To compare the different analgesic protocols for patients receiving total hip arthroplasty(THA). Patients will divided into 3 groups, which are 1. fascia iliaca compartment block with IV-PCA(patient controlled analgesia), 2. femoral nerve and lateral femoral cutaneous nerve block with IV-PCA, 3. IV-PCA only.

90 patients will be enrolled and randomized to the 3 different groups.

1. Inclusion criteria:

   Patient undergoing THA: 20-75 years old, ASA I-III, general anesthesia with intubation, fentanyl IV PCA.

2. Exclusion criteria Alcohol/substance abuse Rheumatoid arthritis Severe coagulation disorder(PLT<80000 or INR > 1.5) Peripheral neuropathy Allergy to opioids or local anesthetics BMI>35

3. The outcome followers are blinded to the intervention provided.

4. Outcome parameters:

   1. Opioid consumption of IV PCA in first 24 hrs.

   2. NSAID consumption

   3. NRS of pain, the timings of follow-up should be: pre-block, 30

      mins post-block, 60 mins post-block, 2 hours post-block, 24hours post-block

   4. sensory block in FN, Obturator Nerve and LFCN

   5. First request of supplemental IV analgesia

Inclusion Criteria:

• ASA I-III, general anesthesia with intubation.
• fentanyl IV PCA

Exclusion Criteria:

• Alcohol/substance abuse
• Rheumatoid arthritis
• Severe coagulation disorder(PLT<80000 or INR > 1.5)
• Peripheral neuropathy
• Allergy to opioids or local anesthetics
• BMI>35