W2: Imaging of the musculoskeletal system Flashcards
What types of scans are commonly used to image MSK problem?
X-ray
CT
MRI
Ultrasound
Bone scan (inject radioactive tracer into blood stream and use to detect tumours)
Bone density scan
What is the use of an x-ray in MSK imaging?
Uses electromagnetic radiation
Gives information on tissue desnity
Good for differentiating and positioning bone, air, liquid and soft tissue.
Gives basic detail information
Identifies fractures, dislocation, arthiritis, cancers etc - large visible changes in strucutres
What information can x-rays not tell use about an MSK injury?
What should we use instead in each instance?
Unable to identify soft tissue injury (MRI or CT)
Subtle fractures (CT)
Exact type of malignancy or grade (biopsy)
What is important practically when ordering an x-ray?
Obtain at least two views eg anterior and lateral
View should include two joints adjacent to the injured bone
May request view of unaffected limb to assess symmetry in children
May consider further iimaging (CT or MRI) for occult fractures of soft tissue injury
What are some difference types of fractures?
Spiral
Oblique - oblique break
Transverse - straight transverse break
Complex/comminuted -
Wedge
Impacted
Displaced
Open/compound
What is a spiral fracture?
Bone is broken from a twisting motion
Fracture line wraps around the bone in a corckscrew like motion
What is an oblique fraction?
Break line is oblique
What is a transverse fracture?
Break line is transverse
What is a complex/comminuted fracture?
Broken into multiple pieces, multiple break points
What is a wedge fracture?
Common in the spine from compression and flexion
result in one piece fully disconnected from the rest of the bone
The remaining bone is often not attached to each other
What is an impacted fracture?
When broken ends of bone are jammed together by force of injury - often cause broken pieces to fragment
Compression of the bone
May also be called a buckle fracture - are most common in children as they are still growing.
What is the difference between a displaced and a dislocation fracture?
Displaced - bone is broken and because of break has moved into the wrong place
Dislocation - bone is not broken but has moved into the incorrect anatomical position
What is meant by an open/compound fracture?
Open wound
Bone pokes out of the skin
What details should be given when describing an x-ray?
Patient demographics
What is the x-ray of?
What is the view of the x-ray?
What does the x-ray show?
Suggest what type of fracture? - where, intra or extraarticular, displaced.
What are the different types of fracture displacement?
Angulation - point loss of shared long axis
Rotation - rotated along shared axis
Change in bone length
Loss of alignment (can overlap with other types)