Femoral head replacement following fracture: an analysis of the surgical approach

The early results of 276 femoral head replacements for displaced fractures of the neck of the femur are described. The procedure was performed in the same hospital by two similar groups of surgeons. Either an anterior or a posterior approach was used. Although there was no statistical difference between the rates of infection and dislocation in the two groups, infection and dislocation occurred more commonly in the posterior approach. Misplacement of the prosthesis and fracture of the upper part of the femoral shaft occurred statistically more frequently in the anterior group.

Hydrocortisone injections for carpal tunnel syndrome

The effects of local hydrocortisone acetate injections in patients with a carpal tunnel syndrome are reported. In a prospective study of sixty one wrists injected, fifty five (90%) had initial symptomatic relief. At review after one year forty one wrists had relapsed (67%) requiring decompression. In view of the poor long term response to injection it was decided to test the accuracy of the sitting technique in a separate consecutive series of twenty six wrists at operation. The needle was found to be correctly sited in twenty four wrists (92%). It is suggested that, as initially considerable symptomatic relief can be achieved, the principal value of steroid injections lies as a palliative remedy whilst decompression is awaited.

Synaptic regeneration in identified neurons of the lamprey spinal cords

Identified reticulospinal neurons whose giant axons were severed after spinal cord transection were filled with horseradish peroxidase. Whole mounts and serial-section light and electron micrographs show axon regeneration across the spinal lesion and the formation of new synapses. Normal swimming activity returns in the spinally transected animals, although the regenerated synapses are in atypical regions of the spinal cord.

Two types of presynaptic configurations in insect central synapses: an ultrastructural analysis

Two structurally distinct types of synapses have been identified in the cockroach metathoracic ganglion. The two synaptic types are distinguished on the basis of (a) the shape and position of the presynaptic density seen by serial thin sectioning and (b) the arrangement and location of vesicle attachment sites (VAS) on the presynaptic membrane obtained from replicas of aldehyde-fixed, freeze-fractured neuropile. Bar-type synapses in thin sections possess a long presynaptic density located in a trough or groove opposite the extracellular space between two contiguous postsynaptic processes. In freeze-fracture, this trough is flanked by two rows of vesicle attachment sites. The second synaptic conformation consists of rows of discrete dense projections located on the convexities of the presynaptic membrane, i.e., directly opposite a single postsynaptic process. This conformation has been correlated with groups of VAS linearly arranged also on the convexities of the presynaptic membrane. These structurally different synapses may represent functionally different contacts within the insect ganglion.

Structure and physiology of denervated and re-innervated cockroach muscle

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