Anterior/Posterior 360Â° Many times a procedure in which both the front and back of the spine are fused will be recommended for a patient who has a previous failed fusion (the initial fusion did not set up), multiple level involvement, or for a patient with a high degree of spinal instability (e.g. fractures), or in the face of a deformity, such as scoliosis, spondylolisthesis, and/or in a high risk category, such as for a patient who smokes. Fusing both the front and back provides a high degree of stability for the spine and a large surface area for the bone fusion to occur. The disc will be approached as with an (ALIF) Anterior Lumbar Interbody Fusion on the front of your spine, where your surgeon will remove the disc (cushion between vertebrae) and any arthritic areas, and place a bone graft between the vertebrae where it eventually fuses to the surrounding vertebrae to stop abnormal motion. With the fusion procedure performed in the back of your spine (Posterior Instrumented Lumbar Fusion), a bone graft and instrumentation will be placed on the sides of the vertebrae where they will grow together to the vertebrae to stop abnormal motion. The bone graft may be one of two types: an autograft (bone taken from your own body usually your pelvis) or an allograft (bone from a bone bank). The “instrumentation” which may include metal rods, screws or hooks, is also used with the bone graft to further stabilize the spine. When the vertebrae have been surgically stabilized, abnormal motion is stopped and function is restored to the spinal nerves.