Chapter 5: Shoulder Flashcards
How is the patient positioned for an AP shoulder
supine or upright at equal distance to the IR
How should the clavicle be demonstrated in an AP shoulder projection
Clavicle demonstrated horizontally
KVP and distance for an AP shoulder
Optimal kVp 65-75, SID 40-48 inches
how is the scapular body in an AP shoulder
Scapular body is curved around rib cage so there is a 35 to 45 degree of obliquity
What should be included in an AP shoulder projection
Include
-glenohumeral joint space
-lateral 2/3 of the clavicle
-proximal third of the humerus
-and superior scapula
What three main parts should be evaluated to detect rotation of the shoulder
Evaluate the scapular body, glenoid cavity and clavicle
how is the scapular body when the patient is rotated toward the affected shoulder
the scapular body is more parallel with the IR and appears wider on the image
how are the glenoid cavity and scapular neck when the patient is rotated toward the affected shoulder
The glenoid cavity and scapular neck are more in profile
how is the clavicle when the patient is rotated toward the affected shoulder
Clavicle is longitudinally foreshortened, medial end is shifted away from the vertebral column
What are some things that would detect there is rotation toward affected shoulder
-thoracic vertebrae on top of scapula
-ribs elongated
-will rotate more on coracoid
-flattening scapula out
-opening joint space of humeral head and glenoid
how is the thorax in a rotation away from effected shoulder
Thorax is demonstrated over a smaller amount of the scapula
how is the scapular body demonstrated in a rotation away from effected shoulder
Scapular body demonstrates increased transverse foreshortening
how is the glenoid demonstrated in a rotation away from effected side
The glenoid cavity is better demonstrated (more on end)
what is the medial clavicular end superimposed over in a rotation away from effected shoulder
Medial clavicular end is superimposed over the vertebral column
Some indications there is rotation away from effected shoulder
- clavicle end is now on spine
-thorax is off of scapular body - glenoid cavity is way far over on humeral head
which type of dislocation is more common ?
anterior dislocations
how is an anterior location?
They are anterior and beneath the coracoid process
(coracoid more anterior)
how is a posterior dislocation
Posterior dislocation result in the humeral head being demonstrated posterior and beneath the acromion process or spine of the scapula
(acromion more posterior)
Key indications it is an anterior dislocation
-head of humerus not within glenoid cavity
-head of humerus is sitting below coracoid process
Key indication that it is a posterior dislocation
- humeral head is below acromion
how is the superior scapular angle when there is an anterior (forward) tilt
will be demonstrated superior to the midclavicle
how is the superior scapular angle when there is a posterior (backward) tilt
superior scapular angle will shown inferior to midclavicle
What tilt is more common
anterior
what should you do when you have a kyphotic patient
With a kyphotic patient angle the central ray cephalic to be perpendicular to the scapular body
how should the superior scapular angle be in an AP shoulder
superior angle should lie directly on clavicle mid-shaft
is the scapula above or below clavicle in an anterior tilt
scapula above clavicle
is the scapular above or below the clavicle in a posterior tilt
below clavicle
what do you look at for indication of a tilt
superior scapular body
what is the lateral epicondyle alligned with
The lateral epicondyle is aligned with the greater tubercle (and the thumb)
what is the medial epicondyle alligned with
the humeral head
how is the lesser tuberical in relation to the greater tubercle
The lesser tubercle is anterior at a right angle to the greater tubercle
how are the epicondyles in a neutral position
neither are in profile
epicondyles 45 degrees with IR
what is in profile in neutral position
partial profile of greater tubercle laterally
and head profile medially
palm against the side, epicondyles at 45° with the IR (partial profile of greater tubercle laterally, and head profile medially
neutral
epicondyles are parallel with IR( greater tubercle in profile laterally, humeral head profile medially, lesser tubercle halfway in between)
external
how are the epicondyles in external
parallel with IR
what is in profile in a external shoulder
-greater tubercle in profile laterally
-humeral head profile medially
-lesser tubercle halfway in between)
how are the epicondyles in an internal rotation
epicondyles are perpendicular with the IR
what is in profile in an internal rotation
Lesser tubercle is demonstrated in profile medially and humeral head is superimposed by the greater tubercle
what is in profile in a grashey
Glenoid cavity is in profile with the glenohumeral joint space open
how is the clavicle in a grashey
Clavicle is longitudinally foreshortened
if there is thorax on image in a grashey, what does that mean
rolled too much ( should not have an thorax superimposition)
how is the patient rotated for a grashey
Patient is rotated 35 to 45° toward affected shoulder
what are you more concerned about for a grashey
joint space
in a grashey, if yjere is more coracoid on humeral head is it over or under rotated
over rotated
in a grashey, if you dont see the coracoid is it over or under rotated
under rotated
how should the shoulder be in a grashey
Shoulder in neutral position and not protracted (moved forward)
how should the CR be for a grashey
CR 1 inch inferior and medial to the coracoid process
Main reason for grashey
-glenoid cavity in profile
-open up glenoid and humeral joint space
how many degrees should you rotate the pateint if you are doing a grashey shoulder on the table
6o degrees
criteria for grashey
-roll shoulder forward so head of humerus is lying flat against ir
-joint space is opened of head of humerus and glenoid cavity
-rib cage over neck of scapular
-clavicle foreshortened
-coracoid is superimposed over head of humerus
positioning for grashey
-rotate pt. 35 to 45 degree oblique
-Palpate the coracoid and acromion
-Rotate Pt. so both coracoid and acromion are superimposed and perpendicular to the IR
how are the coracoid and acromion in a grashey position
superimposed and perpendicular to the IR
space is closed, more than ¼ of the tip of the coracoid process is superimposed over the humeral head, excessive longitudinal foreshortening of clavicle
excessive rotation of grashey
space is closed, less than ¼ of tip of coracoid process is superimposed over humeral head, clavicle shows little foreshortening
insufficient rotation of grashey
what parts form the scapular y
The body, acromion and coracoid processes form a Y
what part is in a lateral position of a scapular y
Scapular body is in a lateral position
what is on end of the scapular y
glenoid cavity
how should the humerus be in a scapular y
the humerus should be over the body
humeral head will be sitting on the glenoid cavity
what border of the scapular is thicker
lateral border
how is the lateral border of the scapula
The lateral border of the scapula is thicker and shows two cortical outlines
what border of the scapula is thinner
medial border
how is the medial border of the scapula
Medial border is thinner and shows only one single thin line
in a scapular y, if the lateral border is next to the ribs is it an excessive or insufficient roatation
excessive
in a scapular y, if the medial boder is next to the ribs is it excessive or insufficient rotation
If medial border is next to the ribs (insufficient)
lateral y view is good for what two things
-fractures and dislocations
humeral shaft is not on the body (humerus has gone anteriorly)
fracture of humeral head
criteria for AP projection of clavicle
-medial end should be over toward spine
-SC and AC joints
-clavicle in entirety (no foreshortening)
-superior angle of scapula should be right on clavicle
what type of rotation for an AP clavicle:
-medial clavicle on the spine
-more scapular and less ribs on scapula
affected side rotated away
in a clavicle, if the medial clavicle is on the spine what time of rotation is it
affected side rotated away
what type of rotation is it when the medial clavicle is off the spine
rotated toward the affected
what type of rotation for ap clavicle
medial clavicle off the spine
clavicle foreshortened
rib cage more over on scapula
what is the angle of ap axial clavicle
15 to 30 angle cephalic
why do we do an axial clavicle
to get medial aspect off of rib cage
where do 80 percent of the fractures of the clavicle happen
middle third
where do 15 percent of fractures of the clavicle happen
at the lateral third
how should ther lateral and middle third of the clavicle be projected
project the lateral and middle thirds of the clavicle superior to the thorax and scapula
how should AC joints be done
Upright and Weight-bearing/Non Weight-bearing
how to detect rotation of ac joints
Detect rotation by evaluation of clavicles and acromion apex( out of profile if rotated towards that side)
what does rotation of ac joints result in
Rotation results in a narrowed or closed AC joint
SID for AC joints
72 inches- bilateral (bc of divergence of the beam)
40 inches- unilateral
where should the weights be for ac joints
on the wrists
breathing for AP scapula
expose on expiration (less air in the lungs)
or shallow (to blur out lungs and ribs)
how should pt be positioned for ap scapula
abduct humerus and supinate hand and flex elbow 90 degrees
for a kyphotic patient what do you do for the ap scapula
Kyphotic patient- angle cephalic /perpendicular to the scapular body
to Take advantage of gravity and max. shoulder retraction, how do you do the patient for a ap scapula
do the patient supine
how should the lateral aspect and superior scapular be for the ap scapula
Lateral aspect should not have thoracic superimposition and superior scapular angle is approx. ¼ inch inferior to the clavicle
positioning for lateral scapula
Oblique patient enough to superimpose scapular borders
Humerus is elevated/ moving scapula around the thoracic cavity( the more you do this the less of obliquity you need)
how do you positiong patient for lateral scapula to see coracoid and acromion and body
arm behind the back - demonstrated coracoid and acromion
look at the lateral body- bring arm above head or
arm across the chest and rest hand on opposite shoulder
(last two will cover up coracoid and acromion but all three will give a good view of the body)
Also known as the lawrence method
Inferosuperior (Axial) Projection
For inferior and superior margins of the glenoid cavity
Inferosuperior (Axial) Projection
how much to angle for the Inferosuperior (Axial) Projection
30 to 35 degrees and abduct the arm 9- degrees
how much do you angle the tube when the arm can not be abducted atleast 60 degrees in an Inferosuperior (Axial) Projection
when the arm can not be abducted atleast 60 degrees angle the tube 20 to 25
what should the CR be for Inferosuperior (Axial) Projection
CR should be parallel to the glenohumeral joint space
arm positioned out at 90 degrees and put hand supinated (epicondyles parallel) -see lesser in profiler anteriorly
Inferosuperior (Axial) Projection
bring arm out to 90 degrees and turn thumb to the floor epicondyles at 45 degrees (lesser will be partially in profile) posterior lateral part of the humeral head is the area of interest
hill sachs defect
correct positioning for inferosuperior projections
epicondyles parallel
hand supinated
lesser tubericle in profile with epicondyles in parallel
hills sachs
lesser only partial in profile when epicondyles are 45 degrees
looking at coracoid (lines up with glenoid cavity)
need to change angle for inferosuperior axial
coracoid should line up with glenoid cavity
-too far forward - too much angle
-too far back - too less of an angle
which two views open up glenoid
grashey and axial
if the arm is not in the way, what is the image for (shoulder or scapula)
scapula
if you see the head of the humerus what view is it for (shoulder or scapula)
shoulder
for the axial views, what two things should line up
glenoid and coracoid
