Tethered cord syndrome from pediatric and adult perspectives: a comprehensive systematic review of 6135 cases.

OBJECTIVE: This study aimed to investigate the differences in clinical features, diagnostic examination, treatment, and pathological results between adult-onset and pediatric-onset tethered cord syndrome (TCS). METHODS: The authors searched the PubMed, Embase, and Cochrane Library databases through January 2023 for reports on TCS, extracting information on clinical features, imaging data, treatment modalities, prognosis, and pathological research results. A total of 6135 cases from 246 articles were included in the analysis. This review was conducted in accordance with the 2020 PRISMA guidelines and registered on PROSPERO. RESULTS: The most common adult clinical manifestations were pain, urinary symptoms, and numbness; in children, they were urinary symptoms, skin lesions, bowel symptoms, and unspecific motor deficits. Surgical treatment was the primary approach for both adults and children, with a higher clinical improvement rate observed in adults. However, adults also had a higher rate of surgical complications than children. TCS pathological studies have not yet identified the differences between adults and children, and the pathogenesis of adult-onset TCS requires further investigation. CONCLUSIONS: Adult-onset and pediatric-onset TCS exhibit certain differences in clinical characteristics, diagnostic examinations, and treatments. However, significant differences have not been found in current pathological studies between adults and children. Systematic review registration no.: CRD42023479450 (www.crd.york.ac.uk/prospero).

Automatic segmentation of spine x-ray images based on multiscale feature enhancement network.

BACKGROUND: Automatic segmentation of vertebrae in spinal x-ray images is crucial for clinical diagnosis, case analysis, and surgical planning of spinal lesions. PURPOSE: However, due to the inherent characteristics of x-ray images, including low contrast, high noise, and uneven grey scale, it remains a critical and challenging problem in computer-aided spine image analysis and disease diagnosis applications. METHODS: In this paper, a Multiscale Feature Enhancement Network (MFENet), is proposed for segmenting whole spinal x-ray images, to aid doctors in diagnosing spinal-related diseases. To enhance feature extraction, the network incorporates a Dual-branch Feature Extraction Module (DFEM) and a Semantic Aggregation Module (SAM). The DFEM has a parallel dual-branch structure. The upper branch utilizes multiscale convolutional kernels to extract features from images. Employing convolutional kernels of different sizes helps capture details and structural information at different scales. The lower branch incorporates attention mechanisms to further optimize feature representation. By modeling the feature maps spatially and across channels, the network becomes more focused on key feature regions and suppresses task-irrelevant information. The SAM leverages contextual semantic information to compensate for details lost during pooling and convolution operations. It integrates high-level feature information from different scales to reduce segmentation result discontinuity. In addition, a hybrid loss function is employed to enhance the network's feature extraction capability. RESULTS: In this study, we conducted a multitude of experiments utilizing dataset provided by the Spine Surgery Department of Henan Provincial People's Hospital. The experimental results indicate that our proposed MFENet demonstrates superior segmentation performance in spinal segmentation on x-ray images compared to other advanced methods, achieving 92.61 ± 0.431 for MIoU, 92.42 ± 0.329 for DSC, and 99.51 ± 0.037 for Global_accuracy. CONCLUSIONS: Our model is able to more effectively learn and extract global contextual semantic information, significantly improving spinal segmentation performance, further aiding doctors in analyzing patient conditions.

Knockdown of best1 Gene in Zebrafish Caused Abnormal Neuronal and Skeletal Development - A Subtype of Craniovertebral Junction Malformation?

OBJECTIVE: To investigate the developmental defects caused by knockdown of best1 gene in zebrafish as a model for a subtype of craniovertebral junction (CVJ) malformation. METHODS: Two antisense morpholinos (MOs) were designed targeting zebrafish best1 to block translation (ATG-MO) or to disrupt splicing (I3E4-MO). MOs were microinjected into fertilized one-cell embryos. Efficacy of splicing MO was confirmed by reverse transcription-polymerase chain reaction. Phenotypes were analyzed and quantified by microscopy at multiple developmental stages. Neuronal outgrowth was assessed in transgenic zebrafish expressing green fluorescent protein in neurons. Skeletal ossification was visualized by Calcein staining. RESULTS: Knockdown of best1 resulted in zebrafish embryos with shorter body length, curved axis, low survival rate, microcephaly, reduced eye size, smaller head and brain, impaired neuronal outgrowth, and reduced ossification of craniofacial and vertebral bone. CONCLUSION: Best1 gene plays critical roles in ophthalmologic, neurological and skeletal development in zebrafish. A patient with a premature stop codon in BEST1 gene exhibited similar phenotypes, implying a subtype of CVJ malformation.

Role of Preoperative Albumin Quotient in Surgical Planning for Posttraumatic Syringomyelia: A Comparative Cohort Study.

OBJECTIVE: Surgical procedures for patients with posttraumatic syringomyelia (PTS) remain controversial. Until now, there have been no effective quantitative evaluation methods to assist in selecting appropriate surgical plans before surgery. METHODS: We consecutively enrolled PTS patients (arachnoid lysis group, n = 42; shunting group, n = 14) from 2003 to 2023. Additionally, 19 intrathecal anesthesia patients were included in the control group. All patients with PTS underwent physical and neurological examinations and spinal magnetic resonance imaging preoperatively, 3-12 months postoperatively and during the last follow-up. Preoperative lumbar puncture was performed and blood-spinal cord barrier disruption was detected by quotient of albumin (Qalb, cerebrospinal fluid/serum). RESULTS: The ages (p = 0.324) and sex (p = 0.065) of the PTS and control groups did not differ significantly. There were also no significant differences in age (p = 0.216), routine blood data and prognosis (p = 0.399) between the arachnoid lysis and shunting groups. But the QAlb level of PTS patients was significantly higher than that of the control group (p < 0.001), and the shunting group had a significantly higher QAlb (p < 0.001) than the arachnoid lysis group. A high preoperative QAlb (odds ratio, 1.091; 95% confidence interval, 1.004-1.187; p = 0.041) was identified as the predictive factor for the shunting procedure, with the receiver operating characteristic curve showing 100% specificity and 80.95% sensitivity for patients with a QAlb > 12.67. CONCLUSION: Preoperative QAlb is a significant predictive factor for the types of surgery. For PTS patients with a QAlb > 12.67, shunting represents the final recourse, necessitating the exploration and development of novel treatments for these patients.

Long-Term Impairment of the Blood-Spinal Cord Barrier in Patients With Post-Traumatic Syringomyelia and its Effect on Prognosis.

STUDY DESIGN: Cohort study. OBJECTIVE: The aim of this study was to explore the association between blood-spinal cord barrier (BSCB) markers and other factors associated with an unfavorable outcome among patients with post-traumatic syringomyelia (PTS) who achieved successful intradural adhesion lysis (IAL). SUMMARY OF BACKGROUND DATA: Only approximately half of PTS patients receiving IAL have a favorable outcome. PATIENTS AND METHODS: Forty-six consecutive patients with PTS and 19 controls (CTRL) were enrolled. All PTS patients underwent physical and neurological examinations and spinal magnetic resonance imaging before and 3 to 12 months after IAL. All patients underwent myelography before surgery. BSCB disruption was detected by increased intrathecal and serum concentrations of albumin, immunoglobulin (Ig)G, IgA, and IgM. A multivariable analysis was performed with a logistic regression model to identify factors associated with unfavorable outcomes. Receiver operating characteristic curves were calculated to investigate the diagnostic value of biomarkers. RESULTS: The ages and general health of the PTS and CTRL groups did not differ significantly. QAlb, IGAQ, IGGQ, and IGMQ was significantly higher in PTS patients than in controls ( P =<0.001). The degree of intradural adhesion was significantly higher in the unfavorable outcome group than in the favorable outcome group ( P <0.0001). QAlb, immunoglobulin (Ig)AQ, IGGQ, and IGMQ was significantly correlated with clinical status ( R =-0.38, P <0.01; R =-0.47, P =0.03; R =-0.56, P =0.01; R =-0.43, P =0.05, respectively). Higher QAlb before surgery (odds ratio=2.66; 95% CI: 1.134-6.248) was significantly associated with an unfavorable outcome. The receiver operating characteristic curve analysis demonstrated a cutoff for QAlb higher than 10.62 with a specificity of 100% and sensitivity of 96.3%. CONCLUSION: This study is the first to detect increased permeability and BSCB disruption in PTS patients. QAlb>10.62 was significantly associated with unfavorable clinical outcomes following intradural decompression. LEVEL OF EVIDENCE: Level III-prognostic.

Genome-Wide Identification and Expression Analysis of the MADS Gene Family in Tulips (Tulipa gesneriana).

To investigate the cold response mechanism and low temperature regulation of flowering in tulips, this study identified 32 MADS-box transcription factor family members in tulips based on full-length transcriptome sequencing, named TgMADS1-TgMADS32. Phylogenetic analysis revealed that these genes can be divided into two classes: type I and type II. Structural analysis showed that TgMADS genes from different subfamilies have a similar distribution of conserved motifs. Quantitative real-time PCR results demonstrated that some TgMADS genes (e.g., TgMADS3, TgMADS15, TgMADS16, and TgMADS19) were significantly upregulated in buds and stems under cold conditions, implying their potential involvement in the cold response of tulips. In summary, this study systematically identified MADS family members in tulips and elucidated their evolutionary relationships, gene structures, and cold-responsive expression patterns, laying the foundation for further elucidating the roles of these transcription factors in flowering and the cold adaptability of tulips.

Endogenous CRISPR-Cas mediated in situ genome editing: State-of-the-art and the road ahead for engineering prokaryotes.

The CRISPR-Cas systems have shown tremendous promise as heterologous tools for genome editing in various prokaryotes. However, the perturbation of DNA homeostasis and the inherent toxicity of Cas9/12a proteins could easily lead to cell death, which led to the development of endogenous CRISPR-Cas systems. Programming the widespread endogenous CRISPR-Cas systems for in situ genome editing represents a promising tool in prokaryotes, especially in genetically intractable species. Here, this review briefly summarizes the advances of endogenous CRISPR-Cas-mediated genome editing, covering aspects of establishing and optimizing the genetic tools. In particular, this review presents the application of different types of endogenous CRISPR-Cas tools for strain engineering, including genome editing and genetic regulation. Notably, this review also provides a detailed discussion of the transposon-associated CRISPR-Cas systems, and the programmable RNA-guided transposition using endogenous CRISPR-Cas systems to enable editing of microbial communities for understanding and control. Therefore, they will be a powerful tool for targeted genetic manipulation. Overall, this review will not only facilitate the development of standard genetic manipulation tools for non-model prokaryotes but will also enable more non-model prokaryotes to be genetically tractable.

Intra-articular Distraction Versus Decompression to Treat Basilar Invagination Without Atlantoaxial Dislocation: A Retrospective Cohort Study of 54 Patients.

OBJECTIVE: The surgical management of basilar invagination without atlantoaxial dislocation (type B basilar invagination) remains controversial. Hence, we have reported the use of posterior intra-articular C1-2 facet distraction, fixation, and cantilever technique versus foramen magnum decompression in treating type B basilar invagination as well as the results and surgical indications for this procedure. METHODS: This was a single-center retrospective cohort study. Fifty-four patients who underwent intra-articular distraction, fixation, and cantilever reduction (experimental group) and foramen magnum decompression (control group) were enrolled in this study. Distance from odontoid tip to Chamberlain's line, clivus-canal angle, cervicomedullary angle, craniovertebral junction (CVJ) triangle area, width of subarachnoid space and syrinx were used for radiographic assessment. Japanese Orthopedic Association (JOA) scores and 12-item Short Form health survey (SF-12) scores were used for clinical assessment. RESULTS: All patients in the experimental group had a better reduction of basilar invagination and better relief of pressure on nerves. JOA scores and SF-12 scores also had better improvements in the experimental group postoperation. SF-12 score improvement was associated with preoperative CVJ triangle area (Pearson index, 0.515; p = 0.004), cutoff value of 2.00 cm2 indicating the surgical indication of our technique. No severe complications or infections occurred. CONCLUSION: Posterior intra-articular C1-2 facet distraction, fixation, and cantilever reduction technique is an effective treatment for type B basilar invagination. As various factors involved, other treatment strategies should also be investigated.

Perioperative Clinical Features and Long-term Prognosis After Oblique Lateral Interbody Fusion (OLIF), OLIF With Anterolateral Screw Fixation, or OLIF With Percutaneous Pedicle Fixation: A Comprehensive Treatment Strategy for Patients With Lumbar Degenerative Disease.

OBJECTIVE: To compare the efficacy of oblique lateral interbody fusion (OLIF), OLIF combined with anterolateral screw fixation (OLIF-AF), and OLIF combined with percutaneous pedicle screw fixation (OLIF-PF) in the treatment of single-level or 2-level degenerative lumbar disease. METHODS: Between January 2017 and 2021, 71 patients were treated with OLIF and combined OLIF. The demographic data, clinical outcomes, radiographic outcomes, and complications were compared among the 3 groups. RESULTS: The operative time and intraoperative blood loss in the OLIF (p<0.05) and OLIF-AF (p<0.05) groups were lower than in the OLIF-PF group. Posterior disk height improvement in the OLIF-PF group was better than in the OLIF (p<0.05) and OLIF-AF (p<0.05) groups. In terms of foraminal height (FH), the OLIF-PF group was significantly better than the OLIF group (p<0.05), but there was no significant difference between the OLIF-PF and OLIF-AF groups (p>0.05) or between the OLIF and OLIF-AF groups (p>0.05). There were no significant differences in fusion rates, the incidence of complications, lumbar lordosis, anterior disc height, and cross-sectional area among the 3 groups (p>0.05). The OLIF-PF group had significantly lower rates of subsidence than the OLIF group (p<0.05). CONCLUSION: OLIF remains a viable option with similar patient-reported outcomes and fusion rates compared with surgeries that include lateral and posterior internal fixation while greatly reducing the financial burden, intraoperative time, and intraoperative blood loss. OLIF has a higher subsidence rate than lateral and posterior internal fixation, but most subsidence is mild and has no adverse effect on clinical and radiographic outcomes.

Detection of Glioma-Related Hotspot Mutations Through Sequencing of Cerebrospinal Fluid (CSF)-Derived Circulating Tumor DNA: A Pilot Study on CSF-Based Liquid Biopsy for Primary Spinal Cord Astrocytoma.

OBJECTIVE: Although cerebrospinal fluid (CSF)-based liquid biopsy was proved to be practical in molecular analysis of intracranial gliomas, liquid biopsy of primary intramedullary astrocytoma was rarely reported. Given the distinct genomic profiles between primary intramedullary glioma and intracranial astrocytoma, whether the feasibility of CSF-based molecular analysis of intracranial gliomas can be replicated in primary spinal cord astrocytoma needs to be investigated. The aim of this pilot study is to evaluate the feasibility of molecular analysis of primary intramedullary astrocytoma through sequencing CSF-derived circulating tumor DNA (ctDNA). METHODS: Two grade IV diffuse midline gliomas, 1 grade II, and 1 grade I astrocytoma were included. Intraoperative collection of peripheral blood and CSF samples was conducted, along with postoperative collection of matched tumor tissues. A panel covering the 1,021 most common driver genes of solid tumors was used for targeted DNA sequencing. RESULTS: CSF-derived ctDNA was detected in 3 CSF samples (2 grade IV diffuse midline gliomas and 1 grade I astrocytoma), 5 mutations were found in both tumor tissues and CSF samples, while 11 mutations and 20 mutations were detected exclusively in tumor tissues and CSF samples, respectively. Importantly, hotspot genetic alterations, including H3F3A K28M, TP53, and ATRX, were identified in CSF and the average mutant allele frequency was often higher in CSF than in tumor tissues. CONCLUSION: CSF-based liquid biopsy showed potential feasibility for molecular analysis of primary intramedullary astrocytoma through sequencing of ctDNA. This approach may assist in diagnosis and prognostic evaluation of this rare spinal cord tumor.

Predicting deep surgical site infection in patients receiving open posterior instrumented thoracolumbar surgery: A-DOUBLE-SSI risk score - a large retrospective multicenter cohort study in China.

BACKGROUND: To develop a practical prediction model to predict the risk of deep surgical site infection (SSI) in patients receiving open posterior instrumented thoracolumbar surgery. METHODS: Data of 3419 patients in four hospitals from 1 January 2012 to 30 December 2021 were evaluated. The authors used clinical knowledge-driven, data-driven, and decision tree model to identify predictive variables of deep SSI. Forty-three candidate variables were collected, including 5 demographics, 29 preoperative, 5 intraoperative, and 4 postoperative variables. According to model performance and clinical practicability, the best model was chosen to develop a risk score. Internal validation was performed by using bootstrapping methods. RESULTS: After open posterior instrumented thoracolumbar surgery, 158 patients (4.6%) developed deep SSI. The clinical knowledge-driven model yielded 12 predictors of deep SSI, while the data-driven and decision tree model produced 11 and 6 predictors, respectively. A knowledge-driven model, which had the best C-statistics [0.81 (95% CI: 0.78-0.85)] and superior calibration, was chosen due to its favorable model performance and clinical practicality. Moreover, 12 variables were identified in the clinical knowledge-driven model, including age, BMI, diabetes, steroid use, albumin, duration of operation, blood loss, instrumented segments, powdered vancomycin administration, duration of drainage, postoperative cerebrospinal fluid leakage, and early postoperative activities. In bootstrap internal validation, the knowledge-driven model still showed optimal C-statistics (0.79, 95% CI: 0.75-0.83) and calibration. Based on these identified predictors, a risk score for deep SSI incidence was created: the A-DOUBLE-SSI (Age, D [Diabetes, Drainage], O [duration of Operation, vancOmycin], albUmin, B [BMI, Blood loss], cerebrospinal fluid Leakage, Early activities, Steroid use, and Segmental Instrumentation) risk score. Based on the A-DOUBLE-SSI score system, the incidence of deep SSI increased in a graded fashion from 1.06% (A-DOUBLE-SSIs score ≤8) to 40.6% (A-DOUBLE-SSIs score>15). CONCLUSIONS: The authors developed a novel and practical model, the A-DOUBLE-SSIs risk score, that integrated easily accessible demographics, preoperative, intraoperative, and postoperative variables and could be used to predict individual risk of deep SSI in patients receiving open posterior instrumented thoracolumbar surgery.

A novel scoring system for assessing adult syringomyelia associated with CM I treatment outcomes.

BACKGROUND: A specific scoring system for syringomyelia is lacking. Our objective was to investigate the value of a novel scoring system (Syringomyelia Outcome Scale of Xuanwu hospital, SOS-XW) in assessing surgical outcomes in the treatment of syringomyelia (SM) associated with Chiari malformation type I (CM I). METHODS: A quantitative evaluation system (SOS-XW) of SM includes 4 parameters: pain (P), sensation (S), movement (M), and syringomyelia tension index (STI). The clinical data of 88 patients with CM I-related syringomyelia treated by foramen magnum and Magendie dredging (FMMD) from January 2018 to January 2019 were retrospectively analysed with a mean follow-up of 14.3 months, and the SOS-XW score was used to assess the efficacy. RESULTS: The higher the SOS-XW score, the more severe was the SM and related symptoms. The mean preoperative score was 5.97, and the postoperative score was 2.66. The symptom improvement rates were 77.78% for P, 69.01% for S, 31.82% for M, and 95.06% for the syringomyelia tension index (STI). The symptom improvement rate of the PSM score was weakly correlated with the improvement rate of STI, R2 = 0.0016. The percentage of PSM (P + S + M) improvement was lower in patients with an STI of 0. The postoperative SOS-XW score was positively correlated with the postoperative JOA score, R2 = 0.8314. The positive detection rate of SOS-XW was higher than that of the JOA score. CONCLUSIONS: To evaluate the surgical procedure efficacy in the treatment of syringomyelia, the SOS-XW score can provide a more objective, detailed, and comprehensive analysis, especially STI. A reduction in STI is the practical standard for assessing the effectiveness of surgery.

Mutational landscape of primary spinal cord astrocytoma.

Primary spinal cord astrocytoma (SCA) is a rare disease. Knowledge about the molecular profiles of SCAs mostly comes from intracranial glioma; the pattern of genetic alterations of SCAs is not well understood. Herein, we describe genome-sequencing analyses of primary SCAs, aiming to characterize the mutational landscape of primary SCAs. We utilized whole exome sequencing (WES) to analyze somatic nucleotide variants (SNVs) and copy number variants (CNVs) among 51 primary SCAs. Driver genes were searched using four algorithms. GISTIC2 was used to detect significant CNVs. Additionally, recurrently mutated pathways were also summarized. A total of 12 driver genes were identified. Of those, H3F3A (47.1%), TP53 (29.4%), NF1 (19.6%), ATRX (17.6%), and PPM1D (17.6%) were the most frequently mutated genes. Furthermore, three novel driver genes seldom reported in glioma were identified: HNRNPC, SYNE1, and RBM10. Several germline mutations, including three variants (SLC16A8 rs2235573, LMF1 rs3751667, FAM20C rs774848096) that were associated with risk of brain glioma, were frequently observed in SCAs. Moreover, 12q14.1 (13.7%) encompassing the oncogene CDK4 was recurrently amplified and negatively affected patient prognosis. Besides frequently mutated RTK/RAS pathway and PI3K pathway, the cell cycle pathway controlling the phosphorylation of retinoblastoma protein (RB) was mutated in 39.2% of patients. Overall, a considerable degree of the somatic mutation landscape is shared between SCAs and brainstem glioma. Our work provides a key insight into the molecular profiling of primary SCAs, which might represent candidate drug targets and complement the molecular atlas of glioma. © 2023 The Pathological Society of Great Britain and Ireland.

Dissection of mendelian predisposition and complex genetic architecture of craniovertebral junction malformation.

The craniovertebral junction (CVJ) is an anatomically complex region of the axial skeleton that provides protection of the brainstem and the upper cervical spinal cord. Structural malformation of the CVJ gives rise to life-threatening neurological deficits, such as quadriplegia and dyspnea. Unfortunately, genetic studies on human subjects with CVJ malformation are limited and the pathogenesis remains largely elusive. In this study, we recruited 93 individuals with CVJ malformation and performed exome sequencing. Manual interpretation of the data identified three pathogenic variants in genes associated with Mendelian diseases, including CSNK2A1, MSX2, and DDX3X. In addition, the contribution of copy number variations (CNVs) to CVJ malformation was investigated and three pathogenic CNVs were identified in three affected individuals. To further dissect the complex mutational architecture of CVJ malformation, we performed a gene-based rare variant association analysis utilizing 4371 in-house exomes as control. Rare variants in LGI4 (carrier rate = 3.26%, p = 3.3 × 10-5) and BEST1 (carrier rate = 5.43%, p = 5.77 × 10-6) were identified to be associated with CVJ malformation. Furthermore, gene set analyses revealed that extracellular matrix- and RHO GTPase-associated biological pathways were found to be involved in the etiology of CVJ malformation. Overall, we comprehensively dissected the genetic underpinnings of CVJ malformation and identified several novel disease-associated genes and biological pathways.

The mechanisms and applications of cryoprotectants in aquatic products: An overview.

Frozen storage technology has been widely used for the preservation of Aquatic products. However, ice crystals formation, lipid oxidation and protein denaturation still easily causes aquatic products deterioration. Cryoprotectants are a series of food additives that could efficiently prolong the shelf life and guarantee the acceptability of frozen aquatic products. This review comprehensively illustrated the mechanism of protein denaturation caused by the ice crystal formation and lipid oxidation. The cryoprotective mechanism of various kinds of antifreeze agents (saccharides, phosphates, antifreeze proteins and peptides) and these cryoprotective structure-activity relationship, application efficiency on the quality of aquatic products were also discussed. Moreover, the advantages and disadvantages of each cryoprotectant are also prospected. Compared with others, antifreeze peptides show higher commercial and application values. While, lots of scientific research works are still required to develop novel antifreeze agent as a versatile ingredient with commercial value, applicable in the aquatic products preservation industry.

Subaxial Lateral Mass Prosthesis for Posterior Reconstruction of Cervical Spine.

BACKGROUND: Posterior facetectomy or lateral mass resection is often used during cervical dumbbell tumor resection, jeopardizing the stability of cervical spine. The space after resection of one or more lateral masses, if left unfilled might hamper bone fusion and structural support. PURPOSE: There were the aims to obtain the relevant morphometry of the lateral mass of the subaxial cervical spine (C3-C7) and to design a lateral mass prosthesis for the posterior reconstruction of the cervical spine. METHODS: The computed tomography (CT) scans of healthy volunteers were obtained. RadiAnt DICOM Viewer software (Version 2020.1, Medixant, Poland) was used to measure the parameters of lateral mass, such as height, anteroposterior dimension (APD), mediolateral dimension (MLD), and facet joint angle. According to the parameters, a series of cervical lateral mass prostheses were designed. Cadaver experiment was conducted to demonstrate its feasibility. RESULTS: Twenty-three volunteers with an average age of 30.1 ± 7.1 years were enrolled in this study. The height of the lateral mass was 14.1 mm on average. The facet joint angle, APD, and MLD of the lateral mass averaged 40.1 degrees, 11.2 mm, and 12.2 mm, respectively. With these key data, a lateral mass prosthesis consisting of a column and a posterior fixation plate was designed. The column has a 4.0-mm radius, 41-degree surface angle, and adjustable height of 13, 15, or 17 mm. In the cadaver experiment, the column could function as a supporting structure between adjacent facets, and it would not violate the exiting nerve root or the vertebral artery. CONCLUSION: This study provided a detailed morphology of the lateral mass of the subaxial cervical spine. A series of subaxial cervical lateral mass prostheses were designed awaiting further clinical application.

Neurological deterioration after posterior fossa decompression for adult syringomyelia: Proposal for a summarized treatment algorithm.

Background: Patients with syringomyelia who present with new neurological symptoms after posterior fossa decompression (PFD) are not uncommon. However, systematic reports on different pathologies are few in the literature. Objective: The purpose of this study was to summarize our experience for failed PFD. Methods: Between January 2015 and December 2019, 85 consecutive failed PFD patients were identified. The neurological courses were summarized with Klekamp J (KJ) or mJOA score system for all patients. Long-term results were summarized with Kaplan-Meier method. Results: Twenty-eight consecutive patients underwent FMDD (Foramen magnum and foramen of Magendie dredging) (Group I), extradural PFD and manipulation of tonsil was significantly associated with lower failure rates. Twenty patients underwent craniocervical fixation (Group II), nine underwent local spinal segment decompression (Group III), six underwent CSF diversion procedures, and one were treated for persistent pain by radiofrequency. Neuropathic pain was most significantly improved in Group I while swallowing improved in Group II within 1 year after the surgery. In the long term, late postoperative deterioration-free possibility in Group II was better than in Group I. All patients in Group III improved (P = 0.0088). Six cases of CSF diversion procedures were relieved in a short time. Pain in one patient persisted after PFD, and trial of radiofrequency failed. Conclusion: Not only does the recurrent cerebrospinal fluid flow obstruct the foramen magnum, but also spinal pathologies and craniocervical instabilities may occur. This study provides the largest summarized clinical experience that may assist surgeons with different therapeutic decisions for failed PFD.

Dural ossification associated with ossification of posterior longitudinal ligament in the cervical spine: a retrospective analysis.

OBJECTIVE: Dural ossification (DO) is common in patients with ossification of the posterior longitudinal ligament (OPLL). The existence of DO makes surgery challenging and increases the risk of complications. The aim of this study was to investigate the incidence, distribution and radiological characteristics of DO associated with OPLL. METHODS: From January 2017 to January 2019, 55 patients with cervical OPLL were treated in our single center using an anterior cervical approach microsurgery. Preoperative CT images of decompressed segments were evaluated to identify imaging signs of DO. The 'double-layer sign' (DLS), 'parenthese sign' (PS) and 'hook sign' (HS) were considered to be characteristic imaging findings of DO in OPLL. Two kinds of confusing signs (false double-layer) were identified. RESULTS: Nineteen segments from 15 patients with OPLL had DO related to OPLL. The incidence of DO in OPLL segments was 30.16% (19/63), and the incidence of DO in patients with OPLL was 27.27% (15/55). DO occurred at the intervertebral space level in 14 cases and at the posterior level of the vertebral body in 5 cases. The sensitivity and specificity of imaging diagnosis were 89.47% (17/19) and 81.82% (36/44), respectively. The positive predictive value was relatively low, 68.00% (17/25), due to the false-positive double-layer sign. The negative predictive value was 94.74% (36/38). CONCLUSION: DO was relatively common in cervical OPLL. DLS might be misdiagnosed. PS and HS can vividly and intuitively describe the imaging features of DO and have high diagnostic accuracy.

A 540° posterior-anterior-posterior approach for 360° fused rigid severe cervical kyphosis: patient series.

BACKGROUND: Treatment of severe rigid 360° fused cervical kyphosis (CK) is challenging and often requires a combined approach for ankylosis release, establishment of sagittal balance, and fixation with fusion. OBSERVATIONS: Four patients with iatrogenic 360° fused severe rigid CK (Cobb angle ≥40°) were enrolled for this retrospective analysis. All patients in the case series were female, with an average age of 27 years. All patients previously underwent posterior laminectomy/laminoplasty and cervical tumor resection when they were children (13-17 years). They underwent correction surgery with a 540° posterior-anterior-posterior approach. Preoperative and final follow-up radiography and computed tomography (CT) were used to evaluate kyphosis correction, internal fixation implants, and bone fusion. The preoperative and final follow-up average C2-7 Cobb angles were -32.4° ± 12.0° and 5.3° ± 7.1°, respectively. Preoperative and final follow-up CK angles averaged -47.2° ± 7.4° and -0.9° ± 16.1°, respectively. The mean correction angle was 46.3° ± 9.6°. At final follow-up, CT showed stable fixation and solid bone fusion. LESSONS: The rare iatrogenic severe kyphosis with 360° ankylosis requires a combined approach. The 540° posterior-anterior-posterior approach can completely release the bony fusion, and the CK can be corrected using an anterior plate. This technique can achieve good results and is an effective strategy.

Dural repair with fat patch for idiopathic spinal cord herniation: operative technique and a review of seven cases.

Background: Idiopathic ventral thoracic spinal cord herniation is a rare disease presented with progressive myelopathy or Brown Séquard syndrome, causing neurological deficits. There is no consensus on etiology and surgical strategy. The purpose of the present study is to report the case series using fat patch for the repair of the ventral dural defect with clinical follow up. Methods: A retrospective review of all cases of idiopathic spinal cord herniation (ISCH) at our institution was performed between January 2017 and June 2021. Clinical data were reviewed including patients' demographic information, symptoms, imaging, operative details, perioperative and postoperative courses, and clinical outcomes, and complications. Japanese Orthopedic Association (JOA) score was calculated preoperatively and postoperatively for the comparison of outcomes. Results: A total of 7 patients were included. Fat patch was applied in all cases, and artificial dural patch was also used in 2 cases. Average operating time and estimated blood loss were 3 hours and 24 minutes and 88.6 mL, respectively. Five of 7 patients improved and 2 patients remained unchanged during follow up (average, 23.4 months; range, 9-42 months). The mean recovery rate (RR) of JOA score was 17.9%. One patient experienced cerebrospinal fluid (CSF) leakage, and 1 patient suffered from surgical related spinal canal stenosis. Conclusions: Surgical treatment using fat patch is an effective strategy for the ventral dural defect repair of ISCH.