[The morphology of the lumbar spinal canal].

Measurements of cast preparations of epidural cavities yielded data characterising the "internal silhouette" of the lumbar vertebral canal. Three groups of different shapes of lumbar vertebral canal were found to be statistically distinguishable from each other. These are determined by the constitution of the patient. The different spatial capacity of the three types and the different relations of the diameters modify the value of the isolated determined distance, for example of the sagittal diameter at L5, which is a clinically extremely relevant factor that must be taken into account.