Question | Answer |
The ankle joint is formed by what three bones | tibia, fibula, talus |
A 15deg internal rotated AP oblique projection is called the | mortise projection |
The mortise position demonstrates the joint and should have even space over entire | talar surface |
What does the mortise joint do for the body | helps stabilize weight |
What is the difference between the AP mortise and AP oblique ankle projections for positioning | internal rotation for mortise is 15-20deg and the ankle is internal rotation of 45deg |
On a true AP of the ankle what is not demonstrated | entire three part joint space of the ankle mortise |
The ankle is what type of joint with what type of movement | synovial joint, sellar or saddle type and movement is flexion and extension |
Which malleolus is longer and is an extension of the fibula | lateral malleolus |
What are the stress views of the ankle important | shows lack of support, from fractures or tears of ligaments |
Before doing a stress view of the ankle what should be ruled out | make sure there is no fracture |
What are the two joints are on the tibia | proximal and distal tibiofibular joints |
Name the 3 Ankle positions (routine) | AP, AP oblique with medial rotation, Lateral |
Positioning for the AP ankle | Center to ankle joint, foot dorsiflexed. |
Positioning for the AP with medial rotation | 15-20 degrees medial rotation, centered to ankle. (demonstrates ankle mortise) |
How do you accurately position for the AP w/ medial rotation? | rotate medially until the malleoli are parallel (equidistant) to the IR. Rotate the whole leg NOT just the ankle or foot. |
What is the visual difference between and AP and AP Mortise? | the joint space on the lateral side of the Mortise will be open. In the AP the Fib is superimposed over part of the talus. |
What is the (rarely used) AP oblique with 45degree medial rotation for? | to show tib/fib joint space. |
Identify rotation on Lateral ankle | talar domes should be superimposed, lateral malleolus superimposed over posterior half of tibia. |
What are Inversion/Eversion view of the Ankle for? | stress views that are used to demonstrate ligament damage. |
What do you do to fit the Tib/Fib on a 14x17? | Try it diagnonally, then try increasing the SID (44-48in) |
T/F There should be partial superimposition of the Tib and Fib at both proximal AND distal ends? | TRUE |
You are _____? | ON FIRE! Someone call 9-1-1! |
Describe positioning for the Lateral TIB/FIB | Mediolateral, flex knee to 45 degrees, center midshaft and include both joints. May increase SID. |
Identify rotation for the Lateral TIB/FIB | Rotation indicated by condyles of femur and ankle joint. Condyles should be superimposed and the proximal head of FIB superimposed by TIB, distal FIB superimposed over posterior half of TIB. |
Identify rotation for AP TIB/FIB | evaluate relationship of the fibula to tibia. Lat. Rot. – fib shifts toward or under tib, obscuring medial mortise. Med. Rot – head of fib draws from beneath tib. |
Boom | Shockalocka! |
AP stress views for the ankle evaluate what? | Stability of the mortise joint |
What anatomy overlaps on an AP ankle? | the distal tibia and fibula overlap eachother and the talus |
What is the anterior tubercle? | An expanded process at the distal anterior and lateral tibia that articulates with the superolateral talus and partially overlaps the fibula anteriorly |
What is the tibial plafond? | The distal tibial joint surface that forms the roof of the ankle. |
What does a true lateral of the ankle require? | The lateral malleolus to be about 1 cm posterior to the medial malleolus. |
T/F? The tibia is the weight bearing bone of the body. | True |
The distal tibiofibular joint is classified as what type of joint? | Fibrous joint and is amphiarthrodial (slightly moveable) of the syndesmosis type. |
The proximal tibiofibular joint is classified as what type of joint? | Synovial joint and is diarthrodial (freely moveable) and is plane (gliding) type |
Where is the fibula located? | Laterally and posteriorly to the tibia. |
What does an AP ankle need to demonstrate? | Slight superimposition of the talus and lateral malleolus and slight superimposition of the distal tibia and fibula. |
T/F The entire mortise joint is open on an AP oblique ankle with medial rotation (mortise). | True |
T/F The intermalleolar line is perpendicular to the IR on a Mortise projection. | False. The intermalleolar line is parallel to the IR. |
What is demostrated on a AP oblique ankle with 45 degree rotation? | The distal tibiofibular joint is open and is in profile. |
T/F The intermalleolar line is perpendicular to the IR on a Mortise projection. | False. The intermalleolar line is parallel to the IR. |
What is demostrated on a AP oblique ankle with 45 degree rotation? | The distal tibiofibular joint is open and is in profile. |
What needs to be visualized on a lateral ankle? | The entire talus and calcaneus, lateral malleolus superimposed over posterior half of tibia and talar domes are superimposed |
What do you look for on inversion/eversion ankle projections? | ligaent attachments |
T/F An AP tib/fib is done bucky. | False. AP tib/fib is done table top |