Inclusion Criteria:  Aged 19 years old or older American Society of Anesthesiologists Physical Status 1-3 Scheduled for elective unilateral total hip arthroplasty  Exclusion Criteria:  Allergy or intolerance to any of the drugs used in the study Hepatic or renal insufficiency Opioid dependency Coagulopathy Pre-existing neurologic or anatomic deficits in the lower extremities Severe psychiatric illness