Total Synthesis and Cytotoxicity Evaluation of Pareitropone and Analogues.

A concise synthesis of pareitropone by oxidative cyclization of a phenolic nitronate is delineated. The use of TMSOTf as an additive to promote the facile formation of a strained norcaradiene intermediate provides convenient access to highly condensed multicyclic tropones in high yields. This synthesis is modular, efficient, and scalable, highlighting the synthetic utility of radical anion coupling reactions in annulation reactions. This work is discussed in the context of total syntheses of the tropoloisoquinoline alkaloids. Also included are the preparation of several congeners and a brief description of their biological activities.

The genomic basis of temporal niche evolution in a diurnal rodent.

Patterns of diel activity-how animals allocate their activity throughout the 24-h daily cycle-play key roles in shaping the internal physiology of an animal and its relationship with the external environment.1,2,3,4,5 Although shifts in diel activity patterns have occurred numerous times over the course of vertebrate evolution,6 the genomic correlates of such transitions remain unknown. Here, we use the African striped mouse (Rhabdomys pumilio), a species that transitioned from the ancestrally nocturnal diel niche of its close relatives to a diurnal one,7,8,9,10,11 to define patterns of naturally occurring molecular variation in diel niche traits. First, to facilitate genomic analyses, we generate a chromosome-level genome assembly of the striped mouse. Next, using transcriptomics, we show that the switch to daytime activity in this species is associated with a realignment of daily rhythms in peripheral tissues with respect to the light:dark cycle and the central circadian clock. To uncover selection pressures associated with this temporal niche shift, we perform comparative genomic analyses with closely related rodent species and find evidence of relaxation of purifying selection on striped mouse genes in the rod phototransduction pathway. In agreement with this, electroretinogram measurements demonstrate that striped mice have functional differences in dim-light visual responses compared with nocturnal rodents. Taken together, our results show that striped mice have undergone a drastic change in circadian organization and provide evidence that the visual system has been a major target of selection as this species transitioned to a novel temporal niche.

Physicochemical and Functional Properties of Yeast-Fermented Cabbage.

Microbial fermentation is often used to improve the functionality of plant-based food materials. Herein, we investigated changes in the physicochemical and functional properties of cabbage during yeast fermentation to develop new products using fermented cabbage. Among the 8 types of food-grade yeast, both Saccharomyces cerevisiae and Saccharomyces boulardii fermented 10% cabbage powder solution (w/w) the most effectively, leaving no soluble sugars after 12 h of fermentation. In addition, the yeast fermentation of cabbage resulted in functionally positive outcomes in terms of sulforaphane content, antioxidant properties, and anti-inflammatory activity. Specifically, the yeast-fermented cabbages contained about 500% more sulforaphane. The soluble fraction (5 µg/ml) of yeast-fermented cabbage had no cytotoxicity in murine RAW 264.7 cells, and the radical-scavenging capacity was equivalent to 1 µg/ml of ascorbic acid. Moreover, cabbage fermented with S. boulardii significantly suppressed both lipopolysaccharides (LPS)-induced nitric oxide production and LPS-induced reactive oxygen species production in RAW 264.7 cells, suggesting a potential anti-inflammatory effect. These results support the idea that yeast fermentation is promising for developing functionally improved cabbage products.

SB2301-mediated perturbation of membrane composition in lipid droplets induces lipophagy and lipid droplets ubiquitination.

Lipid droplets (LDs) are involved in various biological events in cells along with their primary role as a storage center for neutral lipids. Excessive accumulation of LDs is highly correlated with various diseases, including metabolic diseases. Therefore, a basic understanding of the molecular mechanism of LD degradation would be beneficial in both academic and industrial research. Lipophagy, a selective autophagy mechanism/LD degradation process, has gained increased attention in the research community. Herein, we sought to elucidate a novel lipophagy mechanism by utilizing the LD-degrading small molecule, SB2301, which activates ubiquitin-mediated lipophagy. Using a label-free target identification method, we revealed that ethanolamine-phosphate cytidylyltransferase 2 (PCYT2) is a potential target protein of SB2301. We also demonstrated that although SB2301 does not modulate PCYT2 function, it induces the cellular translocation of PCYT2 to the LD surface and spatially increases the phosphatidylethanolamine (PE)/phosphatidylcholine (PC) ratio of the LD membrane, causing LD coalescence, leading to the activation of lipophagy process to maintain energy homeostasis.

AO Spine Adult Spinal Deformity Patient Profile: A Paradigm Shift in Comprehensive Patient Evaluation in Order to Optimize Treatment and Improve Patient Care.

STUDY DESIGN: Modified Delphi study. OBJECTIVE: Adult spinal deformity (ASD) is an increasingly recognized condition, comprising a spectrum of pathologies considerably impacting patients' health and functional status. Patients present with a combination of pain, disability, comorbidities and radiological deformity. The study aims to propose a systematic approach of gathering information on the factors that drive decision-making by developing a patient profile. METHODS: The present study comprises of 3 parts. Part 1: Development of prototype of patient profile: The data from the Core Outcome Study on SCOlisis (COSSCO) by Scoliosis Research Society (SRS) was categorized into a conceptual framework. Part 2: Modified Delphi study: Items reaching >70% agreement were included in a 4 round iterative process with 51 panellists across the globe. Part 3: Pilot testing-feasibility: Content validity and usability were evaluated quantitatively. RESULTS: The profile consisted of 4 domains. 1. General health with demographics and comorbidities, 2.Spine-specific health with spine related health and neurological status, 3. Imaging with radiographic and MRI parameters and 4. Deformity type. Each domain consisted of 1 or 2 components with various factors and their measuring instruments. Profile was found to have an excellent content validity (I-CVIr 0.78-1.00; Ave-CVI 0.92) appropriateness, relevance and usefulness. CONCLUSIONS: The present study, is first to provide a universally applicable multimodal ASD patient profile to methodically describe patients. Physicians are encouraged to assess ASD patients holistically using this profile and not just based on radiographic findings.

Inhibitory Effect of Insulin Treatment on Apoptosis of Intervertebral Disc Cells in a Streptozotocin-Induced Diabetic Rat Model.

STUDY DESIGN: Experimental study using a streptozotocin (STZ)-induced diabetic rat model. PURPOSE: This study aims to investigate whether insulin treatment could attenuate disc cell apoptosis and matrix degradation in a STZ-induced diabetic rat model. OVERVIEW OF LITERATURE: Diabetes is a significant risk factor for disc degeneration due to excessive apoptosis of disc cells and matrix degradation. However, no studies were noted to demonstrate the inhibitory effect of insulin treatment on the apoptosis of disc cells and matrix degradation in diabetic patients. METHODS: Rats were allocated randomly into one of three groups: control, STZ, and STZ-insulin. Diabetes was induced by a single intraperitoneal injection of STZ (65 mg/kg) in the STZ and STZ-insulin groups. The blood glucose level was consistently above 400 mg/ dL in the STZ and STZ-insulin groups 2 weeks after STZ injection. After 2 weeks of STZ injection, the STZ-insulin group was administered insulin treatment (1.5 unit/100 g) daily for up to 4 weeks. Blood glucose of the STZ-insulin rats significantly decreased to normal levels 4 weeks after insulin treatment. The rats were sacrificed 6 weeks after STZ injection, and disc cells and tissues were harvested to investigate the expression of apoptosis markers and matrix metalloproteinases (MMPs). RESULTS: Fas and caspase-8, -9, and -3 expressions were significantly increased in the STZ group, along with increased expressions of MMP-2 and -3. On the contrary, insulin treatment significantly decreased the expressions of Fas, caspase-8, -9, and -3 as well as MMP-2 and -3 in the STZ-insulin group. CONCLUSIONS: The results of the current study demonstrated that insulin treatment attenuates excessive apoptosis of disc cells and matrix degradation in the diabetic rat model. Accordingly, strict blood glucose control should be recommended to prevent disc degeneration in diabetic patients.

Lumbar Interbody Fusion and Osteobiologics for Lumbar Fusion.

Lumbar interbody fusion (LIF) is an excellent treatment option for a number of lumbar diseases. LIF can be performed through posterior, transforaminal, anterior, and lateral or oblique approaches. Each technique has its own pearls and pitfalls. Through LIF, segmental stabilization, neural decompression, and deformity correction can be achieved. Minimally invasive surgery has recently gained popularity and each LIF procedure can be performed using minimally invasive techniques to reduce surgery-related complications and improve early postoperative recovery. Despite advances in surgical technology, surgery-related complications after LIF, such as pseudoarthrosis, have not yet been overcome. Although autogenous iliac crest bone graft is the gold standard for spinal fusion, other bone substitutes are available to enhance fusion rate and reduce complications associated with bone harvest. This article reviews the surgical procedures and characteristics of each LIF and the osteobiologics utilized in LIF based on the available evidence.

An Overview of Antiviral Peptides and Rational Biodesign Considerations.

Viral diseases have contributed significantly to worldwide morbidity and mortality throughout history. Despite the existence of therapeutic treatments for many viral infections, antiviral resistance and the threat posed by novel viruses highlight the need for an increased number of effective therapeutics. In addition to small molecule drugs and biologics, antimicrobial peptides (AMPs) represent an emerging class of potential antiviral therapeutics. While AMPs have traditionally been regarded in the context of their antibacterial activities, many AMPs are now known to be antiviral. These antiviral peptides (AVPs) have been shown to target and perturb viral membrane envelopes and inhibit various stages of the viral life cycle, from preattachment inhibition through viral release from infected host cells. Rational design of AMPs has also proven effective in identifying highly active and specific peptides and can aid in the discovery of lead peptides with high therapeutic selectivity. In this review, we highlight AVPs with strong antiviral activity largely curated from a publicly available AMP database. We then compile the sequences present in our AVP database to generate structural predictions of generic AVP motifs. Finally, we cover the rational design approaches available for AVPs taking into account approaches currently used for the rational design of AMPs.

Factors Affecting the Decision to Initiate Anticoagulation After Spine Surgery: Findings From the AOSpine Anticoagulation Global Initiative.

STUDY DESIGN: Cross-sectional, international survey. OBJECTIVES: To identify factors influencing pharmacologic anticoagulation initiation after spine surgery based on the AOSpine Anticoagulation Global Survey. METHODS: This survey was distributed to the international membership of AOSpine (n = 3805). A Likert-type scale described grade practice-specific factors on a scale from low (1) to high (5) importance, and patient-specific factors a scale from low (0) to high (3) importance. Analysis was performed to determine which factors were significant in the decision making surrounding the initiation of pharmacologic anticoagulation. RESULTS: A total of 316 spine surgeons from 64 countries completed the survey. In terms of practice-specific factors considered to initiate treatment, expert opinion was graded the highest (mean grade ± SD = 3.2 ± 1.3), followed by fellowship training (3.2 ± 1.3). Conversely, previous studies (2.7 ± 1.2) and unspecified guidelines were considered least important (2.6 ± 1.6). Patient body mass index (2.0 ± 1.0) and postoperative mobilization (2.3 ± 1.0) were deemed most important and graded highly overall. Those who rated estimated blood loss with greater importance in anticoagulation initiation decision making were more likely to administer thromboprophylaxis at later times (hazard ratio [HR] = 0.68-0.71), while those who rated drain output with greater importance were likely to administer thromboprophylaxis at earlier times (HR = 1.32-1.43). CONCLUSION: Among our global cohort of spine surgeons, certain patient factors (ie, patient mobilization and body mass index) and practice-specific factors (ie, expert opinion and fellowship training) were considered to be most important when considering anticoagulation start times.

Proximal Junctional Kyphosis in Adult Spinal Deformity: Definition, Classification, Risk Factors, and Prevention Strategies.

Proximal junctional problems are among the potential complications of surgery for adult spinal deformity (ASD) and are associated with higher morbidity and increased rates of revision surgery. The diverse manifestations of proximal junctional problems range from proximal junctional kyphosis (PJK) to proximal junctional failure (PJF). Although there is no universally accepted definition for PJK, the most common is a proximal junctional angle greater than 10° that is at least 10° greater than the preoperative measurement. PJF represents a progression from PJK and is characterized by pain, gait disturbances, and neurological deficits. The risk factors for PJK can be classified according to patient-related, radiological, and surgical factors. Based on an understanding of the modifiable factors that contribute to reducing the risk of PJK, prevention strategies are critical for patients with ASD.

15-year survivorship analysis of an interspinous device in surgery for single-level lumbar disc herniation.

BACKGROUND: Interspinous devices have been introduced as alternatives to decompression or fusion in surgery for degenerative lumbar diseases. This study aimed to investigate 15-year survivorship and risk factors for reoperation of a Device for Intervertebral Assisted Motion (DIAM) in surgery for 1-level lumbar disc herniation (LDH). METHODS: A total of 94 patients (54 men and 40 women) underwent discectomy and DIAM implantation for 1-level LDH, with a mean follow-up of 12.9 years (range, 6.3-15.3 years). The mean age was 46.2 years (range, 21-65 years). Sixty-two patients underwent DIAM implantation for L4-5, 27 for L5-6, and 5 for L3-4. Reoperations due to any reason associated with DIAM implantation level or adjacent levels were defined as failure and used as the end point of determining survivorship. RESULTS: During the 15-year follow-up, 8 patients (4 men and 4 women) underwent reoperation due to recurrence of LDH at the DIAM implantation level, a reoperation rate of 8.5%. The mean time to reoperation was 6.5 years (range, 0.8-13.9 years). Kaplan-Meier analysis showed a cumulative survival rate of the DIAM implantation of 97% at 5 years, 93% at 10 years, and 92% at 15 years after surgery; the cumulative reoperation rate of the DIAM implantation was 3% at 5 years, 7% at 10 years, and 8% at 15 years after surgery. Mean survival time was predicted to be 14.5 years (95% CI, 13.97-15.07). The log-rank test and Cox proportional hazard model showed that age, sex, and location did not significantly affect the reoperation rate of DIAM implantation. CONCLUSIONS: Our results showed that DIAM implantation significantly decreased reoperation rate for LDH in the 15-year survivorship analysis. We suggest that DIAM implantation could be considered a useful intermediate step procedure for LDH surgery. To the best of our knowledge, this is the longest follow-up study in which surgical outcomes of interspinous device surgery were reported.

Anterior Dens Screw Fixation for Traumatic C1-2 Lateral Subluxation With 3-Part Fractures of the C2 Axis (Dens, Lateral Mass, and Hangman Fractures): A Case Report.

INTRODUCTION: To report the first case of traumatic C1-2 lateral subluxation with three-part fractures of the C2 axis (dens, lateral mass, and hangman fractures) that was successfully treated with only anterior dens screw fixation. METHODS: A 56-year-old man was admitted to the hospital complaining of neck and left arm pains caused by a pedestrian traffic accident. Radiologic examination revealed traumatic C1-2 lateral subluxation, type 3 dens fracture (Anderson and D'Alonzo classification), fracture of both C2 lateral masses, and type 1 hangman fracture (Levine and Edwards classification). RESULTS: Preoperative closed reduction of the C1-2 lateral subluxation was successfully achieved by skull traction using a Gardner-Wells tong. The patient underwent anterior dens screw fixation for type 3 dens fracture with posterior angulation. At the 2-year follow-up visit, good reduction of traumatic C1-2 lateral subluxation and solid fusion of all three-part fractures of the C2 axis were achieved with full range of motion and stability at the C1-2 joint. In addition, notable improvement of neck and left arm pains was achieved. DISCUSSION: Preoperative closed reduction and anterior dens screw fixation can be considered as a less invasive and motion-preserving surgery for traumatic C1-2 lateral subluxation with three-part fractures of the C2 axis.

The Psychosocial Effects of Taekwondo Training: A Meta-Analysis.

Taekwondo is a Korean martial art and international sport, and its psychosocial benefits for its trainees have been studied extensively. This review aims to systematically assess and meta-analyze the effects of Taekwondo training on sociality, character, etiquette, and school life adjustment. We searched the RISS, NDSL, and KISS electronic databases between January 1985 and December 2019. We also included gray literature, such as theses, in addition to peer-reviewed articles. R software (version 3.6.2, R Core Team, Vienna, Austria) was used to synthesize the effect sizes and perform moderation analyses. Twenty-eight studies (24 cross-sectional and four intervention studies) were included in the final meta-analysis. Significant positive effects of Taekwondo training were found on sociality (MD = 0.266, 95% CI: 0.191 to 0.341), character (MD = 0.446, 95% CI: 0.331-0.560), etiquette (MD = 0.562, 95% CI: 0.500-0.624), and school life adjustment (MD = 0.308, 95% CI: 0.195-0.421). Overall, the findings of this meta-analysis support that Taekwondo can have a positive impact on the psychosocial factors of trainees. Due to several limitations discussed, well-designed RCTs and multiple levels of Taekwondo intervention studies should be conducted in future research to validate the current findings.

Effects of Taekwondo Training on Body Composition: A Systematic Review and Meta-Analysis.

BACKGROUND: The purpose of this study is to investigate the effect of Taekwondo training on body composition and to evaluate the magnitude of the effect. METHODS: Databases were used to select studies related to the effectiveness of Taekwondo training, and the inclusion criteria were as follows. RESULTS: Thirty-seven studies were selected. We found statistically significant differences from the control group in weight, body mass index (BMI), waist circumference (WC), waist-hip ratio (WHR), body fat mass, body fat percentage, lean mass, and muscle mass. Also, the age group was statistically significant in control variables on weight, BMI, and body fat percentage. CONCLUSIONS: Taekwondo training had a positive effect on body composition, and these results suggest that Taekwondo training is an effective exercise method to lower obesity.

Cervical Myelopathy Caused by Posttraumatic Osteophytes Resulting From Long-Standing Neglected Posterior Atlanto-Occipital Dislocation More Than 30 years: A Case Report.

INTRODUCTION: Traumatic atlanto-occipital dislocation (AOD) is a rare but usually fatal injury. To our knowledge, no study has reported long-standing neglected posterior AOD more than 30 years in a patient who survived and later experienced cervical myelopathy. METHODS: A 75-year-old man presented with symptoms of cervical myelopathy. On history, the patient was diagnosed with posterior AOD that occurred after a fall 31 years ago, but he did not undergo surgery. Radiologic evaluation of cervical spine revealed severe spinal cord compression caused by posttraumatic osteophytes of the C0-C1-C2 joints resulting from long-standing neglected posterior AOD. However, no instability of the C0-C1-C2 joints was found. RESULTS: Laminectomy of the C1 posterior arch was performed without occipitocervical fusion considering the long-standing severe osteoarthritic changes and no instability of the C0-C1-C2 joints. Cervical myelopathy significantly improved, and the patient was doing well without recurrence at the 7-year follow-up. DISCUSSION: To our knowledge, this is the first report of a patient with cervical myelopathy caused by neglected posterior AOD with posttraumatic osteophytes of the C0-C1-C2 joints. Laminectomy of the C1 posterior arch without occipitocervical fusion achieved satisfactory outcomes for cervical myelopathy caused by posttraumatic osteophytes resulting from long-standing neglected posterior AOD more than 30 years.

Proposal of Treatment Strategy for Pedicle Fractures of the C2: An Analysis of 49 Cases.

Spine surgeons often confuse C2 pedicle fractures (PFs) with pars interarticularis fractures. In addition, little information is available about the characteristics and treatment strategies for C2 PFs. We sought to investigate the characteristics of C2 PFs and to propose an appropriate treatment strategy. A total of forty-nine patients with C2 PFs were included in this study. We divided these patients into unilateral and bilateral C2 PF groups. The incidence rates and characteristics of other associated C2 and C2-3 injuries, and other cervical injuries, were evaluated. In addition, treatment methods and outcomes were analyzed. Twenty-two patients had unilateral C2 PFs and twenty-seven patients had bilateral C2 PFs. Among the cases of unilateral C2 PFs, all patients had one or more other C2 fractures, and twenty patients (90.9%) had one or two C2 body fractures. Meanwhile, among the cases of bilateral C2 PF, all patients had two or more other C2 fractures and one or two C2 body fractures. In unilateral C2 PFs, three patients with C2-3 anterior slip or adjacent cervical spine (C1-3) injury underwent surgery and nineteen patients (86.4%) were treated with conservative methods. In bilateral C2 PFs, three patients with C2-3 anterior slip or SCI at C2-3 underwent surgery and twenty-four patients (88.9%) were treated with conservative methods. Our results showed that C2 PFs do not occur alone and are always accompanied by other associated C2 injuries. C2 PFs should, generally, be thought of as a more complex fracture type than hangman's fracture or dens fracture. Despite the complex fracture characteristics, most C2 PFs can be managed with conservative treatment. However, surgical treatments should be considered if the C2 PFs are accompanied by the C2-3 anterior slip and adjacent cervical spine injury.

Hyperacute onset of adjacent segment disease with dorsally migrated herniated nucleus pulposus causing cauda equina syndrome: a case report.

PURPOSE: To report the first case of hyperacute onset of adjacent segmental disease (ASD) with dorsally migrated herniated nucleus pulposus (HNP) causing cauda equina syndrome. METHODS: A 55-year-old female complained of lower back pain with radiating pain in both lower extremities that had not responded to conservative treatment over the previous six months. Plain radiographs and magnetic resonance imaging (MRI) findings revealed degenerative spondylolisthesis with spinal stenosis at L3-4, L4-5, and a slight bulging disc at L2-3. The patient underwent decompressive total laminectomy and posterior fusion at L3-4 and L4-5. The stenotic symptoms improved significantly after surgery, and she was then discharged on postoperative day 7. RESULTS: However, the patient visited the emergency department four days after discharge (postoperative day 11) complaining of sudden onset of bilateral lower extremity weakness and voiding and defecation difficulties. The follow-up MRI showed dorsally migrated huge HNP and a detached posterior longitudinal ligament (PLL) at L2-3, which was diagnosed as hyperacute onset of ASD causing cauda equina syndrome. The patient underwent an emergency second operation consisting of partial laminectomy at L2-3 with removal of the dorsally migrated huge HNP. After the second operation, the symptoms of cauda equina syndrome improved. One year after the second operation, the patient is doing well without recurrence of symptoms. CONCLUSIONS: Our case showed that hyperacute onset of ASD with dorsally migrated huge HNP can cause cauda equina syndrome, even within 2 weeks after lumbar fusion surgery. Therefore, a high index of suspicion, timely diagnosis, and surgical treatment are needed to avoid the catastrophic neurologic complications in similar extremely rare cases.

Challenges to the orthopedic resident workforce during the first wave of COVID-19 pandemic: Lessons learnt from a global cross-sectional survey.

BACKGROUND: The COVID-19 pandemic has caused unprecedented concerns on the safety, well-being, quality of life(QOL), and training of the orthopedic resident physician workforce worldwide. Although orthopedic residency programs across the globe have attempted to redefine resident roles, educational priorities, and teaching methods, the global orthopedic residents' perspective with regards to their safety, well-being, QOL, and training, taking into account regional variances remains unknown. METHODS: A 56-item-questionnaire-based cross-sectional survey was conducted online during the COVID-19 pandemic involving 1193 orthopedic residents from 29 countries across six geographical regions to investigate the impact of the COVID-19 pandemic on the well-being, safety, and training of orthopedic residents at a global level, as well as to analyze the challenges confronted by orthopedic residency programs around the world to safeguard and train their resident workforce during this period. RESULTS: The total response rate was 90.3%(1077/1193). Time spent on residency-training activities decreased by 24.7 h/week (95% CI, -26.5 to -22.9,p < 0.001), with 50.2% (n = 541) residents performing duties outside their residency curriculum. 80.5% (n = 869) residents had no prior experience working in infectious outbreaks. A greater percentage of residents from Middle East, Asia and Europe were redeployed to the COVID-19 frontlines, p < 0.001. Only 46.5% (n = 491) and 58.4% (n = 600) of residents underwent training in critical care or PPE (Personal Protective equipment) usage, respectively; 28.5% (n = 302) residents (majority from Africa, Middle East, South America) reported lack of institutional guidelines to handle infectious outbreaks; 15.4% (n = 160) residents (majority from Africa, Asia, Europe) had concerns regarding availability of PPE and risk of infection. An increase in technology-based virtual teaching modalities was observed. The most significant stressor for residents was the concern for their family's health. Residents' QOL significantly decreased from 80/100 (IQR 70-90) to 65/100 (IQR 50-80) before and during the pandemic, p < 0.001. CONCLUSIONS: The COVID-19 pandemic has significantly impacted the safety, well-being, QOL, and training of the global orthopedic resident physician workforce to different extents across geographical regions. The findings of this study will aid educators, program leaderships, and policy makers globally in formulating flexible, generalizable, and sustainable strategies to ensure resident safety, well-being, and training, while maintaining patient care.

Traumatic Posterior Atlanto-occipital Dislocation With Three-part Jefferson Fracture and Subaxial Distractive Extension Injury.

No previous reports have described combined upper and lower cervical injuries caused by a contrary injury mechanism. A 44-year-old man was transferred complaining of quadriplegia caused by a rear-end collision car accident. CT and MRI findings revealed posterior atlanto-occipital dislocation (AOD) with three-part Jefferson fracture and subaxial distractive extension (DE) injury at the C3-4 and C6-7 levels. MRI showed spinal cord injury at C3-4 and C6-7, which caused quadriplegia and respiratory failure. When the patient arrived at the emergency department, he was already intubated because of respiratory failure. The patient was also hemodynamically unstable after lung injury and pelvic bone fracture. The patient died 1 day after the accident before undergoing surgical intervention. To the best of our knowledge, this is the first report of a case of a traumatic posterior AOD with three-part Jefferson fracture and subaxial DE injury caused by a contrary injury mechanism. Subaxial DE injury, not posterior AOD, caused fatal situation in this case. High index of suspicion and careful radiologic examination are needed to investigate the presence of associated lower cervical spine injury caused by a contrary injury mechanism in traumatic posterior AOD, which may affect treatment, outcome, and prognosis.

Delayed onset postoperative retropharyngeal hematoma after anterior cervical surgery with a sequela of tracheal stricture: a case report.

BACKGROUND: Among the several complications associated with anterior cervical discectomy and fusion (ACDF), airway compromise is considered one of the serious life-threatening conditions and usually requires emergent treatment, including airway establishment and hematoma evacuation surgery. Postoperative retropharyngeal hematoma commonly occurred during the on immediate phase with airway compromise, but have a rarity on late onset of this complication. Enlightened by this existing fact, we report the first case of delayed onset postoperative retropharyngeal hematoma after anterior cervical surgery with a sequela of tracheal stricture. CASE PRESENTATION: A 55-year-old male underwent ACDF for disc herniation at C5-6 that had not responded to conservative treatment over 3 months. The symptoms significantly improved after surgery, and he was discharged on postoperative day 3. On the 7 days after ACDF, the patient complained of sudden-onset left-deviated neck swelling. The follow-up plain radiographs and neck-enhanced computed tomography (CT) scans showed anterior and right lateral displacement of the airway including the trachea by a large retropharyngeal hematoma. We performed an emergent forceful endotracheal intubation that was maintained for 2 days until the patient underwent hematoma evacuation surgery. On the second day after hematoma evacuation surgery, the patient complained of hoarseness with a foul breath odor. Laryngoscopy showed tracheal ischemic mucosal damage that had been induced by forceful endotracheal intubation. Antibiotics and systemic corticosteroids were administered, and the symptoms improved. One month after hematoma evacuation surgery, he complained of dyspnea on exertion, and laryngoscopy showed tracheal stricture. The patient underwent bronchoscopic dilatation and is doing well without recurrence of symptoms. CONCLUSIONS: Early surgery to remove the delayed onset retropharyngeal hematoma, rather than forceful endotracheal intubation followed by delayed surgery, might yield better results and avoid unexpected complications of tracheal stricture.