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This activity reviews lumbar provocative discography and highlights the role of the interventionalist and healthcare team in interpreting and using the results as part of a multimodal model for caring for and identifying patients who are candidates for provocative discography. Objectives: Describe the rationale behind selecting provocative discography for a patient. Explain the anatomy and patho-anatomy of the IVD and posterior annular tears that are often not seen on MRI. Review the risks and alternatives and appropriate medical considerations before performing provocative discograms. Outline the role of provocative discography in surgical planning, including minimally invasive techniques or regenerative injections. Access free multiple choice questions on this topic.

Low back pain (LBP) has been described as a global health concern with a point prevalence estimated at 7.5% of the global population, or around 577.0 million people in 2017. It has been the leading cause of years lived with disability (YLDs) at least from 1990 to 2017.[1] Chronic LBP is the second leading cause of adult disability in the United States, and its prevalence increases with age.[2] While the ancient Greeks and Egyptians suspected a relationship between disease in the lumbar spine and leg symptoms, the modern understanding of lumbar disk herniation did not arise until the mid-1700s, and the first lumbar discectomy was performed by Mixter and Barr in 1932.[3] Discography was first described in 1948 with the early technique performed via a transdural approach. The ensuing decades have seen considerable progress from manual subjective discography to manual and automated injection manometers.[4] Modern imaging studies, especially magnetic resonance imaging (MRI), are likely to show degeneration of multiple levels that may or may not be of any clinical significance to the presenting back and leg pain symptoms. The loss of proteoglycans from the disc gradually increases with age, especially in males, so that around 10% of 50-year-old discs and 60% of 70-year-old discs have severely degenerated.  This leaves a fundamental question of what symptomatic pathology is and what is simply age-related degenerative changes of the spine.[5][6] Provocative discography is a diagnostic modality that potentially has a unique role in answering this question.  It should be noted that there are two distinct forms of disc degeneration: "Endplate-driven" disc degeneration involves endplate defects and inwards collapse of the annulus showing inflammatory endplate changes and Schmorl's nodes, and "annulus-driven" disc degeneration involves a radial fissure and/or a disc prolapse, which is well described in the Modified Dallas Classification System.[7]

Modern imaging studies, especially magnetic resonance imaging (MRI), are likely to show degeneration of multiple levels that may or may not be of any clinical significance to the presenting back and leg pain symptoms. The loss of proteoglycans from the disc gradually increases with age, especially in males, so that around 10% of 50-year-old discs and 60% of 70-year-old discs have severely degenerated.  This leaves a fundamental question of what symptomatic pathology is and what is simply age-related degenerative changes of the spine.[5][6] Provocative discography is a diagnostic modality that potentially has a unique role in answering this question.  It should be noted that there are two distinct forms of disc degeneration: "Endplate-driven" disc degeneration involves endplate defects and inwards collapse of the annulus showing inflammatory endplate changes and Schmorl's nodes, and "annulus-driven" disc degeneration involves a radial fissure and/or a disc prolapse, which is well described in the Modified Dallas Classification System.[7] It has even been shown that the presence of a high-intensity zone on MRI is only a suggestive and screening indication for the diagnosis of discogenic LBP and cannot replace the gold standard of discography.[8] Pressure-controlled manometric discography using certain criteria may be the only way to distinguish asymptomatic discs among morphologically abnormal discs with Grade 3 annular tears in patients with clinical LBP, but manometry is not a mandatory requirement for discography.[9]

It has even been shown that the presence of a high-intensity zone on MRI is only a suggestive and screening indication for the diagnosis of discogenic LBP and cannot replace the gold standard of discography.[8] Pressure-controlled manometric discography using certain criteria may be the only way to distinguish asymptomatic discs among morphologically abnormal discs with Grade 3 annular tears in patients with clinical LBP, but manometry is not a mandatory requirement for discography.[9] In addition to the disc itself, many structures can be responsible for varying degrees of axial spine pain with and without radicular features, and it may be challenging to discern which structures are involved in the clinical LBP syndrome. In addition to primary discogenic pain, which is heterogeneous in and of itself, facet arthritis, medial branch nerve entrapment, endplate edema, Schmorl's nodes, myofascial pain, spinal enthesitis, and sacroiliac joint dysfunction, to name a few, can be responsible for similar patient presentations.  Provocative discography still has a role in particular cases. A "sham" injection may also have a role in teasing out non-physiologic complaints and/or obtaining insight into secondary gain issues. A discography is a diagnostic option that may link a patient’s subjective complaints of spinal pain to symptomatic disc disease when non-invasive imaging, such as MRI, does not indicate clear structural abnormalities.  Post-discogram CT can also provide reasonable anatomic imaging for surgical decision-making. However, this procedure can be uncomfortable, and medical clearance should be considered in medically complex patients with cardiovascular or other high-risk comorbidities. Consideration should also be given to renal function due to the use of a radiographic contrast agent. With a number of regenerative medicine options, such as platelet-rich plasma and other "stem cell" treatments, available and coming on the market, provocative discography is seeing an empiric use in pre-injection planning.[10] Additionally, minimally invasive intradiscal treatments, such as endoscopic diskectomy and intradiscal electrothermal procedures, often benefit from pre-procedure discograms, and/or pre-procedure discograms may be required by third-party payors.

With a number of regenerative medicine options, such as platelet-rich plasma and other "stem cell" treatments, available and coming on the market, provocative discography is seeing an empiric use in pre-injection planning.[10] Additionally, minimally invasive intradiscal treatments, such as endoscopic diskectomy and intradiscal electrothermal procedures, often benefit from pre-procedure discograms, and/or pre-procedure discograms may be required by third-party payors. There are 2 classifications for the discogram: the original Dallas discogram description and the modified Dallas discogram description.[11] Original Dallas Classification System based on contrast extravasation and was originally developed in the pre-CT era.  It is still noted at the time of discogram and may be used when CT scanning is not available. This Original Classification System is graded 0-3 as follows: 0: no extravasation "cotton ball " appearance of the intact nucleus, 1: contrast into the inner annulus, 2: contrast into the outer annulus 3: contrast beyond the outer annulus, commonly running into the anterior epidural space The Modified Dallas Classification system is based on contrast extravasation seen on coronal CT imaging through the disc itself. There are six possible categories in the Modified Dallas Discogram Classification that describe the severity of the radial annular tear. Grade 0 is a normal disc—no contrast material leaks from the nucleus. Grade 1 tear will leak contrast material into the inner 1/3 of the annulus. Grade 2 tear will leak contrast through the inner 1/3 and into the middle 1/3 of the disc. Grade 3 tear will leak contrast through the inner and middle annulus.  The contrast spills into the outer 1/3 of the annulus. Grade 4 tear includes a grade 3 tear, and the contrast is also seen spreading concentrically around the disc.  The concentric spread must be greater than 30 degrees.  A full-thickness radial tear and concentric annular tear merge together. Grade 5 tear ('evil' grade) includes a grade 3 or grade 4 radial tear that has completely ruptured the outer layers of the disc and is leaking contract material out of the disc.  This type of tear is felt to be associated with "chemical radiculopathy," with the low pH of the nuclear material theoretically irritating nerve roots directly.

While complications of discography are rare, there are the risks of: Discitis Meningitis Nerve root injury Superficial infection Skin irritation from prep solution Medication reaction Sequelae of the cardiovascular stress of the procedure Renal injury from contrast (late effect) Vascular injury Bleeding Increased pain Disc herniations While the patient needs to be able to interact with the proceduralist, light sedation is commonly provided. However, it carries its own risks and complications of medication reaction and oversedation with respiratory and/or cardiac complications.

With the worldwide burden of LBP clearly documented, it is an important medical topic and can be thought of as almost a public health crisis.  With LBP being a clinical syndrome with heterogeneity in terms of presentations, etiologies, histories, and exam findings, objective information is always needed.  Finding the appropriate vertebral levels involved in a patient's symptoms can allow for better outcomes and determines the appropriate course of treatment, workup, management, evaluation, and decision-making process regarding lumbar spine surgery, particularly fusion. For improved outcomes, interactions between spine surgeons, neurologists, interventional pain management physicians, as well as physical therapists, and other allied health professionals can and should include data obtained during provocative discography and post-discogram CT scanning.  This is important to plan surgeries, minimally invasive procedures, and therapies for the patient. Primary care physicians and physician extenders are crucial in obtaining an initial history and physical exams, emphasizing common "red flag" symptoms and neurological deficits.[21] In the initial post-procedure period, pain control and monitoring for any post-procedural complications should consist of basic neuro checks and vital signs.  Although rare, later monitoring should consist of observation for constitutional signs or symptoms of fevers, chills, and increasing LBP.  Restarting anticoagulation and/or antiplatelet therapy under appropriate guidance may be indicated depending on the clinical scenario. Clinical follow-up should include actually reviewing the objective and subjective data obtained from the discograms as part of integrated care. In general, the need for meticulous planning and discussion with other professionals involved in managing the patient is highly recommended to lower the rate of complications and improve clinical outcomes.

Nursing, allied health, and other team members need to engage in basic standard-of-care for outpatient post-procedural monitoring and sterile technique during the procedure. This includes basic assistance with set-up and preparation similar to many other outpatient pain management interventional procedures. Antibiotics and light sedation are usually given intravenously, and some of the antibiotics may be mixed with the contrast agent. Team interventions should include capability and protocols for handling any medical emergency either during or post-procedure. Post-procedural nursing care, whether it be in a post-procedure area, post-anesthesia care unit, or return to a regular medical floor, is similar to many other pain management procedures such as epidural steroid injection.  This should include vital signs, neurological checks for any new focal weakness, adequate pain control, and observation for potential late reactions to medications. A greater number of these patients may be MRI incompatible due to implanted cardiac devices and henceforth have a higher risk of postprocedure acute cardiac events. There should be a comparatively low threshold in such patients to notify the physician of chest pain, shortness of breath, or any other unusual symptoms that could be an anginal equivalent or otherwise signal of clinical decline.

Nursing or medical assistant postprocedure monitoring should include basic patient observation, including vital signs and notification of the physician of any deterioration and patient status. Because the patient may have received light sedation with a benzodiazepine or opioid for the procedure, reversal protocols should be implemented, and resuscitation equipment should be readily available in case of an emergency.