Ordinary Disc Herniation Changing into Posterior Epidural Migration of Lumbar Disc Fragments Confirmed by Magnetic Resonance Imaging: A Case Report of a Successful Endoscopic Treatment

The posterior epidural migration of lumbar disc fragments is an extremely rare event with an unknown pathogenesis. To the best of our knowledge, there are no previously reported cases of a change of ordinary disc herniation into the posterior epidural migration of lumbar disc fragments as confirmed by magnetic resonance imaging (MRI). A 26-year-old male presented to our department complaining of left buttock and lateral leg pain. An ordinary herniation was shown in the first MRI. The patient's unilateral symptoms changed into bilateral symptoms while awaiting admission to the hospital. Posterior migrated lumbar disc fragments were shown in the second MRI taken at the time of admission. Microendoscopic surgery providing a detailed observation of the region was performed. Our case indicates that an ordinary lumbar disc herniation may lead to the posterior migration of lumbar disc fragments, and that microendoscopic surgery may provide a treatment.