Iatrogenic neurologic deficit after lumbar spine surgery: A review

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.