Practical 2: MSK XRs Flashcards
Who do greenstick fractures occur in?
children
What might you see in long bones of children on XR?
growth plates visible
How do you describe XRs in terms of brightness?
Radiolucent and radio-opaque
What are the standard views for the C spine?
AP, Lateral and Peg (open mouth)
Why might you request a swimmer’s view in someone?
To assess the C7/T1 junction that may not be visible on lateral view
What 3 lines do you look at on lateral C spine view?
Anterior vertebral line*
posterior vertebral line*
spinolaminar line
*correspond to the longitudinal ligaments
What 3 columns might the C-spine might be described as? If one of these columns is disrupted what does this indicate?
Anterior (ant long. ligament –> ant 1/2 vertebral body)
middle (post. 1/2 vertebral body –> post. long. lig)
posterior (posterior elements of vertebra)
indicates instability
What is special about the role of the anterior longitudinal ligament?
Only ligament to Prevents hyperextension of the spine
others resist hyperflexion
Where do the posterior and anterior longitudinal ligaments run from and to?
posterior: C2 (posterior to body) –> sacrum [n.b. runs w/in the vertebral canal w/ the spinal cord]
anterior: occipital bone base –> sacrum
both are posterior or anterior to the vertebral body
What soft tissue spaces should you look at on a lateral c spine view?
nasopharyngeal
Retropharyngeal
retrotracheal
What would you do if one of the soft tissue spaces on the lateral C spine is >7mm above C5 or > than the width of one vertebral body below C5?
Suggests fracture –> CT scan
What should you look for on a Peg view?
the spaces between the C1 lateral masses and C2 peg/dens should be equidistant and small
what lies anterior to the dens? Why is it important?
The transverse ligament of C1/atlas. Prevents dens fracture affecting the spinal cord
what type of joint is between the dens and C1 anterior arch?
Synovial (therefore affected in RA pts)
is the dens anterior or posterior?
ANterior (don’t get confused by pics)
What is special about the vertebral foramen of the C vertebra?
Wide therefore subluxation may not compress the spinal cord
How are the superior and inferior articular facets of the C vertebra directed?
Superior: supero-posteriorly
inferior: infero-anteriorly
What is special about the spinous processes of the C vertebra?
Bifid
What is a clay shoveler fracture? Why is it called this?
Who can it be seen in acutely?
Fracture of the spinous process (lower c-spine [usually c7])
Clay is sticky –> as you shovel upwards there is a sudden flexion force
Acutely: motor vehicle accident, sudden onset muscle contraction (clay), direct blows to the spine
Are clay shoveler fracture injuries recognised at the time?
No, picked up incidentally when imaging C spine for ther reasons
What is an extension teardrop fracture?
Associated w/ whiplash / read end collision
hyperextesnion of the neck causes the anterior longitudinal ligament to be torn –> fracture of the vertebral body
in severe cases: a vertebral body dislocates posteriorly + compresses spinal cord
(n.b. you can get a flexion teardrop fracture)
What does the ligamentum flavum do?
Binds the lamina of the adjacent vertebrae
What is the special role of the posterior longitudinal ligament (other than preventing hyperflexion)?
prevents posterior disc herniation (protecting the spinal cord)
What does unequal distance of the C1 lateral masses from the peg/dens suggest?
Fracture of the C1 ring
can be equal distance but large also suggesting fracture
