Percutaneous, PMMA-augmented, pedicle screw instrumentation of thoracolumbar ankylotic spine fractures.

Introduction: Fractures in the ankylotic spine may have an insidious presentation but are prone to displace with devastating consequences. The long lever arm of ankylosed spine fragments may lead to pulmonary and great vessel injury and is difficult to adequately immobilize. Conservative treatment will produce in many cases poor outcomes with high morbidity and mortality. Open surgical treatment is also fraught with technical difficulties and can lead to major blood loss and prolonged operative times. In recent years, percutaneous instrumentation of non-ankylotic spine fractures has gained popularity, producing similar outcomes to open surgery with shorter operative times and reduced blood loss and hospital length of stay. We describe our experience implementing these techniques in ankylotic spine patients.

Methods: We retrospectively retrieved from our hospital's electronic health records all patients treated for thoracolumbar spine fractures between 2008 and 2015 with a diagnosis of ankylosing spondylitis (AS) or diffuse idiopathic skeletal hyperostosis (DISH). Operative and postoperative data, results, and complications were tabulated, and radiographic parameters were evaluated.

Results: Twenty-four patients with ankylotic spine disease underwent percutaneous augmented instrumentation between 2008 and 2015. The mean age was 76. All patients had at least one comorbidity. The mean number of ankylosed levels was 14. Mean operative time was 131 min. The average postoperative hemoglobin decrease was 1.21 gr/%, with only 4 patients requiring blood transfusion. 45.8% of the patients had postoperative medical complications. One patient (4.2%) had a superficial postoperative infection, and one patient died in hospital. The average hospital length of stay was 14.55 days. All patients retained their preoperative ASIA grades, and 3 improved one grade. All patients united their fractures without losing reduction.

Conclusions: PMMA-augmented percutaneous instrumentation is an attractive surgical option for this difficult patient subset, especially when compared to other available current alternatives.