Adhesive arachnoiditis - empty thecal sac sign
Recurrent bilateral sciatica. History of lumbar spine surgery.
Loading Stack -
0 images remaining
The prior operation was obviously performed at the L5/S1 level. Here and caudally, the thecal sac appears devoid of its cauda roots.
This is considered as a sign of (prior) adhesive arachnoiditis with adhesions developing between nerve roots and the parietal arachnoid.