Continuous Popliteal Sciatic Nerve Block Versus Single Injection Nerve Block for Ankle Fracture Surgery: A Prospective Randomized Comparative Trial

Objectives: To compare rebound pain and the need for narcotic analgesia after ankle fracture surgery for patients receiving perioperative analgesia through either a continuous infusion or a single injection nerve block. Design: Prospective randomized controlled trial. Settings: Surgeries were performed at 2 hospitals affiliated with a large urban academic medical center. Patients/Participants: Fifty patients undergoing operative fixation of an ankle fracture (AO/OTA type 44). Intervention: Participants were randomized to receive either a popliteal sciatic nerve block as a single shot (SSB group) or a continuous infusion through an On Q continuous infusion pump (On Q group). Main Outcome Measurements: Visual analog scale and numeric rating scale (0-10) pain levels and amount of pain medication taken. Results: For all time points after discharge, mean postoperative pain scores and number of pain pills taken were lower in the On Q group versus the SSB group. Pain scores were significantly lower in the On Q group at the 12 hours postoperative time point (P = 0.002) and at 2 weeks postoperatively. The number of pain pills taken in the first 72 hours was lower in the On Q group (14.9 vs. 20.0; P = 0.036). Overall, 7/23 patients in the On Q group had their pump malfunction and 1 patient accidently removed the catheter. Conclusions: Use of continuously infused regional anesthetic for pain control in ankle fracture surgery significantly reduces "rebound pain" and the need for oral opioid analgesia compared with single-shot regional anesthetic. Level of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.