Lateral Lumbar Interbody Fusion at the L5-S1 Vertebral Level: A Unique Anatomical Case Report

A 57-year-old female presented with L4-L5 and L5-S1 mobile spondylolisthesis and associated stenosis with radiculopathy who failed conservative treatment. This patient underwent lateral lumbar interbody fusion (LLIF) of L4-L5 and L5-S1, and posterior spinal fusion (PSF) with instrumentation. LLIF is a minimally invasive procedure to treat degenerative diseases of the lumbar spine. LLIF at the L5-S1 vertebral level is a relative contraindication secondary to increased risk of injury to the lumbar plexus and access issues at this level during the approach. With the help of imaging, careful preoperative planning can make this a feasible procedure in select patients.