Comparison of segmental pedicle screw instrumentation versus anterior instrumentation in adolescent idiopathic thoracolumbar and lumbar scoliosis

Study Design. A retrospective study. Objective. To compare the results of anterior instrumentation versus segmental pedicle screw instrumentation in adolescent idiopathic thoracolumbar and lumbar scoliosis. Summary of Background Data. Anterior instrumentation is an established method of correcting adolescent idiopathic thoracolumbar and lumbar scoliosis. Posterior segmental pedicle screw instrumentation, with its more powerful corrective force over hooks, could offer significant advantages. Methods. A retrospective analysis was conducted on 36 consecutive female patients with adolescent idiopathic thoracolumbar and lumbar scoliosis who had surgery from December 1997. All had a minimum of 2-year follow-up. Eleven patients had posterior surgery. Results. Mean age at surgery was similar between both groups. Length of surgery was significantly shorter in the posterior group (189 minutes vs. 272 minutes). Length of hospital stay was shorter in the posterior group (6.2 days vs. 8 days). Estimated blood loss, duration of analgesia, and ICU stay did not differ significantly between the 2 groups. No complications were encountered in both groups at the latest follow-up. The magnitudes and flexibility of the thoracolumbar/ lumbar curves did not differ significantly between the 2 groups. The number of levels in the major curve was also similar between the groups. Fusion levels were shorter in the anterior group ( mean, 4.1 vs. 5.0). The percentage correction of scoliosis was similar between the 2 groups at all stages of follow-up, being 74% at 1 week postsurgery, 70% at 6 months postsurgery, 68% at 1 year postsurgery and latest follow-up for the anterior group, and 71% at 1 week postsurgery, 67% at 6 months postsurgery, 68% at 1 year postsurgery, and 67% at the latest follow-up for the posterior group. Thoracolumbar sagittal alignment at T11-L2 was maintained for both groups throughout the follow-up period. The incidence of proximal junctional kyphosis was higher in the posterior group ( P < 0.01). Conclusion. Surgical correction of both the frontal and sagittal plane deformity are comparable to anterior instrumentation. Shorter lengths of surgery and hospital stay are the potential benefits of posterior surgery. Posterior segmental pedicle screw instrumentation offer significant advantages and is a viable alternative to standard anterior instrumentation in idiopathic thoracolumbar and lumbar scoliosis.