The Analysis For Redislocation After Operative Reduction Of Developmental Dislocation Of The Hip Between Dislocation Degree

Objective: Developmental dislocation of the hip(DDH) is one of most frequent deformities in children,As the growth of the age, many typical osteoarthritis patients,some patients even in the years before the need for artificial hip replacement. The goal of treatment of DDH is to achieve a stable and painless hip. Treatment of developmental dislocation of the hip(DDH) is widely used a surgical approach.However, it has been reported that incidence of these complications after open reducti on is 5 %.To explore,the causes of redislocation after one-stage operation of the hip through retrospective study.Methods: We retrospectively reviewed 652 patients with a total of 864 hip joints with DDH, all aged >18 months.All the hip joints were treated with one-stage procedures including open reduction, pelvic osteotomy, and femoral. Patients with known neuromuscular, pathological dislocation of the hip such as previous hip infection and syndromic disorders were excluded. In the 652 patients(864 hips), the mean age at surgerywas 5.8 years(range: 1.5–13.2 years). Two hundred and twelve(32.5%) of the652 patients had bilateral DDH,and 440(67.5%) had unilateral DDH shortening. The patients were divided into four groups according to the degree of dislocation:Group I:Tonnis grade I; Group II: Tonnis grade II; Group III: Tonnis grade III,and Group Ⅳ:Tonnis grade Ⅳ. The latest clinical and radiographic outcomes were evaluated and compared among the four groups. All hip joints were treated with one-stage open reduction and Salter, Pemberton, Dega, Chiari or Steel osteotomy,combined with femoral shortening and derotation osteotomy if necessary, by three senior surgeon.The proximal bone cutting shall be four hole straight steel plate or Angle steel plate fixation. Postoperative to outreach 30 ° to 45 ° bend hip hip herringbone plaster fixed six weeks, preoperative without traction. Finally according to the result of X-ray judge whether there is any postoperative dislocation.Results: The average age was 5.8 years(1.5-13.2 years). The average follow-up time of 6.2(3.2-8.9 years). According to Mc Kay postoperative good or excellent clinical feature parting a total of 79.4%. According to the type Severin image credits, good or excellent 732 hips(84.7%). For radiographic outcomes, 732 hips(84.7%) were classified as good or excellent.14 hips(1.6%)with redislocation and 26 hips(3.0%)with residual acetabular dysplasia. We found the incidence of redislocation and residual acetabular dysplasia was observed in Tonnis grade II and III hip dislocation(p < 0.001).Conclusion: One-stage treatment of DDH had a good outcome. Tonnis grade II and III DDH is a risk factor for redislocation and residual acetabular dysplasia after the one-stage operation.