Decompression and nonfusion dynamic stabilization for spinal stenosis with degenerative lumbar scoliosis: Clinical...

Spinal stenosis with degenerative lumbar scoliosis (DLS) mostly occurs in the elderly population (typically > 65 years old), causing pain in the legs and back, claudication, and spinal deformity. The surgical strategy for DLS is controversial concerning the surgical approach, fusion area, decompression area, correction methods, and ideal angle of curve correction. A nonfusion stabilization system with motion preservation has been recently used for degenerative spinal diseases with favorable outcomes. This study attempted to analyze surgical outcomes after decompression and nonfusion stabilization for spinal stenosis with a mild to moderate degree of DLS.

Twenty-eight patients (21 women and 7 men, with a mean age of 65.3 years) with spinal stenosis and DLS who underwent decompressive surgery and nonfusion stabilization with the Dynesys system were included in this study. Medical records and radiological studies were reviewed to access clinical and radiological outcomes and surgery-related complications.

Fifty-nine segments were decompressed and stabilized without fusion in 28 patients, consisting of 1 segmental stabilization in 8 patients (28.6%, L4-5), 2 segmental stabilizations in 11 patients (39.3%, L3-5), 3 segmental stabilizations in 7 patients (25.0%, L2-5 in 6 patients, L3-S1 in 1 patient), and 4 segmental stabilizations in 2 patients (7.1%, L2-S1 in 1 patient, L1-5 in 1 patient). The mean follow-up period was 30.7 months. Radiologically, the mean lumbar scoliotic angle was 13.7° before surgery, 5.1° at 3 months postoperatively, 3.8° at 12 months postoperatively, 4.2° at 24 months postoperatively, and 3.9° at the last follow-up, which was statistically significant (p < 0.05). Lumbar lordosis and range of motion were preserved. The score on the visual analog scale for leg and back pain significantly decreased, and the Oswestry Disability Index significantly improved after surgery. There were no newly developed neurological deficits or aggravation of neurological symptoms. A radiolucent line around the pedicle screw was observed in 4 patients (14.2%) with 5 screws (2.8%).

Adding nonfusion stabilization after decompressive surgery resulted in a safe and effective procedure for elderly patients with lumbar stenosis with a mild to moderate scoliosis angle (< 30°). Statistically significant improvement of the clinical outcome was obtained at the last follow-up evaluation with no progression of the degenerative scoliosis.