Intraradicular and intradural lumbar disc herniation: experiences with nine cases

BACKGROUND: Intraradicular or intradural disc herniation is a very rare complication of spinal degenerative processes. The aim of our study is to analyze the clinical spectrum, the mechanism, and the treatment of this acute spinal pathology. METHODS: Retrospective clinical examination was performed in nine personal cases of intradural disc herniation: among these, six were associated with lateral perforation, the remaining three with intradural herniation and ventral perforation. A review of the literature concerning mainly the frequency pathogenesis and diagnosis of intradural disc herniation has also been done. RESULTS: Nine cases of intradural herniations comprise 1.51% of the 593 cases of ruptured lumbar disc that underwent surgery from 1980 to 1992. The site most frequently involved is at level L4-L5, and 30% of patients have previously undergone surgery for lumbar disc herniation. Most patients reported in literature and in our present series have been complaining of a chronic history of sciatica, complicated later by bilateral neurologic signs. In the present series, diagnosis was obtained by means of myelography and computerized tomography; magnetic resonance imaging was performed in one case. All patients underwent surgery, reporting excellent results in five cases and good results in the other four. Surgery was performed either with an interlaminar approach or with a bilateral laminectomy in cases of ventral perforation. CONCLUSIONS: There is no typical neuroradiologic picture of intraradicular herniation, while a total or subtotal block is frequently observed in intradural ventral perforations. Dural perforation is often an unexpected intraoperative finding. Surgical treatment is always necessary. Favorable results are obtained if surgical treatment is carried out before the neurologic deficit becomes too pronounced.