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Objective: The craniovertebral junction (CVJ) presents intricate anatomical challenges. In severe or irreducible malformations, complications such as reduction loss and fixation failure may occur, necessitating revision surgery. The posterior facet joint distraction and fusion (PFDF) technique, offers a solely posterior approach for revisions. Hence, we delineate varied revision scenarios, proposing surgical strategies and technical details to enhance outcomes and mitigate risks, thereby enriching the neurosurgical community's repertoire. Methods: This was a retrospective cohort study, analyzed patient data from Xuanwu Hospital, between 2017 to 2023. All patients had a history of surgical treatment for CVJ malformations, and experienced failure or loss of reduction. The distance from the odontoid process tip to the Chamberlain's line (DCL), the atlantodental interval (ADI), clivus‐canal angle, cervicomedullary angle, width of subarachnoid space, CVJ area, and width of syrinx were used for radiographic assessment. Japanese Orthopaedic Association (JOA) scores and SF‐12 scores were used for clinical assessment. Independent sample t‐tests were employed. A significance level of p < 0.05 indicates statistically significant differences. Results: We analyzed data from 35 patients. For patients who underwent PFDF, the postoperative DCL, ADI, and clivus‐canal angle significantly improved. For all patients, the postoperative cervicomedullary angle, width of subarachnoid space, CVJ area, and width of syrinx all demonstrated significant improvement, indicating the relief of neural compression. All patients showed significant improvement in both symptoms and clinical assessments. Conclusion: Severe atlantoaxial joint locking or ligament contracting are the fundamental cause of reduction and fixation failure. Anterior odontoidectomy is indicated for patients with robust bony fusion of the atlantoaxial joint in an unreduced position. The PFDF technique is safe and effective for patients with incomplete atlantoaxial bony fusion. Preoperative assessment of surgical feasibility and vertebral artery status ensures surgical safety and efficacy. [ABSTRACT FROM AUTHOR]

Objective: The anterior controllable antedisplacement and fusion (ACAF) technique is a new procedure for the treatment of cervical ossification of the posterior longitudinal ligament (OPLL) that requires management of the disc adjacent to the ossification. This study describes a novel technique to reduce the number of fixed segments, namely, the "Klotski technique." The efficacy of ACAF using the Klotski technique was compared with that of anterior cervical corpectomy and fusion (ACCF) in the treatment of OPLL with en bloc type dural ossification (DO). Methods: The clinical data of 25 patients with severe OPLL and en bloc type DO who were treated by the ACAF Klotski technique or ACCF at our hospital from January 2020 to January 2022 were retrospectively analyzed. In the Klotski technique, the number of segments fused within the OPLL is limited. The antedisplacement space was designed according to the shape of the vertebrae-OPLL-DO complex (VODC). Then, the entire VODC was antedisplaced as in Klotski. Neurological function and image examination were assessed preoperatively and postoperatively. Complications associated with surgery were recorded. Results: Patients were followed up for 24–36 months. There were 11 patients who were treated with ACAF and 14 patients who were treated with ACCF. At 2 weeks after surgery, the incidence of neurological deterioration was 21.4% (3 of 14) in the ACCF group and 9.1% (1 of 11) in the ACAF group. The incidence of intraoperative cerebrospinal fluid leakage (CFL) was 35.7% (5 of 14) in the ACCF group and 9.1% (1 of 11) in the ACAF group. The postoperative follow-up JOA scores of the patients in both groups were significantly better than their preoperative JOA scores (p<0.05). Conclusion: The Klotski technique for ACAF is a good option for the treatment of patients with en bloc type OPLL-DO, as it limits the number of fused segments, has a low incidence of CFL and neurologic deficits and is associated with good neurological recovery. [ABSTRACT FROM AUTHOR]

Background: This study aims to evaluate the effect of various background reference regions on spinal 18F-FET PET imaging, with a focus on distinguishing between spinal tumors and myelitis. To enhance diagnostic accuracy, we investigated the pons and several other spinal cord area as potential references, given the challenges in interpreting spinal PET results. Results: A retrospective analysis was conducted on 30 patients, 15 with cervical myelitis and 15 with cervical tumors, who underwent O-(2-[18F]-fluoroethyl)-L-tyrosine (FET) PET/MR imaging. The stability of uptake across four regions, including the pons, C2, C2–C7, and T1–T3, was compared. The standardized uptake value ratio (SUVR) was then evaluated using various background regions, and their effectiveness in differentiating between spinal tumors and myelitis was compared. Additionally, we correlated the SUVR values derived from these regions with the Ki-67 proliferation index in tumor patients. The study found no significant difference in SUVmax (U = 110, p = 0.93) and SUVmean (U = 89, p = 0.35) values at lesion sites between myelitis and tumor patients. The pons had the highest average uptake (p < 0.001) compared to the other three regions. However, its coefficient of variation (CV) was significantly lower than that of the C2–C7 (p < 0.0001) and T1–T3 segments (p < 0.05). The SUVRmax values, calculated using the regions of pons, C2–C7 and T1–T3, were found to significantly differentiate between tumors and myelitis (p < 0.05). However, only the pons-based SUVRmean was able to significantly distinguish between the two groups (p < 0.05). Additionally, the pons-based SUVRmax (r = 0.63, p = 0.013) and SUVRmean (r = 0.67, p = 0.007) demonstrated a significant positive correlation with the Ki-67 index. Conclusions: This study suggests that the pons may be considered a suitable reference region for spinal 18F-FET PET imaging, which can improve the differentiation between spinal tumors and myelitis. The significant correlation between pons-based SUVR values and the Ki-67 index further highlights the potential of this approach in assessing tumor cell proliferation. [ABSTRACT FROM AUTHOR]

Background: Diffusion tensor imaging (DTI) has been increasingly recognized for its capability to study microstructural changes in the neuropathology of brain diseases. However, the optimal DTI metric and its diagnostic utility for a variety of spinal cord diseases are still under investigation. Purpose: To evaluate the diagnostic efficacy of DTI metrics for differentiating between cervical spondylosis, myelitis, and spinal tumors. Methods: This retrospective study analyzed DTI scans from 68 patients (22 with cervical spondylosis, 23 with myelitis, and 23 with spinal tumors). DTI indicators, including fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD) and axial diffusivity (AD), were calculated. The Kruskal–Wallis test was used to compare these indicators, followed by Receiver Operating Characteristic (ROC) curve analysis, to evaluate the diagnostic efficacy of each indicator across disease pairs. Additionally, we explored the correlations of DTI indicators with specific clinical measurements. Results: FA values were significantly lower in tumor patients compared to those with cervical spondylosis (p < 0.0001) and myelitis (p < 0.05). Additionally, tumor patients exhibited significantly elevated MD and RD values relative to the spondylosis and myelitis groups. ROC curve analysis underscored FA's superior discriminative performance, with an area under the curve (AUC) of 0.902 for differentiating tumors from cervical spondylosis, and an AUC of 0.748 for distinguishing cervical myelitis from spondylosis. Furthermore, a significant negative correlation was observed between FA values and Expanded Disability Status Scores (EDSSs) in myelitis patients (r = −0.62, p = 0.002), as well as between FA values and Ki-67 scores in tumor patients (r = −0.71, p = 0.0002). Conclusion: DTI indicators, especially FA, have the potential in distinguishing spondylosis, myelitis, and spinal cord tumors. The significant correlation between FA values and clinical indicators highlights the value of FA in the clinical assessment and prognosis of spinal diseases and may be applied in diagnostic protocols in the future. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]