A new methodology for the measurement of the Wiberg angle in infants under 3 months.

This article describes the measurement of the Wiberg center edge angle in infants under 3 months using sonographic images of their hips. In the literature review, there was no reference of the application of this angle in this particular age group. Thus, a methodology has been developed based upon the fact that, at this age, the acetabular roof constitutes a large portion of hyaline cartilage. In this way, it was concluded that it was not possible to apply the original Wiberg method since the center of the femoral head can be only estimated and not accurately determined in plain radiography. For this present study, 400 hips of 200 infants were analyzed. All these hips were classified as type 1a or 1b, according to Graf. The sonographic images were transferred to a Pentium computer through a video Spigot interface. The images were analyzed by software specially developed for this purpose. Since ultrasonography allows the exact recognition of the anatomical elements of the hip joint in young children, software provided the acetabular cartilaginous roof angle that corresponds to the center edge angle in adults. The authors believe that this method will be helpful in the early detection of morphological alterations in the hip joint.