No abstract

Questions remain about the predictive accuracy of somatosensory-evoked and neurogenic motor-evoked potentials. According to the findings in this study, in which there were no false-negative readings and a modest false-positive rate, continued use of these methods is recommended. Higher false-positive rates were seen in patients with greater lability in mean arterial pressure. A wake-up test is recommended for all cases in which threshold monitoring changes occur because cases of spinal cord injury may exist even when monitored variables return to baseline.

Slipped capital femoral epiphysis (SCFE) is a posteromedial displacement of the epiphysis on the metaphysis. Superolateral displacement of the epiphysis, the valgus SCFE, was first described by Müller, although some authors question its existence. We report 4 additional cases and review the literature regarding valgus SCFE. A retrospective review was performed; the child's sex, race, age, weight and height, symptom duration, type of SCFE (stable/unstable), and slip severity were recorded. There were 105 children (67 boys and 38 girls) with 141 idiopathic SCFEs. Four children were noted to have 7 stable valgus SCFEs. Statistically significant differences between the valgus and varus SCFEs were noted for symptom duration and body mass index, and valgus SCFEs tended to be less severe. When combining the data from the literature and the author's institution, there were 22 children with 30 valgus SCFEs at average age of 12.4 +/- 1.8 years; weight, 69.3 +/- 20.6 kg; height, 155.3 +/- 12.4 cm; and body mass index, 27.l +/- 7.1 kg/cm. The demographics of children with valgus SCFE are similar to children with routine SCFE except for sex: 76% of valgus SCFEs occurred in girls. Awareness of valgus SCFEs is necessary for both diagnosis and treatment. In a "valgus" SCFE, Klein line will always be normal, emphasizing the need for lateral radiographs when evaluating all children for SCFE. Single central screw fixation must be approached with caution because the more medial screw entry point places the screw path in immediate proximity to the femoral neurovascular bundle.