Sectional neuroanatomy of the lumbosacral spine (L1-S5).

This paper will review the lumbosacral spine (L1-S5). Procedures performed in the lumbosacral spine include electromyography, spinal stimulator implants, spinal infusion implants for spasticity or pain medications, sacroiliac spine injections, facet blocks, and steroid injections. Complications from these procedures include iatrogenic paraplegia or paraplegia due to transverse myelitis, intravascular penetration, dural puncture, increased pain at the injection site, increased radicular pain, increased spine pain, lightheadedness, nausea, nonspecific headache, and vomiting. Long-term complications include implant infection, implant or catheter dislodgment/kinking, and device failure. This paper provides anatomically accurate schematics of innervations of the lumbosacral spine (L1-S5) that can be used to interpret magnetic resonance images of the muscles and nerves. Cross-sectional schematics of the lumbosacral spine were drawn as they appear on imaging projections. The relevant nerves were color coded. The muscles and skin surfaces were labeled and assigned the color of the appropriate nerves. An organized comprehensive map of the motor innervation of the lumbosacral spine allows the physician to increase the accuracy and efficacy of interventional procedures. This anatomical map could also assist the electromyographer in correlating the clinical and electrophysiological findings on magnetic resonance images.