Retrograde Nailing for Treating Femoral Shaft Fractures: A Review

Rigid intramedullary nailing is an effective procedure for treating fractures of the femoral shaft. Although antegrade nailing is the traditionally used technique, retrograde nailing offers various advantages. A companion article published in the seventh volume of The University of New Mexico Orthopaedics Research Journal addressed antegrade femoral nailing. This review will describe retrograde nailing of femoral shaft fractures, including a brief history, indications, detailed technique, outcomes, advice (or “pearls”), and common failures (or “pitfalls”). Retrograde nailing for treating femoral shaft fractures can provide successful results similar to those of antegrade nailing in general and advantages in particular situations such as more distal shaft, bilateral, and certain associated fractures

Comparison of the Accuracy of X-ray, 2D-CT, 3D-CT, and Physical Modeling in Classification of Fractures about the Elbow Needing Operative Treatment

The goal of this study is to compare the accuracy of using X-ray, 2D-CT, 3D-CT, and physical modeling in classification of fractures about the elbow as a means of evaluating their relative utility in preoperative workup and treatment planning of fractures. Ten patients with fractures about the elbow that required operative fixation underwent preoperative X-ray, 2D-CT, 3D-CT, and physical modeling of their injury. Ten orthopaedic physicians classified each injury using each of those four modalities. The answers given by the 10 physicians were compared to an established correct classification for each case, and that data was used to compare the relative accuracy of each modality. The average accuracy for the given modalities was 62% for X-ray, 76% for 2D-CT, 80% for 3D-CT, and 88% for physical modeling. ANOVA analysis across all modalities revealed findings are statistically significant; however, when compared side by side, only moving from X-ray to 2D-CT yielded significant results. There was greater percentage correct classification achieved using the more advanced modalities, which therefore may theoretically result in more accurate preoperative planning. However, one must view this finding within the context and limits of this study, which is restricted by the relatively small sample size. Future study into methods of fracture characterization should be done to further evaluate findings such as these, with the goal of promoting better patient outcomes

The income gradient in mortality during the Covid-19 crisis: evidence from Belgium

We use population-wide data from linked administrative registers to study the distributional pattern of mortality before and during the first wave of the Covid-19 pandemic in Belgium. Over the March-May 2020 study period, excess mortality is only found among those aged 65 and over. For this group, we find a significant negative income gradient in excess mortality, with excess deaths in the bottom income decile more than twice as high as in the top income decile for both men and women. However, given the high inequality in mortality in normal times, the income gradient in all-cause mortality is only marginally steeper during the peak of the health crisis when expressed in relative terms. Leveraging our individual-level data, we gauge the robustness of our results for other socioeconomic factors and decompose the role of individual vs. local effects. We provide direct evidence that geographic location effects on individual mortality are particularly strong during the first wave of the Covid-19 pandemic, channeling through the local number of Covid infections. This makes inference about the income gradient in excess mortality based on geographic variation misguided

When Employees Retaliate Against Self-Serving Leaders: The Influence of the Ethical Climate

© 2019, Springer Nature B.V. Leaders have been shown to sometimes act self-servingly. Yet, leaders do not act in isolation and the perceptions of the ethical climate in which leaders operate is expected to contribute to employees taking counteractive measures against their leader (that is, employees’ desire for retaliation, and supervisor-directed deviance). We contend that in an ethical climate employees feel better equipped to stand up and take retaliation measures. Moreover, we argue that this is explained by employees’ feelings of trust. In two studies using different methods (an experimental study and a multi-source study), we predict and find evidence that the relationship between self-serving leader behavior and employees’ desire for retaliation and supervisor-directed deviance is stronger when the ethical climate is high rather than low. Moreover, we show that trust in the leader mediates these relationships

Stability of Talar Neck Fracture Fixation: A Biomechanical Comparison of 4.0 Cannulated Headed Screws and Conical Headless Screws

Objective: The purpose of this study was to compare the mechanical stability of cannulated conical variable pitch headless (CH) screws to partially threaded 4.0 cannulated (4.0 C) screws for fixation of talar neck fractures. Methods: A controlled talar neck fracture was produced in 24 sawbone tali. The fractures were stabilized with CH screws in 12 tali and with 4.0 C screws in 12 tali. A Mechanical Testing System machine was used to apply a dorsally-directed shear force to the talar head with the talus body fixed to simulate walking and the clinical mode of failure of talar neck fracture fixation. Stiffness of the fixation devices was calculated for each specimen and the groups statistically compared. The results were confirmed in 10 cadaveric bone specimen. Results: The fixation of talar neck fractures by the CH screws was significantly stiffer than the 4-0 C screw (mean 635 N and 335 N, respectively, P \u3c 0.05). Conclusions: The results of this study support the clinical use of the cannulated conical headless variable pitch screw for talar neck fracture fixation. The improved fixation of this device is likely to decrease the incidence of fixation failure and poor clinical results due to malunion, nonunion,and stiffness. The CH can be placed using the same surgical exposure and ease of a 4.0 C screw,while eliminating the problem of screw head prominence

Effects of Impact and Target Parameters on the Results of a Kinetic Impactor: Predictions for the Double Asteroid Redirection Test (DART) Mission

The Double Asteroid Redirection Test (DART) spacecraft will impact into the asteroid Dimorphos on 2022 September 26 as a test of the kinetic impactor technique for planetary defense. The efficiency of the deflection following a kinetic impactor can be represented using the momentum enhancement factor, β, which is dependent on factors such as impact geometry and the specific target material properties. Currently, very little is known about Dimorphos and its material properties, which introduces uncertainty in the results of the deflection efficiency observables, including crater formation, ejecta distribution, and β. The DART Impact Modeling Working Group (IWG) is responsible for using impact simulations to better understand the results of the DART impact. Pre-impact simulation studies also provide considerable insight into how different properties and impact scenarios affect momentum enhancement following a kinetic impact. This insight provides a basis for predicting the effects of the DART impact and the first understanding of how to interpret results following the encounter. Following the DART impact, the knowledge gained from these studies will inform the initial simulations that will recreate the impact conditions, including providing estimates for potential material properties of Dimorphos and β resulting from DART’s impact. This paper summarizes, at a high level, what has been learned from the IWG simulations and experiments in preparation for the DART impact. While unknown, estimates for reasonable potential material properties of Dimorphos provide predictions for β of 1–5, depending on end-member cases in the strength regime