Scott C. Wilson

Surgical management of soft tissue lesions associated with pelvic ring injury.

Mortality rates associated with pelvic ring injury combined with open wounds have decreased considerably during the past 2 decades. Consequently, increased survivability has heightened the demand for definitive stabilization techniques to address pelvic ring instability. Control of hemorrhage and avoidance of sepsis remain paramount concerns in the initial and later stages of management, respectively. Exclusion of occult and readily apparent perforations of the genital urinary and gastrointestinal tracts is essential when using a multidisciplinary approach. Recognition of open and closed degloving injury patterns and appropriate adherence to treatment guidelines will optimize outcome and avoid catastrophic complication.

Transition metal associations with primary biological particles in sea spray aerosol generated in a wave channel.

In the ocean, breaking waves generate air bubbles which burst at the surface and eject sea spray aerosol (SSA), consisting of sea salt, biogenic organic species, and primary biological aerosol particles (PBAP). Our overall understanding of atmospheric biological particles of marine origin remains poor. Here, we perform a control experiment, using an aerosol time-of-flight mass spectrometer to measure the mass spectral signatures of individual particles generated by bubbling a salt solution before and after addition of heterotrophic marine bacteria. Upon addition of bacteria, an immediate increase occurs in the fraction of individual particle mass spectra containing magnesium, organic nitrogen, and phosphate marker ions. These biological signatures are consistent with 21% of the supermicrometer SSA particles generated in a previous study using breaking waves in an ocean-atmosphere wave channel. Interestingly, the wave flume mass spectral signatures also contain metal ions including silver, iron, and chromium. The nascent SSA bioparticles produced in the wave channel are hypothesized to be as follows: (1) whole or fragmented bacterial cells which bioaccumulated metals and/or (2) bacteria-derived colloids or biofilms which adhered to the metals. This study highlights the potential for transition metals, in combination with specific biomarkers, to serve as unique indicators for the presence of marine PBAP, especially in metal-impacted coastal regions.

Comparison of Fixation Methods for Preventing Pelvic Ring Expansion

Several methods of external and internal fixation are used in urgent situations to lessen intrapelvic bleeding associated with unstable pelvic fractures. Pelvic stabilization limits pelvic expansion and thereby restricts the space for potential blood loss. This study compared several fixation methods using cadaveric pelves to determine which method best prevents pelvic expansion. Three methods of internal fixation and three methods of external fixation were compared. Anteroposterior fixation provided the greatest control against pelvic expansion; however, it is clinically impractical for emergency use. Therefore, external fixation provided the most reliable control of pelvic expansion in the emergency setting.

A simple method to measure compartment pressures using an intravenous catheter

A simple method was investigated to measure compartment pressures using 16-ga intravenous catheters with or without side ports attached by arterial line tubing to a pressure transducer. Pressure measurements from the experimental catheters were within 4 mm Hg of the slit catheter for 99% of all readings, and pressure measurements from the Stryker device were within 5 mm Hg of the slit catheter for 95% of all readings. The addition of one or two side ports to the experimental catheters did not alter the pressure readings. This method is comparable in accuracy to the slit catheter and in simplicity to the Stryker device.

A mechanical comparison and review of transverse, step-cut, and sigmoid osteotomies.

Successful incorporation of massive allografts for the treatment of bone deficiency demands maximizing biologic and mechanical factors. These factors have yet to be mastered, as evidenced by the 8% to 17% nonunion and the 5% to 20% fracture rate. The current study addresses the allograft incorporation process by examining the three construct geometries: transverse, step-cut, and sigmoid. Specimens were plated and mounted on a mechanical testing machine. A rotational displacement was applied, and torsional stiffness (N-m/°), maximum torque (N-m), and maximum displacement (°) were calculated. The sigmoid osteotomies had a torsional stiffness of 1.90 ± 0.68 N-m/° and maximum torque of 18.85 ± 6.63 N-m versus 0.99 ± N-m/° and 14.48 ± 2.15 N-m for the transverse osteotomies; and a maximum angular displacement of 11.60° ± 1.78° versus 5.73° ± 1.6° for the step-cut osteotomies. The step-cut osteotomies consistently failed at the step-cut corners, which acted as stress risers. Computer-aided solid modeling of the contact surfaces showed that the step and sigmoid osteotomy areas were 74% and 44%, respectively, larger than the transverse osteotomy. The sigmoid osteotomy, created with a template and pneumatic drill, seems to offer a mechanical advantage over the transverse and step-cut osteotomies by increasing stability and contact surface area relative to the transverse osteotomy but reducing the stress-riser effect of the step-cut osteotomy.