Arthroscopic hip surgery is being increasingly performed to treat both intraarticular and extraarticular hip diseases. Despite the minimally invasive approach, patients undergoing arthroscopic hip surgery still suffer severe pain due to the complex nature of hip innervation. Postoperative pain reduces patient satisfaction and delay patient recovery and discharge. The efficacy of regional anesthesia techniques in postoperative pain management have been proved in various surgeries. However, it remains controversial whether or not peripheral nerve blocks can significantly improve postoperative analgesia after hip arthroscopy.

Several studies have shown that the fascia iliac block cannot improve postoperative analgesia for hip arthroscopy because it blocks only some branches of the lumbar plexus but not the sacral plexus. Circum-Psoas Block (CPB) which has been defined in recent years is able to block the lumbar plexus nerves as well as sacral plexus such as the sciatic, superior gluteal, and inferior gluteal nerves. Therefore, the investigators predict that it can provide effective postoperative analgesia for hip arthroscopy. In this study, the researchers aim to investigate the effectiveness of CPB in hip arthroscopy.

Inclusion Criteria:

• Primary unilateral ambulatory hip arthroscopy
• Age 18 to 70 years
• ASA physical status I to III
• Ability to follow the protocol.

Exclusion Criteria:

• Age <18 or >70 years of age
• BMI above 40
• Contraindications to peripheral nerve blockade
• Pregnancy
• Chronic pain condition requiring opioid intake at home
• Allergy to opioids or local anesthetics
• Patient refusal