J Trauma
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Vascular injury has been reported in up to one third of patients with posterior knee dislocations, which has led to the routine use of arteriograms in the management of these injuries. Recent studies have shown physical examination (PE) is reliable in detecting significant vascular injuries requiring surgery from other mechanisms. We hypothesized that PE would be similarly sufficient to assess popliteal injury in patients with posterior knee dislocations. ⋯ Nineteen patients (50.0%) had normal vascular examination results, did not receive arteriograms, and had no adverse sequelae, with a mean follow-up of 9.3 months (range 1 day-43 months). Sixteen patients with 17 dislocations (44.7%) underwent arteriography and the findings appeared normal in ten extremities; nine of these extremities had normal pulses and one had a diminished but palpable pulse. A minimal injury (intimal defect, 3; narrowing, 4) was demonstrated in seven extremities, five with normal pulses and two with diminished pulses.(ABSTRACT TRUNCATED AT 250 WORDS)
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To determine the magnitude of the discrepancy in injury death rates between urban and rural counties and which types of injury deaths contribute most to this discrepancy. ⋯ Age-adjusted unintentional injury death rates are higher in the rural counties of Nebraska, even though death rates for the four other leading causes of death (heart disease, cancer, cerebral vascular disease, and pneumonia) and intentional injury are lower. Although farm machinery-related deaths have the largest percentage difference between rural and urban counties, motor vehicle-related deaths are the major contributor to the unintentional injury death rate discrepancy in rural Nebraska.
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The pin-bone interface is the weakest link in the mechanical stability of external skeletal fixation. In this investigation, a canine model was used to characterize the nature of cortical bone reactions at the pin-bone interface. Unilateral external fixators were applied to the tibiae of 61 dogs using six tapered cortical half-pins. ⋯ In inherently unstable oblique osteotomies, and less in stable rigidly fixed transverse osteotomies, immediate postoperative weight bearing caused bone thread resorption and adverse cortical bone remodeling at the entry cortex of external fixation half-pins. The unicortical loosening of half-pins that became evident during the first month of fixation obviously represents a consequence of micromotion and local bone yielding failure caused by high dynamic stresses of the pin-bone interface. Effective precautions should be taken to reduce such stresses.