Sudden Blindness as the Only Symptom Caused by a Small Sphenoid Sinus Mucocele in a Young Child.

Background: Sphenoid sinus mucocele (SSM) represents a relatively rare disease among pediatric population as compared to adults, with a 1% to 3% incidence of all paranasal sinus mucoceles. Since the initial symptoms varied often, SSM caused blindness was scarcely seen. Case Presentation: Here we described an unusual case of small, isolated SSM causing acute visual loss in a 9-year-old girl. The patient first consulted an ophthalmologist for her right blindness. A diagnosis of SSM was suspected indicated by an orbital MRI scan. Thereafter the patient was referred to our department and an endoscopic sphenoidotomy and optic nerve decompression was performed. Surprisingly, her vision was relieved immediately after surgery, followed by dramatic improvement during the postoperative 20-month follow-up period. Conclusion: To our knowledge, a better understanding of SSM in pediatrics is essential for clinicians, including neurologists, ophthalmologists, and otolaryngologists to make early diagnoses and correct treatment by MRI and CT scan. Prompt surgical intervention of endoscopic transnasal sphenoidectomy is a quite safe, effective, and minimally invasive method for patients.

A novel polysaccharide-based bioflocculant produced by Bacillus subtilis 35A and its application in the treatment of dye decolorization, heavy metal ion adsorption and meat product wastewater.

Optimizing the fermentation process of microorganisms with exceptional bioflocculant-producing capabilities is crucial for the production of bioflocculants. The application of bioflocculants to various pollutants highlights their significant advantages in water treatment. Therefore, the culture conditions of Bacillus subtilis 35A with exceptional bioflocculant-producing capabilities were optimized. The bioflocculant (MBF) was obtained by alcohol percipitation from the fermentation supernatant, and its physicochemical properties were analyzed to explore its application in the treatment of dyes, heavy metal ions, and organic wastewater. The results indicate that, using cyclodextrin and yeast extract as carbon and nitrogen sources, after 48 h of fermentation at the initial pH, the bioflocculant (MBF-35A) yielded 10.47 g/L with a flocculation rate of 96.57% for kaolin suspension. The chemical analysis demonstrated that MBF-35A is mainly composed of polysaccharide (81.74%) and protein (16.42%). FITR and XPS analysis indicated that MBF-35A mainly contains major elements such as carbon, nitrogen, and oxygen, with functional groups (-OH, C-O, C-H, and C-O-C) that are beneficial for flocculation. MBF-35A exhibited a dye decolorization efficiency exceeding 95% and removed 41.05 and 48.93% of Cr6+ and Cu2+ ions, respectively. In meat wastewater treatment, the effective removal rates of ammonia nitrogen (26.87%), COD (51.16%), total nitrogen (37.76%), and total phosphorus (55.81%) highlight its potential in organic waste treatment. In brief, not only does MBF-35A exhibit efficient production and excellent flocculation performance as a bioflocculant, but it also shows significant biological and environmental benefits in dye, heavy metal ions, and organic wastewater treatment.

[Progress of allergic rhinitis research based on transcriptome sequencing].

Traditional studies on allergic rhinitis（AR） have mainly adopted animal models and biomolecular approaches. In addition, the advent of transcriptome sequencing technology is promoting the development of AR at the genetic level. Recently, many scholars have focused on the role of common RNA in the pathogenesis of AR, suggesting that breakthroughs have been made in the field of AR bioinformatics analysis. This review aims to summarize the research advances in AR, the development of transcriptome sequencing technology, and the application of transcriptome sequencing in AR, in order to explore potential drug targets for AR treatment and provide new insights into precision medicine.

Incidence and prognosis of olfactory and gustatory dysfunctions related to SARS-CoV-2 Omicron strain infection in China: A national multicenter survey of 35,566 individuals.

Objective: This cross-sectional study aimed to determine the epidemiology of olfactory and gustatory dysfunctions related to COVID-19 in China. Methods: This study was conducted by 45 tertiary Grade-A hospitals in China. Online and offline questionnaire data were obtained from patients infected with COVID-19 between December 28, 2022, and February 21, 2023. The collected information included basic demographics, medical history, smoking and drinking history, vaccination history, changes in olfactory and gustatory functions before and after infection, and other postinfection symptoms, as well as the duration and improvement status of olfactory and gustatory disorders. Results: Complete questionnaires were obtained from 35,566 subjects. The overall incidence of olfactory and taste dysfunction was 67.75%. Being female or being a cigarette smoker increased the likelihood of developing olfactory and taste dysfunction. Having received four doses of the vaccine or having good oral health or being a alcohol drinker decreased the risk of such dysfunction. Before infection, the average olfactory and taste VAS scores were 8.41 and 8.51, respectively; after infection, they decreased to 3.69 and 4.29 and recovered to 5.83 and 6.55 by the time of the survey. The median duration of dysosmia and dysgeusia was 15 and 12 days, respectively, with 0.5% of patients having symptoms lasting for more than 28 days. The overall self-reported improvement rate was 59.16%. Recovery was higher in males, never smokers, those who received two or three vaccine doses, and those that had never experienced dental health issues, or chronic accompanying symptoms. Conclusions: The incidence of dysosmia and dysgeusia following infection with the SARS-CoV-2 virus is high in China. Incidence and prognosis are influenced by several factors, including sex, SARS-CoV-2 vaccination, history of head-facial trauma, nasal and oral health status, smoking and drinking history, and the persistence of accompanying symptoms.

[Research advances of mesenchymal stem cell in allergic rhinitis].

Allergic rhinitis is a chronic nasal mucosal inflammation characterized by upper airway hyperresponsiveness, involving a variety of immune cells and inflammatory mediators. Drugs, immunotherapy, and surgical operation are the principal treatments at present. The study found that mesenchymal stem cells have the ability of immune regulation and have a promising clinical application in the treatment of allergic rhinitis. In this review, the action mechanism of mesenchymal stem cells, the immunomodulatory effect of mesenchymal stem cells on the key cells of allergic rhinitis, and the challenges of clinical application are reviewed, to provide new directions for the treatment of allergic rhinitis.

Expression of NMU and NMUR1 in tryptase-positive mast cells and PBLs in allergic rhinitis patients' nasal mucosa.

BACKGROUND: The neuropeptide U (NMU) has been proven to elicit the release of mediators from mast cells (MCs) through its receptor NMUR1 in allergic inflammatory models. However, little is known about the correlations between NMU and MCs in human allergic rhinitis (AR). OBJECTIVE: The objective of this study is to investigate the expressions of NMU and NMUR1 in the tryptase + MCs and the peripheral blood leukocytes (PBLs) in human nasal mucosa with AR. METHODS: Specimens of nasal mucosa from patients with AR (n = 10) and control patients without AR (n = 8) were collected and soaked in frozen tissue liquid solution (OCT) in tum. Cryostat sections were prepared for immunofluorescence staining. Tryptase was used as a marker to detect mast cells and other tryptase + immune cells. The expression of NMU and NMUR1 was respectively determined by double staining using a confocal microscope. RESULTS: Neither NMU nor NMUR1 were detected in the tryptase + mast cells in the human nasal mucosa. To our surprise, both NMU and NMUR1 were co-expressed with tryptase in the PBLs within peripheral blood vessels in AR and controls. CONCLUSION: Our findings showed that NMU could not influence human nasal tryptase + mast cells directly through NMUR1 in AR. The co-expression of both NMU and NMUR1 with tryptase in the PBLs provided new insight into the potential roles of NMU and tryptase in the circulation PBLs, and the infiltrated PBLs may promote nasal allergic inflammation by producing tryptase and NMU.

Explainable Learning-Based Timeout Optimization for Accurate and Efficient Elephant Flow Prediction in SDNs.

Accurately and efficiently predicting elephant flows (elephants) is crucial for optimizing network performance and resource utilization. Current prediction approaches for software-defined networks (SDNs) typically rely on complete traffic and statistics moving from switches to controllers. This leads to an extra control channel bandwidth occupation and network delay. To address this issue, this paper proposes a prediction strategy based on incomplete traffic that is sampled by the timeouts for the installation or reactivation of flow entries. The strategy involves assigning a very short hard timeout (Tinitial) to flow entries and then increasing it at a rate of r until flows are identified as elephants or out of their lifespans. Predicted elephants are switched to an idle timeout of 5 s. Logistic regression is used to model elephants based on a complete dataset. Bayesian optimization is then used to tune the trained model Tinitial and r over the incomplete dataset. The process of feature selection, model learning, and optimization is explained. An extensive evaluation shows that the proposed approach can achieve over 90% generalization accuracy over 7 different datasets, including campus, backbone, and the Internet of Things (IoT). Elephants can be correctly predicted for about half of their lifetime. The proposed approach can significantly reduce the controller-switch interaction in campus and IoT networks, although packet completion approaches may need to be applied in networks with a short mean packet inter-arrival time.

Favorable cervical extension capacity preventing loss of cervical lordosis after laminoplasty due to spontaneous restoration of initial lordosis.

BACKGROUND CONTEXT: Cervical laminoplasty is a common approach for the treatment of multilevel cervical spondylotic myelopathy (CSM). Postoperative loss of cervical lordosis (LCL) was associated with lower extension motion of the cervical spine before laminoplasty. PURPOSE: To analyze the possible causes of preoperative cervical extension capacity affecting LCL after laminoplasty by evaluating the changes in cervical lordosis (CL) at different stages. STUDY DESIGN/SETTING: Retrospective study. PATIENT SAMPLE: Seventy-two patients undergoing laminoplasty due to multilevel CSM. OUTCOME MEASURES: Radiographic parameters included CL, extension CL (eCL), flexion CL (fCL), range of motion (ROM), extension ROM (eROM), flexion ROM (fROM) and LCL. Clinical outcomes were assessed using the Japanese Orthopedic Association (JOA) and neck disability index (NDI) score. METHODS: The data were recorded before surgery and at 3- and 24-month follow-up. All patients completed a cervical extension test preoperatively. A receiver operating characteristic (ROC) curve of eROM was constructed to discriminate the patients with and without postoperative kyphotic deformity. RESULTS: According to the optimal cut-off value of eROM, the patients were divided into two groups: extension group (eROM≥9.3°) and control group (eROM<9.3°). The radiographic outcomes demonstrated no significant differences in CL, eCL, fCL and ROM between the two groups. Both eROM and fROM were significantly different in the two groups. There was a significant change in CL in the extension group at 3-month follow-up and in the control group at 24-month follow-up. The extension group exhibited significantly lower LCL compared with the control group at follow-up. No significant difference between the two groups was noted in the JOA recovery rate, while the NDI score was significantly different at 24-month follow-up. The positivity ratio of the extension test was significantly greater in the extension group than that in the control group. CONCLUSIONS: eROM in patients with favorable preoperative cervical extension capacity (eROM≥9.3°) consisted of the actual extension capacity and compensatory flexion. The cervical alignment would be spontaneously restored to its initial lordosis in the short term after laminoplasty. These patients had no substantial LCL at 24-month follow-up and would be good candidates for laminoplasty.

[CGRP inhibits proliferation, activation and cytokine secretion of group 2 innate lymphoid cells (ILC2) in peripheral blood from patients with allergic rhinitis].

Objective To investigate the effect of calcitonin gene-related peptide (CGRP) on the regulation of group 2 innate lymphoid cells (ILC2) in the peripheral blood of patients with allergic rhinitis (AR). Methods Peripheral blood mononuclear cells (PBMCs) were extracted from normal healthy individuals and AR patients, then stimulated with CGRP, interleukin 33 (IL-33) and CGRP combined with IL-33 for 3 days, with blank stimulus as control. The percentage of ILC2 in the four groups was measured by flow cytometry. After being sorted, ILC2 was given to CGRP, IL-33 and CGRP combined with IL-33 stimulation for 3 days, with blank stimulus as control. The percentage of IL-5 and IL-13 positive cells in ILC2 was detected by flow cytometry, and the levels of IL-5 and IL-13 in ILC2 supernatant were measured by ELISA. Results The percentage of ILC2 in the peripheral blood of AR patients was significantly higher than that of the control group. The levels of IL-5+ILC2 and IL-13+ILC2 were significantly increased by IL-33 single stimulation after culturing PBMCs. After adding IL-33 combined with CGRP stimulation, the levels of IL-5+ILC2 and IL-13+ILC2 in PBMCs were significantly reduced; after CGRP single stimulation, the levels of IL-5+ILC2 and IL-13+ILC2 in PBMCs were further decreased. After ILC2 was sorted and cultured, the levels of IL-5+ILC2 and IL-13+ILC2 showed significant increase after IL-33 single stimulation. The levels of IL-5+ILC2 and IL-13+ILC2 were decreased by IL-33 and CGRP co-stimulation, and they were further reduced after CGRP single stimulation. Compared to IL-33 single stimulation, IL-5 and IL-13 levels dropped significantly due to the IL-33 and CGRP co-stimulation. The levels of IL-5 and IL-13 were further reduced by CGRP single stimulation. Conclusion CGRP inhibits the proliferation and activation of peripheral blood ILC2 in AR and exert anti-inflammatory effects in AR.

The effect of different sterilization methods on the shelf life and physicochemical indicators of fermented pork jerky.

Background: To determine the effect of different sterilization methods on shelf life and physicochemical parameters of fermented pork jerky. Methods: Various sterilization techniques, including boiling, pasteurization, medium-temperature steam sterilization, high-temperature steam sterilization, ultrasonic sterilization, and ultraviolet sterilization, were employed in this study to treat vacuum-sealed fermented pork jerky. Changes in microbial populations, physicochemical parameters, and sensory evaluations were monitored throughout the storage period. Results: The results indicated the presence of Staphylococcus aureus on the 24th, 21st, 33rd, 24th, 18th, and 15th days in pork jerky subjected to boiling (100°C, 20 min), pasteurization (85°C, 15 min), medium-temperature steam sterilization (105°C, 0.5 Pa, 30 min), high-temperature steam sterilization (121°C, 1.0 Pa, 20 min), ultrasonic sterilization (480 W, 30 kHz, 30 min), and ultraviolet sterilization (254 nm, 100 W/m2, 60 min), respectively. Coliforms, salmonella, and Shigella were not detected in any group during storage. The medium-temperature steam sterilization method yielded the most favorable microbiological results, with an aerobic plate count of less than 1.0 lg CFU/g. However, other physicochemical parameters and sensory evaluations were moderate, with total volatile basic nitrogen (TVB-N) and thiobarbituric acid reactive substances (TBARS) measuring 14.023 mg N/100 g and 0.427 mg MDA/kg, respectively, remaining within acceptable limits. Conclusion: Therefore, considering microbiological indicators as the primary determinant of shelf life and taking into account other physicochemical parameters, the medium-temperature steam sterilization method was identified as the most suitable approach for extending the shelf life of fermented pork jerky while preserving its flavor.

Repair of Oroantral Fistulas Using Free Bone and Mucoperiosteal Flaps After Endoscopic Removal of the Medial Wall of the Maxillary Sinus.

INTRODUCTION: Oroantral fistula (OAF) refers to a pathological connection between the oral cavity and maxillary sinus. It may lead to symptoms that include purulent mucus, nasal congestion, facial swelling, bad breath, and nasal regurgitation of food, all of which negatively impact patients' quality of life. OBJECTIVE: This study presents a novel approach for OAF repair using a 2-layered structure composed of free bone and a mucoperiosteal flap obtained from the medial wall of maxillary sinus. MATERIALS AND METHODS: Ten OAF patients who underwent repair using this method were retrospectively reviewed between August 2015 and June 2022. RESULTS: The extraction of maxillary molars was the most common cause of OAF. The size of the fistulas ranged from 1×2 mm to 5×8 mm. Nine of the 10 patients achieved successful OAF closure following the initial operation using the 2-layer structure composed of free bone and mucoperiosteal flag. One patient was lost to follow-up. The 9 patients were observed for 6 months to 1 year, and they exhibited no obvious complications or recurrence. CONCLUSION: The use of free bone and mucoperiosteal flag from the medial wall of maxillary sinus through an endoscope was effective for OAF repair.

Phosphatidylserine promotes immunotherapy for airway allergy.

Type 1 regulatory T cells (Tr1 cells) play an important role in the maintenance of the immune homeostasis in the body. The induction of Tr1 cell is to be further investigated. The interaction of phosphatidylserine (PS) with TIM3 has immune regulation functions. The objective of this study is to elucidate the role of PS-TIM3 signals in inducing Tr1 cells. In this study, mice were treated using PS or specific immunotherapy by nasal instillation. A murine model of allergic rhinitis was developed using ovalbumin as a specific antigen. We found that PS-containing nasal instillation induced Tr1 cells in the airway tissues. PS promoted gene activities associated with IL-10 through activation of TIM3 in CD4+ T cells. TIM3 mediated the effects of PS on inducing Tr1 cells, in which the TIM3- PI3K-AKT pathway played a critical role. PS boosted allergen-specific immunotherapy by inducing specific antigen Tr1 cell generation. Concomitant administration of PS and SIT resulted in better therapeutic effects on AR. In conclusion, the data demonstrate that PS can promote the specific immunotherapy for AR through inducing antigen specific Tr1 cells in the airway tissues.

A Clinical Study to Assess the Efficacy and Safety of MP-AzeFlu Nasal Spray in Comparison to Commercially Available Azelastine Hydrochloride and Fluticasone Propionate Nasal Sprays in Chinese Volunteers with Allergic Rhinitis.

INTRODUCTION: The objective of the present study was to evaluate the efficacy and safety of MP-AzeFlu nasal spray in comparison to commercially available azelastine hydrochloride and fluticasone propionate sprays in Chinese patients with moderate-to-severe allergic rhinitis (AR). METHODS: We conducted a 14-day multicenter, randomized, double-blind, active controlled prospective clinical study in adult and adolescent patients with AR, who had moderate-to-severe symptoms. The primary efficacy endpoint was the change from baseline in combined 12-h reflective total nasal symptom score (rTNSS) (morning [AM] + afternoon [PM]). The safety profile of the study medications was assessed through the recording, reporting, and analysis of baseline medical conditions, adverse events (AEs), vital signs, and focused nasal examination. Three hundred patients per treatment group were randomized, which led to a total sample size estimation of 900 patients. RESULTS: MP-AzeFlu group showed significantly higher symptom reduction for the entire 2-week treatment period in rTNSS when compared with the AZE group (LS mean difference: - 1.96; 95% CI: - 2.53, - 1.39; p < 0.0001), or the FLU group (LS mean difference: - 0.98; 95% CI: - 1.55, - 0.41; p = 0.0007). The results of adult RQLQ showed improvement in QoL in all treatment groups. Except for dysgeusia (bitter taste) that was reported by more patients (13 [4.3%]) in the MP-AzeFlu group, the incidence of all other TEAEs in the MP-AzeFlu group was comparable or even lower than in other treatment groups. CONCLUSIONS: MP-AzeFlu, when administered as one spray per nostril twice daily for 14 days, alleviated AR symptoms in Chinese patients with moderate-to-severe AR. TRIAL REGISTRATION: Clinicaltrials.gov; NCT03599791, Registered June 29, 2018, retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03599791 .

Verapamil attenuates intervertebral disc degeneration by suppressing ROS overproduction and pyroptosis via targeting the Nrf2/TXNIP/NLRP3 axis in four-week puncture-induced rat models both in vivo and in vitro.

Low back pain is usually caused by intervertebral disc degeneration (IVDD), during which the involvement of oxidation system imbalance and inflammasome activation cannot be neglected. In this study, we aimed to validate the expression level of TXNIP in IVDD and investigate the function and potential mechanism of action of verapamil. TXNIP is upregulated in the degenerate nucleus pulposus in both humans and rats, as well as in tert-butyl hydroperoxide (TBHP)-stimulated nucleus pulposus cells. Administration of verapamil, a classic clinical drug, mitigated the TBHP-induced overproduction of reactive oxygen species and activation of the NLRP3 inflammasome, thus protecting cells from pyroptosis, apoptosis, and extracellular matrix degradation. The Nrf2/TXNIP/NLRP3 axis plays a major role in verapamail-mediated protection. In vivo, a puncture-induced IVDD rat model was constructed, and we found that verapamil delayed the development of IVDD at both the imaging and histological levels. In summary, our results indicate the potential therapeutic effects and mechanisms of action of verapamil in the treatment of IVDD.

Efficacy and safety of CM310 in severe eosinophilic chronic rhinosinusitis with nasal polyps (CROWNS-1): a multicentre, randomised, double-blind, placebo-controlled phase 2 clinical trial.

Background: Severe eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP) remains the most relapsed subtype of uncontrolled CRSwNP. CM310, a humanised anti-interleukin (IL)-4 receptor alpha monoclonal antibody, inhibits IL-4 and IL-13 signaling which underlying eosinophilic inflammation. This study aims to evaluate the efficacy and safety of CM310 in patients with severe ECRSwNP. Methods: A multicentre, randomised, double-blind, and placebo-controlled phase 2 clinical trial was conducted. 56 eligible adult patients with severe ECRSwNP were randomised 1:1 to receive subcutaneously either CM310 (300 mg) or placebo every 2 weeks under the background therapy of mometasone furoate nasal spray (MFNS) for 16 weeks, with 8 weeks of follow-up. Coprimary endpoints included the changes from baseline in nasal polyp score (NPS) and nasal congestion score (NCS) at week 16. Key secondary endpoints included sinus Lund-Mackay CT score, change in sinus volume occupied by disease, University of Pennsylvania Smell Identification Test score, 22-item Sino-nasal Outcome Test score, and total symptom score. Safety, pharmacodynamics, and changes in type 2 inflammation biomarkers were assessed. This study is registered with ClinicalTrials.gov, NCT04805398. Findings: Between April 6, 2021, and March 18, 2022, 27 patients respectively in both the CM310 and placebo groups completed the study. Findings suggested that CM310 improved the coprimary efficacy endpoints of decreasing nasal polyp size and alleviating nasal congestion compared with the placebo. Least squares (LS) mean differences (CM310 vs placebo) of change from baseline in NPS and NCS at week 16 were -2.1 (95% CI -2.9, -1.4; p < 0.0001) and -0.9 (95% CI -1.4, -0.5; p < 0.0001), respectively. Sinus CT scan revealed that Lund-Mackay CT score (LS mean difference [95% CI] -7.6, [-9.4, -5.8]; p < 0.0001) and sinus volume occupied by disease (LS mean difference [95% CI] -37%, [-47%, -28%]; p < 0.0001) were significantly improved with CM310 compared with placebo. In addition, CM310 significantly relieved the daily symptoms of patients with CRSwNP and improved their quality of life reflected by the improvements in the TSS (-2.6 [95% CI -3.5, -1.6]), UPSIT (10.4 [95% CI 6.8, 14.0]) and SNOT-22 score (-19.1 [95% CI -29.8, -8.5]). Compared with placebo, CM310 administration significantly reduced type 2-related biomarkers including the serum TARC and total IgE, and tissue eosinophils. The most common adverse events were upper respiratory tract infection, blood cholesterol increased, and tinnitus, but none were considered drug-related. Interpretation: These findings support CM310 as an effective additional treatment option to the standard of care in patients with severe ECRSwNP. Funding: KeyMed Biosciences (Chengdu) Limited.

Circular RNA PDK1 targets miR-4731-5p to enhance TNXB expression in ligamentum flavum hypertrophy.

Hypertrophic ligamentum flavum (LF) is a main factor responsible for lumbar spinal stenosis (LSS); however, the exact mechanisms of the pathogenesis of these processes remain unknown. This study aimed to elucidate whether circular RNAs and microRNAs regulate the pathogenesis of LF and LSS, especially focusing on circPDK1 (hsa_circ_0057105), a circRNA targeting pyruvate dehydrogenase kinase 1 and differentially expressed in LF tissues between lumbar disk herniation and LSS patients. The circPDK1/miR-4731 and miR-4731/TNXB (Tenascin XB) interactions were predicted and validated by luciferase reporter assay. Colony formation, wound-healing, and MTT assays were used for estimating cell proliferation and migration. Protein expression levels were evaluated using Western blotting. TNXB expression was verified using immunohistochemistry (IHC). Overexpressing circPDK1 promoted the proliferation, migration, and expression of fibrosis-related protein (alpha smooth muscle actin (α-SMA), lysyl oxidase like 2 (LOXL2), Collagen I, matrix metalloproteinase-2 (MMP-2) and TNXB) in LF whereas miR-4731-5p showed opposite effects. The expression of TNXB was promoted by circPDK1; contrary results were observed with miR-4731-5p. Co-overexpression of miR-4731-5p partially reversed the proliferative and fibrosis-prompting effects of circPDK1 or TNXB. The circPDK1-miR-4731-TNXB pathway may be proposed as a regulatory axis in LF hypertrophy, which might shed light on in-depth research of LSS, as well as providing a novel therapeutic target for LF hypertrophy-induced LSS.

Axial superior facet slope may determine anterior or posterior atlantoaxial displacement secondary to os odontoideum and compensatory mechanisms of the atlantooccipital joint and subaxial cervical spine.

OBJECTIVE: To introduce novel parameters in determining directions of os odontoideum (OO) with atlantoaxial displacement (AAD) and compensations of cervical sagittal alignment after displacement. METHODS: Analysis was performed on 96 cases receiving surgeries for upper cervical myelopathy caused by OO with AAD from 2011 to 2021. Twenty-four patients were included in the OO group and divided into the OO-anterior displacement (AD) group and the OO-posterior displacement (PD) group by displacement. Seventy-two patients were included as the control (Ctrl) group and divided into Ctrl-positive (Ctrl-P) group and Ctrl-negative (Ctrl-N) group by axial superior facet slope (ASFS) in a neutral position. ASFS, the sum of C2 slope (C2S) and axial superior facet endplate angle (ASFEA), was measured and calculated by combining cervical supine CT with standing X-ray. Cervical sagittal parameters were measured to analyse the atlantoaxial facet and compensations after AAD. RESULTS: Atlas inferior facet angle (AIFA), ASFS, and ASFEA in Ctrl-P significantly differed from OO-AD.C0-C1, C1-C2, C0-C2, C2-C7, C2-C7 SVA, and C2S in Ctrl-P significant differed from the OO-AD group. C2-C7 SVA and C2S in Ctrl-N significantly were smaller than the OO-PD group. C1-C2 correlated with C0-C1 and C2-C7 negatively in the OO group. Slight kyphosis of C1-C2 in OO-AD was compared with lordosis of C1-C2 in Ctrl-P, inducing increased extension of C0-C1 and C2-C7. Mildly increased lordosis of C1-C2 in OO-PD was compared with C1-C2 in Ctrl-N, triggering augmented flexion of C0-C1 and C2-C7. CONCLUSION: ASFS was vital in determining directions of OO with AAD and explaining compensations. ASFS and ASFEA could provide pre- and intraoperative guidelines. KEY POINTS: • ASFS may determine the directions and compensatory mechanisms of AAD secondary to OO. • ASFS could be achieved by the sum of ASFEA and C2S.