Anatomy of the achondroplastic lumbar canal

The narrowed bony canal in the achondroplastic spine causes varied neurologic problems. The specific anatomic areas seem not to have been directly measured in an autopsy specimen (man of 55; death due to myocardial infarction). An achondroplastic spine was examined radiographically and found to show a decreased interpediculate distance, thick pedicles, inferior facet thickness, and a foraminal 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.