ABSTRACT
Objective To discuss the feasibility of ultrasound in evaluating the effect of closed reduction with cast fixation on developmental dislocation of the hip.Methods Seventy-three cases with unilateral DDH treated by closed reduction with cast fixation under frog position were detected by ultrasound on the medial cross-section of the hips.The position relation between femoral head and acetabulum of the hips were demonstrated,the relevant parameters (the vertical distance between the femoral head and the central line through pubic symphysis) were measured and compared with the contralateral side to understand the situation of the femoral head.Results The contour of the femoral head and the ossification center can be visually displayed,the relative position relation of the femoral head and acetabulum can be demonstrated on the medial cross-section of the hip under frog position by ultrasound to judge the status of closed reduction.The measurement of the ultrasonic parameters can provide quantitative indicator for the status of reduction.Conclusions Ultrasound can be viewed as the first imaging tool to evaluate the effect of closed reduction with cast fixation on developmental dislocation of the hip for it is simple,intuitive and no radiation injury.
ABSTRACT
Objective To discuss the changes of correlative ultrasonic parameter index of normal hips and abnormal hips with developmental dislocation of the hip (DDH) in infants of different months in order to provide objective information for the diagnosis. Methods Three-hundred and seventy-eight normal hips and 244 hips with DDH among 622 hips of 311 infants were detected by ultrasonography(US). The morphology and structure information of hips were observed, and the values of ultrasonic parameter index,including angle α,angle 3, acetabular index( AI), femoral head percentage of cover(FHC) of normal hips and abnormal hips were measured. The values of each parameter index were collected by being divided into different groups (3 months a group) ,then the correlation was analyzed. Results Morphology and structure,position relation between femoral head and acetabulum of the hips were demonstrated by US. Normal or abnormal hips,the degrees of abnormal hips and the types of hips could be judged according to the findingsof US. Analysis of values of parameter index of normal hips:①There was significantly statistical significance in the values of ultrasonic parameter index, such as angle α, angle β, AI, FHC of normal hip between the groups of different age (P＜0.01). ②There was correlation between the age and the values of each parameter index, among which angle α, FHC had positive correlations with age ( r = 0. 537, 0. 554,respectively ) while angle β and Al negative correlations ( r = -0. 465, -0.424, respectively ). ③There was correlation between the values of different parameter index. Both angle β and AI had negative correlation with angle α,among which the latter correlation was closely ( r = - 0. 794). No statistical significance was found between the ultrasonic values of each group under different ages of different type abnormal hips( P ＞0.05) ,but closely negative correlations still existed between angle α and AI. ConclusionsUS can be viewed as an early definite and a screening method of diagnosing DDH.For older infants (above 6 months) it will be more accurate to analyze the ultrasonic parameter index together with the age of infants.