Spine fractures in patients with ankylosing spinal disorders

Abstract

Study design: Retrospective review.

Objective: To describe the spine fracture characteristics, current treatments, and their results in patients with ankylosing spinal disorders (ASD), such as ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH), with the hypothesis that complication and mortality rates are high.

Summary of background data: Spine fractures in patients with ASD are unique and have only been described in relatively small case series.

Methods: Retrospective review of a large consecutive series of patients with spine fractures and ASD over a 7-year period. Complications were stratified according to parameters such as type and number of comorbidities, patient age, and mechanism of injury. Predictors of mortality were analyzed by linear regression. Similarities between patients with AS and DISH were evaluated by chi analysis.

Results: Of the 122 spine fractures in 112 consecutive patients with ASD, the majority were transdiscal extension injuries, most commonly affecting C6-C7. Eighty-one percent of the patients had at least 1 major medical comorbidity. Spinal cord injury was present in 58% of the patients, 34% of whom improved by at least 1 American Spinal Injury Association grade. Nineteen percent of patients had delayed diagnosis of their spine fracture, 81% of whom had resulting neurologic compromise. Surgery was performed on 67% of patients, consisting primarily of multilevel posterior instrumentation 3 levels above and below the injury. Eighty-four percent of all patients had at least 1 complication. Mortality was 32% and correlated with age > or =70 (P < 0.0001), number of comorbidities (P < 0.0001), and low-energy mechanism of injury (P = 0.009). AS patients were younger (P = 0.03) and had a higher risk of delayed fracture diagnosis (P = 0.012), but were otherwise similar to DISH patients.

Conclusion: Patients with spine fractures and ASD are at high risk for complications and death and should be counseled accordingly. Multilevel posterior segmental instrumentation allows effective fracture healing. AS and DISH patients represent similar patient populations for the purpose of treatment and future research.