Ankle Tib Fib

Description:	Ankle Tib/Fib
Category:	Radiology
Created by:	StudyGroup on 2009-11-03

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