Iatrogenic neurologic deficits after lumbar spine surgery are rare 
complications, but important to recognize and manage. Complications such as 
radiculopathy, spinal cord compression, motor deficits (i.e. foot drop with L5 
radiculopathy), and new onset radiculitis, while uncommon do occur. Attempts at 
mitigating these complications with the use of neuromonitoring have been 
successful. Guidance in the literature as to the true rate of iatrogenic 
neurologic deficit is limited to several case studies and retrospective designed 
studies describing the management, prevention and treatment of these deficits. 
The authors review the lumbar spinal surgery literature to examine the incidence 
of iatrogenic neurologic deficit in the lumbar spinal surgery literature. An 
advanced MEDLINE search conducted on May 14th, 2015 from January 1, 2004 through 
May 14, 2015, using the following MeSH search terms "postoperative 
complications," then subterms "lumbar vertebrae," treatment outcome," "spinal 
fusion," and "radiculopathy" were included together with "postoperative 
complications" in a single search. Postoperative complications including 
radiculopathy, weakness, and spinal cord compression were included. The 
definition of iatrogenic neurologic complication was limited to post-operative 
radiculopathy, motor weakness or new onset pain/radiculitis. An advanced MEDLINE 
search conducted on May 14th, 2015 using all of the above terms together yielded 
21 results. After careful evaluation, 11 manuscripts were excluded and 10 were 
carefully reviewed. The most common indications for surgery were degenerative 
spondylolisthesis, spondylosis, scoliosis, and lumbar stenosis. In 2783 patients 
in 12 total studies, there were 56 patients who had reported a postoperative 
neurologic deficit for a rate of 5.7. The rates of deficits ranged from 0.46% to 
17% in the studies used. The average rate of reported neurologic complications 
within these papers was 9% (range 0.46-24%). Thirty patients of a total of 731 
(4.1%) had a new onset neurologic injury after anterior lumber interbody fusion 
or lateral lumber interbody fusion. Thirty-seven out of 2052 (1.9%) patients had 
a neurologic injury after posterior decompression and fusion. Screw malposition 
was responsible for 11 deficits. Spinal surgery for lumbar degenerative disease 
carries a low but definite rate of neurologic deficits. Despite the introduction 
of neuromonitoring, these complications still occur. Interpretation of 
neurologic injury rates for lumbar surgery is limited by the few prospective and 
cohort-matched controlled studies. Likewise, most injuries were associated with 
the placement of instrumentation despite the type of approach.