click below
click below
Normal Size Small Size show me how
Eval Test 3
tib-fib, knee, femur, AP hip, Frog hip, xtable hip & patella
Question | Answer |
---|---|
For AP tib/fib what joints must be included? | both knee and ankle (include at least 1-1 1/2" beyond joints |
What superimposition is there on the AP tib/fib? | partial superimposition of fibula and tibia on proximal and distal ends |
How do you check for rotation on the AP tib/fib? | *interosseous spacing: more space=medial rotation less space=lateral rotation *femoral & tibial condyles in profile *intercondylar eminence centered in the intercondylar fossa |
What is the interosseous spacing? | spacing between the fibula and tibia |
What is the body positioning for the lateral tib/fib? | rotate the body until the patella is placed perpendicular to the IR. |
What is the CR for the AP and lateral tib/fib? | midshaft of lower leg |
On a lateral tib/fib, if there is too much superimposition of the tibia over the proximal head of the fibula how is the knee position in respects to the IR? | the knee is elevated and too far away from the IR. |
On the lateral tib/fib, the femoral condyles may not be superimposed why is this? | due to beam divergence |
How much is the foot and leg inverted on the AP proximal femur? | 15 degrees (just like AP hip) |
How much is the foot and leg inverted for the distal femur? | 5 degrees (just like AP knee) |
On the AP proximal femur, which trochanter should be in profile on the lateral side? | greater |
Which joint should be included on the AP distal femur? and how much should be included? | knee joint must be included; lower margin of IR should be about 2" below knee |
How much is the leg rotated internally on the AP knee? | 3-5 degrees |
What is the CR for the AP, internal and external obliques of the knee? | 1/2" distal to the apex of the patella |
How much is the tube angled for asthenic patients on the AP knee? | 5 degrees caudad; when thighs and buttocks are under 19cm |
How much is the tube angled for hypersthenic patients on the AP knee? | 5 degrees cephalic; when the thighs and buttocks are greater than 24cm |
Which joint space should be open on the AP knee? | tibiofemoral |
How should the patella be positioned on the AP knee? | completely superimposed on the femur and in the center. |
Is it ok for the tibial plateaus to be superimposed on the AP knee? | yes |
How can you detect rotation for the knee? | *position of the patella *superimposition of the fibula & tibia *shape of condyles |
Which oblique knee rotation has less superimposition of the fibula from the tibia? | medial rotation |
On an AP knee, if the knee is bent which joint space closes? | tibiofemoral |
On the lateral knee which anatomy should be perpendicular to the IR? | patella & femoral epicondyles |
How much should the knee be flexed on the lateral? | 20-30 degrees |
What is the CR for lateral knee? | 1" distal to medial epicondyle |
How much is the tube angled on the lateral knee? | 5 to 7 degrees cephalic |
Why is the tube angled on the lateral knee? | because the medial condyle extends lower or more distally than lateral condyle |
Which joint spaces should be open on the lateral knee? | femoropatellar & tibiofemoral |
T/F: On the lateral knee, the fibular head should be free of superimposition of the tibia. | false; if this occurs it means the knee is too close to the IR, and the foot is elevated. There should be slight superimposition on the lateral knee. |
If the knee is bent more than 30 degrees what happens? | over flexion closes the femoropatellar joint space. |
How can you detect rotation on a lateral knee? | *position of the fibula *lack of superimposition of the medial and lateral condyle |
Which condyle has the adductor tubercle connected to it? | medial condyle |
What does it mean when the distal margins of the femoral condyles are not aligned? | incorrect tube angulation |
If the fibula is used to detect rotation, where is it positioned for the knee to be too far away from the IR? | the fibula is anterior and more superimposed by the tibia than normal |
How much do you rotate the knee for internal and external oblique knee? | 45 degrees |
where is the CR placement for medial and lateral oblique knee? | 1/2" distal to apex of patella; midpt of knee |
what does the medial oblique knee demonstrate? | lateral femoral condyle and tibial plateau in profile |
On a medial oblique knee, if the tibiofibular joint space is closed how is the obliquity? | too shallow |
If the fibula is not superimposed whatsoever by the tibia on a lateral knee, how is it rotated? | the knee is too close to the IR, heel is elevated; the fibula is too posterior |
If you are determining rotation on a lateral knee using the medial or lateral condyle, how is the condyle positioned for the knee to be too far away from IR? | the medial condyle is too posterior |
If the knee is elevated on a lateral knee, what are the ways you can tell? | *the medial condyle (adductor tubercle) is too posterior *the fibula is too anterior or superimposed by the tibia more than slightly |
What is the only projection that opens up the tibia and fibula at their proximal articulation? | medial oblique knee |
What does the lateral oblique knee demonstrate? | medial condyle & tibial plateau in profile |
What are the different tunnel views for the knee? | *Camp-coventry Method (PA) *Holmblad Method (PA) *Beclere Method (AP) |
Which tunnel view has the body positioned PA where the body leans forward 20-30 degrees from vertical? | Holmblad Method |
What is the tunnel view that the lower leg is flexed 40 degrees and the CR is perpendicular to the long axis of the lower leg? | Camp-coventry Method |
What do all of the tunnel knee projections have in common? | all the CRs are perpendicular to the tib/fib |
What does it mean when the patella can be seen through the intercondylar fossa? | the knee is over-flexed |
As you flex the knee, how does the patella move? | it moves distally or downward |
What does it mean if the distal margins of the condyles are separated? | there is not enough tube angulation; causing the joint space between the femoral condyles and tibia to be closed. |
what is the CR for the PA patella? | perpendicular to mid patella area |
How much do you flex the knee for a lateral patella? | 5-10 degrees |
What is the CR for the lateral patella? | perpendicular to mid patellofemoral joint |
What are the different tangential projections for the patella? | *settegast Method *inferosuperior (sunrise) projection *bilateral merchant method *hughston method |
What projection has the patient's knee flexed 90 degrees and the CR is between the patella & femoral condyles? | settegast method |
How much is the knee flexed for the inferosuperior sunrise projection? | 40-45 degrees |
What is the CR for the merchant bilateral method? | 30 degrees caudad; midway between patellae |
which projection for the patella is PA and the knees are flexed 45 degrees and the tube is angled through the femoropatellar joint space? | Hughston method |
Which side is the larger condyle normally on? | medial side |
How much should the knees be flexed on the bilateral merchant? | 40 degrees |
How much should the knees be flexed for the Beclere method? | Bontrager: 40-45 degrees Merrill's: 60 degrees |
What is the CR placement for the Beclere method? | 1/2" distal to the apex of the patella |
What is the CR placement for the AP hip? | perpendicular to the femoral neck Merrill's: 2 1/2" distal to midpoint of ASIS & pubic symphysis Bontrager: 1-2" distal to mid-femoral neck |
Where is the femoral neck located? | 1-2" medial and 3-4" distal to ASIS |
What makes the femoral neck foreshortened on the AP Hip? | *externally rotating the foot *foot being in a natural straight position |
Rotating the leg & foot 15 degrees internally affects the visualization of what? | *lesser trochanter *femoral neck (elongates) |
T/F: for the AP hip, you want to include the acetabulum, and adjacent parts of pubis, ischium & ilium. | True |
How much of the proximal femur should be included in the AP hip? | 1/3 |
What is the patient position for the lateral frog-leg hip? | supine; flex knee and hip on affected side with sole of foot against the inside of opposite leg at the knee. |
How much is the recommended abduction for the lateral frog hip? | 45 degrees from vertical |
On the lateral frog hip, how much should the affected side knee be flexed from the table? | 60-70 degrees from the table |
What is the CR placement for the lateral frog-leg hip? | perpendicular to IR; directed to mid-femoral neck |
T/F: on the lateral frog-leg hip, the femoral neck should not be overlapped by the greater trochanter. | false; the femoral neck will be overlapped by the greater trochanter. |
On the lateral frog-leg hip, where is the lesser trochanter positioned almost everytime? | the lesser trochanter should be seen on the posterior surface of the femur. |
What happens when the leg is not flexed enough on the lateral frog? | the greater trochanter is too lateral |
What is flexion responsible for on the lateral frog? | greater trochanter placement |
What happens when the leg is flexed too much on the lateral frog-leg? | the greater trochanter is too medial |
What does abduction demonstrate on the lateral frog-leg hip? | femoral neck; whether its foreshortened or not |
What happens when the affected hip is abducted too much? (80 degrees from vertical) | *foreshortened femoral neck *femoral shaft in profile |
What happens when the affected hip is abducted too little? (20 degrees from vertical) | *femoral neck in profile *femoral shaft is foreshortened |
What does it mean when it says the femoral shaft is foreshortened? | the distance/space between the greater and lesser trochanters is shortened. |
On the tangential patella, what may cause the femoropatellar joint space to be not opened enough? | *incorrect tube angle *knees over-flexed |
What positioning error foreshortens the femoral neck on a lateral frog leg? | too much abduction |
what positioning error places the greater trochanter too medially on a lateral frog leg? | too much flexion |
What positioning error places the greater trochanter too lateral on a lateral frog leg? | too little flexion |
What positioning error foreshortens the femoral shaft on a lateral frog leg? | too little abduction |
On a lateral frog leg if the greater trochanter still remains lateral what positioning error is this? | not enough flexion |
On a lateral frog leg if the greater trochanter moves too medially what positioning error is present? | too much flexion |
Abduction affects what? | femoral neck |
For the xtable lateral hip, how much do you rotate the leg & foot? | 15-20 degrees medially |
T/F: Rotate the leg & foot 15 degrees internally for all xtable lateral hips. | false; do not rotate for trauma patients, this includes prosthesis patients |
How should the IR be aligned for a xtable lateral hip? | IR should be parallel with the long axis of the femoral neck |
What is the CR placement for a xtable lateral hip? | perpendicular to long axis of the femoral neck |
If the foot & leg are inverted, what is the position of the lesser trochanter? | only a small part of the lesser trochanter will be visualized posteriorly. |
How much should the knee be flexed on a lateral femur? | 45 degrees |
For the proximal lateral femur what is the patient positioning? | unaffected leg positioned posterior |
For the distal lateral femur what is the patient positioning? | unaffected leg positioned either posterior or anterior (depends on patient comfort) |
where is the greater trochanter on the proximal lateral femur? | superimposes the whole femoral neck due to beam divergence |
On a distal lateral femur, what if the femoral condyles are not superimposed over each other? | this may happen because of beam divergence; this causes the space between the femoral condyles and tibia to be closed as well |
what space should be open on the distal lateral femur? | femoropatellar joint |