6: Radiology - UST, CT & MRI and lower limb Flashcards
Are upper or lower limb fractures associated with higher morbidity and mortality?
Lower limb fractures
What are some serious complications of immobility due to a lower limb fracture?
Dehydration / starvation
DVT and PE
Pneumonia
Why is CT superior to X-ray for viewing overlapping structures?
X-ray is one image - overlapping bones can’t be separated
CT is cross-sectional - image can be moved forwards and backwards
Which two scans also show soft tissue injuries?
Ultrasound
MRI
What name is given to the dark stripe across bone characteristic of a fracture on X-ray?
Lucency
Lower limb fractures often involve impaction - what does this look like on X-ray?
Sclerosis (dense white)
Where are three common sites for lower limb impaction fractures?
Femoral neck
Tibial plateau
Calcaneus
Pelvic ring fractures typically involve (one / more than one) bone.
more than one bone
as with all bony ring fractures
Who tends to suffer high energy pelvic ring fractures?
Young people
What are the typical mechanisms of high energy pelvic ring fractures?
RTA
Falls from height
What scan is used if more than one fracture is suspected e.g in a pelvic ring fracture?
CT scan
If a pelvic ring fracture is caused by a low energy event, it is described as a ___ fracture.
What is a possible cause in elderly patients?
pathological
osteoporosis
Low energy pelvic ring fractures are difficult to see on X-ray. What scan is used to pick them up?
MRI scan
What is the imaging technique used to view pelvic soft tissue injuries?
MRI scan
What are two examples of acute pelvic soft tissue injuries?
Muscle tears
Tendon avulsion
Hip dislocations tend to occur (anteriorly / posteriorly).
posteriorly
What bony feature tends to fracture in hip dislocations?
Acetabular rim
What are the two main classifications of femoral fractures?
Intracapsular
Extracapsular
Where on the femur do intracapsular fractures occur?
Neck to head
Where on the femur extracapsular fractures occur?
Inferior to neck - greater trochanter and below
Which type of femoral fracture can disrupt the blood supply to the femoral head?
What may this cause?
Intracapsular
Avascular necrosis
What surgical procedure can be carried out to repair an intracapsular femoral fracture with associated AVN?
Hemiarthroplasty
i.e replacing the head of the femur and nothing else
Extracapsular femoral fractures aren’t associated with AVN. What surgical technique is used to repair these fractures?
Internal fixation
i.e screws, rods, plates
What type of femoral fracture is very obvious on X-ray?
Femoral shaft fracture
(Fractures / soft tissue injuries) of the knee are more common.
What imaging techniques are used to view them?
Soft tissue injuries
Ultrasound , MRI scan
What soft tissue structures should be viewed on a lateral X-ray of the knee?
Quadriceps tendon
Suprapatellar fat pad
Patellar tendon
What space fills with effusion following a soft tissue injury of the knee?
Suprapatellar space
When are simple effusions seen?
When is lipohaemarthrosis seen?
Simple effusion - fractures
Haemarthrosis - meniscal / ligament tears (extremely painful)
What aspect of the tibia, close to the knee joint, commonly fractures?
Tibial plateau
What imaging technique best shows tibial plateau fractures?
CT scan
Which imaging technique is used to find extensor mechanism injuries?
Ultrasound
What type of meniscal tear may displace and cause a locked knee?
Bucket handle meniscal tear
What do torn ligaments typically look like on MRI?
White, blurry mess
What type of connective tissue is damaged in OA?
Hyaline cartilage
What is a bony ring found in the leg?
Tibia, fibula and talus together
How do ankle fractures usually occur?
Inversion / eversion of foot
What types of X-ray are taken for ankle fractures?
AP (opposite to CXR) and lateral
The site of a fracture is often hinted at by the ___ ___ ___ around it.
soft tissue swelling
What tends to be disrupted in children?
Epiphyseal growth plates
If joint spaces are larger than they should be, what may be damaged?
Ligaments
What bony prominences of the ankle should be examined for fractures?
Medial and lateral malleoli
What other malleolus may also be fractured?
Where specifically is it found?
Posterior malleolus
Posteroinferior tibia
The base of which metatarsal commonly fractures?
5th
Which foot bone commonly fragments when it fractures?
What is the radiology name for fragmentation?
Calcaneus
Comminution
As in the upper limb, what are commonly mistaken for fractures?
Growth plates
Sesamoid bones
What is the fabella and where is it found?
Sesamoid found within the gastrocnemius posterior to the knee
Where in the foot are sesamoid bones definitely found?
1st metatarsal head
Which scan is used to view ligament tears because it is easier for patients and changes in real time?
Ultrasound
Injury of which ankle tendons are viewed by ultrasound?
Achilles tendon
Medial and lateral complexes
