Lecture 3-Lower Extremity Flashcards
1
Q
What joint spaces should be open in an AP axial foot?
A
-TMT
-Medial and Intermediate cuneiforms
-Navicular-cuneiforms
2
Q
Where should the talus be located in relation to the calcanus for an AP axial foot?
A
Talus superimposes slightly the most distal part of the calcaneus
3
Q
What is the best way to obtain a proper angle for an AP axial foot?
A
The best way to obtain the proper angle is to go perpendicular to the dorsal plane of the foot
4
Q
Which bone to we hit first in an AP axial of the foot; the talus or calcanus?
A
Talus
5
Q
What corrective measures should be taken to correct this image of the AP axial foot?
A
Rotate the foot internally, increase the angle to see through the joint spaces
6
Q
What error(s) have been made in this image of the AP axial foot?
A
-Foot is too internally rotated
-Talus and calcaneus is clipped
7
Q
What corrective measure(s) should be made for this image of the AP axial foot?
A
Need more of a cephalad angle to see joint spaces
8
Q
What joint spaces/spaces should be seen in an oblique foot?
A
-Cuboid-lateral cuneiform
-3rd – 5th proximal MT
-Sinus tarsi
-2nd – 5th intermetatarsal spaces
9
Q
How can you demonstrate the subtalor joint in an AP oblique foot?
A
Dorsiflex the foot 90 degrees
10
Q
What structure is circled?
A
The subtalor joint
11
Q
What errors have been made to this image of the AP oblique foot?
A
Under obliqued, Cannot see the subtalar joint space, clipping the talus
12
Q
What error(s) have been made in this image of the AP oblique foot?
A
-Clipping anatomy, out marker on the lateral side, over rotated-lost the space between phalangies
13
Q
What pathology is visualized in this image?
A
Tarsal coillition and Dancers fracture
14
Q
What error(s) have been made in this image of the AP oblique foot?
A
None; perfect positioning
15
Q
Where should the talar domes be in a lateral foot projection
A
Talar domes superimposed on eachother
16
Q
What joint should be visualized in a lateral foot projection?
A
Subtalor joint visualized
17
Q
T/F
In a lateral foot, the metatarsals should be superimposed
A
False; not superimposed
18
Q
Where should the fibula be in a lateral foot projection?
A
Fibula superimposed in the posterior 1/2 of the tibia
19
Q
What correction needs to made for this image? How can you tell?
A
-Foot needs to be lined up on the lateral aspect
(fibula too posterior)
20
Q
T/F
If calcification in the vessels of the foot, the patient is possibility diabetic
A
True
21
Q
What error(s) have been made in this image of the lateral foot?
A
Knee raised off the table, not dorsi flexed
22
Q
What joint spaces should be open for an AP ankle?
A
-Tibiotalar joint space
-Medial mortise
23
Q
T/F
In an AP ankle, the distal fibula overlaps lateral talus
A
True
24
Q
What error(s) have been made in this image of the AP ankle? How do we know?
A
-Foot externally rotated (Fibula and talus are overlapping too much)
25
What error(s) have been made in this image of the AP ankle?
Foot is internally rotated
26
Why do patients ussually require an angle for the mediolateral ankle?
The ankle is lower than the knee naturally causing tilt
27
Does this patient require an angle for the mediolateral ankle? How much?
10-12 degrees
28
What joint spaces should be seen in an ankle mortise?
3 equal joint spaces around mortise
29
What is the most important ankle image for surgeons?
The ankle mortise
30
If the patient is unable to dorsiflex the foot in an ankle mortise, what should we do?
Angle cephalad
31
# T/F
In an ankle mortise, the fibula should 1/2 superimposed with tthe talus.
False; Distal fibula demonstrated without superimposition
32
What error(s) have been made in this image of the ankle mortise? How do we know?
Have not internally rotated enough because we cannot see joint space
33
What error(s) have been made in this image of the ankle mortise? How do we know?
Apparently not internally rotated enough, I think its just fine
34
What corrective measure(s) need to be made for this image of the ankle mortise?
Needs more internal rotation
35
How many mm distally should the tib and fib be apart?
Have to have at least two mm between tib and fib distally
36
What error(s) have been made in this image of the Ankle mortise? How do we know?
Too much internal rotation (When you see the O, (sinus tarsi) the ankle has been over rotated )
37
What correction(s) need to be made to this image of the Ankle mortise?
-Cephlad angle needs to be used or the patient needs to dorsiflex the foot
38
What joint spaces need to be open in a lateral ankle?
-Tibiotalar joint space
-Subtalar joint
39
# T/F
In a lateral ankle, the talar domes need to be superimposed.
True
40
Where should the fibula be in a lateral ankle radiograph?
Fibula in posterior half of tibia
41
What angle is ussually required for a mediolateral ankle?
5 degrees cephalad
42
# T/F
The position of the talar domes in a lateral ankle depends on the location of the calcaneus and the toes
True
43
What correction should be made to fix this lateral ankle?
A cephalad angle is needed (or lower the knee) and the toes need to go down or the calcaneus up off the IR. Also, align the tibia with the long axis of the IR
44
What corrections need to be made to this image of the lateral ankle?
Bring the toes down and use a cephalad angle
45
What structure is circled?
Sustentaculum tali
46
What error has been made in this image of the lateral ankle?
The knee was raised off the table or not enough of a cephalad angle was used. Additionally, the toes were raised off the table or IR.
47
# T/F
There is no angle needed for a standing lateral
True
48
How could the talar domes become even more superimposed
The marker should have been placed face down and then the image flipped!!! The heel was not moved away from the IR.
49
# What is the error?
**The sinus tarsi is visible in a medio-lateral ankle projection.**
The heel is raised off the IR
## Footnote
Should only see the subtalar joint
50
# What is the error?
The fibula is too anterior
The toes are off the IR
| Sinus tarsi is NOT visible
51
What angle; caudad or cephalad, would be used? Why?
Talus is going opposite angle so we need a caudad
52
What angle would you use for a mediolateral projection?
7-10 degree angle needed
53
In an AP knee, where should the pattella be located?
Patella is slightly lateral to the midline
54
In an AP knee, where should the fibia be in relation to the tibia?
-Lateral condyle of tibia superimposes half of fibular head
-Fibula also roughly half way between the articulating surface of the tibia and the curved part of the metaphysis
| (up and down, left and right)
55
What errors have been made in this image?
-Foot too externally rotated
-Fibular head appears too superior; used too much of a caudad angle
56
What caused the joint space not to be visualized?
The tech centered to superiorly
## Footnote
Could also say that too much caudad angle was used
57
What error was made in this iamge of the AP knee?
Not angled enough caudad (fibular head too low)
## Footnote
NOT INTERNAL BECAUSE CAUDAD WOULD FIX
58
What error was made in this image of the AP knee?
Knee too externally rotated
59
What errors have been made in this image of the AP knee?
-Knee too internally rotated
-Not enough caudad angle used
60
What joint space needs to be open in an Internal (Medial) Oblique Knee?
-Proximal tib/fib joint is open
61
What projection of the knee is best for assessing proximal tib/fib joint, fibular head/neck fractures, and tibial plateau fractures?
Internal (Medial) Oblique Knee
62
Where should the patella be visualized in an Internal (Medial) Oblique Knee
½ of the patella is visualized medial to the femur
63
What projection is this?
Internal (Medial) Oblique Knee
64
What error has been made in this image of the Internal (Medial) Oblique Knee?
| (left knee done PA)
Knee over rotated;looks closer to a lateral
65
Where should the fibular head be located in an External (Lateral) Oblique Knee?
Fibular head is aligned with the anterior edge of the tibia
## Footnote
(fibula in the middle of the tibia is what John likes better)
66
Where should the patella be located in an External (Lateral) Oblique Knee?
Approximately ½ of the patella is visualized lateral to the femur
67
What is the best projection for assessing tibial plateau fractures?
The Oblique Knees
68
What are the differences between the medial and lateral condyles of the femur?
-Medial condyle has roughened area – adductor tubercle
-Lateral condyle is smooth
69
How much should the knee be bent in a lateral knee projection?
30 degree bend
70
What is the difference between the medial and lateral tibial plateuas of the tibia?
-Medial tibial plateau is curved
-Lateral tibial plateau is straight
71
What happens if you cannot tell if the condyle is smooth or rough and you can't see the tibial plateus in the lateral knee?
Look at the height of the fibula on the AP projection
72
What corrections need to be made to this image of the mediolateral knee?
Need to Externally rotate, and increase the cephalad angle used
73
What correction needs to be made to this image of the mediolateral knee?
-Need internal rotation, decrease the cephalad angle
74
What correction needs to be made to this image of the mediolateral knee?
Increase the cephalad angle, externally rotate
75
What correction needs to be made to this image of the mediolateral knee?
Need to use more of a cephalad angle
76
What correction needs to be made to this image of the mediolateral knee?
Need to externally rotate the knee and decrease the cephalad angle used
77
What correction needs to be made to this image of the mediolateral knee?
Less cephalad angle needed
78
What correction needs to be made for this image of the lateromedial knee?
Need more of a caudad angle and internal rotation
79
What correction needs to be made to this image of the lateromedial knee?
Decrease the caudad angle, externally rotate the knee
| (opp rules to a mediolateral)
## Footnote
Fibular head too distal therefore the lateral femoral condyle too distal
80
What correction needs to be made to this image of the lateromedial knee?
Decrease the caudad angle
81
What projection is best to image OA?
PA Standing tunnel is best for OA
82
**What angle is used for a standing PA tunnel view?**
Normally 10 degrees caudad
83
**what angle is used for a standing AP tunnel**
5 degrees caudad
84
# T/F
What projection is best for imaging loose bodies, assessing tibial plateau fractures, OCD, Chondrocalcinosis
Tunnel views (specifically recumbent)
85
# T/F
In standing tunnel views, steeper slopes need less than 10 degrees and lesser slopes need at least 15 degrees
True
86
What error has been made in this image?
Too much of a caudad angle used
87
What projection is this?
Standing AP Tunnel
88
What projection is this?
Standing Tunnel PA
89
How much should the knee be bent for a skyline view?
No more than 30°
90
What indicates proper positioning of a skyline patella view?
1. Need to visualize the depth of the trochlear groove at the origin
2. Width of the patella should be equal to the femur
3. Spike on the medial aspect of the knee
91
What error has been made in this image of the patella?
None; just a patient with arthitis
92
What error has been made in this image? How do we know?
Bent less than 30 because of the shallow groove
93
What is the yellow line indicating?
The trochlear groove
94
# T/F
In a skyline projection, the more you bend the knee, the more distal/closer to the knee the patella goes
True
95
What error has been made in this image?
Knee has been bent more than 30 degrees (femur wider than patella)
96
What error has been made in this image?
Knee has been bent more than 30 degrees
97
What angle would you use for this patient; straight ray, caudad or cephalad?
Caudad
98
What errors have been made in this image of the AP knee?
-Internally rotated
-Not enough caudad angle
99
What error has been made in this image of the AP knee?
-Too externally rotated
100
Where should the greater and lesser trochanters appear in an AP pelvis?
-Lesser trochanters superimposed posteriorly
-Greater trochanters in profile laterally
101
What should the ischial spines be aligned with in an AP pelvis?
Ischial spines are aligned with pelvic brim
102
What 4 things indicate RPO positioning of the pelvis?
1. Symphysis is to the right of the coccyx
2. Left obturator foramen is bigger compared to the right
3. Right ilium is wider or more parallel to IR and left ilium is more in profile
4. Right ischial spine visualized more than left
103
What projection of the pelvis is this?
LPO
104
What error has been made in this image of the AP pelvis?
Legs not internally rotated
105
What rotation of the pelvis is shown?
LPO
106
What projection is shown? List at least 6 reasons to justify your answer.
## Footnote
(7 listed, try to name as many as you can)
RPO
1. Left obturator is more open
2. Lesser trochanter more on the right side
3. Right femoral neck more foreshortened
4. Right illum is flatter
5. Ischial spine more visible on the right side
6. Left SI joint is better in RPO position
7. Spinous process appears more to the left of the pedicles
107
# T/F
In an axiolateral hip, the ischial tuberosity should be demonstrated free of superimposition from the greater trochanter
True
107
Where should the lesser trochanter be in an axiolateral hip?
Lesser trochanter in profile posteriorly
108
# WILL SEE THIS ON CAMRT
On a XTL hip of a suspect # the greater trochanter appeared post to femoral neck, the lesser trochater was superimposed on the femoral neck. What do you do?
Do nothing and send it to packs
109
What correction should be made to this projection of the axiolateral hip?
Need to decrease the angle between the central ray and the side of the femur
## Footnote
The yellow dotted line indicates the angle used to acquire the image on then previous slide. The solid red line indicates the proper position of the CR.
110
What correction needs to be made to this projection of the axiolateral hip?
Need to internally rotate the leg
