Pediatric hip (abduction-internal rotation view)

The abduction-internal rotation view (AIR view), also known as the Von Rosen view, is a radiographic projection of the hip demonstrating the relationship between the femoral head and the acetabulum.

Indications

The von Rosen view is used in the diagnosis of developmental dysplasia of the hip in pediatric patients. This view forces dislocation of the affected hip(s) by abducting the leg to 45 degrees, hip the same principle used in the Ortolani test ¹. 

Patient Position

• patient is supine

• the patient's legs are forcibly abducted to a minimum of 45 degrees

• the femora are internally rotated ¹

Technical Factors

• AP projection

  • centering point

  • midway between the anterior superior iliac spine and the pubic symphysis

• collimation

  • superior to the iliac crest

  • inferior to the proximal third of the femur

  • lateral to the skin margins

• orientation 

  • landscape

• exposure ⁴

  • 63-70 kVp

  • 2-5 mAs

• SID

  • 100 cm

• grid

  • variable based upon pediatric patient size

Image technical evaluation

• bony pelvis is demonstrated from the iliac crest to the proximal third of the femur

• the femur is abducted to at least 45 degrees 

• obturator foramina are equal and open

• subluxed hips will relocate however, fully dislocated hips will not relocate  

Practical points

The resultant radiograph will demonstrate the relationship between the long axis of the femur and the acetabulum. In a child with normal hips, the long axis of the femur will align with the lateral margin of the acetabulum, indicating that the hip is enlocated. In a child with dysplastic hips, the long axis of the femur will align with the anterior superior iliac spine ². 

Abduction of less than 45 degrees may result in a false-positive test ².

This projection is primarily pediatric but may be performed in the evaluation of the adult pelvis.