Abstract
Combining our experience at the Barrow Neurological Institute with a review of the literature, we have defined the indications for fusion of the lumbar spine based on diagnostic categories. Clear indications for fusion include two-or three-column injuries produced by trauma, tumor, or infection; postoperative instability; and isthmic spondylolisthesis. Relative indications include degenerative spondylolisthesis, radiographically proven dynamic instability with pain or neurological findings, adult scoliosis, and mechanical back pain. Fusion is rarely indicated in the setting of routine microdiscectomy; abnormal radiographs without appropriate findings (eg, degenerative disc disease); facet joint syndrome; failed back surgery; or stable spinal stenosis.