Obturator versus femoral nerve block for analgesia after total knee arthroplasty.

Background: Both femoral and obturator nerve blocks have been suggested to be useful in relieving pain after total knee arthroplasty (TKA). We sought to compare their efficacy.

Methods: Sixty patients undergoing elective unilateral TKA under spinal anesthesia received in a randomized, double-blind manner a femoral, obturator, or sham nerve block at the end of surgery.