MSK 2 Flashcards
1
normal trans-scapular y view
95% of shoulder dislocations are
anterior
5% are the WORST
adduction internal rotation and extension is common holding for an individual with
posterior dislocation
cannot externally location
common mechanism of posterior dislocation
High force; direct blow, seizure, MVA or fall SEIZURES
■ Usually will have associated injuries
what % of posterior should dislocations are misdiagnosed
50
seizures
motor vehicle accident
Arm held in abduction, external rotation,
extension
anterior shoulder dislocation
ice cream on a cond lightbulb on a stick is a comon discription of
posterior dislocation in AP view
normal Y
posterior dislocation lateral to the Y
anterior medial to the Y
axial view of posterior humeral head is oppostie to the corocoid process
normal axial
anterior dislocation axial
humeral head overlaps coracoid
this deformity is due to repeated anterior dislocations (and on every baord exam ever per Lauri)
● Hill-Sachs Fx/Deformity
Luxatio Erecta is what kind of fx
Uncommon but distinct shoulder dislocation
● Inferior glenohumeral dislocation
● Arm abducted - held above head, can’t move it (“arm up”)
Humeral head impingement under anterior glenoid rim
○ Predisposes to future dislocations
Hill-Sachs Fx/Deformity
Small fracture of glenoid rim that is frequently caused by reductions that don’t get enough clearing or dislocation
Bankart Fx
bankhart
mechanism behind scapula fx
Significant mechanism, high force, direct impact ○ Ex: Fall from height, MVA
dx of scapula
what views do you need
Often detected on CXR, AP shoulder
need
AP with arm in abduction
○ “Y View” is money! Very useful to detect fx, angulation
○ Order a CT scan (often complex fx’s)
○ CXR mandatory
best view is going to be on your Y
major sites of scapula
6 major sites :
acromion,
coracoid,
spine,
glenoid,
scapular neck,
body
most scapula fractures involve what other connecting
>80% involve body, neck or glenoid
○ Isolated acromion, coracoid fx’s less common
MC site for clavicle fx
what views do you need
Middle third is #1 MC Fx site
need to ask for AP and angeled view
common clavicle fx site in elderly
Distal third – common in elderly
because they fall on the shoulder straight down
clavicle is the only bone that you can describe like this
proximal or distal displacement/angulation
fracture of clavicle near sternum
usually from direct blow
really need to worry about the chest
MC fx in children
clavicle
greenstick fx of clavicle in angeled view
middle third fx with complete displacement and 30 deg superior angulation of PROXIMAL segment
this is the only bone you can describe proximally
Partial tear of AC with no displacement
Type (Grade) I
Disruption of ACL and widening of joint
is characteristic of what type of Acromioclavicular seperation
Type II
what will we see in type II
AC joint > 8mm wide/displaced
Clavicle displaced superiorly
No coracoclavicular space widening
Acromioclavicular (AC) Separation
● Rockwood Classification
type II
in most acromioclavicular sperations weight bearing views are hlepful
○ Type III : Disruption of AC and coracoclavicular ligaments
TYPE III rocwood classification criteria
AC joint disrupted
Clavicle displaced superiorly (riding too high)
Coracoclavicular space wide >13mm
coracoclavicular ligaments are also disrubted here leading do that widening
Compression is what Rockwood Classification
Type IV : Compression
Acromioclavicular (AC) Separation
● Rockwood Classification
Humerus Fracture MC single site of humerus fx
Surgical neck - most common single site
when are we worried about avascular necrosis with humerus fx
Fx at anatomic neck = risk of avascular necrosis
humeral shaft is anything below
surgical next. described in thirds
comminuted compltely displaced mid-shaft fx with 30 deg medial angulation and 2cm shortening
standard views for the elbow
and what are the special views
AP, Lateral (90 degree handskae with figure 8 and fat pads) - standard views
medial lateral oblique and capitellum are all special
adequate films of the elbow
soupination radial head and capitellum NOT superimposed should be fully extended
money shot of the elbow
lateral view
90 degrees forearm in handshake position
condyles are superimposed in a figer 8
two fat pads seen in the elbow lateral film
supinator fat stripe
and anterior fat pad
approach to elbow
Hourglass”? “Fig 8”? True lateral?
where they able to do 90 degree handshake
“Fat pads”? Anterior?
ANY posterior fat pad - ABNORMAL–> tx fx
LOOK AT ANT HUMERAL LINE
RADIOCAPITELLAR LINE
INSPECT RADIAL HEAD
INSPECT DISTAL HUMERUS
INSPECT OLECRANON AND ULNA
sale sign?
special views of the elbow and what they look at specifically
lateral oblique: radiocapitellar
capitellum: radial head
medial oblique-condyles of distal humerous
special view of the elbow medial oblique
condyles
which line of normal alignment is critical in kids for the elbow
where should we see this normally
anterior humeral line
should intersect the middle 1/3
fat pad of elbow indicates
hemarthrosis or effusion
anterior lifted=sail sign =fracture
ANY posterior fat pad =subtle fx of radial head and supracondylar
MC elbow fx in adults
what is the common mechanism
Inspect the Radial Head
● FOOSH injury: “ f all o n o ut s tretched h and” - arm is extended
Mechanism, Sx’s
○ Radiocapitellar line?
○ Posterior Fat Pad?
pain with pronation and supination in suspected elbow fx
suspect radial head fx
look for posterior fat pat
Radiocapitellar line
look for when suspecting radial head fx
should bisect the capitellum and align in all views
60% all elbow fractures in pediatrics are
Supracondylar fx’s = MC elbow fx in kids
MC joint dislocation
FINGER 1
- SHOULDER
- ELBOWS
- HIPS
MC dislocation in children
elbow
MC of dislocation in children and MOA
Elbow Dislocation
Mechanism: Hyperextension
most site of elbow dislocation
90% posterior
fx of the shaft of the ulna
Nightstick Fractures
common fracture of the radius in children
Torus fx’s DISTAL radius
ulnar fx with radial head dislocation
Monteggia Fx/Dislocation
see Ulna look at montteggia
might teggia a second to realize that radial head is in the rong place
MC Monteggia Fx/Dislocation =
4 types – radial head displaced anteriorly into the antecubital fossa is MC
unstable fracture of the arm that needs operative managmenet
Monteggia Fx/Dislocation
OR Galeazzi Fx/Dislocation
radius fx at distal 1/3 with distal ulnar dislocation
Galeazzi Fx/Dislocation
ulna trynig to escape from the paperrazi
Galeazzi Fx/Dislocation
Ulna dislocated at radio-ulnar
and carpal-ulnar joints
with radius fraxture
happens from holding something out and something falling on it
automatic views for the elbow
AP
OBLIQUE
LATERAL
all three should include the distal radius
– distal segment of radius has dorsal (posterior) angulation
Colles Fx
Distal Radius Fx w/ Angulation
types
● FOOSH mechanism
almost all of them are FOOSH
all related to angulation of distal radius
- Colles Fx – distal segment of radius has dorsal (posterior) angulation
● Smith’s Fx – distal radius has ventral/volar (anterior) angulation
● Barton’s Fx – intra-articular, ventral/volar or dorsal angulation
Smith’s Fx
distal radius has ventral/volar (anterior) angulation
intra-articular, ventral/volar or dorsal angulation subluxation
Barton’s Fx
dinner fork deformity seen with this distal radius fx
colle’s
distal radius is angulated _____ in colle’s
● Distal radius has DORSAL angulation/displacement on lateral
most common injury in the distal forearm
fork is the most common utensil used.
50% of colle’s fxs are assoicated with these fractures
50% also have an ulnar styloid fracture
fall of a flexed wrist seen with this distal radial fx
Smith’s
Intra-articular fx of distal radius with displacement, angulation and subluxation of radiocarpal joint.
Barton’s Fracture
Most commonly fractured carpal bone in adults
Scaphoid (Navicular) Fracture
Scaphoid (Navicular) Fracture why are they so important
Midportion (“waist”) fx of schapoid = risk for AVN of Proximal Pole
Which has no independent blood supply
radial artery comes up with tiny little branches
mechanism of schapoid fractures
● FOOSH w/ extreme dorsiflexion of hand, snuffbox tender
scaphoid fracture best view
will get schapoid view if they are tneder in the snuffbox
wrist in ulnar deviation to see this
2nd most common carpal fracture
Triquetrum Fracture
Usually avulsion fx of the dorsal surface
triquetrum fracture best seen on
best seen on lateral b/c triquetrum is the most dorsal carpal bone seen on lateral view
lunate dislocation usually caused by
FOOSH or direct blow to the palm
what happens in a lunate dislocation
rotates towards the palm
spilled teacup
median nerve can be disrupted
Dislocation of capitate from lunate
Perilunate Dislocation
Perilunate Dislocation how is it different from lnuate dislocation
3x more common than lunate
dislocation
● Lateral shows lunate in proper position,
rest of carpals/MC’s dislocated
● Called the “empty teacup”
Scapholunate Dissociation
“David Letterman” sign – space between front teeth
scaphoid isnpt tlaking to luna
saphoid rotates - seen on end on AP view
Boxer’s fx
where do they normally occur
what bone
are they intra-articular?
4th or 5th (usually 5th) metacarpal
neck (technically - not shaft, not
intraarticular) distal shaft ?
Volar angulation of metacarpal head
- describe in degrees
when do you reduce a bozer’s fx
● Reduce >30° angulation
Bennett’s Fracture
an intra-articular fx-dislocation of the base of the thumb (name is not as important as the description)
MOA of bennets
Abductor pollicis longus pulls thumb downward avulsing it off it’s base
comminuted bennet’s
ROLANDO
comminuted comlicated rolando
Phalanx Fractures/Deformities
Volar Plate Fracture- flexer surface
Mallet Finger-dorsal avulsion
Boutonniere Deformity
Hyperextension injusry of the phalnx
ropbbery
basketball
Volar Plate Fracture
dislocation at the PIP
when to send volar to surgery
>30% of articular surface =
unstable, needs surgical repair
Mallet Finger
Dorsal avulsion Fx, base of
● DIP, at extensor insertion ● Untreated = deformity
Disruption of central slip at PIP
Lateral bands intact, hyperextended DIP
Boutonniere Deformity
Disruption of ulnar collateral ligament with avulsion fracture at base of proximal phalanx
Gamekeeper’s Thumb
Acute injury is also called skier’s thumb , breakdancer’s thumb
fixed extension at PIP, Flexion at DIP
Follows untx’d mallet’s
“Swan Neck” Deformity
Distal Phalanx and Tuft Fracture
usually from
what do you need to check
Usually crush injury or skill-saw to fingertip: xray all
● Check ligament function
this is the only open fx that is not a surgical emergency!
Distal Phalanx and Tuft Fracture
Nail bed injury + Fx = open fracture*
dislocation complications (5)
hill sachs
bankfart fx
avulasion fx
joint instability
axillary nerve injury
how does a chauffeur’s/ hutchenson’s fractured differ from a bartons
intraarticular like bartons
but no angulation and no displacement
scaholunate widening is common
what is a die punch or lunate load fraxture
intraarticular
medial distal radios
impaction of the lunate onto the radius
could see a ulnar styloid fracutre as well
tenderness in the snuff box, what view should you order
ulnar edivation
aka
scaphoid view
second most common fractured carpal pone
triquetrum
the most dorsal of the bones!
