ABSTRACT
STUDY DESIGN: case report and review of the literature OBJECTIVES: to report two cases of posterior epidural migration of herniated lumbar intervertebral disc and review the literature Summary of Background Data : Posterior epidural migration of herniated lumbar intervertebral disc is extremely rare. The large size of the fragment eventually exceeded the limits of the anterior epidural space and the fragment subsequently settled posterior the thecal sac because of spatial and size constraints. MATERIALS AND METHODS: Two cases of herniation of intervertebral disc which were caused by posteriorly migrated disc material were treated surgically with open discectomy. The magnetic resonance images, surgical treatment and related literature are reviewed. RESULTS: Preoperative magnetic resonance images of the posterior epidural migration of herniated lumbar intervertebral disc showed a large epidural mass. The mass was of intermediate signal intensity on T1-weighted images, was of low signal intensity on T2-weighted images and was enhanced marginally with gadolinium-DTPA on T1-weighted images. Immediately after operation, a significant reduction of symptoms were achieved. The patients recovered fully at two year follow-up. CONCLUSIONS: Lumbar disc herniation by posterior epidural migration of sequestered fragment can be diagnosed with clinical findings and MRI including Gadolinium-DTPA enhancement. It should be differentiated from epidural mass and could be managed surgically with good results.