This procedure is a minimally invasive surgery used to gain access to the spine through the back so that the damaged disc can be removed and replaced by a bone graft or spacer. One of the advantages to this procedure is a significant reduction in damage to and loss of strength in the back muscles after surgery, and decreased postoperative pain. Conditions including abnormal spine curvature, herniated discs, or lumbar spondylolisthesis can be treated using this procedure.