Subaxial cervical spine fractures in ankylosing spondylitis: management and outcomes from a 10-year population-based cohort.

Abstract

Objective: Patients with ankylosing spondylitis (AS) are predisposed to unstable cervical spine fractures with a high risk of cervical spinal cord injury (cSCI). Evidence regarding optimal management and outcomes in this population remains limited. This study aimed to describe treatment strategies and short-term outcomes in a prospectively collected, population-based cohort.

Methods: This 10-year (2015-2024) population-based study included all traumatic subaxial cervical spine fractures in patients with AS treated at Oslo University Hospital, the sole neurotrauma center serving Southeast Norway. Data were prospectively collected and analyzed for fracture morphology, management approach, surgical technique, complications, and 90-day mortality.

Results: A total of 132 fractures occurred in 127 patients (median age 70 years, 88% male). Most injuries (86%) resulted from low-energy falls. AO Spine type B or C fractures accounted for 94% of the fractures, and 20% were associated with cSCI. Primary management was surgical in 67% and conservative in 33%. Posterior fixation was the predominant surgical approach (77%). Among patients initially managed conservatively, 14% required delayed surgery. Revision surgery was performed in 9%, most commonly for implant failure after anterior-only fixation or deep infection. The 90-day mortality rate was 16% and was independently associated with advanced age, higher American Society of Anesthesiologists class, and in-hospital pneumonia, but not with cSCI, functional status, or treatment modality.

Conclusions: Most AS-related subaxial cervical spine fractures are highly unstable and benefit from early surgical stabilization. Conservative management carries a substantial risk of failure. The high short-term mortality rate reflects patient frailty rather than treatment strategy. Multidisciplinary evaluation and close follow-up are essential, particularly for patients managed nonoperatively.