Surgical Outcomes of Minimally Invasive Stabilization for Spinal Fractures in Patients with Ankylosing Spinal Disorders

Study Design A retrospective study. Purpose To evaluate the clinical and radiological outcomes of ankylosing spinal disorder (ASD) patients with spinal fractures treated by minimally invasive stabilization (MISt) using percutaneous pedicle screws (PPSs). Overview of Literature ASDs, such as ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH), increase susceptibility to spinal fractures because of extremely decreased spinal flexibility. Such fractures tend to be unstable and, consequently, should be treated with multiple-segmental internal fixation. However, conventional internal fixation procedures can severely damage the soft tissue, resulting in severe hemorrhage. Therefore, MISt is the preferred approach to treat spinal fractures in ASD patients. Methods Nine ASD patients (four males and five females; three AS and six DISH patients) with spinal fractures who were treated by MISt using PPSs, were reviewed from April 2009 to August 2016. One patient died of aspiration pneumonia during follow-up (FU), and the remaining eight patients underwent clinical and radiological evaluation. Results The mean age at surgery was 79.6 years (range, 68–95 years). The mean duration of postoperative FU was 14.2 months (range, 3–30 months). All treated fractures were anterior and posterior element injuries with distraction. Three patients presented delayed onset preoperative neurological deficit following trauma. The mean operation time was 179.6 minutes (range, 92–340 minutes). The mean hemorrhage was 103.6 mL (range, unquantifiable to 480 mL). Radiological evaluations at FU showed preservation of the acceptable postoperative correction of the fractured vertebra, as there were no re-collapses of the fractured vertebrae during FU. Conclusions ASD patients must be acknowledged as highly susceptible to unstable spinal fractures, even after relatively mild trauma. MISt using PPSs may be an effective treatment for spinal fractures in such patients