32. Imaging of the Lower Limb Flashcards
Which is the best way to position the feet for a AP hip xray?
Feet turned in - shows the femoral neck well this way
What’s is the best position to get a lateral view x-ray of the hip?
To raise the leg up or turn it out to get a good view of the femoral neck.
Name the places on this AP paediatric hip x-ray (2 years old)
What is the Y shaped epiphyseal plate that occurs at the junction of the ischium, ilium and pubis in a skeletally immature patient called?
Triradiate cartilage
What does the AABCSS search strategy stand for?
Adequacy (is everything included)
Alignment (check alignment lines)
Bones - check for lytic lines (darker) or sclerotic (lighter),
Cartilage - check for symmetry, no signs of dislocation or subluxation
Soft tissues - bladder stones, calcification of prostate
Satisfaction of search - double check
What is the line between the medial aspect of the femoral neck and the inferior aspect of the pubic ramus called?
Shenton’s line
How do traumatic avulsion fractures occur?
When the tendon is stronger than the developing apophyses - pulls off a piece of bone with it.
Which muscles attach to these parts of the pelvis?
Which muscles attach to these parts of the pelvis?
Normal or abnormal?
Abnormal
What is seen a P who has osteoarthritic changes on an X-ray?
Reduced joint space
Osteophtes
Subchondral sclerosis
Which is the best investigation of choice in major trauma? Why?
CT - can quickly diagnose active bleeding, whole body CT can detect injuries and complex fractures - can be 3D reconstructed.
Which is the best investigation for evaluation of avascular necrosis?
MRI
What is it called when contrast is injected into the joint under MRI?
MRI arthrography
Which investigation is best for detecting hip effusions, synovitis, adductor tendon pathology and greater trochanteric pain?
US
What is a tripartite patella?
How do you know it isn’t pathologic?
A normal variant of a patella - can have 2 or more bones in the patella sometimes = multipartite.
Can tell its not pathology by the fact that it has rounded edges
What is found underneath the patella tendon?
Hoffa’s fat pad
What do you need to be aware of in X-rays of children and their knees?
The tibial tubercle can appear fragmented - this is normal.
What is it called when fat is released from the bone marrow in a fracture, which then mixes with blood in the joint capsule of the knee?
How can you identify this on X-Ray?
Lipohaemarthrosis
On Xray - is a darker area above because the fluid/blood floats on top of the fat.
When is a CT of the knee done?
Usually for evaluation of complex fractures - specialist referral.
Also done when P cannot have MRI
On T1 MRI - is fat bright or dark?
Bright
What is common pathology of the menisci of the knee?
Tears and degeneration
What are signs of ACL tear?
Disruption to some or all of the ACL fibres
Bucking of the ACL
May see avulsion of tibial spines
May see anterior tibial translation relative to the femur
Which ligaments of the ankle protect against eversion?
Syndesmotic ligaments - Anterior inferior tibiofibular, posterior inferior tibiofibular, interosseous ligaments.
Which ligaments of the ankle stabilise and protect against inversion?
The lateral ligaments -
ATFL (Anterior tibiofibular ligament)
PTFL
Calcaneofibular ligaments
What on these X-Rays looks abnormal?
Lateral talar shift (=deltoid ligament rupture)
Oblique fracture of the fibula
Posterior malleolus fracture
Subluxation
What pathology of the achilles can be seen in each of these photos?
When is the foot likely to be X-rayed?
Examining for trauma or arthritic changes
R Hand image - 5th metatarsal inferiorly - break (transverse line bad, longitudinal line not necessarily pathology)
What are the symptoms of Charcot foot?
Lack of pain sensation
Dislocations / subluxations due to ligament laxity
Joint space is increased
Metatarsal joints are disrupted
Dislocated tarsal bones can be seen
Which pathologies can be seen in the following X-rays?
When is a CT of the foot done?
To assess complex fractures - such as calcaneal fractures
Enables surgical planning
What soft tissue tumour can be found in the foot?
Morton’s neuroma
