Influence of Blood Pressure on Acute Cervical Spinal Cord Injury Without Fracture and Dislocation: Results From a Retrospective Analysis.

OBJECTIVE: The objective of this study was to investigate the influence of blood pressure on the severity and functional recovery of patients with acute cervical spinal cord injury (SCI) without fracture and dislocation. METHODS: A retrospective case control study analyzed the data of 40 patients admitted to our orthopedics department (Beijing Tiantan Hospital, Capital Medical University) from January 2013 to February 2021. They were diagnosed as acute cervical SCI without fracture and dislocation. Gender, age, height, weight, history of hypertension, postinjury American Spinal Injury Association grade, postinjury modified Japanese Orthopaedic Association (mJOA) score, postoperative mJOA score, 1-year follow-up mJOA score, preoperative mean arterial pressure (MAP), intramedullary T2 hyperintensity, and hyponatremia were collected. The patients were divided into groups and subgroups based on their history of hypertension and preoperative MAP. The effects of history of hypertension and preoperative MAP on the incidence of T2 hyperintensity, hyponatremia, the improvement rate of the postoperative mJOA and 1-year follow-up mJOA scores were analyzed. RESULTS: Patients with history of hypertension had a lower incidence of intramedullary T2 hyperintensity than patients without history of hypertension (P < 0.05). Patients with history of hypertension and patients with a higher preoperative MAP had better neurological recovery at 1 year of follow-up (P < 0.05). CONCLUSIONS: Blood pressure has great influence on acute cervical SCI without fracture and dislocation. Maintaining a higher preoperative MAP is advantageous for better recovery after SCI. Attention should be paid to the dynamic management of blood pressure to avoid the adverse effects of hypotension after SCI.

Morphological analysis of isolated hemivertebra: radiographic manifestations related to the severity of congenital scoliosis.

PURPOSE: The natural history of congenital scoliosis (CS) caused by hemivertebra varies greatly. This study aimed to explore the association between the morphology of hemivertebra and the severity of CS, since the diagnosis of the hemivertebra. METHODS: Patients with isolated (single fully segmented) hemivertebra were enrolled. The degree and progression of deformity were compared by three morphological parameters of hemivertebra, comprising whether the width of hemivertebra extends across the central vertical line of lower adjacent vertebra (midline); the lateral height ratio (LHR, lateral height of hemivertebra× 2/(lateral height of HV-1 plus HV + 1) with the cut-point being 0.9; and the sagittal position of hemivertebra that was divided into the lateral and posterolateral group. RESULTS: In total, 156 patients (mean age 9.7 ± 6.2 years, 81 males) were enrolled. The number of thoracic, thoracolumbar (T12/13-L1), and lumbar hemivertebrae were 63, 41, and 52, respectively. Hemivertebrae across the midline had larger scoliosis and kyphosis (58.3 ± 20.6° vs. 42.8 ± 15.0°, P <  0.001; 45.1 ± 32.5° vs. 29.5 ± 25.7°, P = 0.013, respectively). Hemivertebrae with LHR ≥0.9 was associated with larger scoliosis (55.7 ± 20.6° vs. 41.4 ± 13.3°, P <  0.001). Larger scoliosis and kyphosis were observed in posterolateral hemivertebrae (54.4 ± 21.0° vs. 44.4 ± 15.6°, P = 0.026; 51.4 ± 31.5° vs. 20.6 ± 17.1°, P <  0.001, respectively). Co-occurrence of more than one of the three positive parameters above indicated higher annual progression (5.0 ± 2.2° vs. 3.3 ± 1.3°, P <  0.001). CONCLUSION: Three positive parameters, width across the midline, LHR ≥0.9, and posterolateral position were associated with a more severe deformity in patients with isolated hemivertebra. Hemivertebrae with more than one positive parameter may cause progressive deformity, and thus need prompt surgery. LEVEL OF EVIDENCE: Prognostic, level IV.

Accurate Differentiation of Spinal Tuberculosis and Spinal Metastases Using MR-Based Deep Learning Algorithms.

Purpose: To explore the application of deep learning (DL) methods based on T2 sagittal MR images for discriminating between spinal tuberculosis (STB) and spinal metastases (SM). Patients and Methods: A total of 121 patients with histologically confirmed STB and SM across four institutions were retrospectively analyzed. Data from two institutions were used for developing deep learning models and internal validation, while the remaining institutions' data were used for external testing. Utilizing MVITV2, EfficientNet-B3, ResNet101, and ResNet34 as backbone networks, we developed four distinct DL models and evaluated their diagnostic performance based on metrics such as accuracy (ACC), area under the receiver operating characteristic curve (AUC), F1 score, and confusion matrix. Furthermore, the external test images were blindly evaluated by two spine surgeons with different levels of experience. We also used Gradient-Class Activation Maps to visualize the high-dimensional features of different DL models. Results: For the internal validation set, MVITV2 outperformed other models with an accuracy of 98.7%, F1 score of 98.6%, and AUC of 0.98. Other models followed in this order: EfficientNet-B3 (ACC: 96.1%, F1 score: 95.9%, AUC: 0.99), ResNet101 (ACC: 85.5%, F1 score: 84.8%, AUC: 0.90), and ResNet34 (ACC: 81.6%, F1 score: 80.7%, AUC: 0.85). For the external test set, MVITV2 again performed excellently with an accuracy of 91.9%, F1 score of 91.5%, and an AUC of 0.95. EfficientNet-B3 came second (ACC: 85.9, F1 score: 91.5%, AUC: 0.91), followed by ResNet101 (ACC:80.8, F1 score: 80.0%, AUC: 0.87) and ResNet34 (ACC: 78.8, F1 score: 77.9%, AUC: 0.86). Additionally, the diagnostic accuracy of the less experienced spine surgeon was 73.7%, while that of the more experienced surgeon was 88.9%. Conclusion: Deep learning based on T2WI sagittal images can help discriminate between STB and SM, and can achieve a level of diagnostic performance comparable with that produced by experienced spine surgeons.

Differential diagnosis of benign and malignant vertebral compression fractures: Comparison and correlation of radiomics and deep learning frameworks based on spinal CT and clinical characteristics.

PURPOSE: Differentiating benign from malignant vertebral compression fractures (VCFs) is a diagnostic dilemma in clinical practice. To improve the accuracy and efficiency of diagnosis, we evaluated the performance of deep learning and radiomics methods based on computed tomography (CT) and clinical characteristics in differentiating between Osteoporosis VCFs (OVCFs) and malignant VCFs (MVCFs). METHODS: We enrolled a total of 280 patients (155 with OVCFs and 125 with MVCFs) and randomly divided them into a training set (80%, n = 224) and a validation set (20%, n = 56). We developed three predictive models: a deep learning (DL) model, a radiomics (Rad) model, and a combined DL_Rad model, using CT and clinical characteristics data. The Inception_V3 served as the backbone of the DL model. The input data for the DL_Rad model consisted of the combined features of Rad and DCNN features. We calculated the receiver operating characteristic curve, area under the curve (AUC), and accuracy (ACC) to assess the performance of the models. Additionally, we calculated the correlation between Rad features and DCNN features. RESULTS: For the training set, the DL_Rad model achieved the best results, with an AUC of 0.99 and ACC of 0.99, followed by the Rad model (AUC: 0.99, ACC: 0.97) and DL model (AUC: 0.99, ACC: 0.94). For the validation set, the DL_Rad model (with an AUC of 0.97 and ACC of 0.93) outperformed the Rad model (with an AUC: 0.93 and ACC: 0.91) and the DL model (with an AUC: 0.89 and ACC: 0.88). Rad features achieved better classifier performance than the DCNN features, and their general correlations were weak. CONCLUSIONS: The Deep learnig model, Radiomics model, and Deep learning Radiomics model achieved promising results in discriminating MVCFs from OVCFs, and the DL_Rad model performed the best.

Identification of Origin for Spinal Metastases from MR Images: Comparison Between Radiomics and Deep Learning Methods.

OBJECTIVE: To determine whether spinal metastatic lesions originated from lung cancer or from other cancers based on spinal contrast-enhanced T1 (CET1) magnetic resonance (MR) images analyzed using radiomics (RAD) and deep learning (DL) methods. METHODS: We recruited and retrospectively reviewed 173 patients diagnosed with spinal metastases at two different centers between July 2018 and June 2021. Of these, 68 involved lung cancer and 105 were other types of cancer. They were assigned to an internal cohort of 149 patients, randomly divided into a training set and a validation set, and to an external cohort of 24 patients. All patients underwent CET1-MR imaging before surgery or biopsy. We developed two predictive algorithms: a DL model and a RAD model. We compared performance between models, and against human radiological assessment, via accuracy (ACC) and receiver operating characteristic (ROC) analyses. Furthermore, we analyzed the correlation between RAD and DL features. RESULTS: The DL model outperformed RAD model across the board, with ACC/ area under the receiver operating characteristic curve (AUC) values of 0.93/0.94 (DL) versus 0.84/0.93 (RAD) when applied to the training set from the internal cohort, 0.74/0.76 versus 0.72/0.75 when applied to the validation set, and 0.72/0.76 versus 0.69/0.72 when applied to the external test cohort. For the validation set, it also outperformed expert radiological assessment (ACC: 0.65, AUC: 0.68). We only found weak correlations between DL and RAD features. CONCLUSION: The DL algorithm successfully identified the origin of spinal metastases from pre-operative CET1-MR images, outperforming both RAD models and expert assessment by trained radiologists.

Is diabetes the risk factor for poor neurological recovery after cervical spine surgery? A review of the literature.

The poor prognosis of cervical spine surgery is mainly manifested as poor neurological recovery and the presence of new upper extremity dysfunction that promotes significant psychological and physiological burdens on patients. Many factors influence the prognosis of cervical spine surgery, including the age of patients, the time and mode of surgery, and the surgical technique used. However, in clinical studies, it has been observed that patients with diabetes have a higher probability of poor prognosis after surgery. Therefore, we review the pathophysiology of diabetic neuropathies and discuss its impact on cervical nerve system function, especially in cervical nerve roots and upper limb peripheral nerve conduction.

New Insights into the Regulatory Role of Ferroptosis in Ankylosing Spondylitis via Consensus Clustering of Ferroptosis-Related Genes and Weighted Gene Co-Expression Network Analysis.

Background: The pathogenesis of ankylosing spondylitis (AS) remains undetermined. Ferroptosis is a newly discovered form of regulated cell death involved in multiple autoimmune diseases. Currently, there are no reports on the connection between ferroptosis and AS. Methods: AS samples from the Gene Expression Omnibus were divided into two subgroups using consensus clustering of ferroptosis-related genes (FRGs). Weighted gene co-expression network analysis (WGCNA) of the intergroup differentially expressed genes (DEGs) and protein-protein interaction (PPI) analysis of the key module were used to screen out hub genes. A multifactor regulatory network was then constructed based on hub genes. Results: The 52 AS patients in dataset GSE73754 were divided into cluster 1 (n = 24) and cluster 2 (n = 28). DEGs were mainly enriched in pathways related to mitochondria, ubiquitin, and neurodegeneration. Candidate hub genes, screened by PPI and WGCNA, were intersected. Subsequently, 12 overlapping genes were identified as definitive hub genes. A multifactor interaction network with 45 nodes and 150 edges was generated, comprising the 12 hub genes and 32 non-coding RNAs. Conclusions: AS can be divided into two subtypes according to FRG expression. Ferroptosis might play a regulatory role in AS. Tailoring treatment according to the ferroptosis status of AS patients can be a promising direction.

Influences of Thoracic Spinal Deformity on Exercise Performance and Pulmonary Function: A Prospective Study of 168 Patients with Adolescent Idiopathic Scoliosis.

STUDY DESIGN: A prospective study. OBJECTIVE: The aim of this study was to investigate the factors associated with cardiopulmonary exercise testing (CPET) measurements in patients with adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA: Patients with AIS display restrictive pulmonary dysfunction on pulmonary function testing (PFT). It remains unknown whether thoracic spinal deformity affects exercise performance. METHODS: One hundred and sixty-eight patients with AIS from January 2014 to December 2019 were included. They underwent preoperative spinal radiological assessment, PFT, and CPET. The effects of the thoracic curve magnitude, body mass index, physical activity level and history of bracing on pulmonary function and exercise performance were analyzed. The Student t test and two-tailed Pearson test were used in data analysis. RESULTS: We found significantly reduced forced expiratory volume in 1second (FEV1) in patients with a larger magnitude of the proximal thoracic curve (P < 0.001) and the main thoracic curve (P < 0.001). There was a negative correlation between forced vital capacity (FVC) and the magnitude of the main thoracic curve (P < 0.001) and thoracic hypokyphosis (P < 0.001). In CPET, exercise capacity indicators such as the work rate, peak oxygen intake, and heart rate were not affected by the thoracic curve magnitude. Patients with moderate or severe pulmonary dysfunction had decreased tidal volume (P = 0.01) and ventilatory reserve (P < 0.001), as well as increased respiratory frequency at maximal exercise (P = 0.01). Patients with a moderate or high physical activity level had better exercise capacity, which was reflected by a higher work rate (P = 0.009) and oxygen intake (P < 0.001). CONCLUSION: There was no significant correlation between radiographic parameters and exercise capacity indicators. When the thoracic curve increased, patients had restrictive ventilatory dysfunction, which led to a tachypneic breathing pattern and reduction of ventilatory reserve during exercise. A physiological change of improved peak oxygen intake was demonstrated in patients with a moderate or high physical activity level.Level of Evidence: 3.

The Effect of Traditional Single Growing Rod Technique on the Growth of Unsegmented Levels in Mixed-Type Congenital Scoliosis.

STUDY DESIGN: Retrospective case series. OBJECTIVES: To present outcomes concerning patients with early-onset mixed-type congenital scoliosis (EOMTCS) treated with the traditional single growing rod (TSGR), focusing on the growth of unsegmented levels (USLs). METHODS: Patients with EOMTCS who underwent TSGR and had a minimum of 4 USLs, 4 distractions, and 3-year follow-up were enrolled. Spine radiographs before and after index surgery and at the latest follow-up were evaluated. The length of the concave and convex side of USLs and thoracic parameters were measured. The absolute value and percentage of growth were calculated. RESULTS: Fourteen patients (mean age, 7.3 ± 2.8 years) were enrolled. The average follow-up duration was 4.9 ± 1.2 years, during which time 84 distractions and 8 final fusions were performed. The average number of USLs was 6.3 ± 2.2. The total and annual percent growth of concave side of USLs was significantly higher than convex side (32.2 ± 13.3% vs. 23.9 ± 9.5%, p = 0.007; 6.8 ± 2.7%/year vs. 5.1% ± 2.2%/year, p = 0.007, respectively). The concave-to-convex ratio of USLs increased from 58.6 ± 6.4 ± 7.6% at baseline to 68.8 ± 9.3% at the latest follow-up (p < 0.001). The Campbell's space available for lung ratio increased from 74.9 ± 11.1% at baseline to 89.6 ± 7.0% at the latest follow-up (p < 0.001). CONCLUSIONS: In patients with EOMTCS, unilateral repetitive lengthening with TSGR can accelerate the growth of the concave side of USLs and improve the symmetry of the thorax.

Depression and anxiety in cervical degenerative disc disease: Who are susceptible?

Background: Pre-operative depression and anxiety are associated with poorer patient-reported outcomes following cervical spine surgery. Identification of and interventions for these disorders are key to preventing related negative effects. However, most spine surgeons do not routinely evaluate mental health disorders. Few studies have investigated which patients with cervical degenerative disc diseases (CDDD) are susceptible to depression and anxiety. Objective: To determine the factors associated with depression and anxiety in patients with CDDD. Methods: Three hundred twelve patients with CDDD were recruited in this cross-sectional case-control study. Patients underwent a structured interview to acquire demographic and clinical characteristic information, which included the Neck Disability Index (NDI), modified Japanese Orthopedic Association (mJOA), and Visual Analog Scale (VAS) for neck/arm pain. Depression and anxiety were evaluated using the Zung Self-Rating Depression and Anxiety Scales. Univariate and multivariate logistic regression analyses were used to identify factors associated with depression and anxiety. Results: Of all patients, 102 (32.7%) had depression and 92 (29.5%) had anxiety. Two hundred six (66.0%) patients with neither depression nor anxiety were defined as the control group. Univariate analysis indicated that gender, educational level, occupation type, Charlson comorbidity index, symptom duration, symptomatology, surgery history, NDI, mJOA, VAS-neck, and VAS-arm scores were associated with depression and anxiety (except for symptom duration for anxiety). Multivariate logistic regression analysis indicated that females [odds ratio (OR) 1.81, 95% confidence interval (CI) 1.01-3.23], physical work (OR 2.06, 95% CI 1.16-3.65), poor mJOA score (ORmoderate 2.67, 95% CI 1.40-5.07; ORsevere 7.63, 95% CI 3.85-15.11), and high VAS-neck score (OR 1.24, 95% CI 1.11-1.39) were independent risk factors for depression. Physical work (OR 1.84, 95% CI 1.01-3.35), poor mJOA score (ORmoderate 2.66, 95% CI 1.33-5.33; ORsevere 9.26, 95% CI 4.52-18.99), and high VAS-neck score (OR 1.34, 95% CI 1.19-1.51) were independent risk factors for anxiety. Conclusion: Approximately one-third of patients with CDDD had depression or anxiety. Patients who engaged in heavy work and had severe symptoms (poor mJOA and high VAS-neck scores) are susceptible to depression and anxiety. Additionally, female patients are susceptible to depression. Our findings may help identify CDDD patients with depression and anxiety in clinical practice.

A Rare Manifestation of a Presumed Non-Osteophilic Brain Neoplasm: Extensive Axial Skeletal Metastases From Glioblastoma With Primitive Neuronal Components.

BACKGROUND: Glioblastoma multiforme (GBM) is the most common malignant tumor of the central nervous system. GBM with primitive neuronal component (GBM-PNC) is an aggressive variant identified in 0.5% of GBMs. Extracranial metastasis from GBM-PNC is a rare and challenging situation. METHODS: A special case of early-onset GBM with systemic bone metastasis was enrolled. Clinical data, including patient characteristics, disease course, and serial radiological images were retrieved and analyzed. Tumor tissues were obtained by surgical resections and were made into formalin-fixed paraffin-embedded sections. Histopathological examinations and genetic testing were performed for both the primary and metastatic tumor specimens. RESULTS: A 20-year-old man suffered from GBM with acute intratumoral hemorrhage of the left temporal lobe. He was treated by gross total resection and chemoradiotherapy following the Stupp protocol. Seven months later, he returned with a five-week history of progressive neck pain and unsteady gait. The radiographic examinations identified vertebral collapse at C4 and C6. Similar osteolytic lesions were also observed at the thoracolumbar spine, pelvic, and left femur. Anterior spondylectomy of C4 and C6 was performed. The resected vertebral bodies were infiltrated with greyish, soft, and ill-defined tumor tissue. One month later, he developed mechanical low-back pain and paraplegia caused by thoracolumbar metastases. Another spine surgery was performed, including T10 total en-bloc spondylectomy, T7-9, L2-3, and L5-S1 laminectomy. After the operation, the patient's neurological function and spinal stability remained stable. However, he finally succumbed to the rapidly increased tumor burden and died 15 months from onset because of cachexia and multiple organ failure. In addition to typical GBM morphology, the histological examinations identified monomorphic small-round cells with positive immunohistochemical staining of synaptophysin and CD99, indicating the coexistence of PNC. The next-generation sequencing detected pathogenic mutations in TP53 and DNMT3A. Based on above findings, a confirmed diagnosis of systemic metastases from GBM-PNC (IDH-wild type, WHO grade IV) was made. CONCLUSIONS: The present case highlights the occurrence and severity of extensive axial skeletal metastases from GBM-PNC. This rare variant of GBM requires aggressive multimodal treatment including surgery and chemoradiotherapy targeting PNC. The pathological screening of PNC is recommended in patients with early-onset GBM and intratumoral hemorrhage. Surgery for spinal metastasis is appropriate in patients with chemoradioresistance and relatively good general status, with the objectives of restoring spinal stability and relieving spinal cord compression.

Clinical impact of 3-level anterior cervical decompression and fusion (ACDF) on the occipito-atlantoaxial complex: a retrospective study of patients who received a zero-profile anchored spacer versus cage-plate construct.

PURPOSE: To evaluate changes in the sagittal parameters of the occipito-atlantoaxial complex after three-level anterior cervical decompression and fusion (ACDF) and identify the influential factors by comparing ACDF with a zero-profile anchored spacer (ACDF-Z) versus a cage-plate construct (ACDF-P). METHODS: The cohort comprised 106 patients who underwent three-level contiguous ACDF-Z or ACDF-P for cervical radiculopathy and/or myelopathy. Standing, flexion, and extension radiographs of cervical spine were obtained preoperatively, and 3 and 12 months postoperatively. The assessed cervical sagittal parameters were the platform angle of the axis, Cobb angle, and range of motion (ROM) of C2⁃7, C0⁃1, and C1⁃2. RESULTS: In both the ACDF-Z and ACDF-P groups, the Cobb angle of the upper cervical spine decreased and the C0-1 ROM increased from preoperatively to 3 and 12 months postoperatively (P < 0.01). The alignment restoration was lost at 12 months compared with 3 months in the ACDF-Z group, but not in the ACDF-P group (P < 0.01). The ACDF-P group showed more loss of C2-7 ROM and more compensatory changes in C0-2 ROM than the ACDF-Z group (P < 0.05). CONCLUSION: The Cobb angle decreased and ROM increased significantly as compensatory changes of the atlantooccipital or atlantoaxial joint after both types of ACDF, which may accelerate degeneration. The zero-profile anchored spacer had less impact on the occipito-atlantoaxial complex but was worse at maintaining the alignment restoration, which were contrary to the cage-plate construct. Surgeons should be aware of the impact of multi-level ACDFs on the occipito-atlantoaxial complex.

The effect of cervical intervertebral disc degeneration on the motion path of instantaneous center of rotation at degenerated and adjacent segments: A finite element analysis.

BACKGROUND: The motion path of instantaneous center of rotation (ICR) is a crucial kinematic parameter to dynamically characterize cervical spine intervertebral patterns of motion; however, few studies have evaluated the effect of cervical disc degeneration (CDD) on ICR motion path. The purpose of this study was to investigate the effect of CDD on the ICR motion path of degenerated and adjacent segments. METHOD: A validated nonlinear three-dimensional finite element (FE) model of a healthy adult cervical spine was used. Progressive degeneration was simulated with six FE models by modifying intervertebral disc height and material properties, anterior osteophyte size, and degree of endplate sclerosis at the C5-C6 level. All models were subjected to a pure moment of 1 Nm and a compressive follower load of 73.6 N to simulate physical motion. ICR motion paths were compared among different models. RESULTS: The normal FE model results were consistent with those of previous studies. In degenerative models, average ICR motion paths shifted significantly anterior at the degenerated segment (ß = 0.27 mm; 95% CI: 0.22, 0.32) and posterior at the proximal adjacent segment (ß = -0.09 mm; 95% CI: -0.15, -0.02) than those of the normal model. CONCLUSION: CDD significantly affected ICR motion paths at the degenerated and proximal adjacent segments. The changes at adjacent segments may be a result of compensatory mechanisms to maintain the balance of the cervical spine. Surgical treatment planning should take into account the restoration of ICR motion path to normal. These findings could provide a basis for prosthesis design and clinical practice.

An Unrecognized Ligament and its Ossification in the Craniocervical Junction: Prevalence, Patient Characteristics, and Anatomic Evidence.

BACKGROUND: In the craniocervical junction, the ligaments between the anterior foramen magnum and the anterior arch of the atlas are not well defined, and ossification of the ligaments in this region has rarely been reported. Characterizing the anatomy and ossification of these ligaments may help in the diagnosis and treatment of disorders in this region. QUESTIONS/PURPOSES: (1) What is the prevalence of an unrecognized ossification at the craniocervical junction in patients with cervical spine disorders, and what are the patient characteristics associated with this ossification? (2) Do patients with this ossification have a greater risk of ossification of other structures at the craniocervical junction or cervical spine? (3) Is there an unreported ligament at this ossified site? METHODS: We conducted a retrospective study of 578 hospitalized patients who underwent CT for cervical spine disorders between January 2016 and July 2020. Based on the inclusion criteria, 11% (66 of 578) were excluded because of a cervical or craniocervical tumor, deformity, infection, fracture or dislocation, or prior surgery, leaving 89% (512 of 578) for analysis. These 512 patients had diagnoses of cervical radiculopathy, cervical myelopathy, cervical spondylotic amyotrophy, cervical spinal cord injury without a radiographic abnormality, or axial neck pain. Their mean age was 57 years (range 22-90 years), and 60% of the patients were men. Patient characteristics including age, gender, and diagnosis were retrieved from a longitudinally maintained institutional database. CT images were used to assess the presence of a previously unrecognized ossification and ossification of other structures in the craniocervical junction and cervical spine, including the posterior longitudinal ligament, anterior longitudinal ligament, nuchal ligament, ligamentum flavum, transverse ligament, and apical ligament, as well as diffuse idiopathic skeletal hyperostosis (DISH). The association between these structures was also assessed. This unreported ossification was called the capped dens sign. It was defined and graded from 1 to 3. Grade 3 was defined as the typical capped dens sign. Cervical spine MRI was used to assess whether there was an unreported structure in the same region as where the capped dens sign was detected on CT images. In the database of a recent study, there were 33 patients younger than 41 years. Nine percent (three of 33) were excluded because they did not have cervical spine MRI. MRIs of the remaining 30 patients were assessed. Their mean age was 35 years (range 22-40 years), and 58% were men. All cervical spine CT images and MRIs were reviewed by one senior spine surgeon and one junior spine surgeon twice with a 2-week interval. Blinding was accomplished by removing identifying information from the radiographs and randomly assigning them to each examiner. Any discrepancy with respect to the grade of the capped dens sign was adjudicated by a third blinded senior spine surgeon. Intrarater and interrater reliabilities were assessed by calculating weighted kappa statistics. No ligament or membrane was reported at this site. MRI is not sensitive to identify thin tissue in this region, especially when severe degeneration has occurred. A cadaveric study was conducted to discover a potential ligament between the inferior margin of the foramen magnum and the anterior arch of the atlas, as prompted by the newly discovered ossification in the clinical analysis of this study. Six embalmed human cadaveric craniocervical regions (three male and three female cadavers; median age 56 years, range 45-78 years) were dissected by a senior anatomist and a senior anatomy technician. A mid-sagittal section of the craniocervical junction was created, allowing us to explore the interval between the anterior foramen magnum and anterior arch of the atlas. A histologic analysis was conducted in two of the six cadavers (a male cadaver, 45 years; and a female cadaver, 51 years). Slides were made with 4-µm sections and stained with hematoxylin and eosin. RESULTS: A novel capped dens sign was detected in 39% (198 of 512) of the patients and the most typical capped dens sign was detected in 19% (96 of 512) of patients. The prevalence of this sign was the highest in patients with cervical spondylotic amyotrophy (12 of 25 patients). The prevalence of ossification of the anterior longitudinal ligament, ligamentum nuchae, and apical ligament, as well as DISH, was higher in patients with a capped dens sign than in those without (p = 0.04, p < 0.001, p < 0.001, and p = 0.001, respectively). The capped dens sign was identified in 69% (18 of 26) of the patients with DISH. A thin and short band-like structure or osteophyte was detected on MRI in 87% (26 of 30), in the same region as the capped dens sign. In the cadaveric study, an unreported, distinct ligamentous structure was identified at this ossified site. It originated from the posterosuperior rim of the anterior arch of the atlas to the inferior margin of the foramen magnum, which we called the inter-atlanto-occipital ligament. It was found in all six dissected craniocervical junctions. The histologic analysis revealed dense connective tissue. CONCLUSION: More than one-third of the patients in this series demonstrated CT evidence of a previously unrecognized ossification in the craniocervical junction, which we called the capped dens sign. Anatomic evidence of this sign, which was a previously unidentified ligament, was also newly discovered in this region. This study was conducted among Asian patients and specimens. Further studies among diverse ethnic groups may be needed to generalize the results. An additional well-designed prospective study will be needed to provide further evidence regarding the potential pathophysiology and clinical relevance of the capped dens sign. Furthermore, the cadaveric analysis in this study was only a preliminary report of the ligament; further biomechanical research is needed to investigate its function. CLINICAL RELEVANCE: Knowledge of this novel ligament may improve the diagnosis and treatment of craniocervical stability and dislocation. Ossification of this ligament is correlated with age, cervical spondylotic amyotrophy, and DISH. We wonder whether patients with cervical degenerative disorders who also have a capped dens sign may be at risk for the formation of osteophytes of an uncovertebral joint, which may result in palsy of the upper limb muscles. The capped dens sign may be the craniocervical manifestation of DISH. This possible association between the capped dens sign and DISH should be considered when performing surgery on patients with the capped dens sign.

Bioinformatic analysis of SMN1-ACE/ACE2 interactions hinted at a potential protective effect of spinal muscular atrophy against COVID-19-induced lung injury.

Patients with spinal muscular atrophy (SMA) are susceptible to the respiratory infections and might be at a heightened risk of poor clinical outcomes upon contracting coronavirus disease 2019 (COVID-19). In the face of the COVID-19 pandemic, the potential associations of SMA with the susceptibility to and prognostication of COVID-19 need to be clarified. We documented an SMA case who contracted COVID-19 but only developed mild-to-moderate clinical and radiological manifestations of pneumonia, which were relieved by a combined antiviral and supportive treatment. We then reviewed a cohort of patients with SMA who had been living in the Hubei province since November 2019, among which the only 1 out of 56 was diagnosed with COVID-19 (1.79%, 1/56). Bioinformatic analysis was carried out to delineate the potential genetic crosstalk between SMN1 (mutation of which leads to SMA) and COVID-19/lung injury-associated pathways. Protein-protein interaction analysis by STRING suggested that loss-of-function of SMN1 might modulate COVID-19 pathogenesis through CFTR, CXCL8, TNF and ACE. Expression quantitative trait loci analysis also revealed a link between SMN1 and ACE2, despite low-confidence protein-protein interactions as suggested by STRING. This bioinformatic analysis could give hint on why SMA might not necessarily lead to poor outcomes in patients with COVID-19.

Surgical Scoliosis Correction in Chiari-I Malformation with Syringomyelia Versus Idiopathic Syringomyelia.

BACKGROUND: Both patients with Chiari-I malformation (CIM) with syringomyelia and those with idiopathic syringomyelia (ISm) have a syrinx and can have scoliosis as well. However, there is no literature regarding differences between CIM and ISm in terms of radiographic outcomes and surgical complications after posterior fusion, to our knowledge. The aim of the present study was to compare radiographic features, clinical outcomes, and surgical complications after posterior spinal fusion between patients with CIM-associated scoliosis and those with ISm-associated scoliosis. METHODS: One hundred and twenty patients with syringomyelia-associated scoliosis were retrospectively analyzed. Twenty-one patients with scoliosis secondary to CIM were enrolled and matched by sex, age, and the Cobb angle of the scoliotic curve with 21 patients with scoliosis secondary to ISm. All patients underwent 1-stage posterior fusion surgery. Coronal and sagittal radiographic parameters were evaluated before surgery, immediately after surgery, and at the final follow-up (at least 2 years). We also collected data regarding syringeal features, neurological deficits, intraoperative neuromonitoring, and complications. RESULTS: Sex, age, preoperative coronal/sagittal scoliosis parameters, and neurological deficits were similar between the matched CIM and ISm groups. On average, the CIM group had a longer syrinx (12.3 ± 3.6 versus 8.9 ± 4.5 vertebral levels, p = 0.010) than the ISm group. The CIM and ISm groups showed similar correction rates for primary curves (70.9% ± 10.6% versus 69.5% ± 16.3%, p = 0.739). There were no significant differences in coronal/sagittal correction, intraoperative neuromonitoring abnormalities, surgical complications, or Scoliosis Research Society-22 questionnaire scores between the 2 groups. CONCLUSIONS: Despite matched demographic and scoliotic coronal parameters, patients with CIM had longer syrinxes compared with patients with ISm. One-stage posterior fusion achieved comparable clinical and radiographic outcomes for both CIM- and ISm-associated scoliosis without significant differences in neurological complications. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Genome-Wide Analysis of circular RNAs and validation of hsa_circ_0006719 as a potential novel diagnostic biomarker in congenital scoliosis patients.

Congenital scoliosis (CS) is a form of spinal curvature resulting from anomalous development of vertebrae. Recent studies demonstrated that circRNAs could serve as potential biomarkers of disease diagnosis. Genome-wide circRNAs expression in seven CS patients and three healthy controls was initially detected. Bioinformatics analysis was conducted to explore the potential pathological pathway of CS. Quantitative PCR (qPCR) was performed to validate the selected circRNAs in the replication cohort with 32 CS patients and 30 healthy controls. Logistic regression controlling for gender was conducted to compare the expression difference. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic value. Twenty-two differentially expressed circRNAs were filtered from genome-wide circRNA sequencing. Seven circRNAs were validated by qPCR. Only hsa_circ_0006719 was confirmed to have a higher expression level in the CS group than the healthy control group (P = 0.036). Receiver operating characteristic curve also suggested that hsa_circ_0006719 had significant diagnostic value for CS (AUC = 0.739, P = 0.001). We described the first study of circRNAs in CS and validated hsa_circ_0006719 as a potential novel diagnostic biomarker of CS.

Topical Injection of Tranexamic Acid via a Drain Plus Drain-Clamping to Reduce Blood Loss in Degenerative Lumbar Scoliosis Surgery.

OBJECTIVE: The aim of the present study was to investigate whether an innovative way of administering tranexamic acid (TXA), that is, injecting it retrogradely through the drain and clamping it for 1 h, can reduce postoperative bleeding after degenerative lumbar scoliosis surgery. METHODS: Sixty degenerative lumbar scoliosis patients who underwent posterior lumbar decompression with fusion of three or more levels were retrospectively enrolled and categorized into three groups (TXA, Gelfoam, and control groups). The demographic distribution, operative parameters, length and amount of Hemovac drainage, blood transfusion rate, length of stay, laboratory results (complete blood count and coagulogram), and the postoperative complications were collected and analyzed. RESULTS: The age of patients in the Gelfoam group was significantly younger than in the TXA and control groups (59.75 ± 6.95 vs 66.10 ± 8.80, P = 0.016 and 59.75 ± 6.95 vs 67.90 ± 5.33, P = 0.000, respectively). There were no significant differences in sex, body mass index, comorbid medical status, and operation level between each of the two groups. The three groups did not differ significantly in estimated blood loss during surgery, the mean red blood cell transfusion requirement during hospitalization, and the entire perioperative allogenic blood transfusion rate. The postoperative total blood loss and total drainage were lower in the TXA group than in the control group (1027.14 ± 466.56 vs 1390.07 ± 314.85 mL, P = 0.006; 322.20 ± 187.32 vs 605.50 ± 184.70 mL, P = 0.000, respectively). The length of drainage retention in the TXA group was significantly shorter than in the Gelfoam and control groups (46.10 ± 9.00 vs 68.00 ± 12.31 h, P = 0.000 and 46.10 ± 9.00 vs 76.40 ± 10.97 h, P = 0.000, respectively). The TXA and Gelfoam groups also had significantly shorter hospital stays than the control group (7.50 ± 0.95 vs 9.80 ± 2.44 days, P = 0.000, and 7.90 ± 1.16 vs 9.80 ± 2.44 days, P = 0.003, respectively). At discharge, the mean hemoglobin and hematocrit level were significantly higher in the TXA group compared with the control group (11.77 ± 1.78 g/dL vs 10.67 ± 0.94 g/dL, P = 0.002; 34.82 ± 3.57% vs 31.79 ± 3.85%, P = 0.014). No significant difference was identified with respect to prothrombin time, activated partial thromboplastin time, and D-dimmer among groups (P > 0.05). The three groups were comparable in wound problem incidences. Symptomatic deep vein thrombosis and pulmonary embolism were not observed in this study. CONCLUSION: Topical injection of TXA retrogradely via a drain at the end of a degenerative lumbar scoliosis operation and clamping the drain for an hour can effectively decrease the postoperative blood loss and the length of hospitalization without increasing the complication rate.

Comparison of Radiological Features and Clinical Characteristics in Scoliosis Patients With Chiari I Malformation and Idiopathic Syringomyelia: A Matched Study.

STUDY DESIGN: Retrospective study. OBJECTIVE: To compare syrinx characteristics, scoliotic parameters, and neurological deficits between Chiari I malformation (CIM) and idiopathic syringomyelia (IS) in the scoliotic population. SUMMARY OF BACKGROUND DATA: CIM and IS are common in neuromuscular scoliosis patients; however, differences in syrinx characteristics, scoliotic parameters, and neurological deficits between CIM and IS are unclear. METHODS: Thirty-six patients with scoliosis secondary to CIM were enrolled retrospectively and matched with 36 IS patients for sex, age, scoliosis classification, and Cobb angle. Information on radiographic features of scoliosis and syrinx and neurological deficits was systematically collected. RESULTS: Sex, age, and coronal, and sagittal scoliosis parameters did not differ between the CIM and IS groups. The CIM group had a longer syrinx (12.9 ±â€Š4.0 vertebral levels vs. 8.7 ±â€Š5.5 vertebral levels, P < 0.001), a higher cranial extent (3.6 ±â€Š2.2 vs. 5.2 ±â€Š3.5, P = 0.027), and a lower caudal extent (15.6 ±â€Š2.9 vs. 13.0 ±â€Š4.6, P = 0.006) than the IS group, despite no differences in syrinx/cord (S/C) ratio or syrinx classification. No differences in neurological deficits were identified between the CIM and IS patients. CONCLUSION: With demographic and scoliotic coronal parameters matched, the CIM patients had a longer syrinx, located at a higher cranial and lower caudal level, compared with the IS group. No significant differences in syrinx S/C ratio, sagittal features of scoliosis, or neurological deficits were detected between the two groups. LEVEL OF EVIDENCE: 3.

Impact of Thoracic Cage Dimension and Geometry on Cardiopulmonary Function in Patients With Congenital Scoliosis: A Prospective Study.

STUDY DESIGN: A prospective study of cardiopulmonary function in patients with congenital scoliosis (CS). OBJECTIVE: To investigate the relationship of thoracic cage deformity and exercise tolerance in CS patients. SUMMARY OF BACKGROUND DATA: Congenital thoracic scoliosis and chest deformity lead to restrictive pulmonary dysfunction and in some severe cases cause cardiopulmonary failure. However, it is still unknown the relationship between thoracic deformity and exercise performance. METHODS: Patients with congenital thoracic spinal deformity were included and had radiological assessment of thoracic cage, pulmonary function testing, and cardiopulmonary exercise testing. Thoracic dimension including height, width, and depth were measured and geometry parameters were calculated. Two-tailed Pearson and Spearman correlation test and linear regression analysis were performed to investigate correlation of radiographic parameters, pulmonary function, and physical capacity. RESULTS: Sixty patients (41 females and 19 males) were included, with an average age of 18.9 years. Patients with smaller thoracic height (P < 0.001) and width (P < 0.01) and larger depth (P < 0.05) had significantly worse static pulmonary function. In exercise testing, these patients showed significant tendency of ventilation insufficiency, including lower minute ventilation (P < 0.05), faster breathing frequency (P < 0.05), and smaller tidal volume (P < 0.01). Thoracic depth was negatively correlated to exercise capacity, reflected by work rate (P < 0.001), peak oxygen intake (P < 0.001), and heart rate (P = 0.043). Patients with abnormal thoracic geometry, especially a lower ratio of height to depth and a lower ratio of width to depth, have significantly worse static pulmonary function and exercise capacity (all P < 0.05). CONCLUSION: Decreasing thoracic height and width results in restrictive pulmonary dysfunction. Distortion and asymmetry of the thoracic cage are associated with abnormal breathing pattern and reduction of exercise capacity. LEVEL OF EVIDENCE: 3.