Isolated posterior stabilization in type B and C thoracolumbar fractures associated with ankylosing spine disorders: A single center experience with clinical and radiological outcomes.

Introduction: Fractures in ankylosing spine disorders (ASD) are associated with high complication and mortality rates. During the posterior stabilization of these fractures, reduction is often partial, resulting in the persistence of a significant anterior diastasis. Our objective was to evaluate the safety and efficiency of isolated posterior stabilization in elderly ASD patients, without direct reduction of the anterior diastasis, in terms of clinical and radiological outcomes, complications, and mortality.

Methods: This retrospective study included 46 patients, mean age 79.3 years, with ASD, who underwent isolated posterior stabilization, open or percutaneous, for thoracolumbar fractures. The average follow-up was 21.7 months, with a minimum follow-up of 6 months. Autonomy (Parker score) and radiological results (lordotic angulation) were analyzed pre-and post-operatively.

Results: Autonomy was maintained at the last follow-up, with no significant difference in Parker's score. The consolidation rate was 94.6%. No implant failure was recorded. Despite the absence of an anterior procedure, lordotic angulation was significantly reduced by 2.6° at 6 months (p = 0.02). The rate of surgical complications following open surgeries was 10.9% (n = 5), of which 6.5% were infections. No surgical complications were reported in percutaneous surgeries. The rate of medical complications was 67.4% (n = 31), with a rate of 88.2% in the open surgery group, compared to 55.2% in the percutaneous surgery group. An open approach was associated with a five-fold higher risk of complications (p = 0.049). Nine patients died during follow-up (19.6%).

Conclusions: Isolated posterior stabilization in the treatment of thoracolumbar spine fractures in elderly ASD patients is a safe technique promoting autonomy preservation, and high radiological bony healing with acceptable complication and mortality rates. The persistent anterior gap is partially reduced when the spine is loaded and does not seem to require an anterior procedure, thus decreasing complications. Percutaneous surgery should be the technique of choice to reduce surgical complications.