Can Dynamic Spinal Stabilization Be an Alternative to Fusion Surgery in Adult Spinal Deformity Cases?

Background: Rigid stabilization and fusion surgery are widely used for the correction of spinal sagittal and coronal imbalance (SCI). However, instrument failure, pseudoarthrosis, and adjacent segment disease are frequent complications of rigid stabilization and fusion surgery in elderly patients. In this study, we present the results of dynamic stabilization and 2 - stage dynamic stabilization surgery for the treatment of spinal SCI. The advantages and disadvantages are discussed, especially as an alternative to fusion surgery. Methods: In our study, spinal, sagittal, and coronal deformities were corrected with dynamic stabilization performed in a single session in patients with good bone quality (without osteopenia and osteoporosis), while 2 - stage surgery was performed in patients with poor bone quality (first stage: percutaneous placement of screws; second stage: placement of dynamic rods and correction of spinal SCI 4-6 months after the first stage). One - stage dynamic spinal instrumentation was applied to 20 of 25 patients with spinal SCI, and 2 - stage dynamic spinal instrumentation was applied to the remaining 5 patients. Results: Spinal SCI was corrected with these stabilization systems. At 2 - year follow - up, no significant loss was observed in the instrumentation system, while no significant loss of correction was observed in sagittal and coronal deformities. Conclusion: In adult patients with spinal SCI, single or 2 - stage dynamic stabilization is a viable alternative to fusion surgery due to the very low rate of instrument failure. Clinical Relevance: This study questions the use of dynamic stabilization systems for the treatment of adult degenerative deformities. Level of Evidence: 4.