Sciatic motoneurones were retrogradely labelled with long-lasting fluorescent dyes prior to unilateral nerve crush in either 3-day-old or adult rats. The number of surviving labelled motoneurones at intervals after nerve injury were compared to the number in the contralateral control ventral horn and in unoperated animals. Following adult nerve crush there was no significant reduction in the number of labelled motoneurones, but after neonatal nerve crush the count was reduced to about 35%. Most of the cell death occurred during the first 6 days after nerve injury, mainly from the lower half of the motor column, but about one third died between 6 and 12 days, mainly from the upper part. These results suggest that less mature motoneurones tend to die earliest, before the muscle is reinnervated. Those in the upper, more mature part of the motor pool survive longer but may still die during reinnervation. At least two types of glial cell were secondarily labelled by this method, distinguished by their response to nerve injury.

This series suggests that minimally invasive calcaneal osteotomy surgery can achieve excellent union rates aiding correction of deformity with no observed neurovascular or soft tissue complications. For surgeons experienced in open surgery, there is a short learning curve after appropriate training.

No abstract

No abstract