Provocative diagnostic discography is a procedure that is frequently done to evaluate patients for internal disk disruption at cervical, thoracic, or lumbar levels. Internal disk disruption can occur with radiologic evidence on MRI, CT scan, or x-ray, and yet continue to be a source of significant low back pain and chronic pain. Internal disk disruption consists of communication between the nucleus pulposus of the disk in question and the sphere within the annular fibrosis of the involved disk. Such a tear can occur after result of trauma (most frequently) or disk degeneration. The gold standard for making a diagnosis of radial annular disk tear is the discogram. Some wide annular disk tear may be visible on MRI studies, or even CAT scan studies. However, the use of discography in conjunction with a computerized axial tomography (CAT) scan or magnetic resonance imaging (MRI) scan can serve as a useful tool to define and localize the site of pain generation in patients who have discogenic pain with a normal MRI and CAT scan study.
The discogram is usually done with the patient awake, and the attempt is to identify which disk when accessed with a cannula, and then injected with a contrast material will provoke this modality of pain in these patients. The procedure is done with local anesthetic infiltration and access into the nucleus pulposus is achieved from a posterior oblique approach under fluoroscopic guidance, and injection is done with contrast material under highly aseptic (sterile) conditions.
At the disk level where the patient has pathology, injection of a contrast material results in reproduction of the patient’s low back pain that is easily identified by the patient, and usually frequently associated with radiologic changes on an x-ray and/or MRI scan that suggest that disk level as the source of the patient’s pain. CT scan studies may also be obtained to get a better definition of the cross-sectional spread of the contrast material within the disk in question.
The indication for discography is to rule out internal disk disruption.
Discography should not be done in patients who are highly sensitive to contrast material or who have skin infection that could compromise the safety and sterility of the actual discogram procedure itself. Discogram also should not be done when patients are pregnant, or suspect that they may be pregnant, because of the possible x-ray radiation affect on the fetus. In addition Coumadin and other anticoagulants are contraindicated. However, Coumadin can be discontinued for at least three days before the discogram procedure is performed. The discontinuation of Coumadin should be with the permission and knowledge of the prescribing physician. Coumadin may be resumed soon after the procedure is done, on the same day. The patient should also continue the medications that they have been taking, including routine medications for blood pressure control, diabetes, hypothyroidism, or any other condition.
A Discogram must be done under highly aseptic (sterile) conditions, and the most significant undesirable complication is discitis, with or without infection, as well as allergic reaction to contrast material or spinal headaches. In general, the actual procedure is safe and usually uneventful. The information obtained through a discography can be quite invaluable in planning treatment for these patients with significant low back pain and internal disk disruption. Treatments may include other IDET procedures or lumbar spine fusion by a spine surgeon.
Sedatives may be used in this procedure to reduce anxiety in some patients as need