The study was proposed but never started due to other commitments

The investigators are investigating two ways of treating pain after hip surgery. One way is though a thin tube (called a catheter), and it is placed into the back so that pain-numbing drugs can reach the nerves near the backbone. This is called an "epidural" catheter. Another way is to place the catheter close to the hip, where the surgery is done, so that the pain-numbing drugs can reach some of the nerves more locally. This is called a "fascia iliaca compartment" catheter.

The investigators do not know which way is best to treat pain, or has fewer side effects, or allows a patient to leave hospital faster. Usually, patients would receive only one type of catheter for pain relief. To do this comparison, the investigators would place both catheter types, so that patients help us tell which one works better.

Inclusion Criteria:

• Weight >40 kg
• Radiographic evidence of hip dysplasia amenable to unilateral surgical treatment by periacetabular osteotomy
• Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain subscale >4/20
• Age between 15 and 35 years
• Good or excellent preoperative joint congruency

Exclusion Criteria:

• Hematologic or neurologic contraindications to epidural catheter placement
• Significant renal, hepatic, or cardiac disease
• Peptic ulcer disease
• Bleeding disorders
• Severe asthma
• Hypersensitivity to non-steroidal antiinflammatory drugs
• Developmental delay
• History of substance abuse
• Chronic opioid use
• Chronic pain in non-hip locations