Total hip replacement is one of major orthopedic surgery which result in severe postoperative
pain especially at first 24 hours. Ultrasound guided regional anesthesia has become a part of
multimodal analgesia.Ultrasound guided supra-inguinal fascia iliaca block is a new technique
which can consistently cover femoral and lateral femoral cutaneous nerve. And with large
volume (40ml), it may cover obturator nerve. This technique already proved to be useful for
acute pain control in hip fracture or postoperative control in dynamic hip screw or nail
insertion operation. However, it has not been compared with intrathecal morphine for total
hip replacement yet.