- See: DDH
- ultrasound allows description of the morphology of the acetabulum and the stability of the joint (dynamic examination);
- ultrasound becomes less useful after 6 months of age because of progressive ossification of the femoral head;
- joint stability:
- femoral and acetabulum are evaluated while performing provative tests (Barlow maneuver);
- transducer is placed over the femoral head transverse to the pelvis while the hip is flexed and a Barlow maneuver applied;
- describes the cartilaginous and osseous anatomy of the acetabulum (noting depth and shape);
- Graf classification:
- coronal plane is imaged by placing the transducer over the lateral aspect of the hip;
- type I: normal hip:
- type II < 3 mo physiologic immaturity and > 3 mo mild dysplasia:
- type II hip is immature or mildly dysplastic and has a more shallow acetabulum with a round rim;
- in children younger than 3 months, most of these will spontaneously resolve;
- in children older than age 3 months, the deformity is expected to persist without treatment;
- type III: dislocation
- acetabulum is shallow;
- cartilaginous roof is displaced with eversion of labrum;
- type IV: high dislocation
- acetabular cup is flat and has the worse prognosis;
- femoral head is laterally and superiorly displaced;
- labrum is interposed between the femoral head and the lateral wall of the ilium
Ultrasound screening for hips at risk in developmental dysplasia. Is it worth it?
Ultrasound imaging and secondary screening for congenital dislocation of the hip.
Ultrasound screening of hips at risk for CDH: Failure to reduce the incidence of late cases.
Real-time ultrasound in the diagnosis of congenital dislocation and dysplasia of the hip.