Pelvis Analysis Flashcards
What is the Radiographic appearance of an AP pelvis with rotation to the left?
-left ala wider than right
-left obturator foramen is narrower than right
-left ischial spine is seen without pelvic brim superimposition
-the SP will be seen to the left of the sacrum and coccyx
What is the Radiographic appearance of an AP pelvis with rotation to the right?
-right ala wider than left
-right obturator foramen is narrower than left
-right ischial spine is seen without pelvic brim superimposition
-the SP will be seen to the right of the sacrum and coccyx
In an AP pelvis, where should the femoral epicondyles be positioned in relation to the table?
Parallel
Feet internally rotated 15-20 degrees
What should be the appearance of the proximal femur in an AP with internal rotation of the legs/feet
-femoral neck without foreshortening
-greater trochanter in profile laterally
-lesser trochanter mostly superimposed
What will be the appearance of the proximal femur if the leg/foot is not internally rotated?
-greater trochanter will be superimposed by femoral neck
-lesser trochanter will be in profile medially
-femoral neck will be foreshortened
How is the femoral neck demonstrated with extreme external rotation?
Demonstrated on end
T/F
With suspected fracture of femoral neck or proximal femur, a pelvic projection is ordered instead of an AP hip
True
*pelvic fractures are usually associated with proximal femur fractures
How will an AP pelvis be demonstrated with no internal leg rotation due to trauma?
Foreshortened femoral neck, lesser trochanter without femoral shaft superimposition
How is the proximal femur demonstrated on an AP hip?
Greater trochanter in profile laterally
Femoral neck demonstrated without foreshortening
Lesser trochanter superimposed
What should be at the centre of the exposure field for an AP hip?
Femoral head or neck
How will an AP projection of the hip be demonstrated if the patient is rotated away from the affected side?
-ischial spine is not aligned with pelvic brim, but demonstrated closer to acetabulum
-sacrum and coccyx not aligned with symph
-obturator is widened
How will an AP projection of the hip be demonstrated if the patient is rotated toward from the affected side?
-ischial spine is demonstrated without pelvic brim superimposition
-sacrum and coccyx not aligned with symph
-obturator is narrowed
What will be the Radiographic appearance with an externally rotated leg of 45 degrees?
Femoral epicondyles 60-65 degree angle with the table, the femoral neck is demonstrated on end and the lesser trochanter is demonstrated in profile
What is the Radiographic appearance of the leg is foot is positioned vertically?
Femoral condyle approx. 15-20 degree angle with the table, lesser trochanter in partial profile and femoral neck demonstrated partially foreshortened
What is the Radiographic appearance of there is insufficient flexion of the knees and hips for a frog leg?
Greater trochanter is demonstrated laterally
What is the correct amount of flexion of the knee and hip for a frog leg?
60-70 degrees with the table
What is the Radiographic appearance of there is excessive flexion of the knees and hips for a frog leg?
Greater trochanter demonstrated medially
What is the proper amount of abduction for a frog leg projection?
45 degrees
T/F
On a frog leg projection, if the is the correct amount of abduction (45degrees) the femoral necks are partially foreshortened and the proximal greater trochanter is at a transverse level halfway between the femoral head and lesser trochanter
True
What will be the Radiographic appearance of insufficient abduction for a frog leg (20-30 degrees)
Femoral necks are demonstrated without foreshortening and the prox. GT is at the same transverse level as LT
What will be the Radiographic appearance of excessive abduction for a frog leg (20 degrees to table)
Prox. Femoral shafts with minimal foreshortening, prox. GT af same transverse level as femoral head, femoral neck demonstrated on end
T/F
In a AP oblique Lauenstein, the femoral neck will superimpose the GT and the ischial spine is seen without pelvic brim superimposition
True
What evaluation criteria are used for rotation on AP oblique Lauenstein projections?
-ischial spine (superimposed?)
-symph. (Rotated?)
-obturator (narrowed?)
What is seen on an upside Judet view (internal oblique - affected side up)
Posterior rim
Iliopubic column
What is seen on a downside Judet view (external oblique - affected side down)
Anterior rim
Ilioischial column
-femoral neck demonstrated without foreshortening
-greater and lesser trochanter demonstrated at approx. same height
-LT in profile posteriorly
-GT superimposed by the femoral shaft
-ischial tuberosity in field of view
Axiolateral hip
How do you obtain an axiolateral without femoral neck foreshortening?
CR must be aligned perpendicular to femoral neck
T/F
The IR is parallel to the femoral neck for an axiolateral
True
Axiolateral
Prox. GT is demonstrated prox. To transverse level of LT and is superimposed by a portion of the femoral neck
Angle formed between femur and CR is too large
Axiolateral
Prox. GT is demonstrated distal to the transverse level of the lesser trochanter
*doesn’t happen often because of table and xray tube
The angle between the femur and the CR is too small
How will the femoral neck and GT and LT be demonstrated if there is misalignment of the CR and femoral neck
Increased angle
-femoral neck foreshortened
-GT is closer to femoral head
How will the femoral neck and GT and LT be demonstrated if there is misalignment of the CR and femoral neck
Decreased angle
-doesn’t happen often
-femoral neck foreshortened
-GT is further away from femoral head
On an Axiolateral with insufficient internal rotation of the foot, how will the trochanters be demonstrated?
GT demonstrated posteriorly
LT superimposed over femoral shaft (GT seen posteriorly will increase with external rotation)
-elongated and magnified pubic and ischial bones
-pubic ischium seen in AP projection
-pubic and ischial bones centered to collimation field
AP axial outlet projection
-ischial spines demonstrated equal
-superimposition of ischium and pubic bones
-otter foremen equal in size
-ala elongated
-pelvic inlet centered
AP axial inlet
