The Effects of Various Concentrations of Ropivacaine on the Onset and Duration of Ankle Blocks

Peripheral nerve blocks are essential in ensuring effective regional anesthesia and postoperative analgesia in forefoot surgery for hallux valgus repair, with or without minor concomitant toe procedures. Many factors influence the onset and duration of peripheral nerve blocks. In the advent of ultrasound-guided nerve blocks, the accuracy in administering LA has significantly improved, potentially reducing the required dosage, which is also associated with less risk for toxicity. However, the effect of the concentration of LA on the onset time and duration of ultrasound-guided ankle blocks for forefoot surgery has not yet been studied. This poses a clinically relevant dilemma regarding the necessity of administering lower or higher concentrations of ropivacaine to achieve a clinically relevant faster onset time and longer duration of an ankle block.