Thanks to neonatal screening, idiopathic congenital dislocation of the hip (CDH) is generally diagnosed and treated at an early age. Despite this measure, late diagnosis of CDH still occurs. The goal of this article is to analyse the results of Petit-Morel’s closed reduction (CR) technique in the treatment of CDH diagnosed between 1 and 5 years old. We reviewed 72 hips in 60 patients. The treatment method was the same for all patients, beginning by bilateral longitudinal traction to achieve ‘presentation’ of the hip. It was followed by ‘penetration’ in a hip spica cast made under general anesthesia. The third step was an almost systematic surgical treatment of the remaining acetabular dysplasia. Results were evaluated using the radiological Severin score. Average follow-up was 11.9 years. The failure of CR occurs only twice. In this two cases, open reduction showed intraarticular obstacles to reduction. The only case of avascular necrosis (AVN) occured in one of this two failures of CR. At last follow-up, 95.8% of hips were rated as normal, or midly deformed. Young age at treatment significantly influenced the prognosis in our series. Neither the gender nor the height of the dislocation did appear to have any influence on the result. The patients which did not undergo a periacetabular osteotomy were significantly younger than the other one in the series. Pelvic osteotomy is an integral part of the method, as after 18 months many hips have lost their capacity to correct the remaining dysplasia. However, we only perform this osteotomy if the hip shows no sufficient correction during the semesters following the reduction od the dislocation. Considering Severin score, it is impossible to privilege closed or open reduction, as the results of both methods are close. However, in case of failure of reduction, which occurs in both methods, a second open reduction is much more difficult to achieve than and open reduction in a hip first treated by closed reduction. The results of this second surgery on the hip are poorer, with higher rates of AVN. Moreover, long-term functional and radiological deterioration of the hip is higher after open reduction than closed reduction. Lowest rates of AVN are reported after traction followed by closed reduction compared with exteporaneous reduction or open reduction, thanks to progressive reduction of the hip. Finally, mention should be made of the cost of the treatment. Petit-Morel’s protocole is expensive, both because of the duration of stay in the hospital, and by indirect costs as parent adaptation of its work during the treatment. The cost of open reduction is lower. However, considering the prooved better results of the closed method, requiring lower rates of further surgical procedure, we think that this method is the one to be promoted for treatment of CDH in children between 1 and 5 years old.

The treatment of developmental dysplasia of the hip diagnosed after the first year of life remains controversial. A series of 36 children (47 hips), aged between one and 4.9 years underwent gradual closed reduction using the Petit-Morel method. A pelvic osteotomy was required in 43 hips (91.5%). The patients whose hips did not require pelvic osteotomy were among the youngest. The mean age at final follow-up was 16.1 years (11.3 to 32). The mean follow-up was 14.3 years (10 to 30).

At the latest follow-up, 44 hips (93.6%) were graded as excellent or good according to the Severin classification. Closed reduction failed in only two hips (4.3%) which then required open reduction. Mild avascular necrosis was observed in one (2.1%).

The accuracy of the reduction and associated low complication rate justify the use of the Petit-Morel technique as the treatment of choice for developmental dysplasia of the hip in patients aged between one and five years.