Study design: Prospective study of changes in intervertebral disc degeneration after injection of bupivacaine.
Purpose: To examine whether injection of bupivacaine into human intervertebral discs accelerates their degeneration.
Overview of literature: Bupivacaine is commonly used for therapy and diagnosis of discogenic low back pain. However, several in vitro studies have reported toxic effects of bupivacaine to disc cells. We sought to evaluate whether this finding is clinically relevant.
Methods: We selected 46 patients with low back pain who showed disc degeneration at only one level (L4-L5 or L5-S1) on magnetic resonance imaging (MRI) (discography group, n=18), discoblock group (injection of bupivacaine, n=18), and a control group, n=10). There were no significant differences in baseline characteristics across the 3 groups. The two experimental groups underwent either discography or anesthetic discoblock, respectively. All three groups were followed up 5 years after the examination.
Results: At 5 years follow-up, there was no significant difference in the rate of disc degeneration among the 3 groups (p>0.1). Moreover, X-ray images showed that there was no significant difference in disc height, range of motion, or translation between flex and extension position (p>0.1).
Conclusions: In conclusion, radiologic and MRI findings did not show acceleration of intervertebral disc degeneration at 5 years after a single injection of bupivacaine into human discs.
Keywords: Bupivacaine; Intervertebral disc degeneration; Lumbar vertebrae.