Season 9 Case 10

Hx: trauma survey exam. Fall, pain

Dx? Anything else you may want to consider given the history?

Answer: Ankylosing Spondylitis

We have:

-fused SI joints

-fused pubic symphysis

- interspinous ligament ossification = "dagger spine"

-fused Lspine?

** Look for spine fx!

Ankylosing Spondylitis:

-seronegative spondyloarthropathy (neg Rheum factor) that yields fusion of the spine, SI jts, pubic symphsysis, and sometimes other jts

-assoc w HLA B27 gene
-M>F
-usually presents 3rd-4th decade
-trt: NSAIDS, motion/exercise, TNF-alpha blockers

Ankylosing Spondylitis Imaging

-sacroiliitis is bilateral & symmentric

-Romanus lesion - small vert corner erosion w sclerosis (shiny corner sign) -squaring of vert -"bamboo spine"

-parallel paravert syndesmophytes -"dagger spine" - interspinous lig ossif and so much more!

Ank Spon Complications:

Fractures! - although fused, bones are brittle and don't respond well to extreme motion/trauma. This yields "chalk stick" fx (snaps straight through). Can be subtle so look closely on CT.

Pseudoarthroses are common after fractures (example below).