The aim of the study is to evaluate the effectiveness of ultrasound-guided transversalis fascia plane block (TFPB) and quadratus lumborum block (QLB) on post-operative analgesia in pediatric patients with Developmental Dysplasia of the Hip (DDH)under going open reduction surgeries（Salter acetabular osteotomy，combined with proximal femoral rotation osteotomy）.The effectiveness of TFPB/QLB for perioperative analgesia in lumbar nerves (L1) innervated surgery have been demonstrated in recent studies. However, this regional technique rarely applied to children.The objective of our research is to assess the quality of postoperative analgesia in pediatric patients who had received a preoperative TFPB/QLB for hip surgery.