Diagnostic relevance of pressure-controlled discography

Abstract

Discogenic pain is a leading cause of chronic low back pain. The authors investigated the efficacy of pressure-controlled discography to determine its role in clinical decision-making for the management of patients with discogenic pain. Pressure-controlled discography was performed in 21 patients (51 discs) with pain-provocation, followed by post-discography computerized tomography scans. Pain response was classified as positive response and negative response, and measured with visual analog scale scores. Discographic findings were graded by the modified Dallas discogram scale. Elastance, pain provocation on intradiscal pressure, pressure and volume of initial pain response, and pain response intensity were statistically analyzed. Elastance showed significant differences between Grade 0 and Grade 4 and 5. Decreased elastance with positive pain response group was a good indicator to imply that disc degeneration presumably is a pain generator. Results of pain response were well correlated with intradiscal pressure but not with the amount of injected volume. Among 31 discs of Grade 4 and 5, 74% showed negative pain response and 26% showed positive response. It was concluded that pressure-controlled discography was useful to diagnose discogenic pain and excellent guide in decision-making for spinal operations.

Fig. 1

Elastance of discs in each grade of modified Dallas discogram scale. ^*, p<0.01; ^†, p<0.01.

Fig. 2

Mean viscual analog scale (VAS) scores for discs in each group at three pressure levels. ^*p<0.005, ^†p<0.001, ^‡p<0.05, ^§p<0.001.

Fig. 3

Mean pressures initially evoking pain in Neg-R and Pos-R group. ^*p<0.001, ^†p<0.01.

Fig. 4

Distribution of VAS scores in the Pos-R (gray area) and Neg-R (black areas) groups at 50 psi above opening pressure.