Fovea alta
Fovea alta is a radiographic sign that refers to as an abnormally superior position of the fovea capitis femoris in relation to the acetabular socket.
Usage
Fovea alta is significantly associated with acetabular dysplasia and can be used as an indicator or diagnostic marker for the condition , otherwise, it is not associated with coxa valga.
Fovea alta can be evaluated on plain anteroposterior radiographs of the hip as well as on mid-coronal CT reformats or MR images with the delta angle.
Measurement
The delta angle is formed with the vertex at the femoral head center and lines to the medial edge of the acetabular sourcil and to the superior edge of the fovea capitis femoris.
Interpretation
A delta angle >10° is considered normal, whereas ≤10° indicates fovea alta .
The reported sensitivity, specificity and accuracy of the delta angle on MRI were 69%, 82% and 76% respectively .
History and etymology
The concept of fovea alta as a potential diagnostic marker of dysplasia of the hip in adults was first introduced by Nötzli et al. in 2001 .
See also
