Although there are many surgical methods for the treatment of developmental hip dislocation in older children (>6 years old), many reports have reported unsatisfactory results due to the relatively large age and long duration of the dislocation, resulting in severe lesions of the acetabulum, proximal femur and soft tissues. Some people advocate that the treatment of double hip dislocation in children older than 8 years old should be abandoned. Obviously, simple abandonment of the treatment is not conducive to the physical and mental development of the children, and will certainly bring some late problems. Our hospital has adopted Steel pelvic triple osteotomy combined with other surgeries to treat 36 cases (45 hips) of hip dislocation in children older than 8 years old since 2004, and the therapeutic effect is satisfactory. Clinical data In our group, 36 cases (45 hips) of large-age hip dislocation were 7-16.5 years old at the time of surgery, with an average age of 10.2 years old, among which 11 cases were male and 25 cases were female, 9 cases were bilateral and 27 cases were unilateral. Steel pelvic triple osteotomy was performed in all cases, 32 cases (40 hips) underwent simultaneous cut and reset, and 34 cases (43 hips) underwent simultaneous femoral shortening rotational osteotomy or internal rotation shortening rotational osteotomy. No preoperative bone traction was performed in this group. After surgery, the hip was immobilized in herringbone cast for 6~7 weeks, and the cast was removed for functional exercises. Kirschner’s pin was removed or postponed depending on the osteotomy, and weight-bearing walking was started at 3 months after surgery. Surgical method The patient took the lateral position, sterilized the hip and spread the towel, made a transverse incision 1cm at the head side of the skin fold of the hip, directly to the gluteus maximus muscle, retracted the gluteus maximus muscle, and felt out the sciatic tuberosity. Then the periosteum was incised at the sciatic tuberosity, and the periosteum was peeled as far as possible (sometimes it was difficult to peel), protected by two periosteal strippers, and the bone was amputated with a bone biting forceps for about 1cm, and the incision was closed layer by layer. Then take the anterior Bikini incision of the hip joint, the same Salter osteotomy to expose the ilium. The hip joint was flexed internally, and the pubic branch was peeled medially under the periosteum until the medial aspect of the pubic tubercle, protected by two periosteal strippers or right-angle forceps, and the pubic branch was amputated medially with a bone cutter. The final iliac osteotomy is the same as the Salter osteotomy. At this point, the acetabular segment can be fully mobilized, the acetabular segment is rotated, and a femoral or iliac block is built in. It was fixed with two 2mm Kirschner pins. Results A follow-up of 1.5 to 5.8 years (mean 3.3 years) was obtained in this group. Clinical function and radiographs of all cases were scored and evaluated using Zhou’s congenital hip dislocation efficacy evaluation criteria, of which 26 hips were excellent, 12 hips were good, 5 hips were acceptable, and 2 hips were poor, with an excellent rate of 84.4%. Discussion There are many difficulties in the treatment of developmental hip dislocation in older children, and the key to success lies in achieving centric reset of the femoral head, increasing acetabular coverage of the femoral head, and preventing the occurrence of complications such as necrosis of the femoral head, re-dislocation, and joint stiffness. The results of their treatment are often unsatisfactory. Hartofilakidis et al. had a long-term follow-up of 356 cases of untreated congenital hip dislocation and hip dysplasia, which showed that those with pseudo-acetabular formation developed severe pain due to osteoarthritis at an average age of 32 years, and those without pseudo-acetabular developed hip pain due to muscle fatigue at an average age of 46 years. Therefore, the treatment of hip dislocation in older children should not simply be abandoned, but efforts should be made to improve surgical techniques and outcomes. Salter pelvic osteotomy, with the age of the child, the pubic symphysis and periprosthetic soft tissue structure elasticity decreases, the acetabulum is difficult to be reoriented during the operation.Steel pelvic triple osteotomy, in the cut ilium at the same time also cut the pubic bone and the sciatic bone, to overcome the above shortcomings. Since this procedure utilizes the articular cartilage and subchondral bone, it is an acetabular reconstruction procedure. The triple osteotomy has no hinge and the amputated acetabulum is completely free, therefore there is greater mobility to obtain coverage of the acetabulum both anteriorly and laterally. Therefore, in older children with an AI of about 45°, a Steel pelvic triple osteotomy with no loss of cartilage on the acetabular surface and no reduction in acetabular capacity can result in a stable hip that conforms to normal anatomy. Subtrochanteric shortening rotational osteotomy is very important. In this group, subacromial osteotomy was performed in 43 and 45 hips. Sufficient intraoperative shortening is conducive to reducing joint pressure, reducing femoral head necrosis, and facilitating the recovery of joint function. In this group, the average shortening was 3cm. Due to long-term dislocation, the anterior tilt angle of the children was increased, and the increased anterior tilt angle and neck stem angle had to be corrected during the operation. In this group, the anterior tilt angle was corrected to 10-15°. This is an important step to prevent re-dislocation and widening of the joint space. The joint capsule should be preserved and tightened moderately during the operation. Postoperative cast immobilization for 6~7 weeks, early removal of the cast functional exercise, according to the healing of the osteotomy appropriately prolong the time of extraction. It can reduce the chance of joint stiffness. CONCLUSION The surgical efficacy was significantly improved by improving surgical technique and preoperative as well as postoperative management, so Steel pelvic triple osteotomy is an effective procedure for the treatment of developmental hip dislocation in older children.