Perioperative risk and antiplatelet management in patients undergoing non-cardiac surgery within 1 year of PCI.

Perioperative cardiovascular complications are important causes of morbidity and mortality associated with non-cardiac surgery, especially in patients with recent percutaneous coronary intervention (PCI). We aimed to illustrate the types and timing of different surgeries occurring after PCI, and to evaluate the risk of thrombotic and bleeding events according to the perioperative antiplatelet management. Patients undergoing urgent or elective non-cardiac surgery within 1 year of PCI at a tertiary-care center between 2011 and 2018 were included. The primary outcome was major adverse cardiac events (MACE; composite of death, myocardial infarction, or stent thrombosis) at 30 days. Perioperative bleeding was defined as ≥ 2 units of blood transfusion. A total of 1092 surgeries corresponding to 747 patients were classified by surgical risk (low: 50.9%, intermediate: 38.4%, high: 10.7%) and priority (elective: 88.5%, urgent/emergent: 11.5%). High-risk and urgent/emergent surgeries tended to occur earlier post-PCI compared to low-risk and elective ones, and were associated with an increased risk of both MACE and bleeding. Preoperative interruption of antiplatelet therapy (of any kind) occurred in 44.6% of all NCS and was more likely for procedures occurring later post-PCI and at intermediate risk. There was no significant association between interruption of antiplatelet therapy and adverse cardiac events. Among patients undergoing NCS within 1 year of PCI, perioperative ischemic and bleeding events primarily depend on the estimated surgical risk and urgency of the procedure, which are increased early after PCI. Preoperative antiplatelet interruption was not associated with an increased risk of cardiac events.

Radial versus femoral access for coronary interventions: An updated systematic review and meta-analysis of randomized trials.

OBJECTIVE: It is still debated if benefits associated with radial versus femoral access for coronary angiography and percutaneous coronary interventions (PCI) are due to the access site selection itself, operator expertise or other underlying mechanisms. METHODS: We searched PubMed, Embase, and meeting abstracts for randomized trials comparing radial versus femoral access site for coronary angiography and PCI. Primary safety endpoint was major bleeding. Coprimary efficacy endpoints were stroke and myocardial infarction (MI). This study is registered with PROSPERO. RESULTS: We identified 31 trials (30,096 patients, PCI performed in 21,225 patients). Radial compared to femoral access was associated with a significant risk reduction in major bleeding (OR 0.53, 95%CI 0.42-0.66, I2  = 3.3%). Findings were consistent regardless of clinical characteristics or whether coronary angiography was performed with or without PCI. The benefit of radial access was significantly increased in studies published before 2010 and in patients with chronic coronary syndrome. Risk for stroke (OR 1.11, 95%CI 0.76-1.64, I2  = 0%) and MI (OR 0.90, 95%CI 0.79-1.04, I2  = 0%) were comparable between the groups. Risk for mortality and vascular complications were significantly lower with radial than femoral access. CONCLUSION: In patients undergoing coronary angiography and PCI, radial access is associated with a significant risk reduction in bleeding, vascular complications, and mortality compared to femoral access. The risk of stroke or MI were comparable in patients with radial or femoral access.

Impact of sex on long-term cardiovascular outcomes of patients undergoing percutaneous coronary intervention for acute coronary syndromes.

BACKGROUND: Women with acute coronary syndrome (ACS) generally present with more comorbidities and experience worse clinical outcomes compared with males. However, it is unclear whether this represents genuine sex-related difference or stems from clinical, procedural and socioeconomic factors. METHODS: We analyzed consecutive patients undergoing percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI), non-STEMI or unstable angina at a single tertiary-care center. Exclusion criteria were unknown sex, age < 18 years and PCI with bare metal stent or without stent placement. The study population was stratified according to sex. The primary endpoint was major adverse cardiac and cerebrovascular events (MACCE) defined as the composite of death, spontaneous myocardial infarction, or stroke at 1 year. Secondary endpoints were individual components of MACCE, target vessel revascularization (TVR) and clinically significant bleeding. RESULTS: Of the 7362 patients included, 5031 (68.3%) were men and 2331 (31.7%) women. Women were older and presented with a higher burden of comorbidities while men had more complex coronary anatomy. The incidence of 1 year MACCE was significantly higher among women (8.0% versus 5.6%; p < 0.01) compared to men. Women also experienced a higher rate of bleeding (2.3% vs. 1.4%; p = 0.02) while there were no differences between groups in terms of TVR (8.1% vs. 7.8%; p-value = 0.83). Differences in outcomes were attenuated after multivariable adjustment. Findings were consistent across ACS subgroups. CONCLUSIONS: In a contemporary ACS population treated with drug-eluting stents, women experienced a higher crude rate of 1-year MACCE. This was no longer apparent after accounting for baseline imbalances.

Prevalence and prognostic impact of hsCRP elevation are age-dependent in women but not in men undergoing percutaneous coronary intervention.

BACKGROUND: High-sensitivity C-reactive protein (hsCRP) predicts outcomes after percutaneous coronary intervention (PCI). OBJECTIVE: We studied the prevalence and prognostic impact of hsCRP elevation according to age in men and women undergoing PCI. METHODS: We included patients undergoing PCI at our center from 2010 until 2017, excluding those with myocardial infarction (MI) on presentation, neoplastic disease and hsCRP >10 mg/L at baseline. Elevated hsCRP was defined as >3 mg/L. The outcome of interest was major adverse cardiac events (MACE) consisting of all-cause death, MI and target vessel revascularization. The association between hsCRP elevation and outcomes was assessed using adjusted Cox models. RESULTS: 10,432 men and 4,345 women were included. Elevation of hsCRP was present in 25.7% of men and 37.0% of women (p < .01). In men, prevalence of hsCRP elevation was stable across age strata (ptrend  = .42). In women, hsCRP elevation was most prevalent in patients <50 years (44.6%) and decreased stepwise with increasing age (ptrend < .001). After stratifying the population into age quartiles (Q1: <59 years, Q2: 59-66 years, Q3: 67-74 years, Q4: ≥75 years), hsCRP elevation was associated with increased risk of MACE across all age groups in men (HR [95% CI] Q1: 1.49 [1.12-1.98]; Q2: 1.51 [1.21-2.06]; Q3: 1.76 [1.27-2.51]; Q4: 1.43[1.03-1.97]). In women, hsCRP elevation was associated with increased risk of MACE only among older patients (HR [95% CI] Q1: 1.08 [0.64-0.82]; Q2: 1.52 [0.93-2.46]; Q3: 1.65 [1.08-2.50]; Q4: 1.52 [1.02-1.28]). CONCLUSION: Among patients undergoing PCI, prevalence and prognostic value of hsCRP elevation were age-dependent exclusively in women.

Comparative influence of bleeding and ischemic risk factors on diabetic patients undergoing percutaneous coronary intervention with everolimus-eluting stents.

OBJECTIVE: To investigate the impact of ischemic and bleeding risk factors on long-term clinical outcomes of patients with diabetes mellitus (DM) undergoing percutaneous coronary intervention (PCI) with everolimus-eluting stents. BACKGROUND: Second-generation drug-eluting stents have substantially improved outcomes after PCI in the general population; however, DM patients continue to experience high rates of ischemic and bleeding complications. METHODS: DM patients from the pooled XIENCE V registry were divided into high or low bleeding and ischemic risk groups (HBR, LBR, HIR, and LIR) based on established bleeding (age ≥ 75 years; chronic kidney disease; anemia; prior stroke; oral anticoagulation; thrombocytopenia; prior major bleeding) and ischemic (acute coronary syndrome; prior myocardial infarction [MI]; ≥3 stents implanted; ≥3 vessels treated; ≥3 lesions treated; stent length > 60 mm; bifurcation treated with ≥2 stents; chronic total occlusion) risk factors. The primary outcomes were major adverse cardiac events (MACE; cardiac death, MI, or stent thrombosis) and major bleeding at 4-year follow-up. RESULTS: A total of 3,704 DM patients were divided into four groups (21.5% LBR/LIR; 39.0% LBR/HIR; 15.6% HBR/LIR; 23.9% HBR/HIR). Compared with LBR/LIR patients, those at HBR/HIR and HBR/LIR had a significantly higher risk of MACE (HR (95% CI) 2.7 (1.9-3.9) and 2.2 (1.5-3.2), respectively) and major bleeding (2.7 (1.6-4.8) and 2.6 (1.4-4.7), respectively), while LBR/HIR patients did not. CONCLUSIONS: Among DM patients undergoing PCI, presence of bleeding risk factors was associated with a higher risk of both ischemic and bleeding events, whereas commonly used features of ischemic risk did not impact long-term clinical outcomes.

Incidence, predictors and clinical impact of permanent pacemaker insertion in women following transcatheter aortic valve implantation: Insights from a prospective multinational registry.

OBJECTIVES: To describe the incidence, predictors, and clinical impact of permanent pacemaker insertion (PPI) following transcatheter aortic valve replacement (TAVR) in women. BACKGROUND: Data on pacemaker insertion complicating TAVR in women are scarce. METHODS: The Women's International Transcatheter Aortic Valve implantation (WIN-TAVI) is a prospective registry evaluating the safety and efficacy of TAVR in women. We included patients without preprocedural pacemakers and divided them into two groups: (1) PPI and (2) no-PPI. We identified PPI predictors using logistic regression and studied its clinical impact on the Valve Academic Research Consortium (VARC)-2 efficacy and safety endpoints. RESULTS: Out of 1019 patients, 922 were included in the analysis. Post-TAVR PPI occurred in 132 (14.3%) patients. Clinical and procedural characteristics were similar in both groups. Pre-existing right bundle branch block (RBBB) was associated with a high risk of post-TAVR PPI (OR 3.62, 95% CI 1.85-7.06, p < 0.001), while implantation of balloon-expandable prosthesis was associated with a lower risk (OR 0.47, 95% CI 0.30-0.74, p < 0.001). Post-TAVR PPI prolonged in-hospital stay by a median of 2 days (11 [9-16] days in PPI vs. 9 [7-14] days in no-PPI, p = 0.005), yet risks of VARC-2 efficacy and safety endpoints at 1 year were similar in both groups (adj HR 0.95, 95% CI 0.60-1.52, p = 0.84 and adj HR 1.22, 95% CI 0.83-1.79, p = 0.31, respectively). CONCLUSION: Pacemaker implantation following TAVR is frequent among women and is associated with pre-existing RBBB and valve type. PPI prolongs hospital stay, albeit without any significant impact on 1-year outcomes.

Preprocedural anemia in females undergoing transcatheter aortic valve implantation: Insights from the WIN-TAVI registry.

OBJECTIVES: To assess the impact of anemia on clinical outcomes in female patients enrolled in the Women's InterNational transcatheter aortic valve implantation (WIN-TAVI) registry. BACKGROUND: Anemia is highly prevalent among females who constitute half of TAVI candidates, yet, its clinical significance remains poorly investigated. METHODS: Patients were divided into three groups according to preprocedural hemoglobin (Hb) level: (1) no anemia (Hb ≥12 g/dl), (2) mild-to-moderate anemia (10 ≤ Hb <12 g/dl), and (3) severe anemia (Hb <10 g/dl). The primary outcome was the occurrence of Valve Academic Research Consortium (VARC)-2 efficacy endpoint, a composite of mortality, stroke, myocardial infarction (MI), hospitalization for valve-related symptoms or heart failure or valve-related dysfunction at 1-year follow-up. RESULTS: Hemoglobin level was available in 877 (86.1%) patients: 412 (47.0%) had no anemia, 363 (41.4%) had mild-to-moderate anemia, and 102 (11.6%) had severe anemia. The latter group had a higher prevalence of cardiovascular risk factors. Compared with patients without anemia, severe anemia was associated with a greater risk of VARC-2 efficacy endpoint (adj HR 1.71, 95% CI: 1.02-2.87, p = .04), all-cause death (adj HR 2.36, 95% CI: 1.31-4.26, p = .004) and a composite of death, MI or stroke (adj HR 1.88, 95% CI: 1.10-3.22, p = .02) at 1 year. Moreover, an increased risk of late mortality (adj HR 1.15, 95% CI: 1.02-1.30, p = .03) was observed with every 1 g/dl decrease in hemoglobin level. CONCLUSION: Severe anemia in females undergoing TAVI was independently associated with increased rates of VARC-2 efficacy endpoint and mortality at 1 year.

Overview of medical malpractice in neurosurgery.

Annually, 20% of all practicing neurosurgeons in the United States are faced with medical malpractice litigation. The average indemnity paid in a closed neurosurgical civil claim is $439,146, the highest of all medical specialties. The majority of claims result from dissatisfaction following spinal surgery, although claims after cranial surgery tend to be costlier. On a societal scale, the increasing prevalence of medical malpractice claims is a catalyst for the practice of defensive medicine, resulting in record-level healthcare costs. Outside of the obvious financial strains, malpractice claims have also been linked to professional disenchantment and career changes for afflicted physicians. Unfortunately, neurosurgical residents receive minimal practical education regarding these matters and are often unprepared and vulnerable to these setbacks in the earlier stages of their careers. In this article, the authors aim to provide neurosurgical residents and junior attendings with an introductory guide to the fundamentals of medical malpractice lawsuits and the implications for neurosurgeons as an adjunct to more formal residency education.

Surgical management of spinal metastases from primary thyroid carcinoma: Demographics, clinical characteristics, and treatment outcomes - A retrospective analysis.

Objective: Metastatic spinal tumors represent a rare but concerning complication of primary thyroid carcinoma. We identified demographics, metastatic features, outcomes, and treatment strategies for these tumors in our institutional cohort. Materials and Methods: We retrospectively reviewed patients surgically treated for spinal metastases of primary thyroid carcinoma. Demographics, tumor characteristics, and treatment modalities were collected. The functional outcomes were quantified using Nurik, Modified Rankin, and Karnofsky Scores. Results: Twelve patients were identified who underwent 17 surgeries for resection of spinal metastases. The primary thyroid tumor pathologies included papillary (4/12), follicular (6/12), and Hurthle cell (2/12) subtypes. The average number of spinal metastases was 2.5. Of the primary tumor subtypes, follicular tumors averaged 2.8 metastases at the highest and Hurthle cell tumors averaged 2.0 spinal metastases at the lowest. Five patients (41.7%) underwent preoperative embolization for their spinal metastases. Seven patients (58.3%) received postoperative radiation. There was no significant difference in progression-free survival between patients receiving surgery with adjuvant radiation and surgery alone (P = 0.0773). Five patients (41.7%) experienced postoperative complications. Two patients (16.7%) succumbed to disease progression and two patients (16.7%) experienced tumor recurrence following resection. Postsurgical mean Nurik scores decreased 0.54 points, mean Modified Rankin scores decreased 0.48 points, and mean Karnofsky scores increased 4.8 points. Conclusion: Surgery presents as an important treatment modality in the management of spinal metastases from thyroid cancer. Further work is needed to understand the predictive factors for survival and outcomes following treatment.

The demographic, clinical, and management differences between traumatic dens fracture patients with and without simultaneous atlas fractures.

Introduction: Atlas fractures often accompany traumatic dens fractures, but existing literature on the management of simultaneous atlantoaxial fractures is limited. Methods: We examined all patients with traumatic dens fractures at our institution between 2008 and 2018. We used multivariable logistic regression and ordinal logistic regression to identify factors independently associated with presentation with a simultaneous atlas fracture, as well myelopathy severity, fracture nonunion, and selection for surgery. Results: Two hundred and eighty-two patients with traumatic dens fractures without subaxial fractures were identified, including 65 (22.8%) with simultaneous atlas fractures. The distribution of injury mechanisms differed between groups (χ2 P = 0.0360). On multivariable logistic regression, dens nonunion was positively associated with type II fractures (odds ratio [OR] = 2.00, P = 0.038) and negatively associated with having surgery (OR = 0.52, P = 0.049), but not with having a C1 fracture (P = 0.3673). Worse myelopathy severity on presentation was associated with having a severe injury severity score (OR = 102.3, P < 0.001) and older age (OR = 1.28, P = 0.002), but not with having an atlas fracture (P = 0.2446). Having a simultaneous atlas fracture was associated with older age (OR = 1.29, P = 0.024) and dens fracture angulation (OR = 2.62, P = 0.004). Among patients who underwent surgery, C1/C2 posterior fusion was the most common procedure, and having a simultaneous atlas fracture was associated with selection for occipitocervical fusion (OCF) (OR = 14.35, P = 0.010). Conclusions: Among patients with traumatic dens, patients who have simultaneous atlas fractures are a distinct subpopulation with respect to age, mechanism of injury, fracture morphology, and management. Traumatic dens fractures with simultaneous atlas fractures are independently associated with selection for OCF rather than posterior cervical fusion alone.

Impact of Polyvascular Disease in Patients Undergoing Unprotected Left Main Percutaneous Coronary Intervention.

Percutaneous coronary intervention (PCI) has demonstrated its safety and efficacy in treating left main (LM) coronary artery disease (CAD) in select patients. Polyvascular disease (PolyVD) is associated with adverse events in all-comers with CAD. However, there is little data examining the interplay between PolyVD and LM-PCI, which we sought to investigate in a retrospective single-center study. We included patients who underwent unprotected LM-PCI at a tertiary center from 2012 to 2019. The study population was stratified based on the presence or absence of PolyVD (i.e., medical history of cerebrovascular and/or peripheral artery disease in addition to LM-CAD). The primary outcome was major adverse cardiovascular events (MACE) combining all-cause mortality and spontaneous myocardial infarction within 1 year after index PCI. Overall, 869 patients were included, and 23.8% of the population had PolyVD. Subjects with PolyVD were older and had a greater burden of co-morbidities. After 1-year follow-up, PolyVD patients exhibited significantly higher rates of both MACE (22.8% vs 9.4%, p <0.001) and bleeding events compared with those without PolyVD. MACE was primarily driven by an increase in all-cause mortality (18.3% vs 7.1%, p <0.001). Results persisted after adjusting for confounders. In conclusion, in patients who underwent LM-PCI, the presence of PolyVD is linked to an increased risk of MACE and bleeding after 1 year of follow-up, which highlights the vulnerability of this population.

Variation in academic neurosurgery departments' #neurosurgery social media influence.

Background: Social media use is increasingly common among academic neurosurgery departments, but its relationship with academic metrics remains underexamined. Methods: We examine the relationship between American academic neurosurgery departments' number of followers on Twitter, Instagram, and Facebook and the following academic metrics: Doximity Residency rankings, US News & World Report rankings (USNWR) of their affiliated medical schools, and the amount of NIH funding of those schools. Results: Few departments had disproportionate number of followers. A greater proportion of programs had Twitter accounts (88.9%) than had Instagram (72.2%) or Facebook (51.9%) accounts (p=0.0001). Programs identified as "Influencers" had more departmental NIH funding (p=0.044), more institutional NIH funding (p=0.035), better Doximity residency rankings (p=0.044), and better affiliated medical school rankings (p=0.002). Number of Twitter followers had the strongest correlation with academic metrics, yet only modest correlations were identified to departmental NIH funding (R=0.496, p=0.0001), institutional NIH funding (R=0.387, p=0.0072), Doximity residency rank (R=0.411, p=0.0020), and affiliated medical school ranking (R=0.545,p<0.0001). On multivariable regression, only being affiliated with a medical school in the top quartile on the USNWR rankings, rather than neurosurgery departmental metrics, predicted having more Twitter (OR=5.666, p=0.012) and Instagram (OR=8.33, p=0.009) followers. Conclusion: American academic neurosurgery departments preferentially use Twitter over Instagram or Facebook. Their Twitter or Instagram presences are associated with better performance on traditional academic metrics. However, these associations are modest, suggesting that other factors contribute to a department's social media influence. A department's affiliated medical school may contribute to the department's social media brand.

Atlas fractures with and without simultaneous dens fractures differ with respect to clinical, demographic, and management characteristics.

Background: Patients with simultaneous fractures of the atlas and dens have traditionally been managed according to the dens fracture's morphology, but data supporting this practice are limited. Methods: We retrospectively examined all patients with traumatic atlas fractures at our institution between 2008 and 2016. We used multivariable regression and propensity score matching to compare the presentation, management, and outcomes of patients with isolated atlas fractures to patients with simultaneous atlas-dens fractures. Results: Ninety-nine patients were identified. Patients with isolated atlas fractures were younger (61 ± 22 vs. 77 ± 14, P = 0.0003), had lower median Charlson Comorbidity Index (3 vs. 5, P = 0.0005), had better presenting Nurick myelopathy scores (0 vs. 3, P < 0.0001), and had different mechanisms of injury (P = 0.0011). Multivariable regression showed that having a simultaneous atlas-dens fracture was independently associated with older age (odds ratio [OR] =1.59 [1.22, 2.07], P = 0.001), worse presenting myelopathy (OR = 3.10 [2.04, 4.16], P < 0.001), and selection for surgery (OR = 4.91 [1.10, 21.97], P = 0.037). Propensity score matching yielded balanced populations (Rubin's B = 23.3, Rubin's R = 1.96) and showed that the risk of atlas fracture nonunion was no different among isolated atlas fractures compared to simultaneous atlas-dens fractures (P = 0.304). Age was the only variable independently associated with atlas fracture nonunion (OR = 2.39 [1.15, 5.00], P = 0.020), having a simultaneous atlas-dens fracture was not significant (P = 0.2829). Conclusions: Among patients with atlas fractures, simultaneous fractures of the dens occur in older patients and confer an increased risk of myelopathy and requiring surgical stabilization. Controlling for confounders, the risk of atlas fracture nonunion is equivalent for isolated atlas fractures versus simultaneous atlas-dens fractures.

Traumatic Dens Fracture Patients Comprise Distinct Subpopulations Distinguished by Differences in Age, Sex, Injury Mechanism and Severity, and Outcome.

BACKGROUND: Dens fractures are an increasingly common injury, yet their epidemiology and its implications remain underexamined. METHODS: We retrospectively analyzed all traumatic dens fracture patients managed at our institution over a 10-year period, examining demographic, clinical, and outcomes data. Patient subsets were compared across these parameters. RESULTS: Among 303 traumatic dens fracture patients, we observed a bimodal age distribution with a strong goodness of fit centered at age 22.3 ± 5.7 (R = 0.8781) and at 77.7 ± 13.9 (R = 0.9686). A population pyramid demonstrated a bimodal distribution among male patients, but not female patients, which was confirmed with a strong goodness of fit for male patient subpopulations age <35 (R = 0.9791) and age ≥35 (R = 0.8843), but a weaker fit for a second female subpopulation age <35. Both age groups were equally likely to undergo surgery. Patients younger than age 35 were more likely to be male (82.4% vs. 46.9%, odds ratio [OR] = 5.29 [1.54, 17.57], P = 0.0052), have motor vehicle collision as their mechanism of injury (64.7% vs. 14.1%, OR = 11.18 [3.77, 31.77], P < 0.0001), and to have a severe trauma injury severity score (17.6% vs. 2.9%, OR = 7.23 [1.88, 28.88], P = 0.0198). Nevertheless, patients age <35 were less likely to have fracture nonunion at follow (18.2% vs. 53.7%, OR = 0.19 [0.041, 0.76], P = 0.0288). CONCLUSIONS: The dens fracture patient population comprises 2 subpopulations, distinguished by differences in age, sex, injury mechanism and severity, and outcome, with male dens fracture patients demonstrating a bimodal age distribution. Young, male patients were more likely to have high-energy injury mechanisms leading to severe trauma, yet were less likely to have fracture nonunion at follow-up.

Odontoid fracture type and angulation affect nonunion risk, but comminution and displacement do not: A propensity score matched analysis of fracture morphology.

OBJECTIVE: Odontoid fractures disproportionately affect older patients who have high surgical risk, but also high rates of fracture nonunion. To guide surgical decision-making, we quantified the effect of fracture morphology on nonunion among nonoperatively managed, traumatic, isolated odontoid fractures. METHODS: We examined all patients with isolated odontoid fractures treated nonoperatively at our institution between 2010 and 2019. Multivariable regression and propensity score matching were used to quantify the effect of fracture type, angulation, comminution, and displacement on bony healing by 26 weeks from injury. RESULTS: 303 consecutive traumatic odontoid fracture patients were identified, of whom 163 (53.8 %) had isolated fractures that were managed nonoperatively. Selection for nonoperative management was more likely with older age (OR=1.31 [1.09, 1.58], p = 0.004), and less likely with higher fracture angle (OR=0.70 [0.55, 0.89], p = 0.004), or higher presenting Nurick scores (OR=0.77 [0.62, 0.94], p = 0.011). Factors associated with nonunion at 26 weeks were fracture angle (OR=5.11 [1.43, 18.26], p = 0.012) and Anderson-D'Alonzo Type II morphology (OR=5.79 [1.88, 17.83], p = 0.002). Propensity score matching to assess the effect of type II fracture, fracture angulation> 10o, displacement≥ 3 mm, and comminution all yielded balanced models (Rubin's B<25.0, 0.5  10o (p = 0.015), and there was an 18.2 % lower rate of bony healing for each 10o increase in fracture angle. Fracture displacement≥ 3 mm and comminution had no significant effect. CONCLUSION: Type II fracture morphology and fracture angle > 10o significantly increase nonunion among nonoperatively managed isolated traumatic odontoid fractures, but fracture comminution and displacement ≥ 3 mm do not.