Cervical spine pathology and treatment: a global overview

Using evidence-based imaging referral guidelines to facilitate appropriate imaging: Are they all the same?

RATIONALE AND OBJECTIVES

Countries worldwide have selected, adopted, adapted, and translated evidence-based imaging referral guidelines from radiology professional bodies. This study establishes the concordance of three imaging referral guidelines from the ACR, ESR, and RCR, and examines the emergency department cervical spine imaging appropriateness rates.

MATERIALS AND METHODS

A retrospective analysis of the electronic medical records was performed between October 1st to December 31st, 2022, evaluating 452 radiography and 153 CT imaging referrals. For each case, the initial clinical diagnosis was integrated with the corresponding clinical notes for analysis. Evaluation of the appropriateness rating was dichotomised to either 'indicated' or 'not indicated' for analytical and practical purposes. The inter-rater agreement for the imaging referral guidelines was calculated using Fleiss' Kappa and Cohen's Kappa.

RESULTS

The overall appropriateness rate of X-ray cervical spine imaging referrals was 13.3 % -75.2 %, depending on the imaging referral guidelines utilised. The appropriateness rate of CT cervical spine was 90.8 %, which was an identical rate for all three of the guidelines. Fleiss' Kappa indicated the guidelines for X-ray of the cervical spine had slight agreement (κ = 0.135 (95 % CI, 0.088 to 0.183), p < 0.001) and almost perfect agreement amongst guidelines for CT cervical spine (κ = 1.000 (95 % CI, 0.909 to 1.091), p < 0.001). For pairwise comparison, ACR AC and ESR iGuide for X-ray demonstrated moderate agreement (κ = 0.765, p < 0.001); however, RCR iRefer had no level of agreement with both. For CT, there was almost perfect agreement between all the guidelines.

CONCLUSION

The guidelines demonstrated slight agreement for X-ray cervical spine and almost perfect agreement for CT cervical spine, complicating audit process and influencing audit output. Multidisciplinary buy-in positively impacts CT cervical spine appropriateness rates. Harmonising and prioritising guideline development for commonly encountered clinical scenarios is required.

Investigating the Gene Relation Between Cervical Spondylosis and Depression: Bidirectional Mendelian Randomization Study

Background

Previous observational studies have suggested a potential link between depression and cervical spondylosis (CS). While it is known that depression and CS can coexist, the specific relationship between them is not fully understood. We hypothesize that there may be connections between the two conditions, but the independent causal relationship of depression as a risk factor for CS, remains uncertain. This particular study has important implications for the future clinical treatment of depression and cervical spondylosis because Mendelian randomization has not been widely used in this field. We obtained valuable results through big data analysis and have guiding significance for future research.

Methods

We conducted a two-sample Mendelian randomization (MR) study using data from genome-wide association studies to investigate the causal relationship between depression and CS in individuals of European ancestry. Additionally, we examined the impact of CS on susceptibility to depression using large population-level genetic data (number of depression SNPs: 9,761,853; number of CS SNPs: 9,851,867). The primary approach for data analysis was the inverse-variance weighted (IVW) method to estimate potential causal effects. Furthermore, we performed sensitivity analyses utilizing methods such as Manhattan plot (CMplot), linkage disequilibrium (LD), F-filtering, removal of phenoscanner, MR-Egger, weighted median, MR-PRESSO simple mode weighted mode MR pleiotropy test MR heterogeneity assessment leave-one-out analysis to ensure result robustness.

Results

Our findings indicated that an elevated likelihood of CS was linked to depression [IVW odds ratio (OR): 1.322, 95% confidence interval (CI): 1.205-1.441, P=0.01243]. There was reciprocal evidence of causation, with the genetic predisposition to depression significantly heightening susceptibility to CS [IVW odds ratio (OR): 1.426, 95% confidence interval (CI): 1.236-1.651, P=0.01775].

Conclusion

This investigation provides genetic support for a bidirectional causal association between depression and CS. Specifically, individuals with depression are at greater risk of developing CS. Addressing depression may serve as an effective approach in mitigating or preventing the burden of CS and vice versa.

Efficacy of an allograft cellular bone matrix as an alternative to autograft in anterior cervical discectomy and fusion: radiological results & safety

Background

The predominant surgical procedure employed for patients with symptomatic cervical radiculopathy is anterior cervical discectomy and fusion (ACDF). ACDF typically involves the use of an interbody cage augmented with iliac crest bone graft (ICBG) or local autograft to enhance fusion rate. Substantial complications can arise from autograft use, including donor site morbidity, difficulties with ambulation, and diminished quality of life. This study aims to evaluate the effectiveness and safety of an allograft cellular bone matrix (ACBM) as an osteopromotive bone, in ACDF procedures.

Methods

This retrospective, single-center, consecutive case series included 73 patients who underwent an ACDF procedure. The surgical procedure involved the placement of an interbody cage supplemented with anterior plate fixation and an ACBM within the interbody spacer. Patient charts were reviewed to gather demographic information, radiographic findings, as well as perioperative and post-operative complications. Radiographic fusion was assessed at 6 and 12 months by a blinded, musculoskeletal-trained radiologist and a board-certified spinal surgeon reviewer. Any discrepancies were settled by a third, senior reviewer. Complete fusion was defined as: evidence of bridging bone across the disc space on CT, angular motion <3 degrees, and translational motion <2 mm on lateral radiographs. Complications were analyzed at 6, 12, and 15+ months post-operatively to assess clinical outcomes and device performance.

Results

A total of 73 patients (50 males, 23 females) with an average age of 54.6 (range, 31-77) years underwent an ACDF procedure between C3-T1 with an ACBM. The breakdown of levels operated on was 26%, 32%, 34%, and 8% for one, two, three, and four level procedures, respectively. There were three patients who received spinal injections for pain within the first year post-operatively. There were two patients who required secondary surgery within the first 12 months where supplemental posterior hardware was needed. Notably, there were no instances of cage subsidence, cage migration, cage/graft removal, or reoperation. There were no cases of chronic dysphasia. At 6 months, 45% of patients with available imaging demonstrated complete fusion, while 97.4% of patients with available imaging demonstrated complete fusion at 12 months.

Conclusions

At the 12-month follow-up, our study demonstrates a high fusion rate in a real-world population of up to 4 operative levels. There were no bone graft related complications or incidences of cage migration/subsidence. It is noteworthy that the study involved a significant number of multilevel cases (74% of cases). Despite this, our results align with historical fusion rates and provide support for the utilization of ACBMs as a fusion adjunct in ACDF procedures up to 4 levels.

Prescription Trends of Opioid and Nonopioid Controlled Prescription Adjunctive Analgesics Before and After Cervical Spinal Surgery: A Retrospective Cohort Study

OBJECTIVE

Cervical spine surgery may be needed in those with refractory pain or neurologic deficits to improve outcomes in patients with cervical spine disease. However, consensus varies in the literature on the effect of surgery on opioid use. The objectives of this study were to analyze prescription rates of multiple controlled substances before and after cervical spine surgery and distinguish factors that may have contributed to opioid use after surgery.

DESIGN

This is a retrospective cohort study analyzing prescription trends of various controlled substances in 632 patients who underwent cervical spine surgery from 2019 to 2021.

RESULTS

Opioids have the largest rise in prescriptions at 3- and 6-mo time points after cervical spine surgery. A significant association ( P < 0.001) was found between opioid use 1 yr before and 1 yr after cervical spine surgery. Exposure to opioids before surgery (odds ratio = 2.77, 95% confidence interval = 1.43-5.51, P = 0.003) and higher morphine milligram equivalent dose (odds ratio = 1.02, 95% confidence interval =1.01-1.04, P = 0.012) were found to be associated with opioid use after surgery. Significantly more females were prescribed controlled substances ( P = 0002).

CONCLUSIONS

Higher morphine milligram equivalent dose and opioid exposure before surgery are important factors in predicting postsurgical opioid use.

Identification of a lumped-parameter model of the intervertebral joint from experimental data

Through predictive simulations, multibody models can aid the treatment of spinal pathologies by identifying optimal surgical procedures. Critical to achieving accurate predictions is the definition of the intervertebral joint. The joint pose is often defined by virtual palpation. Intervertebral joint stiffnesses are either derived from literature, or specimen-specific stiffnesses are calculated with optimisation methods. This study tested the feasibility of an optimisation method for determining the specimen-specific stiffnesses and investigated the influence of the assigned joint pose on the subject-specific estimated stiffness. Furthermore, the influence of the joint pose and the stiffness on the accuracy of the predicted motion was investigated. A computed tomography based model of a lumbar spine segment was created. Joints were defined from virtually palpated landmarks sampled with a Latin Hypercube technique from a possible Cartesian space. An optimisation method was used to determine specimen-specific stiffnesses for 500 models. A two-factor analysis was performed by running forward dynamic simulations for ten different stiffnesses for each successfully optimised model. The optimisations calculated a large range of stiffnesses, indicating the optimised specimen-specific stiffnesses were highly sensitive to the assigned joint pose and related uncertainties. A limited number of combinations of optimised joint stiffnesses and joint poses could accurately predict the kinematics. The two-factor analysis indicated that, for the ranges explored, the joint pose definition was more important than the stiffness. To obtain kinematic prediction errors below 1 mm and 1° and suitable specimen-specific stiffnesses the precision of virtually palpated landmarks for joint definition should be better than 2.9 mm.

Biomechanical analysis of cervical spine (C2-C7) at different flexed postures

Musculoskeletal diseases are often related with postural changes in the neck region that can be caused by prolonged cervical flexion. This is one of the contributing factors. When determining the prevalence, causes, and related risks of neck discomfort, having a solid understanding of the biomechanics of the cervical spine (C1-C7) is absolutely necessary. The objective of this study is to make predictions regarding the intervertebral disc (IVD) stress values across C2-C7 IVD, the ligament stress, and the variation at 0°, 15°, 30°, 45°, and 60° of cervical neck angle using finite element analysis (FEA). In order to evaluate the mechanical properties of the cervical spine (particularly, C2-C7), this investigation makes use of computed tomography (CT) scans to develop a three-dimensional FEA model of the cervical spine. A preload of 50 N compression force was applied at the apex of the C2 vertebra, and all degrees of freedom below the C7 level were constrained. The primary objective of this investigation is to assess the distribution of von Mises stress within the IVDs and ligaments spanning C2-C7 at various flexion angles: 0°, 15°, 30°, 45°, and 60°, utilizing FEA. The outcomes derived from this analysis were subsequently compared to previously published experimental and FEA data to validate the model's ability to replicate the physiological motion of the cervical spine across different flexion angles.

Toward Shared Decision-Making in Degenerative Cervical Myelopathy: Protocol for a Mixed Methods Study

BACKGROUND

Health care decisions are a critical determinant in the evolution of chronic illness. In shared decision-making (SDM), patients and clinicians work collaboratively to reach evidence-based health decisions that align with individual circumstances, values, and preferences. This personalized approach to clinical care likely has substantial benefits in the oversight of degenerative cervical myelopathy (DCM), a type of nontraumatic spinal cord injury. Its chronicity, heterogeneous clinical presentation, complex management, and variable disease course engenders an imperative for a patient-centric approach that accounts for each patient's unique needs and priorities. Inadequate patient knowledge about the condition and an incomplete understanding of the critical decision points that arise during the course of care currently hinder the fruitful participation of health care providers and patients in SDM. This study protocol presents the rationale for deploying SDM for DCM and delineates the groundwork required to achieve this.

OBJECTIVE

The study's primary outcome is the development of a comprehensive checklist to be implemented upon diagnosis that provides patients with essential information necessary to support their informed decision-making. This is known as a core information set (CIS). The secondary outcome is the creation of a detailed process map that provides a diagrammatic representation of the global care workflows and cognitive processes involved in DCM care. Characterizing the critical decision points along a patient's journey will allow for an effective exploration of SDM tools for routine clinical practice to enhance patient-centered care and improve clinical outcomes.

METHODS

Both CISs and process maps are coproduced iteratively through a collaborative process involving the input and consensus of key stakeholders. This will be facilitated by Myelopathy.org, a global DCM charity, through its Research Objectives and Common Data Elements for Degenerative Cervical Myelopathy community. To develop the CIS, a 3-round, web-based Delphi process will be used, starting with a baseline list of information items derived from a recent scoping review of educational materials in DCM, patient interviews, and a qualitative survey of professionals. A priori criteria for achieving consensus are specified. The process map will be developed iteratively using semistructured interviews with patients and professionals and validated by key stakeholders.

RESULTS

Recruitment for the Delphi consensus study began in April 2023. The pilot-testing of process map interview participants started simultaneously, with the formulation of an initial baseline map underway.

CONCLUSIONS

This protocol marks the first attempt to provide a starting point for investigating SDM in DCM. The primary work centers on developing an educational tool for use in diagnosis to enable enhanced onward decision-making. The wider objective is to aid stakeholders in developing SDM tools by identifying critical decision junctures in DCM care. Through these approaches, we aim to provide an exhaustive launchpad for formulating SDM tools in the wider DCM community.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/46809.

Previous Emergency Department Admission Is Associated With Increased 90-Day Readmission Following Cervical Spine Surgery: Evidenced Using Propensity Score Matching

STUDY DESIGN

This was a retrospective case-control study.

OBJECTIVE

The objective of this study was to evaluate whether prior emergency department admission was associated with an increased risk for 90-day readmission following elective cervical spinal fusion.

SUMMARY OF BACKGROUND DATA

The incidence of cervical spine fusion reoperations has increased, necessitating the improvement of patient outcomes following surgery. Currently, there are no studies assessing the impact of emergency department visits before surgery on the risk of 90-day readmission following elective cervical spine surgery. This study aimed to fill this gap and identify a novel risk factor for readmission following elective cervical fusion.

METHODS

The 2016-2018 Nationwide Readmissions Database was queried for patients aged 18 years and older who underwent an elective cervical fusion. Prior emergency admissions were defined using the variable HCUP_ED in the Nationwide Readmissions Database database. Univariate analysis of patient demographic details, comorbidities, discharge disposition, and perioperative complication was evaluated using a χ 2 test followed by multivariate logistic regression.

RESULTS

In all, 2766 patients fit the inclusion criteria, and 18.62% of patients were readmitted within 90 days. Intraoperative complications, gastrointestinal complications, valvular, uncomplicated hypertension, peripheral vascular disorders, chronic obstructive pulmonary disease, cancer, and experiencing less than 3 Charlson comorbidities were identified as independent predictors of 90-day readmission. Patients with greater than 3 Charlson comorbidities (OR=0.04, 95% CI 0.01-0.12, P <0.001) and neurological complications (OR=0.29, 95% CI 0.10-0.86, P =0.026) had decreased odds for 90-day readmission. Importantly, previous emergency department visits within the calendar year before surgery were a new independent predictor of 90-day readmission (OR=9.74, 95% CI 6.86-13.83, P <0.001).

CONCLUSIONS

A positive association exists between emergency department admission history and 90-day readmission following elective cervical fusion. Screening cervical fusion patients for this history and optimizing outcomes in those patients may reduce 90-day readmission rates.

Incidence and pattern of traumatic spine injury in a single level I trauma center of southern Iran

PURPOSE

Spine injury is one of the leading causes of death and mortality worldwide. The objective of this study was to determine the incidence, pattern and outcome of trauma patients with spine injury referred to the largest trauma center in southern Iran during the last three years.

METHODS

This is a cross-sectional study conducted between 2018 and 2021 in the largest trauma center in the southern Iran. The data collection form included the age, sex, injury location (cervical, thoracic, and lumbar), canuse of injury (traffic accidents, falls, and assaults), length of hospital stay, injured segment of spine injury, severity of injury, and outcome. Statistical analyzes were performed using SPSS software version 24.

RESULTS

Totally 776 cases of spine injury were identified. The spine injury rate was 17.0%, and the mortality rate was 15.5%. Cervical spine injury (20.4%) more often occulted in motorcycle accident, and thoracic spine injury (20.1%) occulted in falls. The highest and lowest rates of spine injurys were related to lumbar spine injury (30.2%) and cervical spine injury (21.5%), respectively. There was a statistically significant relationship between the mechanism of injury and the location of spine injury (p ≤ 0.001). And patients with lumbar spine injury had the highest mortality rate (16.7%). Injury severity score (OR= 1.041, p ≤ 0.001) and length of stay (OR = 1.018, p ≤ 0.001) were strong predictors of mortality in trauma patients with spine injury.

CONCLUSION

The results of the study showed that the incidence of traumatic spine injury rate was approximately 17.0% in southern of Iran. Road traffic injury and falls are the common mechanism of injury to spine. It is important to improve the safety of roads, passages, and work environment, and increase the quality of cars. Also, paying attention to the pattern of spine injury may assist to prevent the missing diagnosis of SCI in multiple trauma patients.

Existing Funding Sources in Degenerative Cervical Myelopathy Research: Scoping Review

BACKGROUND

Degenerative cervical myelopathy (DCM) is a common, disabling condition of symptomatic cervical spinal cord compression that requires significant research advances to improve patient outcomes. A James Lind Alliance Partnership recently identified the top research priorities for DCM. To effectively address these priorities, appropriate funding of DCM research is essential.

OBJECTIVE

The aim of this paper is to review current funding in DCM research and highlight future research funding opportunities.

METHODS

A systematic search of Web of Science for "cervical AND myelopathy" was conducted. Papers exclusively studying DCM with declared funding and published between January 1, 1995, and March 21, 2020, were considered eligible. Funding sources were classified by country of origin and organization type. A grant search was also conducted using Dimensions.ai (Digital Science Ltd).

RESULTS

A total of 621 papers were included, with 300 unique funding bodies. The top funders were AO Spine (n=87); National Institutes of Health, USA (n=63); and National Natural Science Foundation, China (n=63). Funding sources in the USA (n=242) supported the most DCM research, followed by China (n=209) and Japan (n=116). Funding in the USA was primarily provided by corporate or nonprofit organizations (146/242, 60.3%), while in China, the majority of funding was from institutions (208/209, 99.5%). Dimensions.ai gives an estimate for the total declared grant funding awards for DCM-specific research. Data here showed 180 grants awarded specifically for DCM research, with a total value of US $45.6 million since 1996.

CONCLUSIONS

DCM funding appears to be predominantly from the USA, China, and Japan, aligning with areas of high DCM research activity and underpinning the importance of funding to increasing research capacity. The existing funding sources differ from medical research in general, representing opportunities for future investment in DCM.

Evaluating a novel, low-cost technique for cervical-spine immobilization for application in resource-limited LMICs: a non-inferiority trial

STUDY DESIGN

Non-inferiority trial.

OBJECTIVE

Limited cervical spinal (c-spine) immobilization in resource-limited settings of LMICs suggests alternatives are necessary for patients with traumatic injuries. We propose a novel method of c-spine immobilization using folded towels.

SETTING

Washington University in St. Louis.

METHODS

Using non-inferiority trial design, thirty healthy patients (median age = 22) were enrolled to test the efficacy of folded towels in comparison with rigid cervical collars, foam neck braces, and no immobilization. We measured cervical range of motion (CROM) in six cardinal directions in seated and supine positions. A weighted composite score (CS) was generated to compare immobilization methods. A preserved fraction of 75% was determined for non-inferiority, corresponding to the difference between the median values for CROM between control (no immobilization) and c-collar states.

RESULTS

C-collars reduce median CROM in six cardinal directions in seated and supine positions by an average of -36.83° seated (-17.75° supine) vs. no immobilization. Folded towels and foam neck braces reduced CROM by -27° seated (-16.75° supine) and -14.25° seated (-9.5° supine), respectively. Compared to a 25% non-inferiority margin (permitting an average 9.21° of cervical movement across six cardinal directions), the CS determined folded towels are non-inferior (CS_seated = 0.89, CS_supine = 0.47). Foam neck braces are inferior (CS_seated = 2.35, CS_supine = 2.10). CS > 1 surpassed the non-inferiority margin and were deemed inferior.

CONCLUSIONS

Folded towels are a non-inferior means of immobilizing c-spine in extension and rotation, but not flexion, vs. c-collars. We propose folded towels could be trialed in combination with backboards to deliver affordable and effective prehospital TSCI management in resource-limited settings.

The biomechanical study of cervical spine: A Finite Element Analysis

The biomechanical study helps us to understand the mechanics of the human cervical spine. A three dimensional Finite Element (FE) model for C3 to C6 level was developed using computed tomography (CT) scan data to study the mechanical behaviour of the cervical spine. A moment of 1 Nm was applied at the top of C3 vertebral end plate and all degrees of freedom of bottom end plate of C6 were constrained. The physiological motion of the cervical spine was validated using published experimental and FE analysis results. The von Mises stress distribution across the intervertebral disc was calculated along with range of motion. It was observed that the predicted results of functional spine units using FE analysis replicate the real behaviour of the cervical spine.

Mash-1 modified neural stem cells transplantation promotes neural stem cells differentiation into neurons to further improve locomotor functional recovery in spinal cord injury rats

BACKGROUND

Spinal cord injury (SCI) leads to severe motor and sensory dysfunctions. Neural stem cells (NSCs) transplantation therapy plays a positive role in functional recovery after SCI, but the effectiveness of this therapy is limited by inadequate differentiation ability of transplanted NSCs. Mammalian achaete-scute homologue-1 (Mash-1) has been reported to improve differentiation of NSCs. Thus, this study modified NSCs with Mash-1 to repair SCI.

METHODS

NSCs isolated from rat embryo hippocampus were cultured and identified in vitro and further transfected with the lentiviral vectors (Lv-Mash-1). After establishing a SCI rat model, the rats were transplanted with Mash-1 modified NSCs, the histopathological changes of rat spinal cord were detected by hematoxylin-eosin (HE) staining, and the locomotor activity of rats was evaluated with the Basso, Beattie and Bresnahan (BBB) scale. The NSCs cultured in vitro or extracted from SCI rat spinal cord were identified by immunofluorescence (IF). Mash-1, β3-Tubulin, and NeuN expressions in those cells were determined by Western blotting and reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR).

RESULTS

NSCs isolated from rat embryo hippocampus were Nestin- and NeuN-positive. NSC transplantation modified by Mash-1 increased BBB score of SCI rats and promoted recovery in lesion site of SCI rats. Mash-1 overexpression also promoted β3-Tubulin and NeuN expressions in NSCs cultured in vitro or extracted from spinal cord of SCI rats.

CONCLUSION

Mash-1 overexpression promoted NSC differentiation into neurons, and further improved locomotor functional recovery of SCI rats.

The Advent of Spinoplastics: Easing the Growing Global Disease Burden of Spinal Injury

Epidemiologic studies have demonstrated a growing global disease burden of pathologies affecting the vertebral column. Allograft or implant-based reconstruction and fusion surgeries have been the mainstay of treatment. The efficacy of various surgical methods and the reliability of instrumentation or implants to execute these surgeries continue to be debated in the literature. Advances such as the free-tissue transfer have improved postoperative measures; however, they add high operative risk. The advent of spinoplastics introduces a practical surgical model to augment these spinal surgeries using vascularized bone grafts. As this technique becomes more widespread, it can be utilized to ease the growing disease burden that spinal injury places on both patients and the health care system. Ultimately, it will ameliorate strains on health care resources, reduce health care costs, and improve patient outcomes and quality of life.