Study design: Report of three cases.
Objectives: To describe a rare location of intervertebral disc migration.
Summary of background data: Migration of sequestered disc fragments to the posterior extradural space is rare, and posterior migration of the free fragments causing cauda equina syndrome is exceptionally rare.
Methods: Three patients with posteriorly migrated epidural disc fragments were evaluated with radiograph, computed tomography, and magnetic resonance imaging and underwent surgery.
Results: All of the patients responded well to operative therapy with complete relief of symptoms.
Conclusions: Early surgery should be the first choice of therapy in patients with large posteriorly migrated sequestered disc fragments, to prevent severe neurologic deficits such as cauda equina and conus medullaris syndromes.