Chapter 41 - Radiographic Evaluation of the Hip Flashcards
dunn lateral
performed with 20 deg hip abduction, neutral rotation and with the hip flexed at 90 and 45.
best to show: hip joint, femoral head, acetabulum, and particularly the relationship of the femoral head and acetabulum.
**increased sensitivity for detecting femoral head-neck asphericity (aka CAM deformities)
Frog leg lateral
visualizes the anterior femoral head/neck junction
esp the anterosuperolateral femoral head!
False profile view
best for viewing acetabular coverage anteriorly and posteriorly
patient stands with the hip against the cassette
crossover sign
on AP XR
acetabular retroversion
acetabular index
on AP pelvis XR
aka tonnis angle
horizontal line drawn between acetabular teardrops
line drwn from that line to the lateral edge of the sourcil
normal is <10
lateral center edge angle
<20°: acetabular dysplasia
20° - 25°: borderline acetabular dysplasia
25 - 40°: normal
>40°: pincer morphology of FAI
coxa valga
increased neck shaft angle
coxa vara
decreased neck shaft angle
causes of pincer impingement
coxa profunda, acetabular protrusio, os acetabuli, acetabular retroversion
coxa profunda
acetabular cup is at or medial to the ilioischial line
acetabular protrusio
femoral head is at or medial to the ilioischial line
alpha angle
defined as a line down the femoral neck axis and a line connecting the center of the femoral head to the tart point of the superior femoral head asphericity (you are SUPPOSED to measure this on MRI axial oblique images)
CAM lesion >50
what view best demonstrates osteonecrosis of the hip?
frog leg lateral
radiolucent lesion with a sclerotic rim in superolateral femoral head
ficat classification of osteonecrosis
stage 0, I, pre- radiographic changes
II - pre-collapse, subchondral cysts, sclerosis
III - collapse with femoral head flattening
IV - OA
