The Dislocated Hip on CT Scan: An Argument for the Initial Pelvic Radiograph in Trauma Patients.

This study evaluated the frequency in which a hip dislocation is first diagnosed by computed tomography (CT) scan. A retrospective review was conducted of orthopaedic trauma patients presenting with hip dislocation to a Level 1 trauma center over three years. We recorded whether the patient first received pelvic radiograph (PXR) or CT scan of the pelvis, if the patient underwent closed reduction of the hip prior to CT scan, and if repeat pelvis CT scan was done. Of 83 hip dislocations, 64 patients were sent to CT scanner dislocated; 19 patients first had PXR and underwent closed reduction of the hip prior to CT scan. By obtaining a PXR, reducing the hip prior to CT, the incidence of repeat CT scan decreased from 37% to 11% (p = 0.046). By diagnosing hip dislocation, reducing prior to CT scan, repeat scans can be reduced, thus decreasing cost and radiation exposure to patients. (Journal of Surgical Orthopaedic Advances 29(1):4345, 2020).

Does Traction Decrease the Need for Open Reduction in Femoral Shaft Fractures Treated Within 24 Hours?

This study evaluates whether preoperative skeletal traction reduces the need for open reduction in femoral shaft fractures treated with intramedullary nailing (IMN) within 24 hours. A retrospective review was conducted of femoral shaft fractures undergoing IMN within 1 day of admission. Primary outcome was an open reduction at the time of IMN. Secondary outcomes were blood loss and transfusion requirements. One hundred eighty-four patients were analyzed, 106 in the knee immobilizer group and 78 in the skeletal traction group. Skeletal traction did not reduce the need for an open reduction. The knee immobilizer group required open reduction in 13% (14/106) compared with 14% (11/78) in the skeletal traction group, which was not significant (p $=$ .89). Blood loss and transfusion rates were similar between groups. Skeletal traction does not appear to reduce the need for open reduction at the time of IMN for femoral shaft fractures treated within 1 day of admission. (Journal of Surgical Orthopaedic Advances 27(4):303-306, 2018).

Ligament Mediated Fragmentation of Viscoelastic Liquids.

The breakup and atomization of complex fluids can be markedly different than the analogous processes in a simple Newtonian fluid. Atomization of paint, combustion of fuels containing antimisting agents, as well as physiological processes such as sneezing are common examples in which the atomized liquid contains synthetic or biological macromolecules that result in viscoelastic fluid characteristics. Here, we investigate the ligament-mediated fragmentation dynamics of viscoelastic fluids in three different canonical flows. The size distributions measured in each viscoelastic fragmentation process show a systematic broadening from the Newtonian solvent. In each case, the droplet sizes are well described by Gamma distributions which correspond to a fragmentation-coalescence scenario. We use a prototypical axial step strain experiment together with high-speed video imaging to show that this broadening results from the pronounced change in the corrugated shape of viscoelastic ligaments as they separate from the liquid core. These corrugations saturate in amplitude and the measured distributions for viscoelastic liquids in each process are given by a universal probability density function, corresponding to a Gamma distribution with n_{min}=4. The breadth of this size distribution for viscoelastic filaments is shown to be constrained by a geometrical limit which can not be exceeded in ligament-mediated fragmentation phenomena.

Mouse strain-dependent caspase activation during acetaminophen hepatotoxicity does not result in apoptosis or modulation of inflammation.

UNLABELLED: The mechanisms of acetaminophen (APAP)-mediated hepatic oncotic necrosis have been extensively characterized. However, it was recently demonstrated that fed CD-1 mice have a transient caspase activation which initiates apoptosis. To evaluate these findings in more detail, outbred (Swiss Webster, SW) and inbred (C57BL/6) mice were treated with APAP with or without pan-caspase inhibitor and compared to the apoptosis model of galactosamine (GalN)/endotoxin (ET). Fasted or fed APAP-treated C57BL/6 mice showed no evidence of caspase-3 processing or activity. Interestingly, a minor, temporary increase in caspase-3 processing and activity (150% above baseline) was observed after APAP treatment only in fed SW mice. The degree of caspase-3 activation in SW mice after APAP was minor compared to that observed in GalN/ET-treated mice (1600% above baseline). The pancaspase inhibitor attenuated caspase activation and resulted in increased APAP-induced injury (plasma ALT, necrosis scoring). The caspase inhibitor did not affect apoptosis because regardless of treatment only <0.5% of hepatocytes showed consistent apoptotic morphology after APAP. In contrast, >20% apoptotic cells were observed in GalN/ET-treated mice. Presence of the caspase inhibitor altered hepatic glutathione levels in SW mice, which could explain the exacerbation of injury. Additionally, the infiltration of hepatic neutrophils was not altered by the fed state of either mouse strain. CONCLUSION: Minor caspase-3 activation without apoptotic cell death can be observed only in fed mice of some outbred strains. These findings suggest that although the severity of APAP-induced liver injury varies between fed and fasted animals, the mechanism of cell death does not fundamentally change.