股関節疾患の早期補助診断法としての Fat Pad Sign について

抄録

Lateral capsular shadow and iliopsoas sign in A-P view and fatty radiolucent line anterior to the femoral neck in lateral view were studied retrospectively between normal adult hips and cases of avascular necrosis of the femoral head frequently associated with hydrops. The visible radiolucent line was seen in 93%, 77.5% and 77% respectively of the normal hips with any shape of variations. The collapse type of avascular necrosis (stage 3) had clear radiolucent shadow in 61.5%, 69% and 85.1% respectively.
The involved hip showed the expansion over 5mm in comparison with normal side or any displacement in 80%, 20% and 77% respectively.
It was concluded that lateral capsular shadow lateral to the head in A-P view and radiolucent layer anterior to the hip in lateral view (90 degree of flexion and 45 degree of abduction) are useful as a radiological sign for the diagnosis of intracapsular swelling.