Cervical Discography/Disc Access

Abstract

Cervical discography was first described in the literature by Ralph Cloward and George Smith in the late 1950s. Cervical provocation discography potentially provides a method to obtain pain-generation data with regard to the intervertebral disc. Most importantly, data collection includes pain provocation (i.e., none, discordant, or concordant) correlated with the patient’s clinical scenario. Also, it includes contrast volumes and disc architecture (nucleogram, postdiscography computed tomography [CT]). However, the disc architecture is less useful for cervical discography than for lumbar discography. This is based on the normal anatomy of the disc beyond the second and third decades of life. During the first and second decades of life, lateral tears may normally occur in the annulus fibrosis before complete ossification. These lateral tears and uncinate fissures may result in the complete transverse splitting of the disc. As a result, the visualization of “normal” nucleogram may be uncommon. Analgesic response is not typically part of the standard cervical protocol, and it has not been readily studied.

Keywords

Cervical, Disc, Discography, Discogram, fluoroscopy, neck pain, Provocation, Stimulation

Note: Please see pages ii , iii for a list of anatomic terms/abbreviations used throughout this book.

Cervical discography was first described in the literature by Ralph Cloward and George Smith in the late 1950s. ^1-4Cervical provocation discography potentially provides a method to obtain pain-generation data with regard to the intervertebral disc. ⁵Most importantly, data collection includes pain provocation (i.e., none, discordant, or concordant) correlated with the patient’s clinical scenario. Also, it includes contrast volumes and disc architecture (nucleogram, postdiscography computed tomography [CT]). However, the disc architecture is less useful for cervical discography than for lumbar discography. This is based on the normal anatomy of the disc beyond the second and third decades of life. ^5,6During the first and second decades of life, lateral tears may normally occur in the annulus fibrosis before complete ossification. These lateral tears and uncinate fissures may result in the complete transverse splitting of the disc. As a result, the visualization of “normal” nucleogram may be uncommon. Analgesic response is not typically part of the standard cervical protocol, and it has not been readily studied. ^7,8

Over the last 60 years, the usefulness of discography has been closely examined. In this chapter, the scope of the content will not delve into this potential controversy, but the debate does continue through today. When performing discography, the final needle-tip target is the nucleus pulposus, which is the geometric center of the disc. As compared with the lumbar intervertebral disc, the position of the nucleus pulposus is slightly more anterior in location. This chapter will describe an extradural, right anterior oblique, single-needle, safe and efficient disc access technique. The potential necessity for great vessel displacement is less in this approach compared with the traditional right anterior approach. Correlation with magnetic resonance or CT imaging may be beneficial. The recommended needle gauge is 25 G for intradiscal entry, and the needle tip can be modified as described in Chapter 2 to optimize the needle navigation.

Since the esophagus deviates toward the left, the cervical disc is typically approached from the right. This significantly reduces the likelihood of contacting the esophagus and the devastating potential complication of cervical discitis. Multiplanar imaging will be used to best visualize the needle position.

Trajectory View ( Fig. 29.1 )

Patient is supine. Consider having the patient rotate his or her head slightly leftward.

Confirm the level (with the posteroanterior view).

Oblique the fluoroscope to the right.

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The target needle destination is immediately anterior to the junction of the uncinate process (UP) and vertebral body.
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Place a pillow under the patient’s neck and right scapula region to achieve 5 to 10 degrees of neck extension and leftward rotation.
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Count down from the C2-C3 level to ensure proper identification of levels.

Tilt the fluoroscope’s image intensifier usually caudad.

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Line up the vertebral superior end plate and inferior end plate to the appropriate orientation for each individual level.

Place the needle parallel to the fluoroscopic beam.

Notes on Positioning in the Trajectory View

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Setup is adjusted for each individual level.
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Enter from the right side of the neck because the esophagus lies to the left in the lower neck.
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You may need to displace the great vessels (GV) laterally with your index finger.
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Upon needle entry into the disc, the initial needle tip trajectory should be medial.

Trajectory View Safety Considerations

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Avoid the spinal nerve (SN), vertebral artery (VA), and spinal cord (SC) by remaining anterior to UP.
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Avoid the GV, esophagus, and pharynx/trachea by remaining far lateral. If needed, displace GV with your finger(s) or a sterile, blunt instrument.
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The C7-T1 or even C6-C7 levels may not be directly accessible, depending on the neck anatomy of each individual patient (i.e., a long neck versus a short neck).
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Before using a needle to puncture the skin, palpate the neck to confirm that needle advancement through the skin is not directly over a palpable blood vessel (i.e., an area with a pulse) and is superior to the clavicle (not shown).