The relationship between the treatment of congenital dislocation of the hip and avascular necrosis

Femoral osteotomy is not recommended for children aged 2-3 years with Tönnis grade III developmental dysplasia of the hip

The objective of this study was to compare outcomes following open reduction with and without femoral shortening when treating patients aged 2-3 years with Tönnis grade III developmental dysplasia of the hip (DDH). In this prospective study, 78 patients (6 boys and 72 girls; mean age: 27.8 months; age range: 24-35 months) with Tönnis grade III DDH at our hospital from January 2014 to August 2017 were included. There were 34 hips in the without femoral shortening group and 44 hips in the femoral shortening group. Clinical outcomes were rated using the modified McKay criteria, and the hips were graded using the Severin score. Avascular necrosis (AVN) and redislocation were assessed. Mean follow-up was 26.5 months (range 17-32 months). In the without femoral shortening group (n = 34), there were five patients with AVN (14.7%), and 30 scored excellent and 4 scored good results per the modified McKay criteria. Further, 28 excellent and six good results were obtained using the Severin scale; no patient had redislocation. In the femoral shortening group(n = 44), there were seven patients with AVN (15.9%), and 38 scored excellent and six scored good results per the modified McKay criteria. Further, 31 excellent and 13 good results were obtained using the Severin scale; no patient had redislocation. Additionally, there were no statistically significant differences based on Modified McKay criteria, Severin score and AVN rate. Femoral shortening is not required for children aged 2-3 years with Tönnis grade III DDH.

Evaluation of the risk factors of avascular necrosis of the femoral head in developmental dysplasia of the hip in infants younger than 18 months of age

Sixty-seven dysplastic hips of 54 infants with an average age of 11.9 months were treated by the same surgical technique, including iliopsoas and adductor tenotomies via medial approach and arthrography for verification of the concentric reduction. The average follow-up period was 44.5 months. The rate of overall avascular necrosis (AVN) was 27% and that of severe AVN was 7%. With the numbers available in the study, a statistically significant relationship could not be found between the rate and severity of AVN and several preoperative and intraoperative components such as age, sex, side, dislocation grade, development of the ossific nucleus and qualitv of intraoperative reduction. Nevertheless, hips of infants treated between 13 months and 15 months of age, hips of male patients and left hips had slightly higher ratios of ischemic changes that were not statistically significant.