The rate of arterial injury in trauma patients with pelvic ring fractures has been cited as high as 15%. Addressing this source of hemorrhage is essential in the management of these patients as mortality rates are reported as 50%. Percutaneous techniques to control arterial bleeding, such as embolization and REBOA, are being employed with increasing frequency due to their assumed lower morbidity and invasiveness than open exploration or cross clamping of the aorta.

There are promising results with regards to the mortality benefits of angioembolization. However, there are concerns with regards to morbidity associated with embolization of the internal iliac vessels and its branches including surgical wound infection, gluteal muscle necrosis, nerve injury, bowel infarction, and thigh / buttock claudication.

The primary aim of this study is to determine whether pelvic arterial embolization is associated with surgical site infection (SSI) in trauma patients undergoing pelvic ring fixation.

This observational cohort study was conducted using US trauma registry data from the American College of Surgeons (ACS) National Trauma Database for the year of 2018. Patients over the age of 18 who were transported through emergency health services to an ACS Level 1 or 2 trauma hospital and sustained a pelvic ring fracture treated with surgical fixation were included. Patients who were transferred between facilities, presented to the emergency department with no signs of life, presented with isolated penetrating trauma, and pregnant patients were excluded from the study.

The primary study outcome was surgical site infection. Multivariable logistic regression was performed to estimate treatment effects of angioembolization of pelvic vessels on surgical site infection, adjusting for known risk factors for infection.

Study analysis included 6562 trauma patients, of which 508 (7.7%) of patients underwent pelvic angioembolization. Overall, 148 (2.2%) of patients had a surgical site infection, with a higher risk (7.1%) in patients undergoing angioembolization (unadjusted odds ratio (OR) 4.0; 95% CI 2.7, 6.0; p < 0 .0001). Controlling for potential confounding, including patient demographics, vitals on hospital arrival, open fracture, ISS, and select patient comorbidities, pelvic angioembolization was still significantly associated with increased odds for surgical site infection (adjusted OR 2.0; 95% CI 1.3, 3.2; p=0.003).

This study demonstrates that trauma patients who undergo pelvic angioembolization and operative fixation of pelvic ring injuries have a higher surgical site infection risk. As the use of percutaneous hemorrhage control techniques increase, it is important to remain judicious in patient selection.

Fluoroscopic C-arms are operated by medical radiography technologists (RTs) in Canadian operating rooms (ORs). While they do receive formal, accredited training, most of it is theoretical, rather than hands-on. During their first encounters in the OR, new RTs can experience difficulty achieving the radiographic views required by surgeons, often needing several scout X-rays during C-arm positioning. Furthermore, ambiguous language by surgeons often inadequately conveys their request. The result is often frustration, unnecessary radiation exposure, and added OR time. The purpose of this study was to evaluate the value of artificial X-rays in improving C-arm positioning performance, with inexperienced C-arm users.

We developed an Artificial X-ray Imaging System (AXIS) that generates Digitally Reconstructed Radiographs (DRRs), or artificial X-ray images, based on the relative position of a C-arm and manikin. 30 participants were enrolled in the user study and performed four activities: an introduction session, an AXIS-guided evaluation, a non-AXIS-guided evaluation, and a questionnaire. The main goal of the study was to assess C-arm positioning performance with and without AXIS guidance. For each evaluation, the participants had to replicate a set of target X-ray images by taking real radiographs of the manikin with the C-arm. During the AXIS evaluation, artificial X-rays were generated at 2 Hz for guidance, while in the non-AXIS evaluation, the participants had to acquire real scout X-rays to guide them toward the correct view.

For each imaging task the number of real X-rays and time required per task was recorded, and the C-arm's pose was tracked and compared to the target pose to determine positioning accuracy; these were averaged for each participant and condition. Hypothesis testing on the means and paired t-tests were carried out using a significance level of α=0.05.

On average, users took significantly fewer real scout X-ray images (53% fewer (2.8 vs 6.0), p<0.001) when guided by AXIS. Lateral distance accuracy was improved by 10% for final C- arm positions and by 26% for the most accurate intermediate C-arm positions when guided by AXIS (p<0.05). There was no significant difference in average task time or angular accuracies between the AXIS and non-AXIS evaluations. Overall, we are encouraged by these findings and plan to further develop this system with the goal of deploying it both for training and intraoperative uses.

Pedicle screw fixation is a technically demanding procedure with potential difficulties and reoperation rates are currently on the order of 11%. The most common intraoperative practice for position assessment of pedicle screws is biplanar fluoroscopic imaging that is limited to two- dimensions and is associated to low accuracies. We have previously introduced a full-dimensional position assessment framework based on registering intraoperative X-rays to preoperative volumetric images with sufficient accuracies. However, the framework requires a semi-manual process of pedicle screw segmentation and the intraoperative X-rays have to be taken from defined positions in space in order to avoid pedicle screws' head occlusion. This motivated us to develop advancements to the system to achieve higher levels of automation in the hope of higher clinical feasibility.

In this study, we developed an automatic segmentation and X-ray adequacy assessment protocol. An artificial neural network was trained on a dataset that included a number of digitally reconstructed radiographs representing pedicle screw projections from different points of view. This model was able to segment the projection of any pedicle screw given an X-ray as its input with accuracy of 93% of the pixels. Once the pedicle screw was segmented, a number of descriptive geometric features were extracted from the isolated blob. These segmented images were manually labels as ‘adequate’ or ‘not adequate’ depending on the visibility of the screw axis. The extracted features along with their corresponding labels were used to train a decision tree model that could classify each X-ray based on its adequacy with accuracies on the order of 95%.

In conclusion, we presented here a robust, fast and automated pedicle screw segmentation process, combined with an accurate and automatic algorithm for classifying views of pedicle screws as adequate or not. These tools represent a useful step towards full automation of our pedicle screw positioning assessment system.

Hospital type is an indicator for structures and processes of care. The effect of hospital type on hip fracture in-hospital mortality is unknown. We determine whether hip fracture in-hospital mortality differs according to hospital type.

We retrieved records of hip fracture for 167,816 patients aged 65 years and older, who were admitted to a Canadian acute hospital between 2004 and 2012. For each hospital type we measured and compared the cumulative incidence of in-hospital death by in-patient day, accounting for discharge as a competing event.

The cumulative incidence of in-hospital death at in-patient day 30 was lowest for teaching hospital admissions (7.3%) and highest for small community hospital admissions (11.5%). The adjusted odds of in-hospital death were 12% (95% CI 1.06–1.19), 25% (95% CI 1.17–1.34), and 64% (95% CI 1.50–1.79) higher for large, medium, and small community hospital versus teaching hospital admissions. The adjusted odds of nonoperative death were 1.6 times (95% CI 1.42–1.86), and 3.4 times (95% CI 2.96–3.94) higher for medium and small community hospital versus teaching hospital admissions. The adjusted odds of postoperative death were 14% (95% CI 1.07–1.22) and 20% (95% CI 1.10–1.31) higher at large and medium community hospitals versus teaching hospitals. The adjusted odds of postoperative death were largest at small community hospitals but the confidence interval crossed 1 (OR = 1.25, 95% CI 0.92–1.70).

A higher proportion of hip fracture patients die at non-teaching compared to teaching hospitals accounting for length of stay. Higher mortality at small community hospitals may reflect disparities in access to resources and delay to treatment.

Purpose

The prevention of a subsequent, contralateral hip fracture is targeted as an avoidable event in the elderly. Fall prevention and bone strengthening measures have met with limited success and the urgency of their effect is undetermined. Our objective was to evaluate the time to second hip fracture (the time between a first and a subsequent, contralateral fracture) in elderly patients, using a population-based administrative health data set.

Purpose

Radiographs are the most common imaging modality used to guide orthopaedic interventions. Ultrasound (US) imaging offers potential advantages for intraoperative imaging by its portability and ability to produce real-time 2D or 3D images without radiation to either the patient or surgical team. Our objective in this study was to determine in a live emergency room setting, if a newly-developed image processing method for 3D US would allow us to accurately extract (reproduce) the surfaces of fractured bones.

Purpose

To determine whether there have been changes in the age, sex and subtype specific first hip fracture rates in Canadian province of British Columbia (BC) between 1990 and 2004.

Background

The optimal treatment for pilon fractures remains controversial. We have used early single-stage open reduction and internal fixation to treat these injuries and the purpose of this study was to determine the safety and efficacy of this strategy.