Peripheral nerve blocks for closed reduction of distal radius fractures-A systematic review with meta-analysis and trial sequential analysis.

Background: Peripheral nerve blocks may provide better conditions for closed reduction of distal radius fractures as compared to other more frequently used modalities. In this systematic review, we evaluate existing evidence on the effect and harm of peripheral nerve blocks for closed reduction of distal radius fractures in adults.

Methods: We performed a systematic review with meta-analysis and trial sequential analysis including trials investigating the use of peripheral nerve blocks for closed reduction of distal radius fractures. Co-primary outcomes were (1) the quality of the closed reduction measured as the proportion of participants needing surgery afterwards and (2) pain during closed reduction.

Results: Six trials (n = 312) met the inclusion criteria. One trial reported on the need for surgery with 4 of 25 participants receiving nerve block compared to 7 of 25 receiving haematoma block needing surgery (RR 0.57, 96.7% CI [0.19; 1.71], p = .50). Four trials reported pain during closed reduction. In a meta-analysis, pain was not statistically significantly reduced with a nerve block (-2.1 Numeric Rating Scale (NRS) points (0-10), 96.7% CI [-4.4; 0.2], p = .07, tau = 5.4, I = 97%, TSA-adj. 95% CI [-11.5; 7.3]). No trial sequential boundaries were crossed, and the required information size was not met. Pre-planned subgroup analysis on trials evaluating ultrasound guided peripheral nerve blocks (patients = 110) showed a significant decrease in 'pain during reduction' (-4.1 NRS, 96.7% CI [-5.5; -2.6], p < .01, tau = 0.9, I = 80%). All trial results were at high risk of bias and the certainty of the evidence was very low.

Conclusion: The certainty of evidence on the effect of peripheral nerve blocks for closed reduction of distal radius fractures is currently very low. Peripheral nerve blocks performed with ultrasound guidance may potentially reduce pain during closed reduction. High-quality clinical trials are warranted.