Extreme lateral lumbar interbody fusion (XLIF) is a surgical technique in where the surgeon accesses the intervertebral disc space and fuses the lumbar spine through a side (lateral) approach rather than the anterior or posterior approach. After location of the herniated disc, the surgeon will make two small incisions where one is primarily for a small tube insertion (dilator). A small probe is then entered through the psoas muscle surrounding the pelvic area. A monitoring procedure known as electromyography (EMG) may be used in close observation of avoiding nerves among the surgical area. Once the muscles are split apart and the disc is removed, the surgeon is able to implant the spacer through the same incision along the side of the patient.