Developmental dysplasia of the hip (DDH) is one of the major disorder of the pediatric population with an incidence of 3 to 5 per 1000 children. Open surgical reduction of congenital hip dislocation (CHD) is typically performed after an ineffective closed reduction or older than 18 months. Multiple femoral or pelvic osteotomies and tenotomies are performed during this surgical treatment and cause severe postoperative pain.Since initial description for abdominal surgery, the quadratus lumborum block has experienced several surgeries for postoperative pain management in adults and pediatrics. One of these indication is the hip surgery and described for adult hip arthroplasty. In addition we reported two pediatric cases that single dose transmuscular quadratus lumborum block is an affective analgesia for CHD surgery. The aim of this study was to evaluate the analgesic effect of ultrasound guided transmuscular quadratus lumborum block in pediatric patients undergoing CHD surgery.

Inclusion Criteria:

- American Society of Anesthesiologist's physiologic state I-II patients undergoing hip dislocation surgery

Exclusion Criteria:

• chronic pain
• bleeding disorders
• renal or hepatic insufficiency
• patients on chronic non-steroidal anti-inflammatory medications
• emergency cases
• Incomplete patient forms
• infection of the skin at the site of needle puncture area
• patients with known allergies to any of the study drugs
• American Society of Anesthesiologist's III-IV