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 nerve 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 nerve 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 nerve block. Ankle block may increase the duration of analgesia when compared with no intervention/sham block (MD 431 min; 96.7% CI 208 to 654), but the evidence was very uncertain. Duration was decreased when compared with a sciatic nerve block (MD −410 min; 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 nerve block. The ankle block duration was probably clinically important in both comparisons. The effects on cumulative 24-hour opioid consumption were very uncertain.