Presentation
Full-term newborn with bilateral hip clunk.
Patient Data
Alpha angle measures less than 60 degrees bilaterally, indicating acetabular dysplasia bilaterally.
Bilateral superolateral subluxation/dislocation of the femoral head with only minimal bony coverage of the femoral head by bony acetabulum.
Case Discussion
This is a nice example of bilateral hip dysplasia. Ultrasound of the hip is the modality of choice in the neonate period before beginning of the ossification of the capital femoral epiphyses. Ultrasound has the ability to show the cartilaginous femoral head and allow direct visualization of the actual position of femoral head in relation to the respected acetabulum. Alpha angles, which are the equivalent of acetabular angles on x-ray, are used to assess the degree of acetabular dysplasia and normally they measure more than 60 degrees and less than 60 degrees in cases of acetabular dysplasia.