Outcomes of Odontoid Fractures with Associated Cardiac Arrest: Retrospective Bi-Center Case Series and Systematic Literature Review

Outcomes of Odontoid Fractures with Associated Cardiac Arrest: Retrospective Bi-Center Case Series and Systematic Literature Review | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Outcomes of Odontoid Fractures with Associated Cardiac Arrest: Retrospective Bi-Center Case Series and Systematic Literature Review S. F. Schaible, S. Häckel, N. Rutsch, F. C. Aregger, S. F. Bigdon, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4821074/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 29 Oct, 2024 Read the published version in Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine → Version 1 posted 8 You are reading this latest preprint version Abstract Background: Odontoid fractures from high-energy trauma are associated with significant morbidity and mortality, including spinal cord injury, neurological damage, and cardiac arrest. The literature on odontoid fractures leading to cardiac arrest is limited to isolated case reports. This study aims to conduct a retrospective bi-center case series and a systematic review of existing literature. Methods: We conducted a retrospective bi-center case series on patients with odontoid fractures from high-energy trauma who experienced post-traumatic cardiac arrest with return of spontaneous circulation (ROSC) after CPR from two Level 1 Trauma Centers (2008–2024). The primary outcome was mortality; secondary outcomes included epidemiological, pre-hospital, and in-hospital data, and CT and MRI findings. Additionally, we performed a systematic literature review to summarize existing evidence. Results: The study included 25 patients (mean age 71.1 ± 12.3 years, SD; 8 females). The mortality rate was 92% (23 patients). Median downtime before CPR was 5.0 minutes (IQR: 7.0), with CPR lasting 17.0 minutes (IQR: 13.0), primarily initiated by professionals (60%). All patients were quadriplegic. Type II Anderson d'Alonzo fractures were most common (88%), with all patients showing myelopathy on MRI. Only three patients (12%) underwent surgical intervention due to favorable prognosis. Our literature review identified seven case reports, with two patients surviving and one achieving full recovery. Conclusions: In this case series, patients experiencing cardiac arrest after odontoid fractures exhibited high mortality rates despite comprehensive management at Level 1 trauma centers. Survivors faced significant and enduring morbidity. Cervical injuries spinal injuries heart arrest resuscitation review Figures Figure 1 Figure 2 Figure 3 Figure 4 Background Odontoid fractures constitute a significant proportion of acute cervical spine injuries, accounting for 9–18% of cases. These fractures predominantly affect patients aged 65 years and older, typically resulting from low-energy trauma ( 1 – 3 ). However, they can also occur in younger patients following high-energy trauma, potentially associated with neurological deficits. These fractures significantly impair quality of life and burden patients and healthcare systems. Overall, mortality rates reach 14% within 30 days and 44% within two years, with neurological injury incidence between 2% and 27% ( 4 ). While spinal cord injury (SCI) rarely accompanies low-energy falls, high-energy spine trauma can cause SCI through traction, contusion, compression, or ischemia. In severe cases, acute high-level SCI may trigger cardiac arrest by disrupting the sympathetic nervous system ( 5 – 9 ). Disrupted preganglionic sympathetic interneurons leads to parasympathetic dominance ending in bradyarrhythmias and atrioventricular blocks ( 10 ). In these severe cases of odontoid fractures with subsequent cardiac arrest, immediate intervention requires cardiopulmonary resuscitation (CPR) as a life-saving measure, followed by comprehensive management of polytrauma, including damage control surgery, and intensive or intermediate care based on patient condition and diagnostic imaging findings ( 11 – 13 ). Persistent spinal cord compression necessitates prompt decompression, with subsequent operative stabilization often required for managing the typically unstable fracture patterns of odontoid fractures associated with SCI ( 14 – 21 ). However, in cases of severe spinal cord damage, the prognosis for neurological recovery is poor ( 17 , 18 ). While there is substantial data on the treatment of isolated odontoid fractures and on cardiac arrest independently, the literature addressing the unique combination of odontoid fractures causing cardiac arrest due to high spinal cord or medulla oblongata injuries is notably sparse. The existing studies are primarily isolated case reports, which often document patient mortality within days of the injury. To address this gap, in this study, we present a bi-center case series aimed at exploring the treatments and outcomes of odontoid fractures followed by cardiac arrest with return of spontaneous circulation (ROSC), with the following objectives: first, mortality and descriptive analysis of pre- and in-hospital treatment; second, a systematic review of literature on comparable scenarios; and third, a comparison of our case series with the literature findings. Methods Cohort definition and outcomes After obtaining ethics approval from local ethics committees (Kantonale Ethikkommission Bern [KEK]); BASEC-Nr: Req-2023-00618), we performed a retrospective review of the databases of two Swiss level 1 trauma centers between 2008 and 2024, University Hospital Bern (Inselspital) and Cantonal Hospital Graubuenden Chur. We included all patients who experienced a high-energy trauma according to a recently published definition ( 22 ), who were resuscitated at the accident scene, who achieved ROSC, and who were diagnosed in the emergency department with an odontoid fracture that was determined to be the primary cause for cardiac arrest necessitating the resuscitation. Exclusion criteria were absence of an odontoid fracture, failure to achieve ROSC, incomplete data, patients under 18 years of age, and lack of general consent. Our primary outcome was patients’ mortality. Secondary outcomes included pre-hospital and in-hospital treatment. To collect pre-hospital and in-hospital data, we reviewed reports from the evacuation team, emergency department, and intensive care unit (ICU). Pre-hospital treatment outcomes included the duration of cardiac arrest, duration and providers of CPR (categorized as layperson bystanders, professionals, or both), administered dose of adrenaline, and time to ROSC. In-hospital outcomes encompassed return to consciousness, best neurological status in the ICU, treatment of the odontoid fracture (surgery, conservative, or best supportive care), time to death, time to ICU discharge, and time to hospital discharge. Additionally, we recorded injury mechanisms and epidemiological data from hospital records. We retrospectively classified the fractures identified on the initial whole-body computed tomography (CT) scans, assessing the degree of fracture displacement. If available, magnetic resonance imaging (MRI) studies were evaluated for the presence of myelopathy and stenosis with/without persisting compression of the spinal cord. Additionally, we used the Brain and Spinal Injury Center score (BASIC) score, which evaluates acute traumatic spinal cord injury by grading the axial extent of intramedullary signal abnormalities on T2-weighted MRI on a scale from one to four ( 23 ). Systematic Literature Review On April 1, 2024, we conducted a systematic literature review following the current Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines ( 24 ). Our search included the PubMed, Google Scholar, and Medline databases, using the terms ("odontoid fracture" AND "cardiac arrest") and ("odontoid fracture" AND "arrest") applied to all fields, aimed at comprehensively capturing relevant, referenced, and referencing articles. We included studies with cases of odontoid fractures associated with cardiac arrest before or during emergency department treatment, excluding those where cardiac arrest was unrelated to the odontoid fracture or occurred later during hospitalization. Data from the selected articles were extracted and systematically analyzed, focusing on the same outcomes as described for our own cohort, as well as epidemiological data and study designs. Statistical Methods Descriptive statistics were employed to present the study outcome data. Data collection was conducted using password-protected software, and analysis was performed using R (R Foundation for Statistical Computing, Vienna, Austria). A Shapiro-Wilk test was conducted to assess for normal distribution. Continuous data are presented as mean ± standard deviation (SD) if normally distributed, or as median and interquartile range (IQR) if not. Results We included 25 patients who suffered a high energy odontoid fracture that were identified as the primary cause for immediate cardiac arrest, and that were followed by ROSC after CPR (Fig. 1 and Table 1). Table 1: Title: Cohort demographics, injury characteristics, treatment, and primary outcome Legend: 1 CKD: chronic kidney disease; 2 MI: myocardial infarction; 3 TIA: transient ischemic attack; 4 SCI: spinal cord injury; 5 CHF: congestive heart failure; 6 COPD: chronic obstructive pulmonary disorder a polytrauma indicates an injury severity score (ISS) > 15 ( 25 ) The mean age was 71.1 years ± 12.3 (SD), and eight patients (32%) were female. The dominant trauma mechanisms were bike accidents in ten cases (40%). Three patients (12%) had a polytrauma with an injury severity score (ISS) of 15 or greater ( 25 ). CPR was administered to all patients. In 22 cases (88%), CPR was initiated at the site of the accident. The initiation of CPR was consistently prompt, with a median downtime of just five minutes, followed by comprehensive care at Level 1 trauma centers in all cases. CPR was initiated by professionals in 15 cases (60%), and by layperson bystanders in 10 cases (40%). The median time to professional CPR was 15 minutes. Seventeen patients (68%) of patients received adrenalin at the accident site. The mean duration of CPR was 17 minutes; 25 patients (100%) achieved ROSC. CT scans revealed Type II odontoid fractures according to Anderson d'Alonzo as the predominant fracture pattern (88%), and Type A (60%) according to the AO Spine Upper Cervical Classification. Additionally, four patients (16%) presented with atlantoaxial (C1-C2) dislocation. Twenty-one patients (84%) underwent MRI after CT. Radiographic signs of cervical myelopathy were present in all 21 patients who received an MRI of the cervical spine (84% of all patients). Ongoing compression of the spinal cord/medulla oblongata was present in one patient (4%). Every patient had BASIC Score of three or higher, indicating the absence of residual normal-appearing white matter (Table 2). In total, only two patients (8%) survived, leading to a mortality rate of 92%. All patients who died were treated on the ICU, and supportive treatment was ceased after interdisciplinary evaluation either due to high SCI with respiratory insufficiency (nine patients) or diagnosed brain death due to either hypoxia or head trauma (eleven patients). If contactable, patients were involved in this decision-making. Only one patient (patient 2) regained consciousness on the ICU. Three patients (patients 2, 8, and 19; 12%) had sufficiently favorable prognosis due to neurological and cardiorespiratory improvement and proceeded to surgical fixation. Two of these three patients ultimately survived: The first survivor (patient 2) underwent odontoid screw fixation for an Anderson d’Alonzo type II (AO type II B; M1-3) fracture. The second survivor (patient 19) with an Anderson d’Alonzo type III (AO type III A; M1-3) fracture was treated with an odontoid screw fixation. The third patient (patient 8), presenting with an Anderson d’Alonzo type II (AO type III A; M1-3) fracture, was treated conservatively for the odontoid fracture, but underwent decompression and open posterior stabilization from Th2 to Th7 due to an additional C-Type injury at Th4/5. They ultimately succumbed to their injuries (Table 3 ). Table 2: Title: Cohort characteristics pre-treatment (descriptive statistics) Legend: 1 standard deviation , 2 cardiopulmonary resuscitation , 3 interquartile range , 4 return of spontaneous circulation , 5 Glasgow coma scale , 6 computed tomography , 7 magnetic resonance tomography , 8 Brain and Spinal Injury Center score Table 3 In-hospital outcomes 1 standard deviation , 2 intensive care unit , 3 Glasgow Coma Scale Figure 3: Title: Case example patient number 2 Legend: 73 y/o hospitalized after a domestic fall from a staircase A top: sagittal and bottom: axial T2-weighted MRI imaging showing myelopathy (BASIC grade 4) without stenosis; B top: sagittal and bottom: axial CT imaging: showing posterior arch disruption of the atlas in an Anderson d’Alonzo type II (AO Type II B; M1-3) odontoid fracture with 3 mm displacement; C: intraoperative ap fluoroscopy of a ventral Dens axis screw; the patient regained consciousness on the ICU, was transferred to another ICU after two days, and survived. Systematic literature review In our systematic literature review, the initial search identified 6,630 articles. After screening and applying the inclusion criteria, we narrowed the selection to seven case reports that addressed patients with odontoid fractures associated with cardiopulmonary arrest ( 10 , 26 – 31 ) (Fig. 4 ). These cases involve patients ranging in age from 20 to 68 years, with a mean age of 57 years. The mechanism of injury included car crashes (3 cases), domestic falls or collapses (2 cases), a bike accident (1 case), and a fall in the street (1 case). The odontoid fractures were predominantly Anderson-d'Alonzo type II fractures (4 cases). Two patients underwent surgical treatment. Of those, one patient underwent Glisson’s traction ( 28 ), and one patient received posterior fixation of C1-C2 ( 29 ). Both patients survived. The first patient was weaned off the respirator after four months and became independent after six months ( 28 ). For the second patient, no mid- and long-term follow-up was reported ( 29 ). The remaining five patients succumbed to their injuries shortly after the incident ( 10 , 26 , 27 , 30 , 31 ) (Table 5). Table 5: Title: Published cases of odontoid fractures associated with cardiac arrest (no legend) Discussion Our retrospective analysis of 25 cases from two Level 1 Trauma Centers presents the largest case series to date of odontoid fractures with concurrent cardiac arrest and ROSC after CPR. Despite successful pre-hospital resuscitation, the mortality rate was 92% after mean of 2.0 ± 1.4) days. The global incidence of out-of-hospital cardiac arrest is estimated at 55 cases per 100,000 person-years, with survival rates varying widely due to differences in emergency medical response and public health infrastructure. Typically, shorter downtimes, such as the median of 5 minutes in our cohort, result in much higher survival rates of up to 60% when the downtime is 0–10 minutes, and still in the double digits even when exceeding 20 minutes, as shown by larger series ( 32 , 33 ). Odontoid fractures significantly elevate mortality risks due to various factors, including neurological damage leading to respiratory arrest and complications from immobilization, such as cardiovascular, respiratory, and septic issues, resulting in nearly 15% mortality within 30 days ( 34 , 35 ). Our findings reveal that despite rapid intervention and advanced care, the prognosis for patients suffering from odontoid fractures with concurrent cardiac arrest remains grim: with survival and consciousness recovery rates below 10%, our study echoes observations from earlier case reports that similarly document minimal survival in such scenarios, with only two cases reporting survival ( 28 , 29 ). This underscores the severe impact of the combined scenario of cardiac arrest with odontoid fracture and spinal cord injury, indicating a compounded risk that significantly lowers survival prospects. Conversely, another study analyzing out-of-hospital cardiac arrests found that the optimal cut-off for favorable neurological outcomes is 12 minutes of CPR, which is shorter than the mean duration reported in our cohort ( 36 ). This suggests that considerable damage has already occurred by the time ROSC is achieved. As highlighted in earlier reports, initial cardiac arrests can obscure severe spinal injuries ( 26 ). Odontoid injuries are primarily of two types: one involves potentially fatal complete atlanto-axial (C1-C2) displacement, and the other features slight displacement with complete rupture of the capsular structure, leading to significant instability ( 27 ). Recognizing the latter is crucial for initiating immobilization to prevent further neurological damage. The atlanto-axial vertebrae region has a notably wide margin of safety within the spinal canal, allowing substantial fracture displacement without immediate contact between the odontoid fragment or the posterior ring of the first cervical vertebra and the spinal cord ( 37 ). Acute and severe neurological impairments, such as tetraplegia accompanied by cardiac arrest, often indicate high-energy trauma involving at least temporary high-grade dislocation. However, even low-velocity accidents, like falls from standing height with whiplash mechanisms, can lead to odontoid fractures with neurological impairment and cardiac arrest ( 38 ). In our series, one patient (4%) and two out of seven cases (29%) in our systematic review experienced such trauma ( 10 , 29 ). We support the hypothesis that in these low-energy scenarios, particularly among elderly patients with reduced cervical spine flexibility, the odontoid process can endure high localized forces. This can result in transient dislocation and spinal cord damage despite the low-energy nature of the incident ( 34 , 39 ). It is crucial to consider this mechanism in cases of cardiac arrests following falls, even in seemingly low-energy accidents, to initiate further diagnostics and spinal immobilization promptly. Pathophysiologically, neurogenic shock induced by autonomic dysfunction from high cervical spinal cord injuries typically leads to catastrophic outcomes ( 40 ). This condition primarily disrupts preganglionic sympathetic interneurons that originate in the hypothalamus and exit the spinal cord between T1 and T6. The resultant shift towards parasympathetic dominance triggers severe bradyarrhythmias and atrioventricular blocks ( 10 ). Our case series, which exclusively involved patients with cardiac arrest after odontoid fractures, appears to corroborate this pathophysiology. It is further supported by MRI findings showing severe signs of myelopathy in all patients, consistent with other reported cases ( 10 , 29 , 41 ). Typically, neurological symptoms develop with 7–9 mm of lateral fracture displacement instability ( 34 ). However, in our series, the mean displacement at the time of imaging was less, suggesting that severe dislocation may have occurred during the accident, evidenced by the high rates of myelopathy. Caregivers should consider the connection between odontoid fractures and cardiac arrest, even when trauma CT shows low dislocation. Early suspicion of odontoid fractures, particularly in the elderly, is critical due to their nonspecific presentation and rapid deterioration, as demonstrated by a case where cardiac arrest occurred in the hospital ( 30 ). These findings underscore the necessity of immediate and controlled spinal immobilization in unconscious patients, regardless of the trauma mechanism. Additionally, they highlight the importance of prompt CT imaging and the early involvement of neurosurgery, orthopedics, and critical care specialists to effectively coordinate care in suspected spinal trauma cases. The use of MRI in previous case series has been inconsistent, with no clear guidelines on when to perform it. At our centers, the consensus is to conduct an MRI when spinal trauma is indicated on CT and the patient's neurological status cannot be assessed, typically due to deep sedation, as was the case for all 22 patients in this series. This MRI is scheduled at an appropriate time when more critical issues have been stabilized. This approach is consistent with recommendations from other authors ( 42 ). Additionally, an MRI is considered particularly prudent if neurological injury or ligamentous damage is suspected based on imaging findings or clinical history. The validity of this protocol is underscored by the 100% presence of myelopathy in our cases, indicating a high pretest probability that further supports the utility of this approach. In treating odontoid fractures, the decision between surgical and conservative approaches depends on specific clinical criteria and patient characteristics: Surgical options, including anterior and posterior approaches, provide high rates of fracture stability and fracture union; notably, posterior instrumented fusion of C1-C2 also minimize complications such as dysphagia associated with anterior methods ( 4 ). Conservative approaches are recommended for patients with less severe injuries or significant surgical risks ( 43 ). In our series, two patients underwent successful screw fixation for a type II Anderson d'Alonzo fracture with 3mm displacement and a type III fracture with 4mm displacement, both without dislocation, but high risk of instability and non-union. Both had shown neurological improvement prior to surgery. This was a prerequisite for the chosen treatment. The limitations of this study stem primarily from its design; it is retrospective in nature and includes a relatively small sample size coupled with a brief follow-up period. These factors significantly restrict the generalizability of our findings. However, it is worth noting that despite these limitations, this study represents the largest series to date addressing this rare and severe scenario as per our systematic literature review. The small sample size also prevented the execution of robust statistical analyses, highlighting the need for larger trials. Future research should aim to employ larger sample sizes to facilitate detailed statistical evaluations, such as linear regression, to identify factors associated with the outcomes studied. Conclusion Cardiac arrest in conjunction with odontoid fractures is associated with a high mortality rate. In trauma-related cardiac arrest scenarios, it is critical to maintain a high index of suspicion for potential odontoid fractures. Beyond the immediate life-saving measures such as CPR, effective management includes the proper immobilization of the cervical spine and the timely and accurate use of diagnostic imaging to guide further treatment strategies. Declarations Ethics approval and consent to participate We obtained ethics approval from the local ethics committee (Kantonale Ethikkommission Bern [KEK]); BASEC-Nr: Req-2023-00618). Consent for publication Not applicable Availability of data and materials The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. Competing interests The authors declare that they have no competing interests. Funding No funding was obtained for this study. Authors' contributions SFS and CT analyzed and interpreted the patient data. Additionally, CT reviewed the CT and MRI images. SFS authored the initial draft of the manuscript. All authors have read and approved the final manuscript. Acknowledgements Not applicable References Iyer S, Hurlbert RJ, Albert TJ. Management of Odontoid Fractures in the Elderly: A Review of the Literature and an Evidence-Based Treatment Algorithm. Neurosurgery. 2018;82(4):419–30. Guan J, Bisson EF. Treatment of Odontoid Fractures in the Aging Population. Neurosurg Clin N Am. 2017;28(1):115–23. Good AE, Ramponi DR. Odontoid/Dens Fractures. Adv Emerg Nurs J. 2024;46(1):38–43. Goz V, Spiker WR, Lawrence B, Brodke D, Spina N. Odontoid Fractures: A Critical Analysis Review. JBJS reviews. 2019;7(8):e1. Teasell RW, Arnold JM, Krassioukov A, Delaney GA. Cardiovascular consequences of loss of supraspinal control of the sympathetic nervous system after spinal cord injury. Arch Phys Med Rehabil. 2000;81(4):506–16. Grigorean VT, Sandu AM, Popescu M, Iacobini MA, Stoian R, Neascu C, et al. Cardiac dysfunctions following spinal cord injury. J Med Life. 2009;2(2):133–45. Kim SW, Park CJ, Kim K, Kim YC. Cardiac arrest attributable to dysfunction of the autonomic nervous system after traumatic cervical spinal cord injury. Chin J Traumatol. 2017;20(2):118–21. Miyata K, Mikami T, Koyanagi I, Mikuni N, Narimatsu E. Cervical spinal cord injuries associated with resuscitation from fatal circulatory collapse. Acute Med Surg. 2016;3(2):86–93. Lehmann KG, Lane JG, Piepmeier JM, Batsford WP. Cardiovascular abnormalities accompanying acute spinal cord injury in humans: incidence, time course and severity. J Am Coll Cardiol. 1987;10(1):46–52. Bowers CA, Jost GF, Dailey AT. An odontoid fracture causing apnea, cardiac instability, and quadriplegia. Case Reports in Critical Care. 2012;2012. Teeter W, Haase D. Updates in Traumatic Cardiac Arrest. Emerg Med Clin North Am. 2020;38(4):891–901. DeBehnke DJ, Swart GL. Cardiac arrest. Emerg Med Clin North Am. 1996;14(1):57–81. Lewis J, Perkins GD. Traumatic cardiac arrest. Curr Opin Crit Care. 2023;29(3):162–7. Badhiwala JH, Wilson JR, Witiw CD, Harrop JS, Vaccaro AR, Aarabi B, et al. The influence of timing of surgical decompression for acute spinal cord injury: a pooled analysis of individual patient data. Lancet Neurol. 2021;20(2):117–26. investigators O, Chikuda H, Koyama Y, Matsubayashi Y, Ogata T, Ohtsu H, et al. Effect of Early vs Delayed Surgical Treatment on Motor Recovery in Incomplete Cervical Spinal Cord Injury With Preexisting Cervical Stenosis: A Randomized Clinical Trial. JAMA Netw Open. 2021;4(11):e2133604. Thompson DN. Acute myelopathy: tumoral or traumatic spinal cord compression. Handb Clin Neurol. 2013;112:993–7. Mourelo Farina M, Salvador de la Barrera S, Montoto Marques A, Ferreiro Velasco ME, Galeiras Vazquez R. Update on traumatic acute spinal cord injury. Part 2. Med Intensiva. 2017;41(5):306–15. Ropper AE, Ropper AH. Acute Spinal Cord Compression. N Engl J Med. 2017;376(14):1358–69. Sharwood LN, King V, Ball J, Varma D, Stanford RW, Middleton JW. The influence of initial spinal cord haematoma and cord compression on neurological grade improvement in acute traumatic spinal cord injury: A prospective observational study. J Neurol Sci. 2022;443:120453. Ikpeze TC, Mesfin A. Spinal Cord Injury in the Geriatric Population: Risk Factors, Treatment Options, and Long-Term Management. Geriatr Orthop Surg Rehabil. 2017;8(2):115–8. Pospiech J, Schick U, Stolke D. Indications for surgery in upper cervical spine injury. Neurosurg Rev. 1996;19(2):73–9. Rutsch N, Amrein P, Exadaktylos AK, Benneker LM, Schmaranzer F, Müller M, et al. Cervical spine trauma–Evaluating the diagnostic power of CT, MRI, X-Ray and LODOX. Injury. 2023;54(7):110771. Talbott JF, Whetstone WD, Readdy WJ, Ferguson AR, Bresnahan JC, Saigal R, et al. The Brain and Spinal Injury Center score: a novel, simple, and reproducible method for assessing the severity of acute cervical spinal cord injury with axial T2-weighted MRI findings. J neurosurgery: Spine. 2015;23(4):495–504. Tugwell P, Tovey DPRISMA. 2020. Elsevier; 2021. pp. A5-A6. Baker SP, o'Neill B, Haddon W Jr, Long WB. The injury severity score: a method for describing patients with multiple injuries and evaluating emergency care. J Trauma Acute Care Surg. 1974;14(3):187–96. Barber Ansón M, Orera Pérez Á, Redondo Díez E. Parada cardiorrespiratoria secundaria a fractura de odontoides. Med intensiva (Madr, Ed impr). 2020:65-. Graziano G, Colon G, Hensinger R. Complete atlanto-axial dislocation associated with type II odontoid fracture: a report of two cases. Clin Spine Surg. 1994;7(6):518–21. Kubokura T, Ishikawa K, Nishimura T, Tsubone K. A case of quadriplegia with respiratory paralysis surviving as a candidate for rehabilitation. No Shinkei geka Neurol Surg. 1985;13(11):1237–42. Maeda K, Ichiba T. Unusual clinical course of odontoid fracture: transient prehospital cardiopulmonary arrest. Cureus. 2020;12(12). Pérez-Bovet J, Garcia-Armengol R, Martin Ferrer S. Traumatic epidural retroclival hematoma with odontoid fracture and cardiorespiratory arrest. Spinal Cord. 2013;51(12):926–8. Powell R, Heath K. Quadraplegia in a Patient with an Undiagnosed Odontoid Peg Fracture: The Importance of Cervical Spine Immobilisation in Patients with Head Injuries. BMJ Military Health. 1996;142(2):79–81. Lee ZH, Kim YH, Lee JH, Lee DW, Lee KY, Hwang SY. Association between Cardiac Arrest Time and Favorable Neurological Outcomes in Witnessed Out-of-Hospital Cardiac Arrest Patients Treated with Targeted Temperature Management. J Korean Med Sci. 2020;35(16):e108. Okubo M, Komukai S, Andersen LW, Berg RA, Kurz MC, Morrison LJ, et al. Duration of cardiopulmonary resuscitation and outcomes for adults with in-hospital cardiac arrest: retrospective cohort study. BMJ. 2024;384:e076019. Lenga P, Gülec G, Kiening K, Unterberg AW, Ishak B. Morbidity and mortality related to type II odontoid fractures in octogenarians undergoing surgery: a retrospective study with 5 year follow up. Front Med. 2023;10. Shafafy R, Valsamis E, Luck J, Dimock R, Rampersad S, Kieffer W, et al. Predictors of mortality in the elderly patient with a fracture of the odontoid process: can we use non-spinal scoring systems? Bone Joint J. 2019;101(3):253–9. Park S, Lee SW, Han KS, Lee EJ, Jang D-H, Lee SJ, et al. Optimal cardiopulmonary resuscitation duration for favorable neurological outcomes after out-of-hospital cardiac arrest. Scand J Trauma Resusc Emerg Med. 2022;30(1):5. Tucker S, Taylor B. Spinal canal capacity in simulated displacements of the atlantoaxial segment: a skeletal study. J Bone Joint Surg Br Volume. 1998;80(6):1073–8. Osterhoff G, Scholz M, Disch AC, Katscher S, Spiegl UJ, Schnake KJ, et al. Geriatric odontoid fractures: Treatment algorithms of the German Society for Orthopaedics and trauma based on expert consensus and a systematic review. Global Spine J. 2023;13(1suppl):S13–21. Agunbiade S, Belton PJ, Mesfin FB. Spinal Cord Transection in a Type II Odontoid Fracture From a Ground-Level Fall. Cureus. 2020;12(12). Ruiz IA, Squair JW, Phillips AA, Lukac CD, Huang D, Oxciano P, et al. Incidence and natural progression of neurogenic shock after traumatic spinal cord injury. J Neurotrauma. 2018;35(3):461–6. Barber Ansón M, Orera Pérez Á, Redondo Díez E. Parada cardiorrespiratoria secundaria a fractura de odontoides. Med Intensiva. 2020;44(1):65. Kumar Y, Hayashi D. Role of magnetic resonance imaging in acute spinal trauma: a pictorial review. BMC Musculoskelet Disord. 2016;17:310. Joaquim AF, Patel AA. Surgical treatment of Type II odontoid fractures: anterior odontoid screw fixation or posterior cervical instrumented fusion? NeuroSurg Focus. 2015;38(4):E11. Tables Table 1, 2, 3 and 5 are available in the Supplementary Files section. Additional Declarations No competing interests reported. Supplementary Files Table1.docx Table2.docx Table3.docx Table5.docx Cite Share Download PDF Status: Published Journal Publication published 29 Oct, 2024 Read the published version in Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine → Version 1 posted Editorial decision: Revision requested 18 Sep, 2024 Reviews received at journal 27 Aug, 2024 Reviewers agreed at journal 27 Aug, 2024 Reviewers agreed at journal 31 Jul, 2024 Reviewers invited by journal 30 Jul, 2024 Editor assigned by journal 30 Jul, 2024 Submission checks completed at journal 30 Jul, 2024 First submitted to journal 29 Jul, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4821074","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":337480234,"identity":"4a0dee54-97bc-46a3-ae01-34b6b176773d","order_by":0,"name":"S. F. Schaible","email":"","orcid":"","institution":"University Hospital Bern, Inselspital, University of Bern","correspondingAuthor":false,"prefix":"","firstName":"S.","middleName":"F.","lastName":"Schaible","suffix":""},{"id":337480236,"identity":"777052d5-b73e-422c-a1e6-17e30410c72b","order_by":1,"name":"S. Häckel","email":"","orcid":"","institution":"University Hospital Bern, Inselspital, University of Bern","correspondingAuthor":false,"prefix":"","firstName":"S.","middleName":"","lastName":"Häckel","suffix":""},{"id":337480237,"identity":"a35eec90-c419-4add-ac32-5bb300919dcb","order_by":2,"name":"N. Rutsch","email":"","orcid":"","institution":"University Hospital Bern, Inselspital, University of Bern","correspondingAuthor":false,"prefix":"","firstName":"N.","middleName":"","lastName":"Rutsch","suffix":""},{"id":337480238,"identity":"d9a5f84a-a3e0-4ae8-8b1d-0b3d0f285c49","order_by":3,"name":"F. C. Aregger","email":"","orcid":"","institution":"University Hospital Bern, Inselspital, University of Bern","correspondingAuthor":false,"prefix":"","firstName":"F.","middleName":"C.","lastName":"Aregger","suffix":""},{"id":337480239,"identity":"83c25ee6-0d06-489b-9b55-77a03c212daa","order_by":4,"name":"S. F. Bigdon","email":"","orcid":"","institution":"University Hospital Bern, Inselspital, University of Bern","correspondingAuthor":false,"prefix":"","firstName":"S.","middleName":"F.","lastName":"Bigdon","suffix":""},{"id":337480242,"identity":"10128f02-1c71-45fa-8070-391ceeb81261","order_by":5,"name":"V. Schoenborn","email":"","orcid":"","institution":"Cantonal Hospital Graubuenden","correspondingAuthor":false,"prefix":"","firstName":"V.","middleName":"","lastName":"Schoenborn","suffix":""},{"id":337480243,"identity":"cb55fd76-1dde-4551-aa56-0d790bb42afc","order_by":6,"name":"I. Broger","email":"","orcid":"","institution":"Cantonal Hospital Graubuenden","correspondingAuthor":false,"prefix":"","firstName":"I.","middleName":"","lastName":"Broger","suffix":""},{"id":337480245,"identity":"26c24900-ad76-43c3-9d42-70285736a1ab","order_by":7,"name":"C. E. Albers","email":"","orcid":"","institution":"University Hospital Bern, Inselspital, University of Bern","correspondingAuthor":false,"prefix":"","firstName":"C.","middleName":"E.","lastName":"Albers","suffix":""},{"id":337480246,"identity":"e3bbb689-d2b5-4ecb-8509-9bdfcf302c6d","order_by":8,"name":"C. Tinner","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABB0lEQVRIie2PsUoDQRCGR7bd89o9IuQVJhwkCqe+RsqVwLZql0qUQCrF9nyLq0S7Paa4Jg+QVnyBkzQnCDp7FxDEvbQp9isG9mc+5l+AQGAPiXMAC6Dah20T4eYVAHoUtXab2imiU5KFm+hXcOqmhlbpErtLGTy8lZ/N8XACcUnXL9llWkVU1wiceJSjCklqNXq9FUBPK3PyTIcmyRE48SjKAPFfDgrLSrQkHJMcC4mgu4b/K2Wj1flW+cZ0IdPNV58yNWC52MVWsYh8YgA9ilpzMWnUrCCBrMxQcbHkHtWo8ChxbsRHk92cFtXd+yZanmH8uErrZp4NfVd+EX/O79oPBAKBQA8/4HRVPIvYLKcAAAAASUVORK5CYII=","orcid":"","institution":"University Hospital Bern, Inselspital, University of Bern","correspondingAuthor":true,"prefix":"","firstName":"C.","middleName":"","lastName":"Tinner","suffix":""}],"badges":[],"createdAt":"2024-07-29 10:11:26","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4821074/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4821074/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s13049-024-01277-z","type":"published","date":"2024-10-29T16:20:04+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":64004608,"identity":"4bd4f71c-7269-457f-b6b3-2cf4e7537b6f","added_by":"auto","created_at":"2024-09-04 21:26:42","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":101042,"visible":true,"origin":"","legend":"\u003cp\u003ePatient selection flow chart (no legend)\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-4821074/v1/a4651be4bea1de79cdfdb611.png"},{"id":64004610,"identity":"db483f3d-38d3-416d-bda8-3d2ec97c494f","added_by":"auto","created_at":"2024-09-04 21:26:42","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":130134,"visible":true,"origin":"","legend":"\u003cp\u003eSurvival plot (no legend)\u003c/p\u003e","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-4821074/v1/79718996d88816f108d3ac57.png"},{"id":64004614,"identity":"22213675-cc55-4ed8-b779-185e51148762","added_by":"auto","created_at":"2024-09-04 21:26:42","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":5700459,"visible":true,"origin":"","legend":"\u003cp\u003eCase example patient number 2\u003c/p\u003e\n\u003cp\u003eLegend: 73 y/o hospitalized after a domestic fall from a staircase A top: sagittal and bottom: axial T2-weighted MRI imaging showing myelopathy (BASIC grade 4) without stenosis; B top: sagittal and bottom: axial CT imaging: showing posterior arch disruption of the atlas in an Anderson d’Alonzo type II (AO Type II B; M1-3) odontoid fracture with 3 mm displacement; C: intraoperative ap fluoroscopy of a ventral Dens axis screw; the patient regained consciousness on the ICU, was transferred to another ICU after two days, and survived.\u003c/p\u003e","description":"","filename":"Figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-4821074/v1/1c394431f18d4e0ab450b25c.png"},{"id":64004612,"identity":"1d1cd4a3-d5fa-46ea-abbc-f4aa413a21f2","added_by":"auto","created_at":"2024-09-04 21:26:42","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":210756,"visible":true,"origin":"","legend":"\u003cp\u003ePRISMA 2020 flow diagram for systematic review which included searches of databases and registers only (no legend)\u003c/p\u003e","description":"","filename":"Figure4.png","url":"https://assets-eu.researchsquare.com/files/rs-4821074/v1/6e398a910ba79a72b84365d4.png"},{"id":68207110,"identity":"82f2223d-515b-41d1-ba3c-a96403f4d844","added_by":"auto","created_at":"2024-11-04 16:35:03","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":6451639,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4821074/v1/a75b02fa-5a70-4f6f-bfb9-1a44ba0e4395.pdf"},{"id":64004932,"identity":"afbbdd72-df27-4797-b881-b144b633ccff","added_by":"auto","created_at":"2024-09-04 21:34:42","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":22497,"visible":true,"origin":"","legend":"","description":"","filename":"Table1.docx","url":"https://assets-eu.researchsquare.com/files/rs-4821074/v1/5b918d720d2ecc29b2a0261a.docx"},{"id":64004933,"identity":"26c7025a-9394-472d-af50-954148b0a21c","added_by":"auto","created_at":"2024-09-04 21:34:42","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":17214,"visible":true,"origin":"","legend":"","description":"","filename":"Table2.docx","url":"https://assets-eu.researchsquare.com/files/rs-4821074/v1/c5771fbf1e199b0db4a8e36f.docx"},{"id":64004609,"identity":"455a4d61-4252-4cf7-8880-5774845b8cb9","added_by":"auto","created_at":"2024-09-04 21:26:42","extension":"docx","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":15015,"visible":true,"origin":"","legend":"","description":"","filename":"Table3.docx","url":"https://assets-eu.researchsquare.com/files/rs-4821074/v1/8d46478af15008765b8c75bc.docx"},{"id":64004934,"identity":"f4bbbc5c-8ff1-4c47-a52b-2af7c32cb36f","added_by":"auto","created_at":"2024-09-04 21:34:42","extension":"docx","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":16959,"visible":true,"origin":"","legend":"","description":"","filename":"Table5.docx","url":"https://assets-eu.researchsquare.com/files/rs-4821074/v1/1c005d041d7a4380ee4720b6.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Outcomes of Odontoid Fractures with Associated Cardiac Arrest: Retrospective Bi-Center Case Series and Systematic Literature Review","fulltext":[{"header":"Background","content":"\u003cp\u003eOdontoid fractures constitute a significant proportion of acute cervical spine injuries, accounting for 9–18% of cases. These fractures predominantly affect patients aged 65 years and older, typically resulting from low-energy trauma (\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e–\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). However, they can also occur in younger patients following high-energy trauma, potentially associated with neurological deficits. These fractures significantly impair quality of life and burden patients and healthcare systems. Overall, mortality rates reach 14% within 30 days and 44% within two years, with neurological injury incidence between 2% and 27% (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). While spinal cord injury (SCI) rarely accompanies low-energy falls, high-energy spine trauma can cause SCI through traction, contusion, compression, or ischemia. In severe cases, acute high-level SCI may trigger cardiac arrest by disrupting the sympathetic nervous system (\u003cspan additionalcitationids=\"CR6 CR7 CR8\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e–\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eDisrupted preganglionic sympathetic interneurons leads to parasympathetic dominance ending in bradyarrhythmias and atrioventricular blocks (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). In these severe cases of odontoid fractures with subsequent cardiac arrest, immediate intervention requires cardiopulmonary resuscitation (CPR) as a life-saving measure, followed by comprehensive management of polytrauma, including damage control surgery, and intensive or intermediate care based on patient condition and diagnostic imaging findings (\u003cspan additionalcitationids=\"CR12\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e–\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e). Persistent spinal cord compression necessitates prompt decompression, with subsequent operative stabilization often required for managing the typically unstable fracture patterns of odontoid fractures associated with SCI (\u003cspan additionalcitationids=\"CR15 CR16 CR17 CR18 CR19 CR20\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e–\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e). However, in cases of severe spinal cord damage, the prognosis for neurological recovery is poor (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eWhile there is substantial data on the treatment of isolated odontoid fractures and on cardiac arrest independently, the literature addressing the unique combination of odontoid fractures causing cardiac arrest due to high spinal cord or medulla oblongata injuries is notably sparse. The existing studies are primarily isolated case reports, which often document patient mortality within days of the injury.\u003c/p\u003e \u003cp\u003eTo address this gap, in this study, we present a bi-center case series aimed at exploring the treatments and outcomes of odontoid fractures followed by cardiac arrest with return of spontaneous circulation (ROSC), with the following objectives: first, mortality and descriptive analysis of pre- and in-hospital treatment; second, a systematic review of literature on comparable scenarios; and third, a comparison of our case series with the literature findings.\u003c/p\u003e "},{"header":"Methods","content":"\u003ch2\u003eCohort definition and outcomes\u003c/h2\u003e\u003cp\u003e After obtaining ethics approval from local ethics committees (Kantonale Ethikkommission Bern [KEK]); BASEC-Nr: Req-2023-00618), we performed a retrospective review of the databases of two Swiss level 1 trauma centers between 2008 and 2024, University Hospital Bern (Inselspital) and Cantonal Hospital Graubuenden Chur. We included all patients who experienced a high-energy trauma according to a recently published definition (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e), who were resuscitated at the accident scene, who achieved ROSC, and who were diagnosed in the emergency department with an odontoid fracture that was determined to be the primary cause for cardiac arrest necessitating the resuscitation. Exclusion criteria were absence of an odontoid fracture, failure to achieve ROSC, incomplete data, patients under 18 years of age, and lack of general consent.\u003c/p\u003e\u003cp\u003eOur primary outcome was patients’ mortality. Secondary outcomes included pre-hospital and in-hospital treatment. To collect pre-hospital and in-hospital data, we reviewed reports from the evacuation team, emergency department, and intensive care unit (ICU). Pre-hospital treatment outcomes included the duration of cardiac arrest, duration and providers of CPR (categorized as layperson bystanders, professionals, or both), administered dose of adrenaline, and time to ROSC. In-hospital outcomes encompassed return to consciousness, best neurological status in the ICU, treatment of the odontoid fracture (surgery, conservative, or best supportive care), time to death, time to ICU discharge, and time to hospital discharge. Additionally, we recorded injury mechanisms and epidemiological data from hospital records.\u003c/p\u003e\u003cp\u003eWe retrospectively classified the fractures identified on the initial whole-body computed tomography (CT) scans, assessing the degree of fracture displacement. If available, magnetic resonance imaging (MRI) studies were evaluated for the presence of myelopathy and stenosis with/without persisting compression of the spinal cord. Additionally, we used the Brain and Spinal Injury Center score (BASIC) score, which evaluates acute traumatic spinal cord injury by grading the axial extent of intramedullary signal abnormalities on T2-weighted MRI on a scale from one to four (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e).\u003c/p\u003e\u003ch2\u003eSystematic Literature Review\u003c/h2\u003e\u003cp\u003eOn April 1, 2024, we conducted a systematic literature review following the current Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines (\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e). Our search included the PubMed, Google Scholar, and Medline databases, using the terms (\"odontoid fracture\" AND \"cardiac arrest\") and (\"odontoid fracture\" AND \"arrest\") applied to all fields, aimed at comprehensively capturing relevant, referenced, and referencing articles. We included studies with cases of odontoid fractures associated with cardiac arrest before or during emergency department treatment, excluding those where cardiac arrest was unrelated to the odontoid fracture or occurred later during hospitalization. Data from the selected articles were extracted and systematically analyzed, focusing on the same outcomes as described for our own cohort, as well as epidemiological data and study designs.\u003c/p\u003e\n\u003ch3\u003eStatistical Methods\u003c/h3\u003e\n\u003cp\u003eDescriptive statistics were employed to present the study outcome data. Data collection was conducted using password-protected software, and analysis was performed using R (R Foundation for Statistical Computing, Vienna, Austria). A Shapiro-Wilk test was conducted to assess for normal distribution. Continuous data are presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD) if normally distributed, or as median and interquartile range (IQR) if not.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eWe included 25 patients who suffered a high energy odontoid fracture that were identified as the primary cause for immediate cardiac arrest, and that were followed by ROSC after CPR (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e and Table\u0026nbsp;1).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eTable\u0026nbsp;1:\u003c/p\u003e \u003cp\u003eTitle: Cohort demographics, injury characteristics, treatment, and primary outcome\u003c/p\u003e \u003cp\u003eLegend:\u003c/p\u003e \u003cp\u003e \u003csup\u003e \u003cem\u003e1\u003c/em\u003e \u003c/sup\u003e \u003cem\u003eCKD: chronic kidney disease;\u003c/em\u003e \u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u003cem\u003eMI: myocardial infarction;\u003c/em\u003e \u003csup\u003e\u003cem\u003e3\u003c/em\u003e\u003c/sup\u003e\u003cem\u003eTIA: transient ischemic attack;\u003c/em\u003e \u003csup\u003e\u003cem\u003e4\u003c/em\u003e\u003c/sup\u003e\u003cem\u003eSCI: spinal cord injury;\u003c/em\u003e \u003csup\u003e\u003cem\u003e5\u003c/em\u003e\u003c/sup\u003e\u003cem\u003eCHF: congestive heart failure;\u003c/em\u003e \u003csup\u003e\u003cem\u003e6\u003c/em\u003e\u003c/sup\u003e\u003cem\u003eCOPD: chronic obstructive pulmonary disorder\u003c/em\u003e\u003c/p\u003e \u003cp\u003e \u003csup\u003e \u003cem\u003ea\u003c/em\u003e \u003c/sup\u003e \u003cem\u003epolytrauma indicates an injury severity score (ISS)\u0026thinsp;\u0026gt;\u0026thinsp;15\u003c/em\u003e (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e)\u003c/p\u003e \u003cp\u003eThe mean age was 71.1 years\u0026thinsp;\u0026plusmn;\u0026thinsp;12.3 (SD), and eight patients (32%) were female. The dominant trauma mechanisms were bike accidents in ten cases (40%). Three patients (12%) had a polytrauma with an injury severity score (ISS) of 15 or greater (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eCPR was administered to all patients. In 22 cases (88%), CPR was initiated at the site of the accident. The initiation of CPR was consistently prompt, with a median downtime of just five minutes, followed by comprehensive care at Level 1 trauma centers in all cases. CPR was initiated by professionals in 15 cases (60%), and by layperson bystanders in 10 cases (40%). The median time to professional CPR was 15 minutes. Seventeen patients (68%) of patients received adrenalin at the accident site. The mean duration of CPR was 17 minutes; 25 patients (100%) achieved ROSC.\u003c/p\u003e \u003cp\u003eCT scans revealed Type II odontoid fractures according to Anderson d'Alonzo as the predominant fracture pattern (88%), and Type A (60%) according to the AO Spine Upper Cervical Classification. Additionally, four patients (16%) presented with atlantoaxial (C1-C2) dislocation. Twenty-one patients (84%) underwent MRI after CT. Radiographic signs of cervical myelopathy were present in all 21 patients who received an MRI of the cervical spine (84% of all patients). Ongoing compression of the spinal cord/medulla oblongata was present in one patient (4%). Every patient had BASIC Score of three or higher, indicating the absence of residual normal-appearing white matter (Table\u0026nbsp;2).\u003c/p\u003e \u003cp\u003eIn total, only two patients (8%) survived, leading to a mortality rate of 92%. All patients who died were treated on the ICU, and supportive treatment was ceased after interdisciplinary evaluation either due to high SCI with respiratory insufficiency (nine patients) or diagnosed brain death due to either hypoxia or head trauma (eleven patients). If contactable, patients were involved in this decision-making.\u003c/p\u003e \u003cp\u003eOnly one patient (patient 2) regained consciousness on the ICU. Three patients (patients 2, 8, and 19; 12%) had sufficiently favorable prognosis due to neurological and cardiorespiratory improvement and proceeded to surgical fixation. Two of these three patients ultimately survived: The first survivor (patient 2) underwent odontoid screw fixation for an Anderson d\u0026rsquo;Alonzo type II (AO type II B; M1-3) fracture. The second survivor (patient 19) with an Anderson d\u0026rsquo;Alonzo type III (AO type III A; M1-3) fracture was treated with an odontoid screw fixation. The third patient (patient 8), presenting with an Anderson d\u0026rsquo;Alonzo type II (AO type III A; M1-3) fracture, was treated conservatively for the odontoid fracture, but underwent decompression and open posterior stabilization from Th2 to Th7 due to an additional C-Type injury at Th4/5. They ultimately succumbed to their injuries (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eTable\u0026nbsp;2:\u003c/p\u003e \u003cp\u003eTitle: Cohort characteristics pre-treatment (descriptive statistics)\u003c/p\u003e \u003cp\u003eLegend:\u003c/p\u003e \u003cp\u003e \u003csup\u003e \u003cem\u003e1\u003c/em\u003e \u003c/sup\u003e \u003cem\u003estandard deviation\u003c/em\u003e, \u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u003cem\u003ecardiopulmonary resuscitation\u003c/em\u003e, \u003csup\u003e\u003cem\u003e3\u003c/em\u003e\u003c/sup\u003e\u003cem\u003einterquartile range\u003c/em\u003e, \u003csup\u003e\u003cem\u003e4\u003c/em\u003e\u003c/sup\u003e\u003cem\u003ereturn of spontaneous circulation\u003c/em\u003e, \u003csup\u003e\u003cem\u003e5\u003c/em\u003e\u003c/sup\u003e\u003cem\u003eGlasgow coma scale\u003c/em\u003e, \u003csup\u003e\u003cem\u003e6\u003c/em\u003e\u003c/sup\u003e\u003cem\u003ecomputed tomography\u003c/em\u003e, \u003csup\u003e\u003cem\u003e7\u003c/em\u003e\u003c/sup\u003e\u003cem\u003emagnetic resonance tomography\u003c/em\u003e, \u003csup\u003e\u003cem\u003e8\u003c/em\u003e\u003c/sup\u003e\u003cem\u003eBrain and Spinal Injury Center score\u003c/em\u003e\u003c/p\u003e \u003cp\u003eTable 3 In-hospital outcomes\u003c/p\u003e \u003cp\u003e \u003csup\u003e \u003cem\u003e1\u003c/em\u003e \u003c/sup\u003e \u003cem\u003estandard deviation\u003c/em\u003e, \u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u003cem\u003eintensive care unit\u003c/em\u003e, \u003csup\u003e\u003cem\u003e3\u003c/em\u003e\u003c/sup\u003e\u003cem\u003eGlasgow Coma Scale\u003c/em\u003e\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFigure 3:\u003c/p\u003e \u003cp\u003eTitle: Case example patient number 2\u003c/p\u003e \u003cp\u003eLegend: 73 y/o hospitalized after a domestic fall from a staircase A top: sagittal and bottom: axial T2-weighted MRI imaging showing myelopathy (BASIC grade 4) without stenosis; B top: sagittal and bottom: axial CT imaging: showing posterior arch disruption of the atlas in an Anderson d\u0026rsquo;Alonzo type II (AO Type II B; M1-3) odontoid fracture with 3 mm displacement; C: intraoperative ap fluoroscopy of a ventral Dens axis screw; the patient regained consciousness on the ICU, was transferred to another ICU after two days, and survived.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eSystematic literature review\u003c/h2\u003e \u003cp\u003eIn our systematic literature review, the initial search identified 6,630 articles. After screening and applying the inclusion criteria, we narrowed the selection to seven case reports that addressed patients with odontoid fractures associated with cardiopulmonary arrest (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan additionalcitationids=\"CR27 CR28 CR29 CR30\" citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e) (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e4\u003c/span\u003e). These cases involve patients ranging in age from 20 to 68 years, with a mean age of 57 years. The mechanism of injury included car crashes (3 cases), domestic falls or collapses (2 cases), a bike accident (1 case), and a fall in the street (1 case). The odontoid fractures were predominantly Anderson-d'Alonzo type II fractures (4 cases). Two patients underwent surgical treatment. Of those, one patient underwent Glisson\u0026rsquo;s traction (\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e), and one patient received posterior fixation of C1-C2 (\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e). Both patients survived. The first patient was weaned off the respirator after four months and became independent after six months (\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e). For the second patient, no mid- and long-term follow-up was reported (\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e). The remaining five patients succumbed to their injuries shortly after the incident (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e, \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e) (Table\u0026nbsp;5).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eTable\u0026nbsp;5:\u003c/p\u003e \u003cp\u003eTitle: Published cases of odontoid fractures associated with cardiac arrest (no legend)\u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eOur retrospective analysis of 25 cases from two Level 1 Trauma Centers presents the largest case series to date of odontoid fractures with concurrent cardiac arrest and ROSC after CPR. Despite successful pre-hospital resuscitation, the mortality rate was 92% after mean of 2.0\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4) days.\u003c/p\u003e \u003cp\u003eThe global incidence of out-of-hospital cardiac arrest is estimated at 55 cases per 100,000 person-years, with survival rates varying widely due to differences in emergency medical response and public health infrastructure. Typically, shorter downtimes, such as the median of 5 minutes in our cohort, result in much higher survival rates of up to 60% when the downtime is 0\u0026ndash;10 minutes, and still in the double digits even when exceeding 20 minutes, as shown by larger series (\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eOdontoid fractures significantly elevate mortality risks due to various factors, including neurological damage leading to respiratory arrest and complications from immobilization, such as cardiovascular, respiratory, and septic issues, resulting in nearly 15% mortality within 30 days (\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e, \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e). Our findings reveal that despite rapid intervention and advanced care, the prognosis for patients suffering from odontoid fractures with concurrent cardiac arrest remains grim: with survival and consciousness recovery rates below 10%, our study echoes observations from earlier case reports that similarly document minimal survival in such scenarios, with only two cases reporting survival (\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e). This underscores the severe impact of the combined scenario of cardiac arrest with odontoid fracture and spinal cord injury, indicating a compounded risk that significantly lowers survival prospects. Conversely, another study analyzing out-of-hospital cardiac arrests found that the optimal cut-off for favorable neurological outcomes is 12 minutes of CPR, which is shorter than the mean duration reported in our cohort (\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e). This suggests that considerable damage has already occurred by the time ROSC is achieved.\u003c/p\u003e \u003cp\u003eAs highlighted in earlier reports, initial cardiac arrests can obscure severe spinal injuries (\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e). Odontoid injuries are primarily of two types: one involves potentially fatal complete atlanto-axial (C1-C2) displacement, and the other features slight displacement with complete rupture of the capsular structure, leading to significant instability (\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e). Recognizing the latter is crucial for initiating immobilization to prevent further neurological damage.\u003c/p\u003e \u003cp\u003eThe atlanto-axial vertebrae region has a notably wide margin of safety within the spinal canal, allowing substantial fracture displacement without immediate contact between the odontoid fragment or the posterior ring of the first cervical vertebra and the spinal cord (\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e). Acute and severe neurological impairments, such as tetraplegia accompanied by cardiac arrest, often indicate high-energy trauma involving at least temporary high-grade dislocation. However, even low-velocity accidents, like falls from standing height with whiplash mechanisms, can lead to odontoid fractures with neurological impairment and cardiac arrest (\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e). In our series, one patient (4%) and two out of seven cases (29%) in our systematic review experienced such trauma (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e). We support the hypothesis that in these low-energy scenarios, particularly among elderly patients with reduced cervical spine flexibility, the odontoid process can endure high localized forces. This can result in transient dislocation and spinal cord damage despite the low-energy nature of the incident (\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e, \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e). It is crucial to consider this mechanism in cases of cardiac arrests following falls, even in seemingly low-energy accidents, to initiate further diagnostics and spinal immobilization promptly.\u003c/p\u003e \u003cp\u003ePathophysiologically, neurogenic shock induced by autonomic dysfunction from high cervical spinal cord injuries typically leads to catastrophic outcomes (\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e). This condition primarily disrupts preganglionic sympathetic interneurons that originate in the hypothalamus and exit the spinal cord between T1 and T6. The resultant shift towards parasympathetic dominance triggers severe bradyarrhythmias and atrioventricular blocks (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). Our case series, which exclusively involved patients with cardiac arrest after odontoid fractures, appears to corroborate this pathophysiology. It is further supported by MRI findings showing severe signs of myelopathy in all patients, consistent with other reported cases (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e). Typically, neurological symptoms develop with 7\u0026ndash;9 mm of lateral fracture displacement instability (\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e). However, in our series, the mean displacement at the time of imaging was less, suggesting that severe dislocation may have occurred during the accident, evidenced by the high rates of myelopathy. Caregivers should consider the connection between odontoid fractures and cardiac arrest, even when trauma CT shows low dislocation.\u003c/p\u003e \u003cp\u003eEarly suspicion of odontoid fractures, particularly in the elderly, is critical due to their nonspecific presentation and rapid deterioration, as demonstrated by a case where cardiac arrest occurred in the hospital (\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e). These findings underscore the necessity of immediate and controlled spinal immobilization in unconscious patients, regardless of the trauma mechanism. Additionally, they highlight the importance of prompt CT imaging and the early involvement of neurosurgery, orthopedics, and critical care specialists to effectively coordinate care in suspected spinal trauma cases.\u003c/p\u003e \u003cp\u003e The use of MRI in previous case series has been inconsistent, with no clear guidelines on when to perform it. At our centers, the consensus is to conduct an MRI when spinal trauma is indicated on CT and the patient's neurological status cannot be assessed, typically due to deep sedation, as was the case for all 22 patients in this series. This MRI is scheduled at an appropriate time when more critical issues have been stabilized. This approach is consistent with recommendations from other authors (\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e). Additionally, an MRI is considered particularly prudent if neurological injury or ligamentous damage is suspected based on imaging findings or clinical history. The validity of this protocol is underscored by the 100% presence of myelopathy in our cases, indicating a high pretest probability that further supports the utility of this approach.\u003c/p\u003e \u003cp\u003eIn treating odontoid fractures, the decision between surgical and conservative approaches depends on specific clinical criteria and patient characteristics: Surgical options, including anterior and posterior approaches, provide high rates of fracture stability and fracture union; notably, posterior instrumented fusion of C1-C2 also minimize complications such as dysphagia associated with anterior methods (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). Conservative approaches are recommended for patients with less severe injuries or significant surgical risks (\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e). In our series, two patients underwent successful screw fixation for a type II Anderson d'Alonzo fracture with 3mm displacement and a type III fracture with 4mm displacement, both without dislocation, but high risk of instability and non-union. Both had shown neurological improvement prior to surgery. This was a prerequisite for the chosen treatment.\u003c/p\u003e \u003cp\u003eThe limitations of this study stem primarily from its design; it is retrospective in nature and includes a relatively small sample size coupled with a brief follow-up period. These factors significantly restrict the generalizability of our findings. However, it is worth noting that despite these limitations, this study represents the largest series to date addressing this rare and severe scenario as per our systematic literature review. The small sample size also prevented the execution of robust statistical analyses, highlighting the need for larger trials. Future research should aim to employ larger sample sizes to facilitate detailed statistical evaluations, such as linear regression, to identify factors associated with the outcomes studied.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eCardiac arrest in conjunction with odontoid fractures is associated with a high mortality rate. In trauma-related cardiac arrest scenarios, it is critical to maintain a high index of suspicion for potential odontoid fractures. Beyond the immediate life-saving measures such as CPR, effective management includes the proper immobilization of the cervical spine and the timely and accurate use of diagnostic imaging to guide further treatment strategies.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eEthics approval and consent to participate\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eWe obtained ethics approval from the local ethics committee (Kantonale Ethikkommission Bern [KEK]); BASEC-Nr: Req-2023-00618).\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eConsent for publication\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eNot applicable\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eAvailability of data and materials\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eThe datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eCompeting interests\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eThe authors declare that they have no competing interests.\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eFunding\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eNo funding was obtained for this study.\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eAuthors\u0026apos; contributions\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eSFS and CT analyzed and interpreted the patient data. Additionally, CT reviewed the CT and MRI images. SFS authored the initial draft of the manuscript. All authors have read and approved the final manuscript.\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eAcknowledgements\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eNot applicable\u003c/em\u003e\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eIyer S, Hurlbert RJ, Albert TJ. Management of Odontoid Fractures in the Elderly: A Review of the Literature and an Evidence-Based Treatment Algorithm. Neurosurgery. 2018;82(4):419\u0026ndash;30.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGuan J, Bisson EF. Treatment of Odontoid Fractures in the Aging Population. Neurosurg Clin N Am. 2017;28(1):115\u0026ndash;23.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGood AE, Ramponi DR. Odontoid/Dens Fractures. Adv Emerg Nurs J. 2024;46(1):38\u0026ndash;43.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGoz V, Spiker WR, Lawrence B, Brodke D, Spina N. Odontoid Fractures: A Critical Analysis Review. JBJS reviews. 2019;7(8):e1.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTeasell RW, Arnold JM, Krassioukov A, Delaney GA. Cardiovascular consequences of loss of supraspinal control of the sympathetic nervous system after spinal cord injury. Arch Phys Med Rehabil. 2000;81(4):506\u0026ndash;16.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGrigorean VT, Sandu AM, Popescu M, Iacobini MA, Stoian R, Neascu C, et al. Cardiac dysfunctions following spinal cord injury. J Med Life. 2009;2(2):133\u0026ndash;45.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim SW, Park CJ, Kim K, Kim YC. Cardiac arrest attributable to dysfunction of the autonomic nervous system after traumatic cervical spinal cord injury. Chin J Traumatol. 2017;20(2):118\u0026ndash;21.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMiyata K, Mikami T, Koyanagi I, Mikuni N, Narimatsu E. Cervical spinal cord injuries associated with resuscitation from fatal circulatory collapse. Acute Med Surg. 2016;3(2):86\u0026ndash;93.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLehmann KG, Lane JG, Piepmeier JM, Batsford WP. Cardiovascular abnormalities accompanying acute spinal cord injury in humans: incidence, time course and severity. J Am Coll Cardiol. 1987;10(1):46\u0026ndash;52.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBowers CA, Jost GF, Dailey AT. An odontoid fracture causing apnea, cardiac instability, and quadriplegia. Case Reports in Critical Care. 2012;2012.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTeeter W, Haase D. Updates in Traumatic Cardiac Arrest. Emerg Med Clin North Am. 2020;38(4):891\u0026ndash;901.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDeBehnke DJ, Swart GL. Cardiac arrest. Emerg Med Clin North Am. 1996;14(1):57\u0026ndash;81.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLewis J, Perkins GD. Traumatic cardiac arrest. Curr Opin Crit Care. 2023;29(3):162\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBadhiwala JH, Wilson JR, Witiw CD, Harrop JS, Vaccaro AR, Aarabi B, et al. The influence of timing of surgical decompression for acute spinal cord injury: a pooled analysis of individual patient data. Lancet Neurol. 2021;20(2):117\u0026ndash;26.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003einvestigators O, Chikuda H, Koyama Y, Matsubayashi Y, Ogata T, Ohtsu H, et al. Effect of Early vs Delayed Surgical Treatment on Motor Recovery in Incomplete Cervical Spinal Cord Injury With Preexisting Cervical Stenosis: A Randomized Clinical Trial. JAMA Netw Open. 2021;4(11):e2133604.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eThompson DN. Acute myelopathy: tumoral or traumatic spinal cord compression. Handb Clin Neurol. 2013;112:993\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMourelo Farina M, Salvador de la Barrera S, Montoto Marques A, Ferreiro Velasco ME, Galeiras Vazquez R. Update on traumatic acute spinal cord injury. Part 2. Med Intensiva. 2017;41(5):306\u0026ndash;15.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRopper AE, Ropper AH. Acute Spinal Cord Compression. N Engl J Med. 2017;376(14):1358\u0026ndash;69.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSharwood LN, King V, Ball J, Varma D, Stanford RW, Middleton JW. The influence of initial spinal cord haematoma and cord compression on neurological grade improvement in acute traumatic spinal cord injury: A prospective observational study. J Neurol Sci. 2022;443:120453.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIkpeze TC, Mesfin A. Spinal Cord Injury in the Geriatric Population: Risk Factors, Treatment Options, and Long-Term Management. Geriatr Orthop Surg Rehabil. 2017;8(2):115\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePospiech J, Schick U, Stolke D. Indications for surgery in upper cervical spine injury. Neurosurg Rev. 1996;19(2):73\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRutsch N, Amrein P, Exadaktylos AK, Benneker LM, Schmaranzer F, M\u0026uuml;ller M, et al. Cervical spine trauma\u0026ndash;Evaluating the diagnostic power of CT, MRI, X-Ray and LODOX. Injury. 2023;54(7):110771.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTalbott JF, Whetstone WD, Readdy WJ, Ferguson AR, Bresnahan JC, Saigal R, et al. The Brain and Spinal Injury Center score: a novel, simple, and reproducible method for assessing the severity of acute cervical spinal cord injury with axial T2-weighted MRI findings. J neurosurgery: Spine. 2015;23(4):495\u0026ndash;504.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTugwell P, Tovey DPRISMA. 2020. Elsevier; 2021. pp. A5-A6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBaker SP, o'Neill B, Haddon W Jr, Long WB. The injury severity score: a method for describing patients with multiple injuries and evaluating emergency care. J Trauma Acute Care Surg. 1974;14(3):187\u0026ndash;96.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBarber Ans\u0026oacute;n M, Orera P\u0026eacute;rez \u0026Aacute;, Redondo D\u0026iacute;ez E. Parada cardiorrespiratoria secundaria a fractura de odontoides. Med intensiva (Madr, Ed impr). 2020:65-.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGraziano G, Colon G, Hensinger R. Complete atlanto-axial dislocation associated with type II odontoid fracture: a report of two cases. Clin Spine Surg. 1994;7(6):518\u0026ndash;21.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKubokura T, Ishikawa K, Nishimura T, Tsubone K. A case of quadriplegia with respiratory paralysis surviving as a candidate for rehabilitation. No Shinkei geka Neurol Surg. 1985;13(11):1237\u0026ndash;42.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMaeda K, Ichiba T. Unusual clinical course of odontoid fracture: transient prehospital cardiopulmonary arrest. Cureus. 2020;12(12).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eP\u0026eacute;rez-Bovet J, Garcia-Armengol R, Martin Ferrer S. Traumatic epidural retroclival hematoma with odontoid fracture and cardiorespiratory arrest. Spinal Cord. 2013;51(12):926\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePowell R, Heath K. Quadraplegia in a Patient with an Undiagnosed Odontoid Peg Fracture: The Importance of Cervical Spine Immobilisation in Patients with Head Injuries. BMJ Military Health. 1996;142(2):79\u0026ndash;81.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLee ZH, Kim YH, Lee JH, Lee DW, Lee KY, Hwang SY. Association between Cardiac Arrest Time and Favorable Neurological Outcomes in Witnessed Out-of-Hospital Cardiac Arrest Patients Treated with Targeted Temperature Management. J Korean Med Sci. 2020;35(16):e108.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOkubo M, Komukai S, Andersen LW, Berg RA, Kurz MC, Morrison LJ, et al. Duration of cardiopulmonary resuscitation and outcomes for adults with in-hospital cardiac arrest: retrospective cohort study. BMJ. 2024;384:e076019.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLenga P, G\u0026uuml;lec G, Kiening K, Unterberg AW, Ishak B. Morbidity and mortality related to type II odontoid fractures in octogenarians undergoing surgery: a retrospective study with 5 year follow up. Front Med. 2023;10.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShafafy R, Valsamis E, Luck J, Dimock R, Rampersad S, Kieffer W, et al. Predictors of mortality in the elderly patient with a fracture of the odontoid process: can we use non-spinal scoring systems? Bone Joint J. 2019;101(3):253\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePark S, Lee SW, Han KS, Lee EJ, Jang D-H, Lee SJ, et al. Optimal cardiopulmonary resuscitation duration for favorable neurological outcomes after out-of-hospital cardiac arrest. Scand J Trauma Resusc Emerg Med. 2022;30(1):5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTucker S, Taylor B. Spinal canal capacity in simulated displacements of the atlantoaxial segment: a skeletal study. J Bone Joint Surg Br Volume. 1998;80(6):1073\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOsterhoff G, Scholz M, Disch AC, Katscher S, Spiegl UJ, Schnake KJ, et al. Geriatric odontoid fractures: Treatment algorithms of the German Society for Orthopaedics and trauma based on expert consensus and a systematic review. Global Spine J. 2023;13(1suppl):S13\u0026ndash;21.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAgunbiade S, Belton PJ, Mesfin FB. Spinal Cord Transection in a Type II Odontoid Fracture From a Ground-Level Fall. Cureus. 2020;12(12).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRuiz IA, Squair JW, Phillips AA, Lukac CD, Huang D, Oxciano P, et al. Incidence and natural progression of neurogenic shock after traumatic spinal cord injury. J Neurotrauma. 2018;35(3):461\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBarber Ans\u0026oacute;n M, Orera P\u0026eacute;rez \u0026Aacute;, Redondo D\u0026iacute;ez E. Parada cardiorrespiratoria secundaria a fractura de odontoides. Med Intensiva. 2020;44(1):65.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKumar Y, Hayashi D. Role of magnetic resonance imaging in acute spinal trauma: a pictorial review. BMC Musculoskelet Disord. 2016;17:310.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJoaquim AF, Patel AA. Surgical treatment of Type II odontoid fractures: anterior odontoid screw fixation or posterior cervical instrumented fusion? NeuroSurg Focus. 2015;38(4):E11.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable 1, 2, 3 and 5 are available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scandinavian-journal-of-trauma-resuscitation-and-emergency-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"stre","sideBox":"Learn more about [Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine](http://sjtrem.biomedcentral.com)","snPcode":"13049","submissionUrl":"https://submission.nature.com/new-submission/13049/3","title":"Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine","twitterHandle":"@SJTREM","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Cervical injuries, spinal injuries, heart arrest, resuscitation, review","lastPublishedDoi":"10.21203/rs.3.rs-4821074/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4821074/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground:\u003c/h2\u003e \u003cp\u003eOdontoid fractures from high-energy trauma are associated with significant morbidity and mortality, including spinal cord injury, neurological damage, and cardiac arrest. The literature on odontoid fractures leading to cardiac arrest is limited to isolated case reports. This study aims to conduct a retrospective bi-center case series and a systematic review of existing literature.\u003c/p\u003e\u003ch2\u003eMethods:\u003c/h2\u003e \u003cp\u003eWe conducted a retrospective bi-center case series on patients with odontoid fractures from high-energy trauma who experienced post-traumatic cardiac arrest with return of spontaneous circulation (ROSC) after CPR from two Level 1 Trauma Centers (2008\u0026ndash;2024). The primary outcome was mortality; secondary outcomes included epidemiological, pre-hospital, and in-hospital data, and CT and MRI findings. Additionally, we performed a systematic literature review to summarize existing evidence.\u003c/p\u003e\u003ch2\u003eResults:\u003c/h2\u003e \u003cp\u003eThe study included 25 patients (mean age 71.1\u0026thinsp;\u0026plusmn;\u0026thinsp;12.3 years, SD; 8 females). The mortality rate was 92% (23 patients). Median downtime before CPR was 5.0 minutes (IQR: 7.0), with CPR lasting 17.0 minutes (IQR: 13.0), primarily initiated by professionals (60%). All patients were quadriplegic. Type II Anderson d'Alonzo fractures were most common (88%), with all patients showing myelopathy on MRI. Only three patients (12%) underwent surgical intervention due to favorable prognosis. Our literature review identified seven case reports, with two patients surviving and one achieving full recovery.\u003c/p\u003e\u003ch2\u003eConclusions:\u003c/h2\u003e \u003cp\u003eIn this case series, patients experiencing cardiac arrest after odontoid fractures exhibited high mortality rates despite comprehensive management at Level 1 trauma centers. Survivors faced significant and enduring morbidity.\u003c/p\u003e","manuscriptTitle":"Outcomes of Odontoid Fractures with Associated Cardiac Arrest: Retrospective Bi-Center Case Series and Systematic Literature Review","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-09-04 21:26:37","doi":"10.21203/rs.3.rs-4821074/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-09-18T17:26:35+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-08-27T08:15:27+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"13850647927833623984093466368458658871","date":"2024-08-27T07:06:24+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"158617304911361463301772880374843102227","date":"2024-07-31T04:47:22+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-07-30T18:40:33+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-07-30T11:49:45+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-07-30T11:47:21+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine","date":"2024-07-29T10:10:01+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scandinavian-journal-of-trauma-resuscitation-and-emergency-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"stre","sideBox":"Learn more about [Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine](http://sjtrem.biomedcentral.com)","snPcode":"13049","submissionUrl":"https://submission.nature.com/new-submission/13049/3","title":"Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine","twitterHandle":"@SJTREM","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"482d5791-3dfa-4d7f-81fc-1f71252b5096","owner":[],"postedDate":"September 4th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-11-04T16:25:05+00:00","versionOfRecord":{"articleIdentity":"rs-4821074","link":"https://doi.org/10.1186/s13049-024-01277-z","journal":{"identity":"scandinavian-journal-of-trauma-resuscitation-and-emergency-medicine","isVorOnly":false,"title":"Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine"},"publishedOn":"2024-10-29 16:20:04","publishedOnDateReadable":"October 29th, 2024"},"versionCreatedAt":"2024-09-04 21:26:37","video":"","vorDoi":"10.1186/s13049-024-01277-z","vorDoiUrl":"https://doi.org/10.1186/s13049-024-01277-z","workflowStages":[]},"version":"v1","identity":"rs-4821074","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4821074","identity":"rs-4821074","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}