Arachnoiditis ossificans in a patient with ankylosing spondylitis, syringomyelia, and a history of spinal surgery

BACKGROUND AND OBJECTIVE: In this article, we describe a patient unusual presenting with both arachnoiditis ossificans and syringomyelia. We have reviewed the patient's evaluation, surgery, and treatment. CASE DESCRIPTION: This patient developed paraparesis following thoracolumbar spinal surgery to treat kyphosis secondary to ankylosing spondylitis. RESULTS: We performed a T9-T11 total laminectomy, drained the cyst, dissected and removed the calcified plaques posterior to the cord, and decompressed the neural structures. CONCLUSION: Symptomatic arachnoiditis ossificans (AO) a rare clinical manifestation is characterized by the calcification or ossification of the spinal arachnoid. The occurrence of AO with syringomyelia is rare. To date, a few cases with both AO and ankylosing spondylitis have been reported.