48 terms

3:Radiology, Upper Limb

What is an example of a pathologic fracture?
minor trauma causing fracture within osteoporotic bone
Characterize the following fractures:
greenstick: incomplete fracture
spiral: spiral around the bone
comminuted: multiple pieces
transverse: goes straight across
compound: break in the skin
torus: seen in children, small buckle in bone
What is the difference between an overriding and distracting fracture?
overriding: bayonette position, pieces are overlapping
distracting: pieces pulled apart, soft tissue found between
How many views do you want for a case involving shoulder trauma?
at least 2
What is the most common injury to the shoulder?
fracture of the clavicle
What injuries are most common for middle aged people? What about the elderly?
middle aged: shoulder dislocation, AC joint separation
elderly: surgical neck fractures
How can you tell the difference between a fracture and a dislocation on an image?
in a dislocation, one joint will be out of position
in a fracture, both joints are where they're supposed to be
What view is best for evaluating a fractured scapula?
trans-scapular "Y" view
How many views would you want for most joint evaluations?
What type of dislocation comprises more than 95% of all shoulder dislocations?
anterior and inferior displacement
What should you always do before reducing a dislocation?
get an image of it
Posterior dislocation of the shoulder is best viewed using an AP image
false-it's often missed on AP views
Y-image can easily show posterior dislocation
What will a patient look like if he/she has a Luxatio Erecta dislocation?
statue of liberty; inferior dislocation of shoulder due to hyperabduction
What is FOOSH?
Fall On an OutStretched Hand
A/C separation may "disappear" if the patient does what?
lies supine (reduces load on the A/C joint)
On T2 weighted MRIs, tendons usually appear ______. Bright areas are indicative of _____.
dark (no signal); tendonitis or fluid
What is the image of choice for rotator cuff tears?
MR scan
What part of the ulna does the radius overlap on a lateral elbow image?
coronoid process
What is a sail sign?
an elevated anterior fat pad of the humerus on a lateral elbow image
it is common to see an anterior and posterior humeral fat pad on a lateral elbow image
false: there should never be a posterior fat pad
What does fat pad elevation indicate?
joint distension
What is the anterior humeral line, and what should it indicate?
a line drawn along the anterior aspect of the humeral shaft on a lateral image; it passes through the middle 1/3 of the capitulum in bones that are not fractured
What is the radiocapitellar line, and what should it indicate?
a line bisecting the proximal radial shaft and extending proximally; this line should pass through the capitulum in every view
What demographic is more likely to have radial fractures?
What demographic is more likely to have distal humeral injuries?
What is a nightstick fracture?
fracture of the ulna caused by direct blunt force
this is always a defensive fracture, never a FOOSH
What does the presence of an epiphysis near the end of a long bone indicate?
image of a child--epiphysis is the growth plate
What happens in a Monteggia fracture?
the radius dislocates anteriorly, pulling on the ulna via the interosseus membrane, resulting in a fractured ulna
How many views would you want for a traumatic wrist injury?
What are the common wrist image views?
AP; lateral; oblique; scaphoid view
What bones in a lateral image should line up?
distal radius, lunate, capitate, 3rd metacarpal
Which is normal in a lateral image:
an anteriorly-sloping angled radius
a straight/horizontal angled radius
What is the most common area of fracture in the upper extremity?
the wrist
What fractures account for 75% of all wrist injuries?
distal radius and ulna
What is a Colles fractures?
fracture within 1-2cm of the carpal bones, with posterior and lateral displacement of the distal fragments (silver fork deformity); always posteriorly angled
What is Smith's fracture?
an anteriorly-angled Colles fracture
Fracture through the midportion of the scaphoid bone can cause aseptic necrosis to the ______ portion of the bone.
Necrosis of bones in the wrist cause them to appear more ______ compared to the other bones.
What is unique about the blood supply to the scaphoid bone?
the radial A supplies the distal portion first, then reaches back to supply the proximal portion
How can you recognize a lunate dislocation?
the lunate's moon shape faces any other direction but toward the metacarpals on a lateral image
How can you recognize a perilunate dislocation?
the lunate appears fine, but everything distally from it looks jacked
How does carpal tunnel syndrome affect sensation of the hand and wrist?
loss of sensation of the first three digits; forearm and wrist pain
MR scan is indicated in cases of carpal tunnel syndrome
false; nerve-conduction velocity tests are indicated, but MR is the scan of choice if you decide to do one anyway
What is RSD?
reflex sympathetic dystrophy, a chronic, painful, and progressive neurological condition that affects skin, muscles, joints, and bones
Where does RSD usually develop?
in an injured limb, or following surgery
What images do you need for a case involving hand fractures?
AP, lateral
What is Bennett's fracture?
fracture at the base of the first metacarpal, usually due to hyperextension/abduction of the thumb (evulsion fracture)
What is a Boxers fracture?
fracture of the distal metacarpal