Assessment of pelvic fractures in severely traumatized, clinically unstable patients presents a diagnostic problem. Traditional plain-radiographic classifications of the fracture are of limited preoperative value to the surgeon who must apply corrective force in opposition to the original force vector causing the fracture. Computed tomographic scanning is an effective method of examining the pelvis but is time consuming and may be impractical in cases of severe injury. In a retrospective analysis of the plain radiographs of 142 cases of pelvic fracture, four patterns of force were identified, presenting distinctive, recognizable radiographic appearances. These patterns are anteroposterior compression, lateral compression, vertical shear, and a complex pattern. The resulting classification of pelvic fracture, based on radiographic and clinical findings, correlates with associated injury to soft-tissue structures and enables the surgeon to begin corrective procedures rapidly.

When people perform two tasks simultaneously, the tasks are often executed slower and with more errors than when they are carried out as single tasks. This is called dual task interference. With functional magnetic resonance imaging (fMRI), we show that concurrently performed visual and somatosensory reaction time (RT) tasks engage almost identical volumes of cortical and subcortical motor structures. Moreover, dual RT tasks engaged additional cortical regions that are not activated by the component RT tasks had they been performed as single tasks. When the inter-stimulus interval was <300 ms, the first task interfered with the second, and a field in the right inferior frontal gyrus (RIFG) appeared with activity correlated with the increased RT to the second stimulus. This activation was spatially distinct from the cortical activity of the main effect of dual task performance. Thus, the performance of single RT tasks, dual RT tasks and dual RT tasks that interfere differ psychophysically and in the brain structures subserving these tasks. A short occupancy of the common motor structures can explain the interference effect. The increased activity of the RIFG correlated with the interference effect is very likely to be a specific outcome of situations where two concurrent tasks interfere with each other. The brain appears to recruit the RIFG for a subsequent (delayed) response when there is interference between dual tasks.

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with sonography many weeks before its appearance on the radiograph. The sonographic appearance of new bone consists of echogenic foci within the distraction site, which become aligned in the longitudinal plane and which increase in number and size until they coalesce as echodense bone, which does not allow throughtransmission of the ultrasound beam. In addition, sonograms showed 1.5-cm and 2-cm cysts within the distraction site in two patients in whom they were not visible on the radiographs.Timely percutaneous aspiration allowed continued normal bone generation. We conclude that sonography is useful for the detection of new bone formation at the distraction site in patients undergoing the llizarov procedure.

Blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) was used to test at which levels of the neuroaxis signals are elicited when different modalities of sensory information from the limbs ascend to cortex cerebri. We applied graded electric stimuli to the rat hindlimbs and used echo-planar imaging to monitor activity changes in the lumbar spinal cord and medulla oblongata, where primary afferents of painful and nonpainful sensation synapse, respectively. BOLD signals were detected in ipsilateral lumbar spinal cord gray matter using sufficiently strong stimuli. Using stimuli well below the threshold needed for signals to be elicited in the spinal cord, we found BOLD responses in dorsal medulla oblongata. The distribution of these signals is compatible with the neuroanatomy of the respective synaptic relay stations of the corresponding sensory pathways. Hence, the sensory pathways conducting painful and nonpainful information were successfully distinguished. The fMRI signals in the spinal cord were markedly decreased by morphine, and these effects were counteracted by naloxone. We conclude that fMRI can be used as a reliable and valid method to monitor neuronal activity in the rat spinal cord and medulla oblongata in response to sensory stimuli. Previously, we also documented BOLD signals from thalamus and cortex. Thus, BOLD responses can be elicited at all principal synaptic relay stations along the neuroaxis from lumbar spinal cord to sensory cortex. Rat spinal cord fMRI should become a useful tool in experimental spinal cord injury and pain research.