Efficacy of popliteal block in postoperative pain control after ankle fracture fixation: a prospective randomized study.

OBJECTIVES: To compare postoperative pain control in patients treated surgically for ankle fractures who receive popliteal blocks with those who received general anesthesia alone.

DESIGN: Institutional Review Board approved prospective randomized study.

SETTING: Metropolitan tertiary-care referral center.

PATIENTS: All patients being treated with open reduction internal fixation for ankle fractures who met inclusion criteria and consented to participate were enrolled.

INTERVENTIONS: Patients were randomized to receive either general anesthesia (GETA) or intravenous sedation and popliteal block.

MAIN OUTCOME MEASURES: Patients were assessed for duration of procedure, total time in the operating room, and postoperative pain at 2, 4, 8, 12, 24, and 48 hours after surgery using a visual analog scale.

RESULTS: Fifty-one patients agreed to participate in the study. Twenty-five patients received popliteal block, while 26 patients received GETA. There were no anesthesia-related complications. At 2, 4, and 8 hours postoperatively, patients who underwent GETA demonstrated significantly higher pain. At 12 hours, there was no significant difference between the 2 groups with regard to pain control. However, by 24 hours, those who had received popliteal blocks had significantly higher pain with no difference by 48 hours.

CONCLUSIONS: Popliteal block provides equivalent postoperative pain control to general anesthesia alone in patients undergoing operative fixation of ankle fractures. However, patients who receive popliteal blocks do experience a significant increase in pain between 12 and 24 hours. Recognition of this "rebound pain" with early narcotic administration may allow patients to have more effective postoperative pain control.