A Randomized Controlled Trial Assessing the Effect of a Continuous Subcutaneous Infusion of Local Anesthetic Following Elective Surgery to the Great Toe.

Local anesthetic use for wound infusions, single injection, and continuous nerve blocks for postoperative analgesia is well established. No study has investigated the effect of a continuous block of the saphenous and superficial peroneal nerves at the level of the ankle joint following first ray surgery. A double blind randomized controlled trial was designed. One hundred patients with hallux valgus and rigidus requiring surgical correction were recruited and randomized to receive a postoperative continuous infusion at the ankle of normal saline or ropivacaine for 24 hours. Pain scores were recorded on postoperative days 1 and 7. There were more females than males. Follow-up was 100%. There were no significant differences in demographic data between the 2 randomized groups. There was no significant difference between the absolute visual analog scale scores on day 1 (P = .14) and day 7 (P = .16); nor was there a significant difference in reduction in scores between days 1 and 7 (P = .70). This study has shown no benefit to postoperative analgesia with the use of a continuous infusion of ropivacaine at the ankle. We, therefore, cannot currently recommend its use in the way described. Further studies may still identify a role for continuous local anesthetic infusions at the ankle to improve postoperative analgesia.

LEVELS OF EVIDENCE: Level I : Prospective randomised control trial.