Non-Fusion Surgery for Degenerative Spondylolisthesis Using Artificial Ligament Stabilization

Abstract

A retrospective study. To report midterm clinical and radiographic results of Graf artificial ligament stabilization in the treatment of degenerative spondylolisthesis and to evaluate the role of this procedure and its surgical indications for surgical success. Nonfusion surgeries including artificial disc replacement and ligamentoplasty are increasingly gaining interest to avoid adverse effects of spinal fusion. Sixty-four consecutive patients with degenerative spondylolisthesis underwent artificial ligament stabilization. Surgical indication was symptomatic degenerative spondylolisthesis with <25% of vertebral slip, coronal facet tropism, and minimal disc space narrowing. Radiographic and clinical assessments were performed before surgery, immediately after surgery, and at the final follow-up. Mean follow-up period was 67 months (36-112 months). Visual analog scales of low back pain and sciatic symptoms were significantly improved. Radiographic assessments demonstrated that segmental lordosis was maintained in 12.2 degrees , and flexion-extension motion was averaged 4.7 degrees at the final follow-up. Facet arthrodesis spontaneously occurred in 12 cases (18.8%) at an average of 59.5 months after surgery. Although vertebral slip was not improved, postoperative disc space narrowing was minimal. Additional surgeries were required in 4 cases for adjacent segment pathologies (6.3%). One patient (1.6%) underwent consequent spinal arthrodesis at the ligamentoplasty level. Artificial ligament stabilization did not improve the vertebral slip but maintained lordosis and preserved segmental motion in 80% of patients. This procedure is an effective alternative to spinal arthrodesis in the treatment of symptomatic degenerative spondylolisthesis (Grade I) with minimal disc space narrowing and coronal facet tropism.