The efficacy and safety of ankle blocks for foot and ankle surgery: A systematic review with meta-analysis and trial sequential analysis

Background Peripheral nerve blocks may be essential elements in a multimodal pain management regime following foot and ankle surgery. We assessed the effects of ankle blocks compared with no intervention/sham block or a sciatic block in patients undergoing surgery of the foot or ankle. Methods We searched CENTRAL, Medline, and Embase for randomised clinical trials comparing ankle block with no intervention/sham block or a sciatic block for patients undergoing surgery of the foot or ankle. Our primary outcomes were duration of analgesia and cumulative 24-hour opioid consumption. We followed the recommendations of the Cochrane Handbook, and performed meta-analysis, Trial Sequential Analysis (TSA), and assessed the risk of bias and certainty of the evidence using the GRADE approach. Results We included five trials (362 participants) comparing ankle block with no intervention/sham block and three trials (247 participants) comparing ankle block with a sciatic block. Ankle block may increase the duration of analgesia when compared with no intervention/sham block (MD 431minutes; 96.7% CI 208 to 654), but the evidence was very uncertain. Duration was decreased when compared with a sciatic block (MD -410 minutes; 96.7% CI -462 to -358). The ankle block duration was probably important in both comparisons. The effects on cumulative 24-hour opioid consumption were very uncertain in both comparisons. Conclusions Ankle block may increase the duration of analgesia when compared with no intervention/sham block, but the evidence was very uncertain, and decrease the duration of analgesia when compared with a sciatic block. The ankle block duration was probably clinically important in both comparisons. The effects on cumulative 24-hour opioid consumption were very uncertain.