality, or wearable sensors, these methods have limitations, such as limited discrimination or inconvenience for simple screening. Consequently, there is a need to develop effective screening methods.

MATERIALS AND METHODS

Totally, 297 asymptomatic volunteers and 258 DCM patients were enrolled. This system comprises a wearable acceleration/gyro sensor. The acceleration/gyro sensor was placed on the little finger of the participants to perform 40 cycles of full-range G&R as quickly as possible. The collected data were then transformed into kinematic parameters using sensor-based software and R studio software (version: RStudio 2022.07.2+576, Boston, USA). Gender, age, and body mass index (BMI) subgroups (classified as BMI<18.5-below normal weight; 18.5≤BMI<25-normal weight group; BMI≥25-overweight group) were matched as predictor variables, and 201 pairs were matched. Nonparametric analysis using the Mann-Whitney U test was used for diagnosing the differences between the two groups, and Kruskal-Wallis's test followed by the Mann-Whitney U test was used for analyzing the differences among three different age groups (<40, 41-60, and >60 yr group). The cut-off value of 10s G&R cycles and a combined parameter were determined using receiver operating characteristics curve analysis, area under the curve, and Youden index.

RESULTS

The authors found that little finger kinematic parameters were significantly lower in DCM patients than in asymptomatic participants. The optimal diagnostic indicator appeared to be the average of the top 10 linear accelerations with an area under the curve of 0.923.

CONCLUSION

The Finger Kinematic Test System is an objective, practical, and quantitative utility that appears to have the capacity to diagnose and evaluate the severity of DCM.

LEVEL OF EVIDENCE

3.

Predictive Value of the Diffusion Magnetic Resonance Imaging Technique for the Postoperative Outcome of Cervical Spondylotic Myelopathy

BACKGROUND

Diffusion magnetic resonsance imaging (dMRI) can potentially predict the postoperative outcome of cervical spondylotic myelopathy (CSM).

PURPOSE

To explore preoperative dMRI parameters to predict the postoperative outcome of CSM through multifactor correlation analysis.

STUDY TYPE

Prospective.

POPULATION

Post-surgery CSM patients; 102 total, 73 male (52.42 ± 10.60 years old) and 29 female (52.0 ± 11.45 years old).

FIELD STRENGTH/SEQUENCE

3.0 T/Turbo spin echo T1/T2-weighted, T2*-weighted multiecho gradient echo and dMRI.

ASSESSMENT

Spinal cord function was evaluated using modified Japanese Orthopedic Association (mJOA) scoring at different time points: preoperative and 3, 6, and 12 months postoperative. Single-factor correlation and t test analyses were conducted based on fractional anisotropy (FA), mean diffusivity, intracellular volume fraction, isotropic volume fraction, orientation division index, increased signal intensity, compression ratio, age, sex, symptom duration and operation method, and multicollinearity was calculated. The linear quantile mixed model (LQMM) and the linear mixed-effects regression model (LMER) were used for multifactor correlation analysis using the combinations of the above variables.

STATISTICAL TESTS

Distance correlation, Pearson's correlation, multiscale graph correlation and t tests were used for the single-factor correlation analyses. The variance inflation factor (VIF) was used to calculate multicollinearity. LQMM and LMER were used for multifactor correlation analyses. P < 0.05 was considered statistically significant.

RESULTS

The single-factor correlation between all variables and the postoperative mJOA score was weak (all r < 0.3). The linear relationship was stronger than the nonlinear relationship, and there was no significant multicollinearity (VIF = 1.10-1.94). FA values in the LQMM and LMER models had a significant positive correlation with the mJOA score (r = 5.27-6.04), which was stronger than the other variables.

DATA CONCLUSION

The FA value based on dMRI significantly positively correlated with CSM patient postoperative outcomes, helping to predict the surgical outcome and formulate a treatment plan before surgery.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY: Stage 2.

Structural Myelopathies

OBJECTIVE

This article illustrates the clinical importance, diagnosis, and management of degenerative and nondegenerative structural myelopathies. It also aims to create a diagnostic approach for the evaluation of patients with suspected degenerative myelopathies.

LATEST DEVELOPMENTS

There is considerable interest in developing diagnostic methods that can assist in deciding if surgery is indicated in patients with structural myelopathy and the optimal timing for surgery. Diffusion tensor imaging has emerged as a promising imaging modality although it is not used routinely in clinical practice. Neuroprotective medications and interventions are being studied in patients with degenerative myelopathies.

ESSENTIAL POINTS

Structural myelopathies and particularly degenerative myelopathies are common disorders that are routinely encountered in clinical practice, with symptoms that frequently overlap with other neurologic disorders. The prompt diagnosis and treatment of patients are essential in achieving good functional outcomes.

Degenerative Cervical Myelopathy: A Concept Review and Clinical Approach

STUDY DESIGN

Narrative review.

OBJECTIVE

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

SUMMARY OF BACKGROUND DATA

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

METHODS

An extensive literature review was conducted.

RESULTS

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

CONCLUSIONS

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

Systematic review protocol for complications following surgical decompression of degenerative cervical myelopathy

BACKGROUND

Degenerative Cervical Myelopathy (DCM) is one of the most common degenerative disorders of cervical spine and sources of cord dysfunction in adults. It usually manifests with neurologic presentations such as loss of dexterity and gait issues. Treatment for moderate and severe cases of DCM is surgical decompression of the region. There are many approaches available for surgical intervention which could be categorized into anterior and posterior based on the side of neck where operation takes place. Additionally, for certain cases the hybridized anterior-posterior combined surgery is indicated. While there are many technical differences between these approaches with each having its own advantages, the complications and safety profiles of them are not fully disclosed. This protocol aims to systematically search for current reports on complications of surgical decompression methods of DCM and pool them for robust evidence generation.

METHOD

Search will be carried out in PubMed, Scopus, and Cochrane databases for retrospective and prospective surgical series, cohorts, or trials being performed for DCM with at least a sample size of 20 patients. Query strings will be designed to capture reports with details of complications with no year limit. Studies not being original (e.g., review articles, case reports, etc.), not in English, having patients younger than 18-years-old, and not reporting at least one complication will be excluded. Two independent reviewers will review the titles and abstracts for first round of screening. Full text of retrieved studies from previous round will be screened again by the same reviewers. In case of discrepancy, the third senior reviewer will be consulted. Eligible studies will then be examined for data extraction where data will be recorded into standardized form. Cumulative incidence and 95% confidence intervals of complication will be then pooled based on generalized linear mixed models with consideration of approach of surgery as subgroups. Heterogeneity tests will be performed for assessment of risk of bias.

DISCUSSION

This systematic review is aimed at providing practical information for spine surgeons on the rates of complications of different surgical approaches of DCM decompression. Proper decision-making regarding the surgical approach in addition to informing patients could be facilitated through results of this investigation.

Resting-state functional magnetic resonance imaging indices are related to electrophysiological dysfunction in degenerative cervical myelopathy

The age-related degenerative pathologies of the cervical spinal column that comprise degenerative cervical myelopathy (DCM) cause myelopathy due spinal cord compression. Functional neurological assessment of DCM can potentially reveal the severity and pathological mechanism of DCM. However, functional assessment by conventional MRI remains difficult. This study used resting-state functional MRI (rs-fMRI) to investigate the relationship between functional connectivity (FC) strength and neurophysiological indices and examined the feasibility of functional assessment by FC for DCM. Preoperatively, 34 patients with DCM underwent rs-fMRI scans. Preoperative central motor conduction time (CMCT) reflecting motor functional disability and intraoperative somatosensory evoked potentials (SEP) reflecting sensory functional disability were recorded as electrophysiological indices of severity of the cervical spinal cord impairment. We performed seed-to-voxel FC analysis and correlation analyses between FC strength and the two electrophysiological indices. We found that FC strength between the primary motor cortex and the precuneus correlated significantly positively with CMCT, and that between the lateral part of the sensorimotor cortex and the lateral occipital cortex also showed a significantly positive correlation with SEP amplitudes. These results suggest that we can evaluate neurological and electrophysiological severity in patients with DCM by analyzing FC strengths between certain brain regions.

Classification and prognostic factors of patients with cervical spondylotic myelopathy after surgical treatment: a cluster analysis

Identifying potential prognostic factors of CSM patients could improve doctors' clinical decision-making ability. The study retrospectively collected the baseline data of population characteristics, clinical symptoms, physical examination, neurological function and quality of life scores of patients with CSM based on the clinical big data research platform. The modified Japanese Orthopedic Association (mJOA) score and SF-36 score from the short-term follow-up data were entered into the cluster analysis to characterize postoperative residual symptoms and quality of life. Four clusters were yielded representing different patterns of residual symptoms and quality of patients' life. Patients in cluster 2 (mJOA RR 55.8%) and cluster 4 (mJOA RR 55.8%) were substantially improved and had better quality of life. The influencing factors for the better prognosis of patients in cluster 2 were young age (50.1 ± 11.8), low incidence of disabling claudication (5.0%) and pathological signs (63.0%), and good preoperative SF36-physiological function score (73.1 ± 24.0) and mJOA socre (13.7 ± 2.8); and in cluster 4 the main influencing factor was low incidence of neck and shoulder pain (11.7%). We preliminarily verified the reliability of the clustering results with the long-term follow-up data and identified the preoperative features that were helpful to predict the prognosis of the patients. This study provided reference and research basis for further study with a larger sample data, extracting more patient features, selecting more follow-up nodes, and improving clustering algorithm.

Early surgery compared to nonoperative management for mild degenerative cervical myelopathy: a cost-utility analysis

BACKGROUND CONTEXT

Degenerative cervical myelopathy (DCM) is a form of acquired spinal cord compression and contributes to reduced quality of life secondary to neurological dysfunction and pain. There remains uncertainty regarding optimal management for individuals with mild myelopathy. Specifically, owing to lacking long-term natural history studies in this population, we do not know whether these individuals should be treated with initial surgery or observation.

PURPOSE

We sought to perform a cost-utility analysis to examine early surgery for mild degenerative cervical myelopathy from the healthcare payer perspective.

STUDY DESIGN/SETTING

We utilized data from the prospective observational cohorts included in the Cervical Spondylotic Myelopathy AO Spine International and North America studies to determine health related quality of life estimates and clinical myelopathy outcomes.

PATIENT SAMPLE

We recruited all patients that underwent surgery for DCM enrolled in the Cervical Spondylotic Myelopathy AO Spine International and North America studies between December 2005 and January 2011.

OUTCOME MEASURES

Clinical assessment measures were obtained using the Modified Japanese Orthopedic Association scale and health-related quality of life measures were obtained using the Short Form-6D utility score at baseline (preoperative), 6 months, 12 months and 24 months postsurgery. Cost measures inflated to January 2015 values were obtained using pooled estimates from the hospital payer perspective for surgical patients.

METHODS

We employed a Markov state transition model with Monte Carlo microsimulation using a lifetime horizon to obtain an incremental cost utility ratio associated with early surgery for mild myelopathy. Parameter uncertainty was assessed through deterministic means using one-way and two-way sensitivity analyses and probabilistically using parameter estimate distributions with microsimulation (10,000 trials). Costs and utilities were discounted at 3% per annum.

RESULTS

Initial surgery for mild degenerative cervical myelopathy was associated with an incremental lifetime increase of 1.26 quality-adjusted life years (QALY) compared to observation. The associated cost incurred to the healthcare payer over a lifetime horizon was $12,894.56, resulting in a lifetime incremental cost-utility ratio of $10,250.71/QALY. Utilizing a willingness to pay threshold in keeping with the World Health Organization definition of "very cost-effective" ($54,000 CDN), the probabilistic sensitivity analysis demonstrated that 100% of cases were cost-effective.

CONCLUSIONS

Surgery compared to initial observation for mild degenerative cervical myelopathy was cost-effective from the Canadian healthcare payer perspective and was associated with lifetime gains in health-related quality of life.

Evaluating tissue injury in cervical spondylotic myelopathy with spinal cord MRI: a systematic review

PURPOSE

Cervical Spondylotic Myelopathy (CSM) is a degenerative condition that leads to loss of cervical spinal cord (CSC) integrity. Various spinal cord Magnetic Resonance Imaging (MRI) methods can identify and characterize the extent of this damage. This systematic review aimed to evaluate the diagnostic, biomarker, and predictive utilities of different spinal cord MRI methods in clinical research studies of CSM. The aim was to provide a comprehensive understanding of the progress in this direction for future studies and effective diagnosis and management of CSM.

METHODS

A comprehensive literature search was conducted on PubMed and EMBASE from 2010 to 2022 according to PRISMA guidelines. Studies with non-human subjects, less than 3T magnetic field strength, non-clinical design, or not quantitatively focusing on the structural integrity of CSC were excluded. The extracted data from each study included demographics, disease severity, MRI machine characteristics, quantitative metrics, and key findings in terms of diagnostic, biomarker, and predictive utilities of each MRI method. The risk of bias was performed using the guide from AHRQ. The quality of evidence was assessed separately for each type of utility for different MRI methods using GRADE.

RESULTS

Forty-seven studies met the inclusion criteria, utilizing diffusion-weighted imaging (DTI) (n = 39), magnetization transfer (MT) (n = 6), MR spectroscopy (n = 3), and myelin water imaging (n = 1), as well as a combination of MRI methods (n = 12). The metric fractional anisotropy (FA) showed the highest potential in all facets of utilities, followed by mean diffusivity. Other promising metrics included MT ratio and intracellular volume fraction, especially in multimodal studies. However, the level of evidence for these promising metrics was low due to a small number of studies. Some studies, mainly DTI, also reported the usefulness of spinal cord MRI in mild CSM.

CONCLUSIONS

Spinal cord MRI methods can potentially facilitate the diagnosis and management of CSM by quantitatively interrogating the structural integrity of CSC. DTI is the most promising MRI method, and other techniques have also shown promise, especially in multimodal configurations. However, this field is in its early stages, and more studies are needed to establish the usefulness of spinal cord MRI in CSM.

Predictive Factors Associated with Chronic Neck Pain in Patients with Cervical Degenerative Disease: A Retrospective Cohort Study

Purpose

To explore the predictive factors of neck pain (NP) in patients with cervical degenerative disease by retrospectively analyzing their occupational and demographic characteristics and to provide a valuable reference for preventing and treating chronic NP.

Patients and Methods

We retrospectively reviewed the occupational and demographic data of patients with cervical degenerative disease who had undergone anterior cervical surgery between June 2021 and December 2022 at our center. The patients were divided into NP and no-NP groups based on whether they had chronic NP before surgery. Relevant occupational and demographic data from all patients were statistically analyzed, and all variables were made categorical. Forward stepwise logistic regression models were constructed for preoperative chronic neck pain to explore the possible risk factors associated with chronic neck pain.

Results

The differences in smoking, being an office worker, BMI, and disease types between NP and no-NP groups were statistically significant. In contrast, there were no statistically significant in age, sex, academic level, duration, and degeneration grade between the two groups. Moreover, further logistic regression analysis indicated that smoking, being an office worker, having an abnormal BMI, and cervical spondylotic radiculopathy (CSR) were related to chronic neck pain.

Conclusion

The present study indicated that smoking, being an office worker, having an abnormal BMI, and CSR were predisposing risk factors for NP associated with cervical degenerative disease. Although intervertebral disc degeneration is the pathology basis of NP, the degeneration grade was not related to the occurrence of NP in our current study. Therefore, quitting smoking, avoiding sedentariness, and maintaining a normal BMI may prevent NP to some extent.

Degenerative Cervical Myelopathy: An Overview

Degenerative cervical myelopathy (DCM) is a spinal condition of growing importance due to its increasing prevalence within the ageing population. DCM involves the degeneration of the cervical spine due to various processes such as disc ageing, osteophyte formation, ligament hypertrophy or ossification, as well as coexisting congenital anomalies. This article provides an overview of the literature on DCM and considers areas of focus for future research. A patient with DCM can present with a variety of symptoms ranging from mild hand paraesthesia and loss of dexterity to a more severe presentation of gait disturbance and loss of bowel/bladder control. Hoffman's sign and the inverted brachioradialis reflex are also important signs of this disease. The gold standard imaging modality is MRI which can identify signs of degeneration of the cervical spine. Other modalities include dynamic MRI, myelography, and diffusion tensor imaging. One important scoring system to aid with the diagnosis and categorisation of the severity of DCM is the modified Japanese Orthopaedic Association score. This considers motor, sensory, and bowel/bladder dysfunction, and categorises patients into mild, moderate, or severe DCM. DCM is primarily treated with surgery as this can halt disease progression and may even allow for neurological recovery. The surgical approach will depend on the location of degeneration, the number of cervical levels involved and the pathophysiological process. Surgical approach options include anterior cervical discectomy and fusion, corpectomy, or posterior approach (laminectomy ± fusion). Conservative management is also considered for some patients with mild or non-progressive DCM or for patients where surgery is not an option. Conservative treatment may include physical therapy, traction, or neck immobilisation. Future recommendations include research into the prevalence rate of DCM and if there is a difference between populations. Further research on the benefit of conservative management for patients with mild or non-progressive DCM would be recommended.

Investigation of the Efficacy of Bilateral Osteoligamentous Decompression via Hemilaminectomy in Cervical Spondylotic Myelopathy: A Clinical Study

OBJECTIVE

Cervical stability may deteriorate and kyphotic spinal deformities may develop in cervical spondylotic myelopathy (CSM) after laminectomy or laminoplasty. This study aimed to investigate the therapeutic efficacy of the "bilateral osteoligamentous decompression via unilateral hemilaminectomy approach (UHBOLD)" technique in CSM patients.

METHODS

The study included 34 adult patients who underwent UHBOLD surgery for CSM between 2016 and 2022. A record was made for all patients of age, gender, number of operated levels, preoperative and postoperative long-term follow-up VAS scores, Nurick grade values and mJOA scores, kyphosis angles measured on X-ray, and spinal canal areas measured on T2-weighted MR axial images.

RESULTS

Preoperative VAS scores of the patients were 6 (4-9), Nurick grade values were 3 (2-5), mJOA scores were 10.50 ± 3.42, kyphosis angles were -13.34 ± 13.69° and spinal canal areas were 87.11 ± 28.30 mm2. In postoperative long-term follow-up of these patients, VAS scores were 2 (1-5), Nurick grade values were 1 (0-5), mJOA scores were 13.94 ± 3.09, kyphosis angles were -15.07 ± 12.78° and spinal canal areas were 149.65 ± 42.57 mm2. A statistically significant difference was determined between the preoperative and the postoperative long-term follow-up VAS scores, Nurick grade values, mJOA scores, and spinal canal areas (P < 0.001). Kyphosis angles were not different (P = 0.198), and no instability was observed in any patient in long-term follow-up.

CONCLUSIONS

The UHBOLD technique performed in multilevel CSM patients did not cause any change in cervical lordosis angle in long-term follow-up, did not cause cervical kyphotic deformity or cervical instability, and significantly improved Nurick grade values, and VAS and mJOA scores.

Pathophysiology and surgical decision-making in central cord syndrome and degenerative cervical myelopathy: correcting the somatotopic fallacy

Our understanding of Central Cord Syndrome (CCS), a form of incomplete spinal cord injury characterized by disproportionate upper extremity weakness, is evolving. Recent advances challenge the traditional somatotopic model of corticospinal tract organization within the spinal cord, suggesting that CCS is likely a diffuse injury rather than focal lesion. Diagnostic criteria for CCS lack consensus, and varied definitions impact patient identification and treatment. Evidence has mounted for early surgery for CCS, although significant variability persists in surgical timing preferences among practitioners. A demographic shift toward an aging population has increased the overlap between CCS and Degenerative Cervical Myelopathy (DCM). Understanding this intersection is crucial for comprehensive patient care. Assessment tools, including quantitative measures and objective evaluations, aid in distinguishing CCS from DCM. The treatment landscape for CCS in the context of pre-existing DCM is complex, requiring careful consideration of pre-existing neurologic injury, patient factors, and injury factors. This review synthesizes emerging evidence, outlines current guidelines in diagnosis and management, and emphasizes the need for ongoing research to refine our understanding and treatment strategies for this evolving patient population.

Clinicoradiological Risk Factors Associated with Inability to Achieve Minimum Clinically Important Difference in Operated Cases of Cervical Spondylotic Myelopathy

STUDY DESIGN

This is a retrospective cohort study.

PURPOSE

This study aimed to identify the clinicoradiological risk factors associated with the inability to achieve minimum clinically important difference (MCID) on the modified Japanese Orthopaedic Association (mJOA) Scale in operated cases of cervical spondylotic myelopathy (CSM).

OVERVIEW OF LITERATURE

Only a few studies have evaluated the outcomes of surgery performed for CSM using MCID on the mJOA scale.

METHODS

We analyzed 124 operated CSM cases from March 2019 to April 2021 for preoperative clinical features, cervical sagittal radiographic parameters, and magnetic resonance imaging (MRI) signal intensities (SI). The risk factors associated with missing the MCID (poor outcome) on mJOA at the final follow-up were identified using binary logistic regression. Multivariate analysis was used to find significant risk factors, and odds ratios (OR) were computed.

RESULTS

A total of 110 men (89.2%) and 14 women (10.8%) with an average age of 53.5±13.2 years were included in the analysis. During the last follow-up, 89 cases (72.1%) achieved MCID (meaningful gains following surgery) while 35 (27.9%) could not. The final model identified the following parameters as significant risk factors for poor outcome: increased duration of symptoms (OR, 6.77; p=0.001), lower preoperative mJOA scale (OR, 0.75; p=0.029), the presence of multilevel T2-weighted (T2W) MRI SI (OR, 4.79; p=0.004), and larger change in cervical sagittal vertical axis (ΔcSVA) (OR, 1.06; p=0.013). Also, an increase in cSVA postoperatively correlated with a reduced functional recovery rate (r=-0.4, p<0.001).

CONCLUSIONS

Surgery for CSM leads to significant functional benefits. However, poorer outcomes are observed in cases of greater duration of symptoms, higher preoperative severity with multilevel T2W MRI SI, and a larger increase in the postoperative cSVA (sagittal imbalance).

Ultrasonic Bone Scalpel versus Conventional Methods for Osteotomy in Posterior Surgery for Cervical Spondylotic Myelopathy: A Review and Meta-Analysis

Posterior methods for cervical myelopathy include laminoplasty and laminectomy with/without fusion. A more recent innovation in these treatments is the use of an ultrasonic bone shaver for osteotomy. In this study, we examined the perioperative results after laminectomy/laminoplasty between conventional methods (rongeur/high-speed drill) vs. piezosurgery-based instruments. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed and the search was performed on four databases (PubMed, Scopus, EMBASE, and Google Scholar). Seven comparative studies were chosen after thorough screening by the authors and a meta-analysis was performed between piezosurgery and conventional technique to ascertain intraoperative and postoperative results after laminectomy/laminoplasty. The analysis includes four retrospective cohort studies and three randomized controlled trials published between 2015 and 2022. The mean age ranged from 55.5 to 64.2 years. Blood loss was significantly reduced in the piezosurgery group, other findings were not significant. On subgroup analysis, laminoplasty dramatically reduced blood loss and the rate of iatrogenic dural rips in the piezosurgery group. The use of ultrasonic bone shaver for osteotomy in cervical spondylotic myelopathy is related to significantly decreased blood loss and no significant increase in postoperative drainage, operative time, complication rate, and functional outcomes as compared to traditional techniques. We noticed significantly reduced blood and rate of dural tears in the laminoplasty subgroup with the use of ultrasonic bone shaver, which was not mirrored in the laminectomy subgroup. Careful intraoperative handling of the instrument can help prevent iatrogenic dural tears and nerve damage.

Blood-spinal cord barrier disruption in degenerative cervical myelopathy

Degenerative cervical myelopathy (DCM) is the most prevalent cause of spinal cord dysfunction in the aging population. Significant neurological deficits may result from a delayed diagnosis as well as inadequate neurological recovery following surgical decompression. Here, we review the pathophysiology of DCM with an emphasis on how blood-spinal cord barrier (BSCB) disruption is a critical yet neglected pathological feature affecting prognosis. In patients suffering from DCM, compromise of the BSCB is evidenced by elevated cerebrospinal fluid (CSF) to serum protein ratios and abnormal contrast-enhancement upon magnetic resonance imaging (MRI). In animal model correlates, there is histological evidence of increased extravasation of tissue dyes and serum contents, and pathological changes to the neurovascular unit. BSCB dysfunction is the likely culprit for ischemia-reperfusion injury following surgical decompression, which can result in devastating neurological sequelae. As there are currently no therapeutic approaches specifically targeting BSCB reconstitution, we conclude the review by discussing potential interventions harnessed for this purpose.

Analysis of gene expression profiles and experimental validations of a rat chronic cervical cord compression model

Cervical spondylotic myelopathy (CSM) is a severe non-traumatic spinal cord injury (SCI) wherein the spinal canal and cervical cord are compressed due to the degeneration of cervical tissues. To explore the mechanism of CSM, the ideal model of chronic cervical cord compression in rats was constructed by embedding a polyvinyl alcohol polyacrylamide hydrogel in lamina space. Then, the RNA sequencing technology was used to screen the differentially expressed genes (DEGs) and enriched pathways among intact and compressed spinal cords. A total of 444 DEGs were filtered out based on the value of log₂(Compression/Sham); these were associated with IL-17, PI3K-AKT, TGF-β, and Hippo signaling pathways according to the GSEA, KEGG, and GO analyses. Transmission electron microscopy indicated the changes in mitochondrial morphology. Western blot and immunofluorescent staining revealed neuronal apoptosis, astrogliosis and microglial neuroinflammation in the lesion area. Specifically, the expression of apoptotic indicators, such as Bax and cleaved caspase-3, and inflammatory cytokines, such as IL-1β, IL-6, and TNF-α, were upregulated. The activation of IL-17 signaling pathways was observed in microglia instead of neurons or astrocytes, the activation of TGF-β and inhibition of Hippo signaling pathways were detected in astrocytes instead of neurons or microglia, and the inhibition of PI3K-AKT signaling pathway was discovered in neurons rather than microglia of astrocytes in the lesion area. In conclusion, this study indicated that neuronal apoptosis was accompanied by inhibiting of the PI3K-AKT pathway. Then, the activation of microglia IL-17 pathway and NLRP3 inflammasome effectuated the neuroinflammation, and astrogliosis was ascribed to the activation of TGF-β and the inhibition of the Hippo pathway in the chronic cervical cord of compression. Therefore, therapeutic methods targeting these pathways in nerve cells could be promising CSM treatments.

Postoperative Rehabilitation to Improve Outcomes After Cervical Spine Fusion for Degenerative Cervical Spondylosis: A Systematic Review

Postoperative rehabilitation has recently been identified as a high-priority research topic for improving surgical outcomes for degenerative cervical spondylosis (DCS). However, there remains no consensus on specific rehabilitation strategies. Thus, the objective of this study was to evaluate the effectiveness of postoperative rehabilitation strategies for short-term and long-term outcomes after cervical spine fusion for DCS. A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines using the PubMed, Scopus, and Ovid Medline databases. All level I-IV therapeutic studies in the English language investigating the outcomes of postoperative rehabilitation strategies after cervical spine fusion for DCS were included. Nine studies with 895 patients with DCS (747 anterior-only fusion, 55 patients with posterior-only fusion, 93 patients with physiotherapy alone) were included in this analysis, with 446 (49.8%) patients receiving physiotherapy alone or standard postoperative therapy and 449 (50.2%) patients receiving standard postoperative therapy with additional intervention or augmentation. These interventions included pulsed electromagnetic field (PEMF) stimulation, telephone-supported home exercise program (HEP), early cervical spine stabilizer training, structured postoperative therapy, and a postoperative cervical collar. One level II study demonstrated that PEMF led to increased fusion rates at six months postoperatively compared to standard therapy alone, one level II study demonstrated that postoperative cervical therapy in addition to standard therapy was better than standard therapy alone in the improvement of neck pain intensity, one level IV study demonstrated home exercise therapy led to an improvement in neck pain, arm pain, and disability, and six level II studies reported no difference in clinical outcome measures between augmented or targeted therapy and standard postoperative therapy for DCS. In conclusion, there is moderate evidence to suggest that there is no significant difference in clinical and surgical outcomes between standard postoperative therapy and augmented or targeted postoperative therapy for cervical fusion in the setting of cervical spondylosis. However, there is some evidence to support that certain therapeutic modalities, such as PEMF stimulation, may lead to improved fusion rates, clinical outcomes, and patient satisfaction when compared to standard postoperative therapy protocols. There is no evidence to support a difference in effectiveness with different types of postoperative rehabilitation strategies between anterior and posterior fusions for DCS.

Increased blood flow of spinal cord lesion after decompression improves neurological recovery of degenerative cervical myelopathy: an intraoperative ultrasonography-based prospective cohort study

INTRODUCTION

Surgical decompression is a highly effective therapy for degenerative cervical myelopathy (DCM), but the mechanisms of neurological recovery following decompression remain unclear. This study aimed to evaluate the spinal cord blood flow status after sufficient decompression by intraoperative contrast-enhanced ultrasonography (CEUS) and to analyze the correlation between neurological recovery and postdecompressive spinal cord blood perfusion in DCM.

MATERIALS AND METHODS

Patients with multilevel DCM were treated by ultrasound-guided modified French-door laminoplasty using a self-developed rongeur. Neurological function was evaluated using the modified Japanese Orthopaedic Association (mJOA) score preoperatively and at 12 months postoperatively. Spinal cord compression and cervical canal enlargement before and after surgery were assessed by magnetic resonance imaging and computerized tomography. The decompression status was evaluated in real time by intraoperative ultrasonography, while the spinal cord blood flow after sufficient decompression was assessed by CEUS. Patients were categorized as favourable (≥50%) or unfavourable (<50%) recovery according to the recovery rate of the mJOA score at 12 months postoperatively.

RESULTS

Twenty-nine patients were included in the study. The mJOA scores were significantly improved in all patients from 11.2±2.1 preoperatively to 15.0±1.1 at 12 months postoperatively, with an average recovery rate of 64.9±16.2%. Computerized tomography and intraoperative ultrasonography confirmed adequate enlargement of the cervical canal and sufficient decompression of the spinal cord, respectively. CEUS revealed that patients with favourable neurological recovery had a greater increased blood flow signal in the compressive spinal cord segment after decompression.

CONCLUSIONS

In DCM, intraoperative CEUS can clearly reflect spinal cord blood flow. Patients with increased blood perfusion of the spinal cord lesion immediately after surgical decompression tended to achieve greater neurological recovery.

Diffusion Basis Spectrum Imaging Identifies Clinically Relevant Disease Phenotypes of Cervical Spondylotic Myelopathy

STUDY DESIGN

Prospective cohort study.

OBJECTIVE

Apply a machine learning clustering algorithm to baseline imaging data to identify clinically relevant cervical spondylotic myelopathy (CSM) patient phenotypes.

SUMMARY OF BACKGROUND DATA

A major shortcoming in improving care for CSM patients is the lack of robust quantitative imaging tools to guide surgical decision-making. Advanced diffusion-weighted magnetic resonance imaging (MRI) techniques, such as diffusion basis spectrum imaging (DBSI), may help address this limitation by providing detailed evaluations of white matter injury in CSM.

METHODS

Fifty CSM patients underwent comprehensive clinical assessments and diffusion-weighted MRI, followed by DBSI modeling. DBSI metrics included fractional anisotropy, axial and radial diffusivity, fiber fraction, extra-axonal fraction, restricted fraction, and nonrestricted fraction. Neurofunctional status was assessed by the modified Japanese Orthopedic Association, myelopathic disability index, and disabilities of the arm, shoulder, and hand. Quality-of-life was measured by the 36-Item Short Form Survey physical component summary and mental component summary. The neck disability index was used to measure self-reported neck pain. K-means clustering was applied to baseline DBSI measures to identify 3 clinically relevant CSM disease phenotypes. Baseline demographic, clinical, radiographic, and patient-reported outcome measures were compared among clusters using one-way analysis of variance (ANOVA).

RESULTS

Twenty-three (55%) mild, 9 (21%) moderate, and 10 (24%) severe myelopathy patients were enrolled. Eight patients were excluded due to MRI data of insufficient quality. Of the remaining 42 patients, 3 groups were generated by k-means clustering. When compared with clusters 1 and 2, cluster 3 performed significantly worse on the modified Japanese Orthopedic Association and all patient-reported outcome measures (P<0.001), except the 36-Item Short Form Survey mental component summary (P>0.05). Cluster 3 also possessed the highest proportion of non-Caucasian patients (43%, P=0.04), the worst hand dynamometer measurements (P<0.05), and significantly higher intra-axonal axial diffusivity and extra-axonal fraction values (P<0.001).

CONCLUSIONS

Using baseline imaging data, we delineated a clinically meaningful CSM disease phenotype, characterized by worse neurofunctional status, quality-of-life, and pain, and more severe imaging markers of vasogenic edema.

LEVEL OF EVIDENCE

II.

Recent Advancements in Epidural Etanercept for Pain Management in Radiculopathy: A Literature Review

The most common etiology of low back and neck pain is associated with spinal cord pathologies. Regardless of origin, low back and neck pain are some of the most common causes of disability worldwide. Mechanical compression due to spinal cord diseases, such as degenerative disc disorders, can lead to radiculopathy, which manifests as numbness or tingling and can progress to loss of muscle function. Conservative management, such as physical therapy, has not been proven effective in treating radiculopathy, and surgical treatments have more risks than benefits for most patients. Epidural disease-modifying medications, such as Etanercept, have been recently explored due to their minimal invasiveness and direct effects on inhibiting tumor necrosis factor-α (TNF-α). Therefore, this literature review aims to evaluate epidural Etanercept's effect on radiculopathy caused by degenerative disc diseases. Epidural Etanercept has been shown to improve radiculopathy in patients with lumbar disc degeneration, spinal stenosis, and sciatica. Further research is needed to compare the effectiveness of Etanercept with commonly used treatments such as steroids and analgesia.

Clinical and Radiological Outcome of Disc Arthroplasty for the Treatment of Cervical Spondylotic Myelopathy

Introduction: The aim of this study is to evaluate the clinical and radiological results of cervical disc arthroplasty (CDA) in patients with cervical spondylotic myelopathy (CSM) using the CP ESP® disc prosthesis. Materials and Methods: Prospectively collected data of 56 patients with CSM have been analyzed. The mean age at surgery was 35.6 years (range: 25–43 years). The mean follow-up was 28.2 months (range: 13–42 months). The range of motion (ROM) of the index segments, as well as upper and lower adjacent segments, was measured before surgery and at final follow-up. The C2-C7 sagittal vertical axis (SVA), C2-C7 cervical lordosis (CL), and T1 slope minus cervical lordosis (T1s-CL) were analyzed as well. Pain intensity was measured preoperatively and during follow-up using an 11-point numeric rating scale (NRS). Modified Japanese Orthopaedic Association (mJOA) score was assessed preoperatively and during follow-up for the clinical assessment of myelopathy. Surgical and implant-associated complications were analyzed as well. Results: The NRS pain score improved from a mean of 7.4 (±1.1) preoperatively to a mean of 1.5 (±0.7) at last follow-up (p < 0.001). The mJOA score improved from a mean of 13.1 (±2.8) preoperatively to a mean of 14.8 (±2.3) at last follow-up (p < 0.001). The mean ROM of the index levels increased from 5.2° (±3.0) preoperatively to 7.3° (±3.2) at last follow-up (p < 0.05). Four patients developed heterotopic ossifications during follow-up. One patient developed permanent dysphonia. Conclusions: CDA showed good clinical and radiological outcome in this cohort of young patients. The motion of index segments could be preserved. CDA may be a viable treatment option in selected patients with CSM.

The Role of Magnetic Transcranial Stimulation in the Diagnosis and Post-Surgical Follow-Up of Cervical Spondylotic Myelopathy

Degenerative cervical myelopathy (DCM) consists of spinal cord damage due to its compression through the cervical spine. The leading cause is degenerative. The diagnosis is clinical, and the therapeutic approach is usually surgical. Confirmation of the diagnostic suspicion is done by magnetic resonance imaging (MRI); however, this test lacks functional information of the spinal cord, the abnormality of which may precede involvement in neuroimaging. Neurophysiological examination using somatosensory evoked potentials (SSEPs) and transcranial magnetic stimulation (TMS) allows for an evaluation of spinal cord function, and provides information in the diagnostic process. Its role in the post-surgical follow-up of patients undergoing decompressive surgery is being studied. We present a retrospective study of 24 patients with DCM and surgical decompression who underwent neurophysiological tests (TMS and SSEP) before, 6, and 12 months after surgery. The result of the TMS and the SSEP in the post-operative follow-up did not correlate with the clinical outcome, either subjective or measured by clinical scales at six months. We only found post-surgical improvement of central conduction times (CMCTs) in patients with severe pre-surgical motor impairment on TMS. In patients with normal pre-surgical CMCT, we found a transient worsening with return to baseline at the one-year follow-up. Most patients presented pre-surgical increased P40 latency at diagnosis. CMCT and SSEP were more related to clinical outcomes one year after the surgical procedure and were very useful in diagnosing.