Ultrasound-guided disc pain induction test for diagnosis of discogenic lumbar pain: A cross-sectional study

Background: Several methods can be used to diagnose discogenic pain, but only discoblock can diagnose discogenic pain definitively. This study aimed to examine the usefulness of an ultrasound-guided disc pain induction test for a simple and accurate diagnosis of the culprit lesion. Methods: We included 41 patients with lumbar pain in whom pain was induced by an ultrasound-guided disc pain induction test. All patients had confirmed pain at L1/2 to L5/S1 based on an ultrasound-guided disc pain induction test and underwent X-ray photography and magnetic resonance imaging. Seventeen patients who required injection due to severe pain underwent discoblock procedures for discs with the most intense pain, and visual analog scale (VAS) scores were obtained before and after the procedure for these patients. We analyzed the association between painful discs and radiological findings. Results: Pain induction was noted in a total of 65 discs, and the pain was induced in 23 patients in only one disc. All patients had disc degeneration of Pfirrmann classification grade 1 or higher, with more significant disc degeneration in painful discs than in painless discs. There was no significant relationship between the presence or absence of pain and Modic type. The average VAS measurements improved significantly from 9.5 (pre-procedure) to 2.5 (post-procedure). These results suggest that the most painful discs were the causes of discogenic lumbar pain. Conclusions: Our ultrasound-guided disc pain induction test may help diagnose disc degeneration and identify culprit lesions, even when multiple discs exhibit findings of degeneration.