Efficacy of Popliteal Block in Postoperative Pain Control After Ankle Fracture Fixation: A Prospective Randomized Study

SLR - February 2013 - Gelbmann

Reference: Goldstein RY, Montero N, Jain SK, Egol KA, Tejwani NC. Efficacy of Popliteal Block in Postoperative Pain Control After Ankle Fracture Fixation: A Prospective Randomized Study. Journal of Orthopedic Trauma. 2012; 26(10): 557-561

Scientific Literature Review

Reviewed by: David Gelbmann, DPM
Residency Program: St. John Hospital and Medical Center, Detroit, MI

Podiatric Relevance:
Open reduction and internal fixation of ankle fractures, as well as myriad other foot and ankle surgical procedures, are generally performed under either general anesthesia or spinal anesthesia. Regional anesthesia is beneficial over general anesthesia in that it has been known to provide a longer duration of postoperative analgesia. In addition, it allows for avoidance of airway manipulation and leads to decreased postoperative nausea and vomiting when compared to general anesthesia, while still providing the intraoperative anesthesia and muscle relaxation necessary for the procedure. The use of a more localized form of regional anesthesia, such as a popliteal block, may afford even better postoperative analgesia following lower extremity procedures. Postoperatively, this may: reduce the number of nursing interventions, limit narcotic use, decrease the amount of nonsurgical time spent in the operating room, shorten patient stay in the post anesthesia care unit, and prevent the need for hospital admission for pain management.

Methods:
This prospective, randomized study compared postoperative pain control in 51 patients undergoing open reduction with internal fixation of closed ankle fractures. Twenty-five patients received a popliteal block using 0.25 percent marcaine with 1:200,000 epinephrine along with intravenous sedation, and 26 received general endotracheal anesthesia (GETA). Patients were assessed for duration of procedure, total time in the operating room, and postoperative pain at two, four, eight, 12, 24, and 48 hours after surgery using a visual analog scale (VAS).

Results:
At two, four, and eight hours postoperatively, patients who underwent GETA demonstrated significantly higher pain. At 12 hours, there was no significant difference between the two groups with regard to pain control. However, by 24 hours, those who had received popliteal blocks had significantly higher pain than those who received GETA: 62.8 versus 39.5 on the VAS. By 48 hours postoperatively there was no difference. Tourniquet time, time to incision, and time to case end were not significantly different between the two groups. Patients receiving popliteal blocks were discharged, on average, 10 hours earlier than those receiving general anesthesia alone. There were no complications related to anesthesia in either group.

Conclusions:
The results of this study suggest that popliteal blocks provide equivalent postoperative pain control to general anesthesia alone in patients undergoing operative fixation of ankle fractures, while providing even better analgesia up to 12 hours postoperatively. However, patients receiving popliteal blocks experience a significant increase in pain between 12 and 24 hours postoperatively. Recognition of this "rebound pain" and timely administration of narcotics can minimize this phenomenon, allowing for more effective postoperative pain control. Patients and nursing staff must be counseled on the importance of bridging to oral narcotics before the regional block wears off.