Are femoral nerve blocks effective for early postoperative pain management after hip arthroscopy?

PURPOSE: To evaluate the utility of femoral nerve blocks in postoperative pain control after hip arthroscopy.

METHODS: Forty consecutive patients scheduled for hip arthroscopy were randomized into 2 groups for postoperative pain control. Half were to receive routine intravenous narcotics for pain scores of 7 or above in the postanesthesia care unit (PACU), and the other half were to receive a femoral nerve block in the PACU for the same pain scores. Data were compared with respect to patient sex, patient age, traction times, type of procedure, nausea, overall patient satisfaction with analgesia, and duration of time in the PACU.

RESULTS: Thirty-six patients had initial pain scores of 7 of 10 or greater on a visual analog scale. Of these patients, 16 were randomized to receive postoperative morphine and 20 to receive a femoral nerve block. There were no significant differences between the 2 groups with respect to sex, age, traction times, or type of procedure performed. Patients who received morphine had a significantly longer time to discharge from the PACU (216 minutes) than the femoral nerve block group (177 minutes). The morphine group was also significantly more likely to report postoperative nausea (75%) than the femoral nerve block group (10%). Patients receiving femoral nerve blocks were significantly more likely to be satisfied with their postoperative pain control (90%) than those who had received morphine (25%). All of the patients receiving a femoral nerve block stated that they would undergo the block again if they needed another hip arthroscopy.

CONCLUSIONS: On the basis of all criteria studied (quality of pain relief, length of stay in the PACU, side effects, and patient satisfaction), a femoral nerve block is an excellent alternative to routine narcotic pain medication in patients undergoing hip arthroscopy.

LEVEL OF EVIDENCE: Level II, randomized controlled trial.