A 14-year-old girl with spastic quadriplegic cerebral palsy and progressive neuromuscular scoliosis presented with back pain 6 months after posterior spinal fixation. CT of the lumbar spine revealed numerous ossified dural plaques (Fig. 1, arrows). Semitransparent volume-rendered CT reconstruction shows the distribution of intraspinal ossifications (gray amorphous regions with white stippling) in the nerve root sleeves and caudal recess (Fig. 2). The pedicle screws (white areas) at L5 are evident superiorly.

Fig. 1
figure 1

Axial non-contrast CT image of the spine

Fig. 2
figure 2

Volume-rendered CT reconstruction

Arachnoiditis ossificans is a rare chronic meningeal inflammatory process that typically affects adults [1]. The pathogenesis is unknown but thought to be the result of end-stage adhesive arachnoiditis secondary to prior spinal surgery or trauma, subarachnoid hemorrhage or previous lumbar taps/injections [1, 2]. Ossified dural plaques can be asymptomatic or might cause pain, myelopathy, radicular signs, sensory disturbance or incontinence [1, 2].