1Department of Orthopedic Surgery, Takashima Hospital, 2Department of Radiology, Takashima Hospital
Ultrasonography, Congenital dislocation of the hip joint, Acetabular dysplasia, Mass screening
The ultrasonic examination of the hip joints of the new born baby and infant has been applied to diagnose the congenital dislocation of the hip joint (CDH) since Graf introduced the method in 1980. In this study, we performed mass screening for CDH using Graf's ultrasonic method on a total of 154 subjects (308 hip joints) ranging from 5 days to 10 months old during the period between May, 1985 and June, 1986. Normal structures of the hip joints of 151 subjects (302 hip joints) could be obtained on ultrasonogram. Beside these ultrasonograms of normal hip joints, 2 cases of CDH were observed. In these cases, ultrasonograms of CDH showed the femoral head and neck located outward and upward, and so the femoral neck-head-ilium line was distinctly interrupted. However, the acetabular dysplasia could not be detected with Graf's method because of impossibility to image both joints synchronously due to technical difficulty and to apply the Hilgenreiner line as the standard line. Therefore we have designed a new device with which the right and left images could be obtained at the same time. We examined 65 subjects (130 hip joints) by ultrasonography using the new device and could have the acetabular angle for diagnose of the acetabular dysplasia. In 28 of these subjects, the acetabular angle on ultrasonograms was compared with the alpha angle on X-ray pictures. The acetabular angle gained with ultrasonography was 31.9±3.9 degrees and average 7.1 degrees larger than the alpha angle showed 24.8±4.8 degrees by X-ray examination. Fairly severe acetabular dysplasia could have been detected by ultrasonography using the new device.