Incidental finding of arachnoiditis ossificans in the lumbar spine

Abstract

Incidental finding of arachnoiditis ossificans in the lumbar spineA 56-year-old female presented with symptoms of flatback syndrome, including poor posture, back pain, and difficulty mobilizing. She had a lumbar epidural steroid injection several years previously for 'sciatica'. On examination, the patient demonstrated positive sagittal imbalance despite increased pelvic retroversion, and exaggerated knee flexion. Neurological exam was normal. T1and T2-weighted magnetic resonance imaging (MRI) unexpectedly demonstrated calcification of the cauda equina, most dramatically at L4/5 (Fig. 1(a)-(d)). Computed tomography (CT) showed ankylosis resulting in reversal of normal lumbar lordosis and confirmed calcifications in the lumbar region of the spinal canal, most pronounced at L4/5 (Fig. 1(e) and (f)), likely Type III arachnoiditis ossificans (AO). 1