Factors predictive of immobilization complications in pediatric polytrauma.

OBJECTIVES: To determine in a cohort of children with polytrauma which variables are predictive of the development of complications related to immobilization. DESIGN: A retrospective study of children with polytrauma and at least one major musculoskeletal injury. A stepwise forward logistic regression analysis was used to determine variables predictive of complications related to immobilization. PARTICIPANTS: Ninety-three children with polytrauma were studied; motor vehicle incidents accounted for 80 percent of the injuries. The average age was 8.0 +/- 4.1 years. There were 152 fractures in the ninety-three children. The average Modified Injury Severity Scale (MISS) was 24.5 +/- 13.6. There were thirty-five complications in twenty-two children, and four children died. RESULTS: Two variables were predictive of complications related to immobilization: age and MISS score. Complications related to immobilization were positively associated with being older than seven years of age (p = 0.027; odds ratio = 9.5; 95 percent confidence interval 1.4, 64.9) and having a MISS score greater than forty (p = 0.005; OR = 14.1; 95 percent confidence interval 2.2, 89.1). Timing of surgery showed a trend (p = 0.097) but did not reach statistical significance. CONCLUSIONS: Complications of immobilization in children with polytrauma are associated with age greater than seven years and a MISS score greater than forty. Further study is needed to evaluate the effect of early fracture stabilization. Timing of osteosynthesis showed a trend but did not reach statistical significance in this study.

Reliability of roentgenogram evaluation of pedicle screw position.

STUDY DESIGN: This was a human cadaver study of the accuracy of biplanar roentgenography in determining pedicle screw position. OBJECTIVE: To determine the independent accuracy of radiologic evaluation of screw placement and to determine if there are any particular screw malpositions that are more likely to produce a false sense of acceptable screw position. SUMMARY OF BACKGROUND DATA: Other investigators have reported the correlation between radiologic evaluation and anatomic dissection. However, in those studies the radiologic evaluation was not independent of the surgeons placing the screws. There has been no comment in the literature regarding particular screw malpositions that would lead the surgeon into a false sense of successful screw placement. METHODS: Pedicle screws were placed in cadaver spines, and biplanar roentgenograms of the specimens were evaluated by independent observers. The results of the roantgenogram evaluation then were compared to those of the anatomic dissection. RESULTS: The accuracy of roentgenogram evaluation varied from 73% to 83%, depending on the experience of the surgeon grading the roentgenograms. Screws misplaced medially into the spinal canal are more likely to give the surgeon a false sense of successful screw placement. CONCLUSIONS: The surgeon must not rely solely on the roentgenograms, but instead continue to use tactile sensory skills, anatomic knowledge, and additional modalities such as electromyography monitoring.

Ocular inflammation stimulated by intravitreal interleukin-8 and interleukin-1.

Interleukin-8 (IL-8), a cytokine with neutrophil chemotactic and activating properties, is known to be stimulated by IL-1. Fischer rats are more resistant to inflammation than Lewis rats probably due to a higher corticosteroid stress response. To determine the role of IL-8 in ocular inflammation, the effect of intravitreal injection of IL-8 was compared with that of IL-1 in both Lewis and Fischer rats. The IL-8, IL-1 alpha, or sterile balanced salt solution (control) was injected into one eye of each animal. Both IL-8 and IL-1 alpha caused inflammation in the eye of both strains, as detected by leukocyte counts of the anterior chamber and histopathologic examination. The eyes of animals injected with a cytokine had significantly higher numbers of leukocytes compared with eyes of control animals. Histopathologic examination confirmed these findings. The IL-1 alpha induced inflammation more consistently and more severely than the most effective dose of IL-8. This finding agreed with the concept of IL-1 initiating a cascade of inflammatory mediators including IL-8, which acts more specifically on a smaller population of leukocytes. A contralateral response was observed in the uninjected eye of experimental and control animals. The contralateral response in animals receiving the cytokines was significantly greater than that in controls. Lewis rats show a higher inflammatory response to the injections than do the Fischer rats. These data suggest that IL-8 may be active as one component in neutrophil-mediated ocular inflammation.