Neurologic deficit following lateral lumbar interbody fusion

Lateral lumbar interbody fusion (LLIF) is a minimally invasive technique that has gained growing interest in recent years. We performed a retrospective review of the medical records and operative reports of patients undergoing LLIF between March 2006 and December 2009. We seek to identify the incidence and nature of neurological deficits following LLIF. New occurring sensory and motor deficits were recorded at 6 and 12 weeks as well as 6- and 12 months of follow-up. Motor deficits were grouped according to the muscle weakness and severity and sensory deficits to the dermatomal zone. New events were correlated to the patient demographics, pre-operative diagnosis, operative levels, and duration of surgery. At each post-operative time-point patients were queried regarding the presence of leg pain. A total of 235 patients (139 F; 96 M) with a total of 444 levels fused were included. Average age was 61.5 and mean BMI 28.3. At 12 months' follow-up, the prevalence of sensory deficits was 1.6%, psoas mechanical deficit was 1.6% and lumbar plexus related deficits 2.9%. Although there was no significant correlation between the surgical level L4-5 and an increased psoas mechanical flexion or lumbar plexus related motor deficit, a trend was observed. Independent risk factors for both psoas mechanical hip flexion deficit and lumbar plexus related motor deficit was duration of surgery. LLIF is a valuable tool for achieving fusion through a minimally invasive approach with little risk to neurovascular structures.