Proximal femoral resection for older children with spastic hip disease.

Thirteen patients (19 hips) who underwent proximal femoral resection arthroplasty for symptomatic subluxation or dislocation of the hip were reviewed retrospectively. All had severe neurological involvement, and when older were non-ambulatory with spastic quadriplegia or myelodysplasia. Resections were either at the level of the neck (nine hips) or in the subtrochanteric region (10 hips). The latter provided a better operative result than did the former. Poor clinical results noted were continued pre-operative pelvic obliquity, postoperative adduction contracture, and bony contact between the pelvis and the remaining proximal femur or its heterotopic ossification.

Thermosensitive single-unit activity of in vitro hypothalamic slices.

Single-unit activity was recorded in vitro from tissue slices of rat preoptic area-anterior hypothalamus. The thermosensitivity of 139 units was determined by their changes in firing rate in response to changes in slice temperature. Of these neurons, 30% were warm sensitive, 10% were cold sensitive, and 60% were temperature insensitive. These proportions are similar to results obtained in whole-animal studies, indicating that this is a viable preparation. It also suggests that hypothalamic neuronal thermosensitivity is not dependent on peripheral afferent input. All units had low firing rates (less than 10 imp/s) at 37 degrees C, and 83% of the warm-sensitive units were most thermosensitive above 37 degrees C. This supports the concept that afferent input determines the level of firing rate and range of thermosensitivity of warm-sensitive neurons. The cold-sensitive units also displayed maximal thermosensitivity above 37 degrees C, which would be expected if cold-sensitive neurons received inhibitory synaptic input from nearby warm-sensitive neurons.