Arthroscopic stabilization of traumatic, first-time anterior shoulder dislocations is an effective and safe treatment that significantly reduces the recurrence rate of shoulder dislocations in young athletes when compared with conventional, nonoperative treatment.

Arterial injuries in nonpenetrating low-energy injuries to the extremities are rare but can occur when joint injuries put the vessels in traction against their immobile attachments to the long bones. The most common injuries are to the popliteal artery (because of its tethered nature proximal to the popliteal fossa) and the brachial artery (because it is tethered to the humerus proximal to the elbow). The second reported case of an aneurysm of the anterior tibial artery resulting from an inversion injury to the ankle is described.

Coxa saltans, or snapping hip, can be attributable to a number of causes. Coxa saltans externa typically occurs when the thickened portion of the iliotibial band snaps over the greater trochanter as the hip is flexed. This condition generally resolves with a course of nonoperative treatment. We have treated three patients with Z-plasty of the iliotibial band, which has the highest published success rate in the English language literature. Only one of three patients was able to return to full activities postoperatively. In our small series, this method of surgical treatment in an active duty military population yielded less than optimal results.

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N 2 O emission from automobile has been regulated by the United States Environment Protection Agency due to its higher global warming potential compared to CO 2. Responding to this, an instrument for fast sensing of ultra-low concentration of N 2 O from automobile has become an urgent need. In this study, an instrument based on the quantum cascade laser spectroscopy has been developed and applied for certification testing of ultra-low N 2 O in automobile exhaust. The pulsed quantum cascade laser can emit coherent lights in the mid-infrared region where N 2 O shows strong absorption and better control of wavelength. Therefore, a very low detection limit can be achieved and interference of co-existing gases can be avoided using a super fine resolution of the mid-infrared spectrum. The US Code of Federal Regulations Parts 1065/1066 allows measuring N 2 O from sample storage bags, from a continuous dilute stream or a raw exhaust stream. Typically, batch (bag) sampling has better accuracy and repeatability, but continuous sampling is more efficient in terms of test cell running time and provides test-mode emissions. In this study, the quantum cascade laser analyzer has been applied to investigate correlations between bag sampling and continuous dilute exhaust sampling using a fleet of vehicles with a wide range of N 2 O emission levels all meeting United States Environment Protection Agency emission standards. Very good correlation between these two sampling methods was observed for the majority of tests conducted and in best case the difference was less than 61%. The direct injection gasoline vehicle emits higher N 2 O than conventional port injection gasoline vehicles. The quantum cascade laser analyzer has been successfully applied for United States Environment Protection Agency N 2 O certification test.