Background: Spondylolisthesis is one of the most encountered spine conditions and few topics in spine surgery have received more intense debate and been the subject of more research investigations. The term was first utilized in the 1960s by Newman and Stone. It is derived from the root Greek terms “spondylos” meaning vertebra and “olisthesis” meaning to slip forward. Spondylolisthesis can be caused by several mechanisms, and a classification system developed by Marchetti and Bartlozzi has been described. Degenerative Spondylolisthesis with Intact Neural Arch is The most common form of spondylolithesis, secondary to degeneration of facet joints and disc, the most common site of structural deformity to be at the L4-5 level. Women are more commonly affected than men, and the prevalence of the condition increases with age. In contrast, isthmic spondylolisthesis usually occurs at L5-S1 and is more common in men. Different methods of spinal fusion have been developed since Albee first reported on posterior fusion in 1911. Initially, a direct posterior approach and then a posterolateral intertransverse process fusion was developed followed by anterior interbody lumbar fusion. Posterior lumbar interbody fusions (PLIFs) and circumferential 360o fusions were developed later. Over the years, there have been differing opinions among physicians as to appropriate procedures to use for various spinal etiologies. Posterior lumbar interbody fusion after lumbar disc removal was first reported by Jaslow in 1946. Wiltbergerof the United States reported using dowels for intervertebral fusion. More recently, Steffe, Brantigan, and Ray have reported on the use of posterior segmental instrumentation or the use of cage implants for PLIF. Using special curets and shavers, discectomy is performed across to the opposite side. Disk height is reestablished using special distractors or pedicle screws. One or two interbody grafts are placed. When using a single interbody device, emphasis is placed on crossing the midline. The addition of bilateral pedicle screw instrumentation is recommended to restore spinal stability.