CT-diskography in the evaluation of the postoperative lumbar spine. Preliminary results

Lumbar discography

STUDY DESIGN

A comprehensive review of the literature dealing with lumbar discography was conducted.

OBJECTIVE

The purpose of the review is to update the North American Spine Society position statement published in 1994 that addressed criticisms of lumbar discography, to identify indications for

SUMMARY OF BACKGROUND DATA

Lumbar discography remains a controversial diagnostic procedure. There are concerns about its safety and clinical value, although many support its use in specific applications.

METHODS

Articles dealing with lumbar discography were reviewed and are summarized in this report.

RESULTS

Most of the recent literature supports the use of discography in selected patients. Although not to be taken lightly, many of the serious complications and high complication rates reported before 1970 have decreased since then because of improvement in injection technique, imaging and contrast materials.

CONCLUSIONS

Most of the current literature supports the use of discography in select situations. Indications for discography include, but are not limited to: (1) Further evaluation of demonstrably abnormal discs to help assess the extent of abnormality or correlation of the abnormality with the clinical symptoms. Such symptoms may include recurrent pain from a previously operated disc and lateral disc herniation. (2) Patients with persistent, severe symptoms in whom other diagnostic tests have failed to reveal clear confirmation of a suspected disc as the source of pain. (3) Assessment of patients who have failed to respond to surgical intervention to determine if there is painful pseudarthrosis or a symptomatic disc in a posteriorly fused segment and to help evaluate possible recurrent disc herniation. (4) Assessment of discs before fusion to determine if the discs within the proposed fusion segment are symptomatic and to determine if discs adjacent to this segment are normal. (5) Assessment of candidates for minimally invasive surgical intervention to confirm a contained disc herniation or to investigate dye distribution pattern before chemonucleolysis or percutaneous procedures. Lumbar discography should be performed by those well experienced with the procedure and in sterile conditions with a double-needle technique and fluoroscopic imaging for proper needle placement. Information assessed and recorded should include the volume of contrast injected, pain response, with particular emphasis on its locations and similarity to clinical symptoms, and the pattern of dye distribution. Frequently, discography is followed by axial computed tomography scanning to obtain more information about the condition of the disc.

Discography of lumbar discs after surgical treatment for disc herniation

STUDY DESIGN

Eighty-three patients were identified who had discography performed at a disc level that had been subject to previous laminectomy and partial discectomy, and who had also undergone discography at one or more additional levels. The results of these studies were retrospectively reviewed.

OBJECTIVE

To define the results of discography performed on previously operated discs.

SUMMARY OF BACKGROUND DATA

It is not uncommon for the physician to encounter patients with complaints of persistent chronic back pain after surgical treatment of a lumbar disc herniation. Although such patients are frequently studied by discography, there is very little scientific literature to document the expected results.

METHODS

A retrospective study of the results of discography on previously operated disc was performed.

RESULTS

A positive pain response was significantly more likely in the previously operated discs than in the unoperated discs (P < 0.0001). Posterior extravasation of dye was noted in 34% (35 of 102) of the postoperative discs and 21% (29 of 136) of the unoperated discs. Positive concordant pain provocation was noted in 48 (75%) of the 64 discs showing posterior dye extravasation; 28 were postoperative discs and 20 were unoperated discs.

CONCLUSIONS

Patients presenting with disabling back pain who had previously undergone surgical treatment for a herniated nucleus pulposus show a high (72%) incidence of concordant pain with discography of the previously operated level. Only 34% of the previously operated discs demonstrated posterior extravasation of discography dye. Persistence of a posterior anular defect was associated with a higher incidence of positive concordant pain response.

Lumbosacral spine imaging: physioanatomic method

Noninvasive evaluation of low back and leg pain has progressed rapidly over the past decade. The development of computed tomography, single-photon emission-computed tomographic bone scan, and magnetic resonance imaging has markedly increased diagnostic accuracy in detecting pathologic conditions. With this increased accuracy has come recognition of a 50% prevalence of underlying abnormalities in patients between 20 and 60 years old who have no symptoms. When such patients have a back injury, subsequent imaging will show in half of the population studied abnormalities that are not related to an acute injury. Degeneration of the spine progresses in all patients throughout their lifetime, and nearly all of the population will have back discomfort at some time. Political- and judicial-based compensation for back injuries related to accidents and on-the-job injuries provides an incentive for patients not to improve on therapy and to exaggerate symptoms, further complicating the clinical evaluation of their condition. The goal of physioanatomic noninvasive and invasive imaging evaluation presented in the following chapters is to increase specificity by differentiating pain generators from asymptomatic underlying pathologic conditions. When used with intensive conservative management and psychologic testing, this physioanatomic approach has resulted in much better treatment outcomes in our experience. The physioanatomic approach is quite simple, consisting of rigorous correlation of pathologic changes demonstrated by noninvasive imaging modalities (computed tomography, single-photon emission-computed tomographic bone scan, and magnetic resonance), or invasive modalities (diskography-enhanced computed tomography, nerve root block and facet block) with the patient's symptoms to evaluate whether the symptoms and the pathologic lesion are concordant or discordant. Patient symptoms and history are evaluated by use of a pain drawing and information sheet. The patient's pain pattern is categorized into a nonspecific pattern or into one of four recognizable pathway patterns (radicular, dorsal ramus, polyneuropathy, and sympathetic). Because each spinal lesion is typically manifested primarily via one of the four symptom pathways, the distribution of expected symptoms from each pathologic feature can be compared with the patient's pain drawing, and an assessment of the significance of imaged lesions can be made. The patient's presenting symptoms are also used to determine the most cost-effective and efficacious use of initial diagnostic imaging evaluation. In a minority of patients the findings on noninvasive imaging either will not correlate with the patient's symptoms or will demonstrate multiple abnormalities that could account for the patient's symptoms. In these patients, invasive techniques are extremely helpful in defining a pain generator or pain generators.(ABSTRACT TRUNCATED AT 400 WORDS)