Lower Limb: Lesson 12 & 13 (Critique - Knee & Distal Femur)
No -Way too flexed!
Is this an accurate Mediolateral Lateral Knee? Why or why not?
No -Too internally rotated -Patella shifted medially -Fibular head further way from Tibia
Is this an accurate PA Flexion? Why or why not?
AP oblique with medial rotation The AP medial oblique of the knee will create less superimposition of the tibia over the fibular head, allowing for greater visualization of the styloid process of the fibula.
Which projection of the knee will best demonstrate the styloid process of the fibula?
Proximal tibiofibular articulation A 45 degree medial rotation will free the head of the fibula from superimposition and demonstrate the articulation between the proximal tibia and fibula.
What is clearly demonstrated on an AP oblique projection of the knee in medial rotation?
-Patient has "knocked knees"
What is happening in this AP Standing Knees?
-The patient is bowlegged -It helps to sometimes switch the IP crosswise to get all on the anatomy on image
What is happening wit this AP Standing Knees?
-Patient has "knocked knees"
What is happening with this AP Standing Knee?
-The patient is bowlegged -It helps to sometimes switch the IP crosswise to get all on the anatomy on image
What is happening with this AP Standing Knee?
D. AP of both knees with weight-bearing
Which of the following projections of the knee best demonstrates the narrowing of the joint space? A. AP B. AP oblique C. Lateral D. AP of both knees with weight-bearing
3 and 4 only The medial femoral condyle will be in profile with superimposition of the fibula by the tibia.
For an AP external oblique knee image with accurate positioning, the: 1. Fibular head is demonstrated free of tibial superimposition 2. Lateral femoral condyle is demonstrated in profile 3. Fibular head, neck, and shaft are superimposed by the tibia 4. Medial condyle is shown in profile
1 and 3 only The knee is internally rotated. The adductor tubercle, situated on the medial condyle, will be in profile and fibular head and tibial superimposition will be increased.
If the lateral femoral condyle is situated anterior to the medial femoral condyle on a lateral knee image with poor positioning, which of the following is true? 1. The fibular head demonstrates increased tibia superimposition. 2. The adductor tubercle will be located on the anterior condyle. 3. The distal surface of the anterior condyle will appear flatter. 4. The fibular head will demonstrate a decrease in tibial superimposition.
No -Too externally rotated -Patella shifted laterally -Fibula too superimposed
Is this an accurate Modified Merchant View (Patella)? Why or why not?
Yes -Open patellofemoral joint space -Patella in profile
Is this an accurate Modified Merchant View (Patella)? Why or why not?
No -Knees are not flexed enough -Cannot view fossa or joint spaces well
Is this an accurate PA Flexion? Why or why not?
No -Patient is too flexed (when we flex our knee the patella is pulled downward) -Patella superimposed on fossa -CR too superior
Is this an accurate PA Flexion? Why or why not?
Yes -Intercondyllar eminences match up with intercondyllar fossa -Good view of joint spaces -Fibular head slightly superimposed with Tibia -Condyles symmetrical -Patella above fossa -CR at knee joint -Mag marker
Is this an accurate PA Knee Flexion? Why or why not?
1, 3, and 4
A lateral knee image with accurate positioning demonstrates: 1. Superimposed femoral condyles 2. The fibular head without tibial superimposition 3. An open femorotibial joint space 4. One fourth of the distal femur and proximal lower leg
B. The fibular head will appear less superimposed by the tibia than a true lateral
A lateral knee radiograph that is over-rotated toward the image receptor can be recognized by which of the following? A. The fibular head will appear more superimposed by the tibia than a true lateral B. The fibular head will appear less superimposed by the tibia than a true lateral C. The medial condyle of the femur will appear more posterior D. Both A and C are correct
rotate the knee medially
A radiograph of an AP knee reveals rotation with almost total superimposition of the fibular head and the proximal tibia. What must the technologist do to correct this positioning error on the repeat exposure?
2 and 4 only Medial rotation of the knee will increase magnification of the lateral condyle and free the fibular head from tibial superimposition.
An AP knee image obtained with the knee medially rotated demonstrates: 1. A larger appearing medial femoral condyle than lateral condyle 2. A larger appearing lateral femoral condyle than medial condyle 3. The fibular head with increased tibial superimposition 4. The fibular head with decreased tibial superimposition
-Intercondyllar line parallel to IP -Includes 2" below knee joint -No rotation -Open knee joint
An accurate AP Distal Femur will show:
-Tibia completely superimposed over Fibula -Medial condyle in profile -Patella shifted Laterally -Intercondyllar eminences shifted laterally away from center of intercondyllar fossa
An accurate AP External Oblique Knee will show?
-Lateral condyle in profile -Patella shifted medially -Medial condyle foreshortened -Good view of Lateral Tibial Plateau -Fibular head slightly superimposed in Tibia -Intercondyllar eminence shifted medially -CR at knee joint -Mark Lateral Side -Mag marker present
An accurate AP Internal Oblique Knee shows:
-Symetrical condyles -Patella in middle of knee (they naturally shift slightly lateral) -superimposition of Fibula with Tibia -CR at knee joint -Mag marker
An accurate AP Knee shows:
-Hip to Ankle joint anatomy on film -Mag marker by knee -No rotation
An accurate Hip to Ankle will show:
-Intercondyllar line perpendicular to IP -Patella perpendicular to IP -Condyles lined up a decent amount as to not rotate femur too much
An accurate Lateral Distal Femur will show:
-Patelofemoral joint space open (not too close, not too far) -Symmetrical superimposition of femoral condyles posteriorly and anteriorly (no rotation) -Adductor tubercle is visible (back of knee) ***may ask this patient to flex knee slightly -
An accurate Mediolateral Lateral Knee will show:
-Open patellofemoral joint space -Patella in profile
An accurate Modified Merchant View (Patella) will show:
-Intercondyllar eminences match up with intercondyllar fossa -Good view of joint spaces -Fibular head slightly superimposed with Tibia -Condyles symmetrical -Patella above fossa -CR at knee joint -Mag marker
An accurate PA Knee Flexion (Rosenberg) will show:
2 and 3 only External rotation of the knee, or positioning the patella too close to the IR on a lateral knee projection will result in decreased superimposition between the head of the fibula and tibia, and the medial condyle will be visualized anterior to the lateral condyle.
If the patient's patella was positioned too close to the IR for a lateral knee image, the: 1. Fibula would be demonstrated with increased tibial superimposition 2. Fibula would be demonstrated with decreased tibial superimposition 3. Medial femoral condyle is anterior to the lateral femoral condyle 4. Medial condyle is distal to the lateral femoral condyle
No -Too internally rotated -Patella shifted medially -Fibula not superimposed enough
Is this an accurate AP Distal Femur? Why or why not?
Yes -Intercondyllar line parallel to IP -No rotation -Includes 2" below knee joint
Is this an accurate AP Distal Femur? Why or why not?
No -Too AP -Fibula not completely behind Tibia -Medial condyle not in profile
Is this an accurate AP External Oblique Knee? Why or why not?
No -Too Lateral
Is this an accurate AP External Oblique Knee? Why or why not?
Yes -Tibia completely superimposed over Fibula -Medial condyle in profile -Patella shifted Laterally
Is this an accurate AP External Oblique Knee? Why or why not?
No -Too AP -Fibualr head too superimposed on Tibia
Is this an accurate AP Internal Oblique Knee? Why or why not?
No -Too lateral
Is this an accurate AP Internal Oblique Knee? Why or why not?
Yes -Lateral condyle in profile -Patella shifted medially -Medial condyle foreshortened -Good view of Tibial Plateau -Fibular head slightly superimposed in Tibia -Intercondyllar eminence positioned laterally compared to intercondylar fossa
Is this an accurate AP Internal Oblique Knee? Why or why not?
No -Fibula not as superimposed onto Tibia -Patella shifted medially -Intercondylar eminences shifted medially away from center of intercondylar fossa.
Is this an accurate AP Knee? Why or why not?
No -Too externally rotated -Condyles are not symmetrical (Medial Condyle in profile & Lateral Condyle not easily visualized) -Too much superimposition with Fibula and Tibia -Patella shifted laterally
Is this an accurate AP Knee? Why or why not?
Yes -Symetrical condyles -Patella in middle of knee (they naturally shift slightly lateral) -superimposition of Fibula with Tibia -CR at knee joint -Just missing mag marker
Is this an accurate AP Knee? Why or why not?
No -Image too dark and grainy -CR too superior
Is this an accurate AP Standing Knees? Why or why not?
Yes -Knees are not rotated -Fibulas slightly imposed in Tibias - **CR may be too inferior but not a repeat image
Is this an accurate AP Standing Knees? Why or why not?
No -Too externally rotated -Knee is too close to the table
Is this an accurate Lateral Distal Femur? Why or why not?
No -Too internally rotated
Is this an accurate Lateral Distal Femur? Why or why not?
No -Too internally rotated (knee away from IP)
Is this an accurate Lateral Distal Femur? Why or why not?
Yes -Even though the condyles are not aligned you can tell that the femur is not rotated -Includes 2" below knee joint
Is this an accurate Lateral Distal Femur? Why or why not?
No -CR too superior -Patelofemoral joint space closed -No mag marker
Is this an accurate Mediolateral Lateral Knee? Why or why not?
No -Knee is internally rotated (up off table) -Patella too far from table -Adductor tubercle too posterior (adductor tubercle follows the patella) ***remove block from under knee to fix
Is this an accurate Mediolateral Lateral Knee? Why or why not?
No -Knee is not flexed -Medial condyle too inferior -No open joint space ***Angle cephalic or raise up ankle slightly
Is this an accurate Mediolateral Lateral Knee? Why or why not?
No -Too externally rotated -Adductor tubercle not visible -Patella too close to table -Fibular head not superimposed enough ***block up knee to fix
Is this an accurate Mediolateral Lateral Knee? Why or why not?
No -Knees are falling outward -Patellas shifted laterally
Is this an accurate Modified Merchant View (Patella)? Why or why not?
No -Patellofemoral joint space closed
Is this an accurate Modified Merchant View (Patella)? Why or why not?
No -Tibia is superimposing patellofemoral joint space **to fix this angle the tube more horizontally to throw the tibia down and out of the way
Is this an accurate Modified Merchant View (Patella)? Why or why not?
an MRI procedure
The best method of evaluating injuries to the menisci and the ligaments of the knee joint involves:
Under-rotation of the knee towards the IR (Knee too far away from table) If the adductor tubercle is in profile posteriorly, this indicates under-rotation of the knee, and should be accompanied by increased superimposition of the tibia over the fibular head. The knee should be externally rotated to bring the patella closer to the IR.
The posterior visibility of the adductor tubercle on a lateral knee projection indicates: