Preliminary Result of Revision Fusion Surgery for Thoracolumbar Spine Using Revision Rod

Abstract

The need for revision fusion surgery after spinal fusion has increased. A revision rod that connects to the previous rod was newly developed for revision surgery. The purpose of this study was to analyze the clinical and radiological results after spinal fusion revision surgery using revision rods. Materials and Methods: Twenty-one patients who underwent revision fusion surgery after spinal fusion in two university hospitals with minimum 1 year follow-up were reviewed. This study assessed 16 cases of adjacent-segment disease, four cases of thoracolumbar fracture, and one case of ossification of ligament flavum. The Oswestry Disability Index (ODI) and numerical rating scale (NRS) were evaluated as clinical outcomes, and the union rate, lordosis or kyphosis of the revision level, lumbar lordosis, T5-12 kyphosis, and proximal junctional kyphosis angle were evaluated as the radiological outcomes. Results: The average ODI was 54.6±12.5 before surgery and improved to 29.8±16.5 at the final follow-up. The NRS for back pain and leg pain was 5.0±1.7 and 6.4±2.0 before surgery, which changed to 2.9±1.6 and 2.9±2.2 at the final follow-up. Lumbar lordosis was 18.1°±11.9° before surgery and 21.1°±10.3° at the final follow-up. Proximal junctional kyphosis was 10.8°±10.1° before surgery, and 9.2°±10.5° at the final follow-up. These angles were not changed significantly after surgery. Bony union was successful in all cases except for one case who underwent posterolateral fusion. Conclusion: Revision surgery using a newly developed revision rod on the thoracolumbar spine achieved good clinical outcomes with successful bony union. No problems with the newly developed revision rod were encountered.