Osteotomy of lumbar spinous process to increase surgical exposure.

A unilateral laminotomy does not always give adequate exposure to disk, nerve or lateral recess. Bilateral laminotomy with removal of a spinous process may result in segmental instability. These problems can be overcome by osteotomy of one or more spinous processes. After doing this a unilateral or bilateral exposure can be obtained by retraction of the process. At the end of the operation the spinous process is replaced in normal alignment and appears to unite spontaneously to its base by bone.