Fundamentals of sonographic diagnosis of infant hip dysplasia.

Since 1978 we have examined 3,500 infant hips by ultrasonography. We classified these hips into four basic categories: (a) normal, according to age; (b) delayed ossification (dysplasia); (c) partial dislocation (subluxation); and (d) dislocation (total luxation). Ultrasound provides no exposure to radiation and can differentiate soft tissue much better than radiography. It clearly offers a new tool for infant screening with the potential for widespread application.