Frequency of Acetabulum Retroversion Formation after Reorienting Pelvic Osteotomies in Children Over 7 Years Old with Developmental Dysplasia of the Hip

Background. One of the reasons for the development of the "pincer" type of femoroacetabular impingement are various reorienting pelvic osteotomies, which are widely used in the treatment of children with developmental dysplasia of the hip (DDH). The aim of the study was to evaluate the frequency of formation of retroversion of the acetabulum after reorienting pubic-iliac, iliac-sciatic and triple pelvic osteotomies in children over 7 years old with DDH I-II degree according to Crowe. Material and Methods. The retrospective study is based on the results of radiometry of 60 patients (69 hip joints) at an average age of 11.6 +/- 2.9 years with DDH I-II degree according to Crowe who underwent surgical treatment in 2014-2016. The patients were divided into three groups of 20 patients each. Group I underwent an iliac osteotomy. Group II underwent an ilio-sciatic osteotomy. In group III patients, the acetabulum was reoriented by triple (pubo-ilio-sciatic) pelvic osteotomy. In addition to standard radiometry of the hip joints, the following indicators were evaluated: signs of acetabular retroversion ("cross-over", "posterior wall", "ischial spine"), as well as the index of acetabular retroversion (ARI). Results. The assessment of the main radiometric parameters of the spatial position and the correction value of the acetabulum was carried out at least 36 months after the surgical treatment. There were no statistically significant differences in the radiometric parameters of the spatial orientation of the acetabulum in group I and II patients (p>0.05), except for the degree of bone coverage, which was significantly higher in group II patients (p<0.05) than in group II patients, which indicated the presence of hypercorrection. In patients of group III, the values of the above-mentioned indicators varied within the physiological values. Retroversion of the acetabulum was observed in more than half of the patients in group I and in almost all patients in group II. In group III patients, acetabular retroversion was observed in only 3 patients. Conclusion. In the vast majority of cases, a double pelvic osteotomy (pubo-iliac and ilio-sciatic) leads to the formation of hypercorrection of the acetabular fragment and its retroversion in comparison with a triple pelvic osteotomy. The pathological orientation of the acetabulum, despite the achieved stability of the hip joint, can be a morphological substrate for the development of femoro-acetabular impingement and, as a result, coxarthrosis. In the treatment of children with DDH over 7 years old the operation of choice is a triple pelvic osteotomy.