We report the MR features in two patients presenting with symptomatic thecal impingement by posterior epidural cysts linking a bilateral lumbar spondylolysis. Large fluid-filled channels bridging the ruptured partes interarticulares were present in spite of the absence of significant arthritic changes within the adjacent facet joints.
Duprez, T., Mailleux, P., Bodart, A., Coulier, B., Malghem, J., & Maldague, B. (1999). Retrodural cysts bridging a bilateral lumbar spondylolysis: a report of two symptomatic cases. Journal of Computer Assisted Tomography, 23(4), 534-537. https://doi.org/10.1097/00004728-199907000-00008 (Original work published 1999)