Knee Flashcards
Orientation for AP projection knee
10x12 lengthwise
Where is the central Ray directed for AP knee
1/2 inch inferior to the patellar apex
Variable depending on the measurement between the anterior superior iliac spine (ASIS) and the tabletop
What is the evaluation for AP knee
- Entire knee without rotation
- Femoral condyles symmetric and tibia intercondyler eminence center
- slight superimposition of the fibular head if the tibia is normal
*patella completely superimposed on the femur - open femorotibial joint space with interspaces of equal width on both sides if the knee is normal
What are the ASIS measurements?
<19 cm 3-5 degrees caudad
19-24 cm 0 degrees
>24 cm 3-5 degrees cephalad
AP knee patient position
Supine
Lateral knee IR size & orientation
10X12 inches lengthwise
True OR false the Lateral knee is not mediolateral projection
False it is 😜
For lateral knee should you turn the patient on the affected or unaffected side?
And how much should you flex the knee 🐙
Affected and flex that knee 20-30 degrees
Tell me about the central ray for lateral knee where is it directed? 👀
~It is directed 1 inch distal to the medial epicondyle
-REMEMBER angle the CR 5~7 degrees CEPHALAD 😎
To prevent fragment separation and or unhealed patellar fractures, the knee should not be flexed more than how many degrees?
10° 🥳
What are some evaluation criteria for the lateral projection of the knee?
-Knee flex 20 to 30° and true lateral position as demonstrated by femoral condyles superimposed
-fibular head and tibia slightly superimposed(over rotation causes less superimposition, and under rotation causes more super imposition)😑
-patella in lateral profile
-Open patellofemoral joint space
-Open join space between femoral condyles and tibia
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What are the evaluation criteria for lateral knee regarding anterior surface of the medial condyle and inferior surface of the medial condyle and lateral condyle. There are four.😘
Anterior surface of the medial condyle closer to the patella results from over rotation toward the image receptor
Anterior surface of the medial condyle farther from the patella results from under rotation away from the IR
Inferior surface of medial condyle are caudal to lateral condyle results from insufficient valid central
Inferior surface of lateral condyle caudal to medial condyle results from too much cephalad central angle
Why would we do an AP projection knee weight-bearing method standing?
It is used for the examination of arthritic knees and often reveals narrowing of joint space that appears normal on nonweightbearing study
Where is the central ray directed for AP projection of knees weight-bearing?
1/2 inch below the apices of the patellae
For AP oblique knees, the limb is rotated how many degrees
45°
True or false the AP oblique projection of the knee medial rotation is the most common?
True❤️
Where is the CR directed for oblique knee?
Directed 1/2 inferior to the patellar Apex
the angle is variable depending on the ASIS and table top measurement (same thing as AP knees)
Give me the evaluation criteria for oblique projection of the knees 🤔
-Tibia and fibula separated at their proximal articulation (tibiofibular articulation clearly demonstrated)
-Posterior tibia
-Lateral condyles of the femur and tibia
-Both tibial plateaus
-Margin of the patella projecting slightly beyond the medial side of the femoral condyle
Open knee joint
What is the position of the patient for a lateral knee?
Lateral recumbent
PA Axial Project
HOLMBLAD METHOD
Part Position? CR angle?
Part: Flex knee 70 degrees (from full extension)
CR: PERP
PA Axial Project
HOLMBLAD METHOD
Evaluation/Reason?
Evaluation: OPEN intercondylar fossa
Apex of Patella NOT superimposing fossa
For the lateral projection of the patella (mediolateral), you flex the affected knee how many degrees? And what’s the reason?
5° to 10°
Open patellofemoral joint space
PA Axial Project
HOLMBLAD METHOD
Pt position?
Pt Position: 1. standing with knee flexed on stool
2. Standing w/ knee flexed & placed in contact w/ IR
3. Kneeling on table
PA Axial Projection
CAMP-COVENTRY METHOD
Reason and Part position?
Open intercondylar fossa
PP: Flex Knee 40 or 50 degree angle
AP Axial Projection
BECLERE METHOD
Evaluation/Reason?
Evaluation: ~ OPEN intercondylar fossa
~ Intercondylar eminence and knee joint space
AP Axial Projection
BECLERE METHOD
Position of Part?
PP: Flex knee to place FEMUR at 60 degree angle to Long axis of TIBIA
Patella
PA Projection
Orientation? And CR?
10x12 LW
CR: PERP to Midpopliteal area (exiting patella)
Name the projection
Hughston Method (tangential projection)
Patella
PA Projection
Pt position?
Pt position: PRONE (if painful place sandbag under thigh & leg to relieve pressure)
Patella
PA Projection
Part Position?
PP: Center patella
Patella = PARALLEL w IR ~ Rotate heel 5-10 degrees laterally
Why do we do the Hughston method?
To see the patella in profile
Name this projection
Merchant Method (tangential projection)
Name the projection
Settegast Method, Sunrise Method (tangential projection)
What’s the angle of hughston method? & what’s the cr directed to?
45 & patellofemoral joint
Position of part for settegast method, tangential projection
Flex knee slowly as much as possible, or until the patella is perpendicular to the IR
With slow even flexion, the patient should be able to tolerate the position if desired loop along strip of bandage around the patient’s ankle or foot, have them grasp that shit
What’s the CRFor Settegast method, tangential projection
Perpendicular to the joint space between the patella in the femoral condyles, when the joint is perpendicular
When the joint is not perpendicular, the degree of the CR depends on the degrees of flexion of the knee
Angulation typically 15 to 20°
