Computed tomography in failed back syndrome.

A significant number of patients complain of recurrent symptoms following lumbar spine surgery. The main differential diagnosis is between post-operative epidural fibrosis and recurrent disc protrusion. Computed tomography is generally preferred to myelography for making this distinction, not least by the patient. Intravenous contrast medium can further improve diagnostic specificity. This article reviews the practical aspects and diagnostic accuracy of computed tomography in failed back syndrome, and draws attention to the potential pitfalls and less common abnormalities which may be encountered.