Lecture 3-Lower Extremity Flashcards
What joint spaces should be open in an AP axial foot?
-TMT
-Medial and Intermediate cuneiforms
-Navicular-cuneiforms
Where should the talus be located in relation to the calcanus for an AP axial foot?
Talus superimposes slightly the most distal part of the calcaneus
What is the best way to obtain a proper angle for an AP axial foot?
The best way to obtain the proper angle is to go perpendicular to the dorsal plane of the foot
Which bone to we hit first in an AP axial of the foot; the talus or calcanus?
Talus
What corrective measures should be taken to correct this image of the AP axial foot?
Rotate the foot internally, increase the angle to see through the joint spaces
What error(s) have been made in this image of the AP axial foot?
-Foot is too internally rotated
-Talus and calcaneus is clipped
What corrective measure(s) should be made for this image of the AP axial foot?
Need more of a cephalad angle to see joint spaces
What joint spaces/spaces should be seen in an oblique foot?
-Cuboid-lateral cuneiform
-3rd – 5th proximal MT
-Sinus tarsi
-2nd – 5th intermetatarsal spaces
How can you demonstrate the subtalor joint in an AP oblique foot?
Dorsiflex the foot 90 degrees
What structure is circled?
The subtalor joint
What errors have been made to this image of the AP oblique foot?
Under obliqued, Cannot see the subtalar joint space, clipping the talus
What error(s) have been made in this image of the AP oblique foot?
-Clipping anatomy, out marker on the lateral side, over rotated-lost the space between phalangies
What pathology is visualized in this image?
Tarsal coillition and Dancers fracture
What error(s) have been made in this image of the AP oblique foot?
None; perfect positioning
Where should the talar domes be in a lateral foot projection
Talar domes superimposed on eachother
What joint should be visualized in a lateral foot projection?
Subtalor joint visualized
T/F
In a lateral foot, the metatarsals should be superimposed
False; not superimposed
Where should the fibula be in a lateral foot projection?
Fibula should be 1/2 superimposed with the tibia
What correction needs to made for this image? How can you tell?
-Foot needs to be lined up on the lateral aspect
(fibula too posterior)
T/F
If calcification in the vessels of the foot, the patient is possibility diabetic
True
What error(s) have been made in this image of the lateral foot?
Knee raised off the table, not dorsi flexed
What joint spaces should be open for an AP ankle?
-Tibiotalar joint space
-Medial mortise
T/F
In an AP ankle, the distal fibula overlaps lateral talus
True
What error(s) have been made in this image of the AP ankle? How do we know?
-Foot externally rotated (Fibula and talus are overlapping too much)
What error(s) have been made in this image of the AP ankle?
Foot is internally rotated
Why do patients ussually require an angle for the mediolateral ankle?
The ankle is lower than the knee naturally causing tilt
Does this patient require an angle for the mediolateral ankle? How much?
10-12 degrees
What joint spaces should be seen in an ankle mortise?
3 equal joint spaces around mortise
What is the most important ankle image for surgeons?
The ankle mortise
If the patient is unable to dorsiflex the foot in an ankle mortise, what should we do?
Angle cephalad
T/F
In an ankle mortise, the fibula should 1/2 superimposed with tthe talus.
False; Distal fibula demonstrated without superimposition
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
What error(s) have been made in this image of the ankle mortise? How do we know?
Not internally rotated enough (medial joint space not open enough)
What corrective measure(s) need to be made for this image of the ankle mortise?
Needs more internal rotation
How many mm distally should the tib and fib be apart?
Have to have at least two mm between tib and fib distally
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 )
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
What joint spaces need to be open in a lateral ankle?
-Tibiotalar joint space
-Subtalar joint
T/F
In a lateral ankle, the talar domes need to be superimposed.
True
Where should the fibula be in a lateral ankle radiograph?
Fibula in posterior half of tibia
What angle is ussually required for a mediolateral ankle?
5 degrees cephalad
T/F
The position of the talar domes in a lateral ankle depends on the location of the calcaneus and the toes
True
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
What corrections need to be made to this image of the lateral ankle?
Bring the toes down and use a cephalad angle