Nerve injury during the transpsoas approach for lumbar fusion

A lateral transpsoas approach to achieve interbody fusion in the lumbar spine using either the extreme lateral interbody fusion or direct lateral interbody fusion technique is an increasingly popular method to treat spinal disease. Dissection and dilation through the iliopsoas muscle places the lumbosacral plexus at risk for injury, but there is very limited information in the published literature about adverse clinical events resulting in postoperative motor deficits or reports of failure of electrophysiological monitoring to detect nerve injury. The authors present 2 cases of postoperative motor deficits following the transpsoas approach not detected by intraoperative monitoring, review the medical literature, and discuss strategies for complication avoidance.