Axial Fracture Research Articles

Numerical investigation of the cavity shedding mechanism in a Venturi reactor

The shedding mechanism is a hot topic in cavitation research, and the shedding mechanisms induced by the re-entrant jet and bubbly shock, respectively, have been long studied and debated. In this study, based on experimental research, a numerical investigation of a Venturi reactor is performed using a self-developed compressible cavitation phase-change solver in order to determine the shedding mechanism. Through the quasi-periodic evolution of the cavity, combined with the contour of streamwise velocity and pressure, the main characteristics and physical signs of the re-entrant jet and bubbly shock mechanisms are studied. The effect of the pressure ratio on the shedding mechanism is also studied. It was found that, in a Venturi reactor with a long throat, the evolution of cavitation is divided into an inception stage, a development stage, two shedding stages, and a collapse stage. The main characteristic of the shedding mechanism induced by the re-entrant jet is the separation between the cavity and the wall. The physical sign of this type of shedding is the axial fracture of the whole cavity. Shedding induced by the re-entrant jet dominates the first shedding in the diffusion section. The main characteristic of the bubbly shock shedding mechanism is damage to the cavity caused by pressure waves or shocks, which accelerates cavity shedding and restrains cavity development. The physical sign of this type of shedding is circumferential defects and fractures in the cavity. The second shedding is jointly caused by the re-entrant jet and bubbly shock. The second shedding cavity may collapse rapidly or merge with the newly formed cavity, which can damage or strengthen the newly formed cavity, respectively. With the decrease of the pressure ratio, the effect of the bubbly shock shedding mechanism is weakened.

Comparative Propensity-Weighted Mortality After Isolated Acute Traumatic Axis Fractures in Older Adults.

Introduction:In older patients with axis fractures, the survival benefit from surgery is unclear due to high baseline mortality. Comparative effectiveness research can provide evidence from population level cohorts. Propensity weighting is the preferred methodology for reducing bias when analyzing national administrative cohort data for these purposes but has not yet been utilized for this important surgical conundrum. We estimate the effect of surgery on mortality after isolated acute traumatic axis fracture in older adults.Materials and Methods:We used a retrospective population-based cohort of Medicare patients and generated a propensity score-weighted nonsurgical cohort and compared mortality with and without surgery. This balanced the comorbid conditions of the treatment groups. Incident fractures were defined using a predetermined algorithm based on enrollment, code timing, and billing location. The primary outcome was adjusted all-cause 1-year mortality.Results:From 12 372 beneficiaries with 1-year continuous enrollment and a coded axis fracture, 2676 patients met final inclusion/exclusion criteria. Estimated incidence was 16.5 per 100 000 person-years overall in 2014 (95% confidence interval [CI]: 15.0-18.0) and was stable from 2008 through 2014. Patients with axis fracture had a mean age of 82.8 years, 30.2% were male, and 91.9% were Caucasian. Mortality was 3.8 times higher (CI 3.6-4.1) compared with the general population of older US adults. Propensity-weighted mortality at 1 year for nonsurgical patients was 26.7 of 100 (CI: 24.5-29.0). Mortality for surgical patients was significantly lower (19.7/100; CI 14.5-25.0). Risk difference was 7.0 fewer surgical deaths per 100 patients (CI: 1.3-12.7). Surgical patients aged 65 to 74 years had the largest difference in mortality with 11.2 fewer deaths per 100 (CI: 1.1-21.3).Discussion:Patients with axis fractures are predominantly older Caucasian women and have a higher mortality rate than the general population. Propensity-weighted mortality at 1-year was lower in the surgical patients with the largest risk difference occurring in patients 65 to 74 years old.Conclusions:Surgery may provide an independent survival benefit in patients aged 65 to 75 years, and the mortality difference diminishes thereafter.

Comparative Propensity-Weighted Mortality After Isolated Acute Traumatic Axis Fractures in Older Adults

Comparative Propensity-Weighted Mortality After Isolated Acute Traumatic Axis Fractures in Older Adults

Gender Disparities in Surgical Treatment of Axis Fractures in Older Adults

Study Design:Retrospective cohort study.Objectives:Gender appears to play in important role in surgical outcomes following acute cervical spine trauma, with current literature suggesting males have a significantly higher mortality following spine surgery. However, no well-adjusted population-based studies of gender disparities in incidence and outcomes of spine surgery following acute traumatic axis injuries exist to our knowledge. We hypothesized that females would receive surgery less often than males, but males would have a higher 1-year mortality following isolated traumatic axis fractures.Methods:We performed a retrospective cohort study using Medicare claims data that identified US citizens aged 65 and older with ICD-9 (International Classification of Diseases, Ninth Revision) code diagnosis corresponding to isolated acute traumatic axis fracture between 2007 and 2014. Our primary outcome was defined as cumulative incidence of surgical treatment, and our secondary outcome was 1-year mortality. Propensity weighted analysis was performed to balance covariates between genders. Our institutional review board approved the study (IRB #16-0533).Results:There was no difference in incidence of surgery between males and females following acute isolated traumatic axis fractures (7.4 and 7.5 per 100 fractures, respectively). Males had significantly higher 1-year weighted mortality overall (41.7 and 28.9 per 100 fractures, respectively, P < .001).Conclusion:Our well-adjusted data suggest there was no significant gender disparity in incidence of surgical treatment over the study period. The data also support previous observations that males have worse outcomes in comparison to females in the setting of axis fractures and spinal trauma regardless of surgical intervention.

Ankylosing spondylitis: antiquity and differential diagnosis - a case study of a Bronze Age skeleton from Norabak, southeastern Armenia.

An excavation of a burial mound at Norabak site (Southeast Armenia) unearthed four burial chambers, the central one contained a single skeleton radiocarbon dated to about 1400-1200 BCE. The skeleton was observed to have a polyarticular erosive arthropathy, primarily affecting the spine, with diagnostic features of ankylosing spondylitis. The antiquity of ankylosing spondylitis is questioned in the literature, because there are few reliable and descriptive reports from prehistoric sites. Excellent preservation of the skeleton from Norabak made it possible to perform a detailed analysis of the pathologic changes and to support the diagnosis of ankylosing spondylitis in this 3000-years-old individual. Apart from the main pathology, the skeleton had a dens axis fracture of the C2 vertebra a few days before death, as well as a likely associated fracture of the C1 vertebra. This type of fracture has a high risk of displacement into the vertebral canal with severe neurological consequences. Thus, we were presented with an opportunity to reconstruct a possibly fatal event in the life of this individual. The described case provides further evidence that ankylosing spondylitis is a disease of fairly great antiquity.

Conservative management of sacroiliac luxation fracture in cats: medium- to long-term functional outcome.

The aim of this study was to determine the functional medium- to long-term outcome for cats with a conservatively managed sacroiliac luxation fracture (SILF). Inclusion criteria were conservative management of SILF in cats with no other concurrent fractures of the pelvic weightbearing axis and availability of radiographs for review. Radiographic measurements of percentage displacement of the sacroiliac joint and the sacral index were obtained and fracture configuration was assessed. A specific owner questionnaire was completed a minimum of 6 months after the injury. The questionnaire assessed the ability of the cat to perform normal activities, the time to recovery, any behavioural changes and any requirement for long-term analgesia. Seventeen cats met the inclusion criteria, and 13 owners completed the questionnaire. Twelve cats had an excellent outcome, with no difficulty performing normal activities. One cat had a good outcome, with slight or occasional difficulty performing normal activities. Our study provides evidence to support the current guidelines of conservative management of SILF. The inherent bias of case selection in our population implies that this treatment cannot be recommended for all cases of SILF.

Anterior Hollow Screw Fixation Combined with Posterior Lateral Mass Screws Fixation to Treat A Huge Tear Drop Fracture of The Axis

Teardrop fracture of axis is rarely seen, especially the huge type. The surgical approach is controversial and individualized in the literature. We reported a special case to share our experience of anterior hollow screw fixation combined with posterior unilateral lateral mass screws fixation to treat a huge teardrop fracture of the axis (HTDFA). A 42-year-old male was referred to our department; he presented neck pain after a vehicle accident. Neck movement was limited with no neurological compromise. Cervical x-rays showed a huge tear drop fracture of the anterior–inferior corner of the axis，the lower cervical spine degeneration and poor cervical curvature. Cervical CT confirmed the avulsed ratio of inferior endplate of axis up to 62%. Cervical MRI showed the anterior longitudinal ligament disruption associated with disk injury and instability of C2-3. In order to save the motion segment of C2-3 and decrease the possibility of lower cervical degeneration if C2-3 fusion occurs, a surgical plan involving anterior reduction, hollow screw fixation combined with posterior unilateral mass screws fixation was performed. The 3 months postoperative x-ray and CT scan showed the tear drop fragment had completely healed. The internal fixations were removed timely for 6 months after surgery. The patient had an excellent function of cervical spine without any clinical symptoms. The 12 months postoperative X-ray showed radiographic union of the bony fragment and a good motion range without any instability. We conclude that anterior hollow screw fixation combined with posterior unilateral lateral mass screws fixation can be the treatment of choice for HTDFA

Strain design method of buried pipeline crossing fault

Faults are ground ruptures and disoperations that occur in crustal rock strata. Long distance buried pipeline crossing a fault zone is prone to axial fracture, lateral dislocation or buckling failure, which can cause the leakage of the pipeline medium or secondary disasters. Therefore, we established a finite element model of buried pipelines crossing a strike-slip fault, taking active faults and pipelines as the research objects, and considering the material nonlinearity of pipeline and fault soil, the nonlinear geometric deformation of the pipeline and the contact nonlinearity between pipes. The mechanical response behavior of buried pipelines under fault displacement loads was analyzed, and the influence of pipeline size and material, fault site soil conditions and pipeline operation conditions on pipeline mechanical properties was studied. According to the influential law of parameters, dimensionless factors such as pipe material, the cohesive force of soil and internal pressure of the pipeline were adopted. Multiple linear and nonlinear regression theories were utilized to fit the simplified formula for strain calculation of buried pipeline crossing a strike-slip fault. Our model is available for reference in the design and safety assessment of the buried pipeline crossing the strike-slip fault.

Mechanically Relevant Anatomy of the Axis Vertebra and Its Relation to Hangman's Fracture: An Illustrated Essay.

To describe the biomechanically relevant anatomy of the Axis vertebra and the load transfer patterns within the bone, and on that basis, to postulate its mechanism of injury, a literature review was conducted of the anatomy and biomechanics of Axis fractures. Two hypotheses have been presented: the internal gear hypothesis and the leaf spring hypothesis. Both are based on the trabecular anatomy of the vertebra and its load transmission patterns. The relationship of the Axis with Hangman’s injury is also discussed. According to the leaf spring hypothesis, the C2 pedicle corresponds to the shackle in the assembly and constitutes the weak link. The trabecular architecture of the Axis is such that the primary compression of the trabeculae is directed from the superior facet to the C2–3 endplate, with few trabeculae directed to the inferior facet. Along with the trabecular void in this area, this renders the isthmus vulnerable to trauma. The isthmus of the Axis is biomechanically susceptible to injury due to its unique anatomy in relation to the whole cervical spine and the internal load transmission patterns of the bone. The author suggests that in the flexion type of Hangman’s injury, the C1–2 posterior ligaments are disrupted and need to be addressed.

Sclerostin antibody reduces long bone fractures in the oim/oim model of osteogenesis imperfecta.

Osteogenesis imperfecta type III (OI) is a serious genetic condition with poor bone quality and a high fracture rate in children. In a previous study, it was shown that a monoclonal antibody neutralizing sclerostin (Scl-Ab) increases strength and vertebral bone mass while reducing the number of axial fractures in oim/oim, a mouse model of OI type III. Here, we analyze the impact of Scl-Ab on long bones in OI mice. After 9 weeks of treatment, Scl-Ab significantly reduced long bone fractures (3.6 ± 0.3 versus 2.1 ± 0.8 per mouse, p < 0.001). In addition, the cortical thickness of the tibial midshaft was increased (+42%, p < 0.001), as well as BMD (+28%, p < 0.001), ultimate load (+86%, p < 0.05), plastic energy (+184%; p < 0.05) and stiffness (+172%; p < 0.01) in OI Scl-Ab mice compared to OI vehicle controls. Similar effects of Scl-Ab were observed in Wild type (Wt) mice. The plastic energy, which reflects the fragility of the tissue, was lower in the OI than in the Wt and significantly improved with the Scl-Ab treatment. At the tissue level by nanoindentation, Scl-Ab slightly increased the elastic modulus in bones of both OI and Wt, while moderately increasing tissue hardness (+13% compared to the vehicle; p < 0.05) in Wt bones, but not in OI bones. Although it did not change the properties of the OI bone matrix material, Scl-Ab reduced the fracture rate of the long bones by improving its bone mass, density, geometry, and biomechanical strength. These results suggest that Scl-Ab can reduce long-bone fractures in patients with OI.

Numerical study of the oil whirl phenomenon in a hydrodynamic journal bearing

The journal bearings are one of the main components of the rotating machines and always bear considerable weight and dynamic stresses. Bearing defect may cause bending and eventually axis fracture and, in some cases, lead to an increase in the temperature of other components. One of the most important challenges of this type of bearings is the instability of the oil film layer, which appears as oil whirl and oil whip. The main objective of this research is the numerical analysis of the journal bearing of a centrifugal pump and the investigation of variations in the eccentricity and the rotation of the bearing to detect the instability resulting from the oil whirl and whip. For this purpose, assuming the steady and laminar flow, the Reynolds theory modified by the Elrod–Adams cavitation model is utilized. In addition, the finite element method is used for the numerical solution. The results indicate that the pressure on the bearing shell increases considering the effect of the oil whip phenomenon. Moreover, by increasing the eccentricity ratio, the pressure applied to the bearing increases and the mass fraction of the oil film decreases. After that, in order to improve the performance, by creating a horizontal groove in a simple bearing (without groove), the oil whirl and whip are numerically analyzed and the effect of the eccentricity as well as the rotational speed of the modified bearing is investigated. Numerical results indicate that the presence of the groove in the bearings causes the pressure on the grooved bearings to decrease dramatically. As a result, the probability of occurrence of the oil instability phenomenon in this case will be less than simple state (no groove). In addition, in this case, it could be observed that as the rotational speed of the grooved bearing increased, the pressure applied around the groove bearing from the oil film increases. However, the pressure applied to the grooved bearings is much less than the pressure applied to the simple bearings.

Proximal radius fracture morphology following axial force impact: a biomechanical evaluation of fracture patterns

BackgroundThe most common location for articular fractures of the radial head is often reported to be the anterior lateral aspect of the radial head with the arm in neutral position. However, these findings mainly base on clinical observations rather than precise biomechanical measurements. The purpose of this study was to evaluate the formation of proximal radius fractures, the association between axial forces and fracture morphology, energy to failure and bone stiffness in a biomechanical in-vitro setup.Methods18 fresh-frozen cadaveric radii performed axial load compression with 10 mm/min loading until bone failure. Energy to failure and bone stiffness were recorded. Proximal radial head fracture morphology and affection of the anterolateral quadrant were optically analyzed.ResultsAll radii survived a compression load of 500 N. The mean compressive forces that lead to failure were 2,56 kN (range 1,30 – 7,32). The mean stiffness was 3,5 kN/mm (range 2,0 – 4,9). 11 radial neck fractures and 7 radial neck and radial head multifragment fractures were documented. The anterolateral quadrant was involved in 78% of tested radii.ConclusionThe anterolateral quadrant of the radial head (in neutral position of the forearm) is confirmed to be the most common location for articular radial head fractures in a biomechanical setting. In case of a fall on the outstretched arm radial neck fractures should be securely ruled out due to prior occurrence to radial neck and head fractures.

Min-invasive surgical treatment for multiple axis fractures: A case report

Min-invasive surgical treatment for multiple axis fractures: A case report

Upscaling of CO2 injection in a fractured oil reservoir

The purpose of this study is to present the numerical evaluation of the upscaling of secondary and tertiary CO2 flooding at reservoir pressure and temperature. In all simulation cases, CO2 is injected from the top of the fracture in a fracture-matrix block system and displaces oil toward the bottom of the block. Our numerical models provide comprehensive sensitivity analyses that are proved to be important for the upscaling of CO2 injection from lab to reservoir scale. In addition, we address the scale dependency of the diffusion mechanism in a large matrix-fracture domain.In our earlier studies, we have conducted a significant number of reservoir-condition CO2 flood experiments by employing fractured core systems and North Sea reservoir oil. Our experimental and numerical studies are proved to be useful to investigate the complex physical phenomena affecting the efficiency of CO2 injection in oil recovery from a fracture reservoir. The height of the core plugs used in our experiments varies from 7 to 28 cm while the fracture spacing varies between ∼4 cm and 12 cm. In all cases, we find the important role of diffusion mechanism in increasing oil recovery in a fracture-matrix system at the lab scale. However, the field matrix block size is often 1-to-2 orders of magnitude larger than that in the lab scale. Recovery mechanisms are significantly affected by the matrix dimension. For instance, the impact of diffusion mechanism on oil recovery may alter with the size of the matrix block and the fracture spacing. This highlights the importance of upscaling from lab to the field scale that is addressed in this study.We employ a compositional reservoir simulation with a developed equation of state (EOS) to model CO2 injection in a fracture-matrix system at reservoir conditions. In all the numerical simulations, the single-porosity (SP) model consists of a single axial fracture with a typical fracture aperture of 1 mm. The SP model also contains a single matrix block that feeds the producer through fracture next to it. The dimension of the fracture-matrix block varies in the SP models to account for the scale dependency of the results. In our modeling framework, we assume a network of open fractures that are homogenously distributed in the reservoir and links the oil in the matrix to the production wells. We initialize the matrix with the North-Sea-Chalk-Field (NSCF) live oil and the fracture with the injected gas (CO2). The whole displacement process is operated at the constant reservoir conditions of 3750 psia and 110 °C, representing typical NSCF reservoir conditions. Prior to conducting simulations, we successfully tune EOS parameters against the extensive PVT data, sampled from a specific fractured NSCF reservoir. The tuned EOS model assures the proper estimation of the complex phase and volumetric properties for CO2 and oil mixtures at reservoir conditions. In addition, the multi-component diffusion coefficients that are tuned using experimental data are employed as input parameters for the compositional simulations.We study the effect of several key parameters on oil recovery; e.g. matrix block size, fracture spacing, CO2 injection rate, density difference, vaporization and the diffusion. The results show that the mass transport is mainly dominated by diffusion in the lab scale which is not the case for the large matrix block size. Finally, we test the accuracy of the dual-porosity (DP) model against the SP model at various displacement conditions. Results show that when diffusion and vaporization are significant the DP model fails to predict the results of the SP reservoir model.Our findings are an important step towards modeling the tertiary-CO2 flooding in an actual fracture-chalk system. We also provide some important inputs that are necessary for upscaling tertiary-CF from a lab-scale into a field-scale reservoir model.

Experimental and numerical investigations on the effect of fracture geometry and fracture aperture distribution on flow and solute transport in natural fractures

The impact of fracture geometry and aperture distribution on fluid movement and on non-reactive solute transport was investigated experimentally and numerically in single fractures. For this purpose a hydrothermally altered and an unaltered granite drill core with axial fractures were investigated. Using three injection and three extraction locations at top and bottom of the fractured cores, different dipole flow fields were examined. The conservative tracer (Amino-G) breakthrough curves were measured using fluorescence spectroscopy. Based on 3-D digital data obtained by micro-computed tomography 2.5-D numerical models were generated for both fractures by mapping the measured aperture distributions to the 2-D fracture geometries (x-y plane). Fluid flow and tracer transport were simulated using COMSOL Multiphysics®.By means of numerical simulations and tomographic imaging experimentally observed breakthrough curves can be understood and qualitatively reproduced. The experiments and simulations suggest that fluid flow in the altered fracture is governed by the 2-D fracture geometry in the x-y plane, while fluid flow in the unaltered fracture seems to be controlled by the aperture distribution. Moreover, we demonstrate that in our case simplified parallel-plate models fail to describe the experimental findings and that pronounced tailings can be attributed to complex internal heterogeneities. The results presented, implicate the necessity to incorporate complex domain geometries governing fluid flow and mass transport into transport modeling.

Displaced humeral surgical neck fractures: classification and results of third-generation percutaneous intramedullary nailing

The high rates of complications and reoperations observed with the early designs of first-generation (unlocked) and second-generation (bent design) humeral intramedullary nail (IMNs) have discouraged their use by most surgeons. The purpose of this study was to report the results of a third-generation (straight, locking, low-profile, tuberosity-based fixation) IMN, inserted through a percutaneous approach, for the treatment of displaced 2-part surgical neck fractures. We performed a retrospective review of 41 patients who underwent placement of a third-generation IMN to treat a displaced 2-part surgical neck fracture (AO/OTA type 11A3). The mean age at surgery was 57 years (range, 17-84 years). After percutaneous insertion through the humeral head, the IMN was used as a reduction tool. Static locking fixation was achieved after axial fracture compression ("back-slap" hammering technique). Patients were reviewed and underwent radiography with a minimum of 1 year of follow-up; the mean follow-up period was 26 months (range, 12-53 months). Preoperatively, 3 types of surgical neck fractures were observed: with valgus head deformity (Type A = 8 cases), shaft translation without head deformity (Type B = 19 cases), or with varus head deformity (Type C = 14 cases). At final follow-up, all fractures went on to union, and the mean humeral neck-shaft angle was 132° ± 5°. We observed 2 malunions and 1 case of partial humeral head avascular necrosis. No cases underwent screw migration or intra-articular penetration. At last review, mean active forward elevation was 146° (range, 90°-180°) and mean external rotation was 50° (range, 20°-80°). The mean Constant-Murley score and Subjective Shoulder Value were 71 (range, 43-95) and 80% (range, 50%-100%), respectively. Antegrade insertion of a third-generation IMN through a percutaneous approach provides a high rate of fracture healing, excellent clinical outcome scores, and a low rate of complications. No morbidity related to the passage of the nail through the supraspinatus muscle and the cartilage was observed. The proposed A, B, and C classification allows choosing the optimal entry point for intramedullary nailing.

Anatomy of the dens and its implications for fracture treatment: an anatomical and radiological study.

The most common injuries to the upper cervical spine are fractures of the dens axis. Therefore, the purpose of our study was to answer three questions, namely (1) whether the size of the dens is adequate at all levels to accommodate two screws, (2) what the angle of the posterior tilt of the dens is in a healthy individual and (3) compare the measured variables between the sexes. The cohort comprised 50 males and 50 females CT examination of the craniocervical junction. We measured the five diameters of the dens and posterior dens angulation angle (PDAA) and screw insertion angle (SIA). The same dimensions were measured in a control group, consisting of 40 non-pathological second cervical vertebrae specimens. On CT scans, the mean PDAA was 162.7 degrees in males and 160.26 degrees in females; the mean SIA was 62.0 degrees in males and 60.2 degrees in females. On specimens, the mean PDAA was 169.47 degrees in males and 166.95 degrees in females; the mean SIA was 65.42 degrees in males and 64.47 degrees in females. All obtained values were higher in males; regardless of their measuring on either CT scans or specimens, differences between males and females were statistically significant (p<0.05) in a, c, d and e values. The values of our measurements correlate with the dimensions identified previously in other studies. Based on our clinical experience and measurements, we presume that two 3.5-mm screws can be inserted into the dens of all adult patients, except for those with pronounced anatomical anomalies. Posterior dens angulation angle is slightly larger than we expected. The dens is significantly larger in males almost in all measurement. These slides can be retrieved under Electronic Supplementary Material.

Wednesday, September 26, 2018 10:35 AM – 12:00 PM Cervical Spine Trauma: 25. CT imaging of the spine in pediatric trauma patients: prevalence of fractures and mechanisms of injury

BACKGROUND CONTEXT Computed tomography (CT) scans have become ubiquitous in the assessment of the trauma patient because of its diagnostic acuity in assessing head and axial skeletal pathology. Consensus recommendations exist for limiting the ionizing radiation dose as it pertains to CT head imaging in the pediatric population. However, little published data exist assessing the diagnostic yield of current practices in the pediatric population. As pressure mounts to diagnose emergent pathologies in the emergency department, children are at risk for a relatively high cumulative burden as sequela of medical imaging such as an increased lifetime attributable risk of cancer. PURPOSE To evaluate the diagnostic yield of CT scans of the spine in pediatric trauma patients STUDY DESIGN/SETTING Retrospective, Level I trauma center. PATIENT SAMPLE Patients 18 and under, undergoing CT scans in the ER 1/2013-12/2015. OUTCOME MEASURES Presence of fracture. METHODS Medical records of pediatric trauma patients who arrived at the emergency department and underwent spinal CT were reviewed. We reviewed the CT scans as well as the radiology reports for fractures. Medical records were reviewed for mechanism of injury and management for these patients as well as demographics. Factors associated with pediatric patients with fractures were then compared to those without fractures. RESULTS A total of 831 patients underwent CT scans in to the ER. Average age was 13.86 years (0.24-18.99) with 43% (355) females and 57% (476) males. The racial demographics were as follows: 70% Caucasian, 20% African American, 1.4% Asian, with the remainder listed as other or not available. The most common mechanism of injury (MOI) was motor vehicle accident (MVA) (26%) followed by sports injury (18%), then fall from height (15%) bicycle/motor bike (14%). Other mechanisms of injury were pedestrian struck (9.5%), assault (5%), syncope (3%), direct head blow (3%), neck pain (2%), fall from standing (1%), seizure (1%), strangulation/hanging ( CONCLUSIONS It is important to consider the long-term implications when deciding to expose a pediatric patient to radiation. In this study we found the overall axial fracture rate to be low (6.1%). The fractures were distributed throughout the mobile spine and sacrum. Of the fractures that were detected 54% were transverse process and compression fractures. Pediatric trauma CT scanning best practices focusing on MOI most likely resulting in spine fractures (MVA, bike/motor bike, sport injuries) should be investigated. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Surgically Relevant Patterns in Triplane Fractures: A Mapping Study.

Triplane ankle fractures are complex transitional fractures that often necessitate surgical treatment. Axial fracture lines determine optimal screw trajectories for fixation. The purpose of our study was to identify fracture patterns in triplane fractures by illustrating fracture lines in the axial plane of the distal tibial metaphysis and epiphysis. We retrospectively reviewed records of children presenting with ankle fractures at 1 center from January 2007 through June 2017. Thirty-three cases of triplane fractures with available computed tomographic (CT) scans were identified. Fractures in the axial plane of the metaphysis were identified 10 mm proximal to the physis, and fractures in the epiphysis were identified midway between the physis and distal tibial articular surface. Fracture lines were drawn and were superimposed on unfractured bone templates to generate fracture maps, and heat maps were then created to show areas of high and low fracture densities. In the metaphysis, the most common fracture pattern was medial-lateral lines in the posterior metaphysis. This metaphyseal pattern was consistent across 2, 3, 4, and 5-part fractures. There were clear zones of rare fracture involvement in the anterior and anterolateral metaphysis. In the epiphysis, anterior-to-posterior fracture lines were common in the anterior epiphysis. All cases had an epiphyseal fracture exit through the anterior epiphysis. Fracture extension into the posteromedial epiphysis was a feature of all fracture classes. Fracture mapping of triplane fractures suggests consistent axial fracture patterns in the metaphysis and epiphysis with additional class-dependent fractures in the epiphysis. This study provides visual guidelines to assist surgeons in understanding the axial fracture patterns of individual triplane fractures for surgical planning.

Predictors of 30-Day Outcomes in Octogenarians with Traumatic C2 Fractures Undergoing Surgery

Predictors of surgical outcomes following traumatic axis (C2) fractures in octogenarians remain undercharacterized. Patients age ≥80 years undergoing cervical spine surgery following traumatic C2 fractures were extracted from the National Sample Program of the National Trauma Data Bank (2003-2012). Outcomes include overall inpatient complications, individual complications with an incidence >1%, hospital length of stay (HLOS), discharge disposition, and mortality. Demographics, comorbidities, and injury predictors were analyzed using multivariable regression. Odds ratios (OR), mean differences, and 95% confidence intervals (CIs) were calculated. Statistical significance was assessed at P < 0.05. The cohort of 442 patients was 48.6% male and had a mean age of 84.3 ± 2.7 years. The distribution of admissions was 42.3% to the hospital floor, 40.3% to the intensive care unit (ICU), 7.7% to telemetry, 2.0% to the operating room, and 7.7% to other/unknown. Mortality was 9.7%, mean HLOS was 13.1 ± 9.2 days, the rate of complications was 38.5%, and 81.5% of survivors were discharged to a nonhome facility. Injury severity was predictive of mortality and overall complications. History of bleeding disorder/coagulopathy predicted mortality (OR, 4.02; 95% CI, 1.07-15.05), overall complications (OR, 3.01; 95% CI, 1.09-8.32), cardiac arrest (OR, 8.19; 95% CI, 1.06-63.54), and renal complications (OR, 10.36; 95% CI, 2.13-50.38). History of congestive heart failure predicted mortality (OR, 3.10; 95% CI, 1.10-8.69). ICU admission (vs. floor) predicted overall complications (OR, 2.01; 95% CI, 1.23-3.27) and pneumonia (OR, 4.65; 95% CI, 1.91-11.30). Telemetry admission (vs. floor) predicted unplanned intubation (OR, 7.76; 95% CI, 1.24-48.49). In this cohort of octogenarians undergoing surgery for traumatic C2 fracture, injury severity and a history of bleeding disorder/coagulopathy were identified as risk factors for inpatient complications and mortality. Heightened surveillance should be considered for ICU and/or telemetry admissions for the development of complications. These findings warrant consideration by the clinician, patient, and family to inform clinical decisions and goals of care.