The primary objective of this study was to compare the efficacy of local injection of a local anesthetic with a glucocorticoid versus a local anesthetic with saline to treat low back pain due to lumbosacral transitional vertebras (LSTV) with a pseudoarticulation.

A randomized placebo-controlled double-blind study was conducted in patients with unilateral low back pain ascribed clinically to LSTV. Patients were randomized to lidocaine plus saline (LS group) or lidocaine plus cortivazol (LC group) injected locally under computed tomography guidance. The primary outcome measure was the 24-hour mean visual analog scale (VAS) score for low back pain 4 weeks after the injection.

Of 16 randomized patients, 15 were included in the analysis, 8 in the LS group and 7 in the LC group. The mean VAS pain score at week 4 was not significantly different between the two groups. In the two groups pooled, the mean VAS pain score decreased significantly from baseline to week 4, from 5.52±0.99 to 3.86±2.55 (P≤0.05). The difference remained significant at week 12. Significant improvements occurred in the EIFEL disability index and items of the Dallas Pain Questionnaire. No adverse events were recorded.

In patients with chronic low back pain consistent with a symptomatic LSTV type II or IV in the Castellvi classification, a local injection of lidocaine with or without cortivazol may provide sustained improvements in pain and function. The underlying mechanism is unclear.