Spinal Fracture in Ankylosing Spondylitis

Sagittal-reformatted CT image of a patient with known ankylosing spondylitis shows a through-and-through fracture involving the ossified syndesmophyte and the body of C7 to its posterior cortex.

Facts: Ankylosing Spondylitis (AS)

• Rheumatologic condition with progressive ossification of spinal ligaments and ankylosis of facet joints leading to total stiffness
• Patients with AS often have osteoporosis as a result of chronic inflammation, disuse and from the use of steroid medication; therefore they are at risk of developing fracture.
• Minor trauma (or even no trauma) can result in fractures of ankylosed spine

Facts: Fractures in Ankylosing Spondylitis

• Different pattern than in a normal spine
• Fracture line goes entirely through bone, either through vertebral body, ossified ligaments or both
• Fracture can "open up" in flexion or extension
• Can be complicated by epidural bleeding, secondary displacement (either hyperflexion or hyperextension), loss of fixation and increased mortality

Reference:

Olerud C, Frost A, Bring J. Spinal fractures in patients with ankylosing spondylitis. Eur Spine J 1996;5:51-55.