Magnetic resonance imaging of the femoral head morphology of the hip after normal children and DDH with closed and open reduction / 国际儿科学杂志

ABSTRACT

Objective To investigate the shaping rules of the femoral heads in the morphological perspective.The research objects are hips of normal children and children who have developmental dysplasia of the hip(DDH) and after closed reduction or limited open reduction.At the same time measuring and analyzing normal hip femoral head form changing with the children's age.Methods Collecting the DDH cases that after closed reduction and limited open reduction from June 2013 to December 2015.The follow-up period was more than 1 year.MRI images were collected before surgery,6 months after surgery,1 year after surgery,and 2 years after surgery.In addition,normal hip joint MRI images from 0 to 18 years old were collected for controlled study.Descriptive data on the affected side,healthy side and normal hip joint morphology of the hip dislocation were statistically analyzed.Results (1) The mean eccentricity of femoral head in normal hip decreased from (0.362 ±0.069) at 1-2 years to(0.141 ±0.028) at 18-19 years.(2) The eccentricity of femoral head before closed reduction and limited open reduction were both greater than those of healthy side.There was no significant difference in the eccentricity of the femoral head between the healthy side and the affected side at 1 year after closed reduction (P =0.211).There was no significant difference in the diameter of the bilateral femoral heads (P =0.871).The eccentricity of the bilateral femoral heads remained different at 2 years after limited open reduction (P =0.028),and the diameter of the affected femoral head exceeded the healthy side 1 year after surgery (P =0.001).Conclusion The shape of the femoral head of normal children gradually approaches the spherical shape with age.One year after closed reduction of DDH,the shape and size of the affected femoral head are close to the healthy side,and the femoral head of the affected side increases more than the healthy side in 1 ～ 2 years after open reduction and the morphology is still different.