Anatomy of the achondroplastic lumbar canal.

The narrowed bony canal in the achondroplastic spine cases varied neurologic problems. The specific anatomic areas seem not to have been directly measured in an autopsy specimen. An achondroplastic spine was examined radiographically and found to show decreased interpediculate distance, thick pedicles, inferior facet thickness, and for animal stenosis in the lumbar canal. These findings have direct application to surgical treatment insofar as simple laminectomy for achondroplastic dwarfs may be insufficient to produce neural canal decompression. The problem is likely to require thorough exposures of facets and foramen.