|Subject:||Cervical and Thoracic Discography|
|Policy #:||RAD.00053||Current Effective Date:||04/15/2014|
|Status:||Reviewed||Last Review Date:||02/13/2014|
Discography, also known as provocative discography, has been used in the diagnosis of cervical and, to a limited extent, thoracic pain syndromes in individuals being considered for surgical intervention. The contemporary use of discography involves a pressure-monitored injection of one to three (1-3) ml of contrast agent through a fine needle introduced into the center (nucleus pulposus) of an intervertebral disc followed by CT imaging to evaluate the nature and extent of suspected abnormal vertebral disc morphology. The rationale is that if a disc is symptomatic, stressing that disc will reproduce the individual's pain while stressing adjacent discs will not. The objective is to characterize the pain response (if any) on disc injection and observe whether discographic pain is concordant, i.e. able to reproduce the individual's pain syndrome.
NOTE: This document is limited to the discussion of cervical and thoracic discography. For information on lumbar discography, refer to CG-SURG-29 Lumbar Discography.
Investigational and Not Medically Necessary:
Cervical and thoracic discography are each considered investigational and not medically necessary for all indications.
Although the technique of cervical discography was first described decades ago (Cloward, 1963), the value of cervical and thoracic discography has been explored in only a small number of studies and remains unproven. Cervical discography has been recommended as a tool to identify specific intervertebral levels causing neck pain as a guide to pre-operative cervical fusion planning for individuals with axial neck pain and cervical spondylosis (Wieser, 2007).
Although cervical discography has been considered by some to be a useful diagnostic tool, it has been criticized by others for failing to contribute unique information beyond that available from standard imaging studies despite its inherent risks. The risk of disc space infection following cervical discography has been reported to range from 1% to 4% (Guyer, 1997; Osti, 1990). In another study, complications associated with discography include spinal cord injury, hematoma and rare reports of epidural abscess with quadriplegia (Connor, 1993). As indicated in the study by Boswell (2007), complications secondary to cervical discography include, but are not necessarily limited to discitis, subdural abscess, spinal cord injury, vascular injury, epidural and prevertebral abscess. In a more recent study, researchers reported the results of a meta-analysis that estimated the incidence of discitis after cervical discography, delineated the consequences of discitis, and identified factors that may influence complication rates. Studies pertaining to cervical discography were identified by a literature review and bibliographic search. These studies were screened for inclusion into the meta-analysis by 2 reviewers. Data collected included clinical and demographic variables such as age, gender, morbidities, number of study participants, number of discograms, use of prophylactic antibiotics, type of surgical prep, number of needles used, and the number of participants and discs infected. Cervical discography was complicated by post-procedural discitis in 22 of 14,133 disc injections (0.15 %) and 21 of 4,804 participants (0.44 %). Only 1 participant suffered from an infection at more than one spinal level. The authors concluded that the rate of discitis after cervical discography is relatively low and can perhaps be further decreased by the use of prophylactic intra-discal antibiotics (Kapoor, 2010).
Parfenchuck and colleagues (1994) studied the correlation between discography and MRI in 52 participants with cervical discogenic pain. They found no correlation between either pain response or morphology as seen on discography and MRI. They observed that while some MRI patterns do correlate well with positive or negative cervical discography, several other MRI patterns are equivocal. They concluded that MRI may be a useful adjunct to discography, but that some MRI findings cannot be considered pathologic, and discography is required to diagnose discogenic pain syndrome in those individuals.
Schellhas et al (1996) reported a small prospective correlation of MRI and discography in individuals with asymptomatic and chronic neck pain. Ten asymptomatic participants and ten "non-litigious" chronic neck pain participants underwent cervical discography after magnetic resonance imaging. Disc morphology and provoked responses were recorded at each level studied C3-C7. In the asymptomatic group, 17 of 20 discs found to be normal on MRI had painless annular tears on discography. In the symptomatic group, 11 of 40 discs appeared normal on MRI while 10 of these showed annular tears on discography. Two of the 10 discs in symptomatic individuals (MRI normal, but discography abnormal) were concordantly painful with intensity ratings of at least 7/10. In this small study, the authors reported that discographically normal discs (N=8) were never painful in either group, while intensely painful discs on discography had tears of both the inner and outer disc annulus. They concluded that significant cervical disc annular tears are often missed on MRI, and that MRI cannot reliably identify the source(s) of cervical discogenic pain. Although prospective in design, this study is limited by its very small size.
Zheng and colleagues (2004) looked at the correlation between MRI and cervical discography in degenerative disc disease in 55 individuals with cervical discogenic pain. All participants went on to anterior cervical discectomy and fusion, and postoperative pain relief was assessed by the participants. Successful cervical fusion was achieved in 95% of individuals, and the overall satisfactory result was reported at 76 %. In this study, 161 cervical discs were studied with discography and 79 levels were positive. Of 79 discs with positive discography, only 58 (73%) had an abnormal MRI. Of 82 levels studied with negative discography, only 40 (49%) had a normal MRI. From these observations, the authors concluded that a combination of clinical symptoms, MRI, and discography provided the most information for decision making and can improve the management of cervical discogenic pain. The limitations of this study include its retrospective design and lack of a randomized control.
Two reviews of cervical discography identified only 10 studies meeting a minimal evidence threshold; all but three were retrospective and none included a randomized control (Buenaventura, 2007; Shah, 2005) In only four of these studies were the sensitivity and specificity for the test calculated. Carragee et al (2006) and others have questioned the validity of discography in both the lumbar and cervical spine. They reported that the specificity of discography is dependent upon the psychological profile of the participant. Nordin and colleagues undertook a broader review of the assessment of neck pain and concluded that no evidence supports using cervical discography in assessing neck pain (Nordin, 2008).
Manchikanti, and colleagues (2009b) performed a systematic review of studies on cervical discography as a diagnostic test for chronic spinal pain. The authors noted that the limitations of the review included "a paucity of literature, poor methodologic quality, and very few studies performed utilizing IASP [International Association for the Study of Pain] criteria." The researchers rated the evidence for cervical discography at only II-2 ("from at least one properly conducted diagnostic accuracy study of adequate size").
Onyewu and colleagues (2012) conducted a systematic review of the diagnostic accuracy of cervical discography. Using the modified Agency for Healthcare Research and Quality (AHRQ) accuracy evaluation and United States Preventive Services Task Force (USPSTF) level of evidence criteria, the systematic review indicated the strength of evidence is limited for the diagnostic accuracy of cervical discography.
The American College of Radiology's panel on musculoskeletal imaging for chronic neck pain did not recommend discography for the evaluation of individuals with chronic neck pain. On a scale of 1 to 9, the Expert Panel assigned discography an appropriateness criterion of 1, signifying the least appropriate test (Daffner, 2005). The American Society of Interventional Pain Physicians' evidence-based practice guidelines in the management of chronic spinal pain (Boswell et al, 2007) indicates that among the diagnostic interventions, the evidence is strong for lumbar discography, whereas, the evidence is limited for cervical and thoracic discography.
While discography of the thoracic spine has many similarities to the technique used in the lumbar spine, inadvertent pleural puncture and pneumothorax add to the potential risks of the procedure. Schellhas and colleagues (1994) analyzed the results of thoracic discograms after MR imaging in a retrospective series of 100 subjects with spinal pain. There were no serious complications in the series. They found that approximately 75% of discs with annular tears, intrinsic degeneration, and/or endplate deformities were painful during discography and clinically concordant with the subject's pain approximately 50% of the time. The authors concluded that thoracic discography can be performed safely as a diagnostic procedure to determine if degenerated discs on MRI are related to clinical symptoms. The limitations of this study include its retrospective, uncontrolled design.
In a case-control series conducted by Wood and colleagues (1999), 10 asymptomatic volunteers and 10 adults with chronic thoracic pain were studied with MRI of the thoracic spine, followed by four-level discography. Provocative responses were graded on a scale of 0 to 10. The mean pain response in the asymptomatic volunteers was 2.4/10 and on discography 27 of 40 discs studied in asymptomatic volunteers were abnormal with endplate changes, annular tears, and/or herniations. Three discs in the asymptomatic group were found to be intensely painful, with all three showing endplate changes (Schmorl's nodes) and annular tears typical of Scheuermann's disease (juvenile kyphosis). In the group with chronic thoracic pain, the average pain response was 6.3/10 (P<0.05). Of the 46 discs studied in the symptomatic individuals, 24 were concordantly painful (reproduced the subject's chronic pain syndrome) while 17 had non-concordant pain/pressure and 5 had no response. In the asymptomatic control group, 10 of 40 discs which appeared normal on MRI showed annular pathology on discography. In the symptomatic group 21 of 48 discs were judged normal on MRI. However, on discography only 10 were judged as normal. The authors concluded that thoracic discography may demonstrate disc pathology not seen on MRI, but the study was limited by its small size and was not designed to demonstrate a clinical outcome benefit of thoracic discography in the management of individuals with chronic spinal pain.
In 2008, Singh and colleagues undertook a systematic review of thoracic discography and identified the same two articles for review. The authors characterized these two studies as II-3, i.e. evidence obtained from diagnostic studies of uncertainty, and concluded that these studies supported a weak recommendation based on low quality or very low quality evidence.
In 2012, Singh and colleagues performed another systematic review to assess the diagnostic accuracy of thoracic discography with respect to chronic, function limiting, thoracic or extrathoracic pain. The studies were evaluated using a methodological quality assessment tool (Quality Appraisal of Reliability Studies [QAREL]). Based on the quality of evidence developed by the U.S. Preventive Services Task Force (USPSTF), the researchers found only two studies that met the inclusion criteria. The authors indicated that the evidence and clinical value of thoracic provocation discography is limited (poor).
As mentioned above, The American Society of Interventional Pain Physicians' evidence-based practice guidelines in the management of chronic spinal pain indicates that the evidence is limited for thoracic discography (Boswell, 2007).
Cervical and Thoracic Discography
Shah et al (2005) and Buenaventura et al (2007) performed extensive reviews of the literature evaluating the diagnostic accuracy of discography in the management of chronic spinal pain. Studies were scored according to the Agency for Healthcare Research and Quality (AHRQ; West, 2002) and Quality Assessment of Diagnostic Accuracy (QUADAS; Whiting, 2003) rating scales for diagnostic testing. For inclusion, studies first had to meet at least 50% of the total possible points for each scale. Evidence was then classified into five levels: conclusive, strong, moderate, limited, or indeterminate. The authors concluded in their review of the evidence through November 2006 that there is only "moderate" evidence supporting the role of discography in identifying a subset of individuals with cervical discogenic pain and only "limited" evidence supporting the role of discography in identifying individuals with thoracic discogenic pain. In their review, the authors defined "moderate" evidence as evidence obtained from comparative studies with non-randomized concurrent or historical controls, single arm trials or interrupted time series without a parallel control group. "Limited" evidence was defined as well-designed non-experimental studies from more than one center or research group; or conflicting evidence with inconsistent findings in multiple trials.
While cervical and thoracic discography may demonstrate disc pathology and concordant pain, there is insufficient evidence from controlled clinical trials to demonstrate a favorable impact on the clinical outcome of individuals with discogenic pain in either the cervical or thoracic spine. The American Society of Interventional Pain Physicians' evidence based practice guidelines in the management of chronic spinal pain (Boswell, 2007) concluded that the evidence is limited for both cervical and thoracic discography. The American College of Radiology's panel on musculoskeletal imaging for chronic neck pain does not recommend cervical discography for the evaluation of individuals with cervical spondylosis, assigned the procedure an appropriateness criterion of 1, signifying the least appropriate test. Also, the American College of Radiology clinical appropriateness criteria on myelopathy acknowledges that when treating individuals with cancer or an infectious disease, it may be necessary to study the entire spine or even the entire skeleton despite a specifically localized myelopathic level. However, the ACR found that even in these situations, there was no high-quality evidence which supports the use of discography in the evaluation of myelopathy (ACR, 2010; ACR, 2011).
While discography has been studied extensively in the lumbar spine, it has been evaluated less so in cervical discs, and even less frequently in thoracic discs. At this time, there is not sufficient evidence from controlled trials to evaluate whether cervical and thoracic discography result in improved outcomes in individuals with chronic cervical or thoracic spine pain. Until there is more scientific evidence demonstrating the efficacy and improved outcomes with this test for individuals experiencing cervical or thoracic pain, the clinical value and diagnostic utility of cervical and thoracic discography remain unproven.
Discography involves the pressure-controlled injection of a water-soluble contrast material directly into the center (nucleus pulposus) of the vertebral disc. Information is then documented about the amount of dye accepted, the pressure necessary to inject the material, the pattern of the opaque material, and the reproduction of the individual's pain. For a response to be considered positive, concordant pain must be produced; and for the test to be considered valid, there must be at least one or more discs that do not elicit pain upon injection which serve as an internal control. Discography is a procedure used to characterize the architecture of the intervertebral disc and to determine if the disc is a cause of an individual's chronic spinal pain. Since discography is an invasive diagnostic test, it is generally reserved for chronic spinal pain in individuals refractory to conservative therapies in whom disc pathology is felt to be a likely cause of the individual's pain and surgery is being considered. While lumbar discography may be of value in the treatment planning of individuals with discogenic low back pain (see CG-SURG-29 Lumbar Discography), its utility in the diagnosis and management of cervical and thoracic discogenic pain is less well studied.
The discographer relies only on pain reproduction from a suspected disc, and with a positive response the results may be either true-positive or false-positive. Those skeptical of the utility of discography suggest that discography may reveal the subclinical potential of a disc with abnormal morphology to cause pain, but contend that does not prove that the disc is actively a source of the individual's complaints. Lacking are randomized, prospective controlled trials demonstrating the results of cervical and thoracic discography can be used to achieve improved clinical outcomes.
The following codes for treatments and procedures applicable to this document are included below for informational purposes. Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy. Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage of these services as it applies to an individual member.
When services are Investigational and Not Medically Necessary:
|62291||Injection procedure for discography, each level; cervical or thoracic|
|72285||Discography, cervical or thoracic, radiological supervision and interpretation|
|ICD-9 Diagnosis||[For dates of service prior to 10/01/2014]|
|ICD-10 Diagnosis||[For dates of service on or after 10/01/2014]|
Peer Reviewed Publications:
Government Agency, Medical Society, and Other Authoritative Publications:
|Reviewed||02/13/2014||Medical Policy & Technology Assessment Committee (MPTAC) review. Updated review date, Rationale, References and History sections.|
|Reviewed||02/14/2013||MPTAC review. Updated review date, Rationale, References and History sections.|
|Reviewed||02/16/2012||MPTAC review. Updated review date, Rationale, References and History sections.|
|Reviewed||02/17/2011||MPTAC review. Updated review date, References and History sections.|
|Reviewed||02/25/2010||MPTAC review. Updated review date, References and History sections.|
|Reviewed||02/26/2009||MPTAC review. Updated review date, Rationale, References and History sections.|
|New||02/21/2008||MPTAC initial document development. Document created to address cervical and thoracic discography. Lumbar discography addressed in CG-SURG-29 Lumbar Discography.|