60 patients with moderate-to-severe pain during hip flexion immediately after total hip arthroplasty were randomized to be administered a lateral femoral cutaneous nerve block or saline. Patients were assessed for pain over 45 minutes after administration. Patients then underwent crossed-over to the other treatment. Results demonstrated significantly lower pain scores at 45 minutes in those treated with the lateral femoral cutaneous nerve block compared to saline, though not at earlier time points. Additionally, nonresponse to block was high among all patients.