A systematic review of the use of corticosteroid injections with and without local anaesthetic for trigger finger.

BACKGROUND

Trigger finger causes pain, catching, and locking of the finger, with corticosteroid injection being the first-line treatment. Injections with local anaesthetic may reduce immediate pain, but it has been suggested that added volume worsens pain. This systematic review aimed to evaluate studies investigating pain following corticosteroid injection for trigger finger, with or without local anaesthetic. Evaluation of the topic: We performed a prospectively registered systematic review (PROSPERO ID: CRD42024502361) following PRISMA guidelines. We searched PubMed, Cochrane Library, and Embase database for randomised trials or prospective cohort studies investigating pain following injection with corticosteroid with or without local anaesthetic. Patient demographic data, injection details and outcomes including visual analogue scale (VAS) pain scores were collected and summarised. Two articles including 98 patients (135 injections) were included. One article compared steroid injection with local anaesthetic and adrenaline to steroid injection with placebo (0.9% saline), and found that omitting local anaesthetic had a lower immediate VAS pain score (2.0 vs. 3.5; P < 0.01) however all injections contained the same volume. The second study measured VAS pain scores at multiple time points, and a recollection score for patients injected with either corticosteroid alone (1mL), corticosteroid and 1% xylocaine (2 mL), or corticosteroid and 0.9% saline (2 mL). VAS pain scores were similar in the steroid alone and steroid and local anaesthetic group at 1 minute post-injection and highest in the steroid and saline group. The local anaesthetic group had the lowest pain score 10 minutes post-injection. Meta-analysis of outcomes in these heterogeneously reported studies was not possible.

CONCLUSION

Corticosteroid injection for trigger finger varies considerably and outcomes are reported inconsistently. The evidence suggests that the addition of local anaesthetic may increase immediate pain due to volume effect or lowered pH but reduce early post-injection pain. Further well-designed randomised studies are needed to guide treatment decisions.