Good outcomes of percutaneous fixation of spinal fractures in ankylosing spinal disorders

The ankylosed spine is prone to trauma even with after application of force at low energy levels. Multi-level vertebral bony fusions produce long lever arms, susceptible to fracture, with an increased risk of neurological injury. Additional problems result from delayed presentation and osteoporosis. These patients are also often at high risk of complications, making conventional open spinal surgery less appealing. We present the outcomes of percutaneous fixation and its advantages in this high risk group of patients.

A retrospective review of a series of 10 patients with a diagnosis of either ankylosing spondylitis or diffuse idiopathic skeletal hyperostosis (DISH). All patients had sustained a spinal fracture between January 2009 and January 2013 and underwent percutaneous fixation using Medtronic longitude system (Minneapolis, USA) with Polyaxial screws. All were followed up with outcomes, complications and functional scores (Oswestry Disability Index (ODI) and Pain Visual Analogue scores (VAS).

The mean patient age was 68. There was a delayed presentation in seven patients, of which two presented with neurological compromise. The neurological deficit did not change with surgery and there were no neurological complications as a result of surgery. The mean length of stay was 24 days, with no direct surgical complications. The mean drop in haemoglobin level was 2.1, with three patients requiring a blood transfusion. The patients were followed up to a mean of 22 months, with a mean ODI of 16 and pain VAS of 1.1. At the time of follow up, two patients had died with no loss to follow up.

Even minor trauma can result in fracture in the ankylosed spine, requiring a high index of suspicion from the physician. The risks of missing such a fracture are significant neurological injury. The biomechanics of the spine are significantly altered, and treatment is demanding. We propose that minimally invasive spinal surgery can achieve good outcomes, low complication rates and high rates of satisfaction.