1
Q
is the thumb on the lateral or medial aspect
A
Lateral (radius side)
2
Q
what is at the extreme lateral and medial edges of the radius and ulna
A
Radial and ulnar styloids are at the extreme lateral and medial edges keep it in the same plane
2
Q
what articulation should be open in a pa wrist
A
Radioulnar articulation is open
3
Q
what is rotation controlled by for a pa wrist
A
hand, elbow, and humerus keep in the same plane
4
Q
for a pa wrist where is limited superimposition
A
Superimposition of the MCP bases is limited
5
Q
what better demonstrates the ulna styloid process in a pa wrist
A
when the humerus, elbow, and forearm are in the same plane 90 degrees
6
Q
what type of fracture is the ulnar styloid process likely to get
A
an avulsion fracture
7
Q
what type of fracture happens when there is hyperextension or hyperflexion of a joint
A
avulsion
8
Q
What do you do to bring the carpal bones closer for PA wrist
A
curl fingers up to bring carpal bones in contact with IR
9
Q
What’s the CR for PA wrist
A
CR Perpendicular to midcaarpal area or carpal bones
10
Q
What should you make sure you get for PA wrist
A
make sure you get up to McP bases up to radius / ulna
11
Q
What should be visible on all PA wrist images
A
Scaphoid fat stripe
12
Q
what is adequate to demonstrate the schaphoid fat stripe
A
contrast and density
13
Q
It is convex and located lateral to the scaphoid in an uninjured wrist
A
scaphoid fat stripe
13
Q
A change in the covexity may indicate the presence of a…
A
joint effusion
radial side fracture of the scaphoid radial styloid process
or proximal first metacarpal
14
Q
how should the scaphoid fat pad be?
A
Convexed
15
Q
How much should you get for carpal bones, radius/ ulna, and proximal MCP for PA wrist
A
carpal bones in center 1/4 of distal ulna and radius plus 1/2 of the proximal MCP are included in the field
16
Q
what projection shows better carpal interspaces
A
AP wrist
17
Q
fluid can buldge out
A
joint effusion
18
Q
can die off when there is a fracture
A
scaphoid
18
Q
how are the hand and wrist rotated in this oblique position?:
the MC bases and carpal bones on the medial aspect of the wrist are superimposed( whereas laterally they are not)
A
Hand and wrist rotated externally into an oblique position
18
Q
what wrist rotation best demonstrates the trapezium and trapzoid.
decreased space between 4th and 5th MCP
- Radioulnar articulation closes
A
external rotation of wrist
19
Q
causes the laterally located carpal bones and MC bases to be superimposed and increases visibility of the pisiform and hamate hook
- radioulnar atriculation close
A
Internal rotation of the hand and wrist
20
Q
What should you look for to see if there’s a rotation of the wrist
A
Look at the 3rd MCP to see if is straight or not
21
away from the body
abduction
21
towards the midline of the body
adduction
22
what determines the positioning of the placement of the ulnar styloid
humerus and elbow
22
what happens if the humerus remains in a vertical position
If humerus remain in a vertical position the ulna and radius cross over and the ulnar styloid is no longer in profile
22
when elbow is bent at 90 degrees what is in profile
the ulna styloid process
23
Abduction the humerus to position the elbow in the lateral position and humeral epicondyles aligned perpendicular to IR
brings the ulna styloid process in profile
23
what are parallel with each other
radius and ulna
23
what type of rotation is it when the pisiform is out by itself
internal rotation
24
what MC should you be looking at if you are concerned if there is rotation
the third MC- it should be straight
25
what is concave and slants 11 degrees from posterior to anterior
Distal radial carpal articular surface
26
how many degrees does the distal radial carpal surface concave and slant from posterior to anterior
11 degrees
27
CR perpendicular Forearm is positioned parallel with IR for PA wrist, the slant of the distal radius causes the
regular x-ray
the posterior radial margin to project slightly distal to the anterior radial margin obscuring the radiocarpal joints
27
when the radius is straight out
the posterior and anterior aspect do not superimposed each other
28
if posterior radial margin is extremely distal to the anterior margin , how was the proximal forearm
the proximal forearm was elevated higher than the distal forearm ( elbow was raised)
29
if anterior radial margin is extremely distal to the posterior margin how was the proximal forearm positioned
the proximal forearm was positioned lower than distal forearm (elbow lowered)
30
what would you do to superimpose the distal radial margins and demonstrate the radioscaphoid and radiolunate joints as open spaces
- posterior aspect towards proximal
- anterior aspect more distal
the proximal aspect of the forearm should be positioned slightly lower than the distal forearm(5 to 6 degrees)
(so half of the 11 degrees)
31
what should you do when you have a thick or muscular forearm
proximal forearm it may be necessary to extend the arm off the IR or table in order to position it parallel with the IR
- lower proximal forearm parallel with IR
32
how to put the wrist in a neutral position
To put the wrist in a neutral position, flex the patient’s fingers (curl fingers), flexing the until the MC are angled to 10-15 degrees with the IR
32
results in obscured 3rd -5thCM joint spaces and severely foreshortened scaphoid (signet ring configuration) and triangular lunate
distal portion goes anterior
Flexion
-fingers are straight out
33
when there is foreshortening of the schaphoid what is visible
visible signet ring (white circle)
33
results in foreshortened MC and closed 2nd-3rd CM joint spaces , decreased scaphoid foreshortening, and triangular lunate
scaphoid elongating
Extension (hand extended up)
-pullinh distal part of scaphoid up elongating it
34
Excessive foreshortening and signet ring configuration of scaphoid
- Lunate is triangular
- 3rd -5th CM places are obscured
wrist flexion
35
what can you do to fix the wrist flexion
The hand needs to be extended*Curl the patient’s finger
35
Foreshortened MCP Closed 2nd-3rd CMC joint spaces
- Decreased scaphoid foreshortening
- brought fifngers up
- elongated scaphoid
- triangular lunate
- bases of the metacarpals are obscuring distal row of carpal bones
wrist extension
36
distal scaphoid to shift anteriorly (towards palmar surface) and increase foreshortening as if forms the signet ring configuration
- hand towards thumb
- lunate will shift medially towards ulna
- ring (flexion)
radial deviation
37
how will the lunate shift in a radial deviation
Lunate will shift medially toward the ulna
38
distal scaphoid tilts posteriorly (dorsally) and demonstrate decrease foreshortening
- elongate scaphoid
- lunate will shift laterally towards the radius
ulnar deviation
39
why is ulnar deviation or radial deviation typically done
for wrist joint mobility
40
what is ulnar deviation used for
to demonstrate the scaphoid better - elongates it
41
Note the long axis of the 3rd MCP, use to judge
if foreshortening is due to flexion or extension of carpal bones or radial and/or ulnar deviation
42
make sure make sure you have contrast and density
to demonstrate scaphoid fat stripe
43
PA oblique projection is how many degrres
45 degrees oblique
44
What is best demonstrated in a PA 0blique wrist
trapezoid and trapezium are demonstrated without superimposition
45
what joint space is open for a PA oblique wrist
Trapeziotrapezoidal joint
46
What is demonstrated in profile for a PA oblique wrist
Scaphoid tuberosity and waist
47
Small degree of trapezoid and capitate superposition is present
- slight space between 4th and 5th MCP joint
- lateral aspect is best demonstrated
- lower thumb to not foreshroten it and not obscure trapezium
PA oblique wrist
48
if under-rotated for an oblique wrist how is the trapezoid and trapezium
If under rotated the trapezoid and trapezium are superimposed
49
how is trapeziotrapezoidal joint space when the wrist is under rotated for an oblique
The trapeziotrapezoidal joint space is obscured
50
The trapezoid demonstrates minimal capitate superimposition
under rotated pa oblique wrist
51
The long axis of the 3rdmetacarpal and midforearm are aligned long axis of the collimation field, what position is the wrist in
the wrist is in a neutral position.
52
does radial or unlar deviation increase the foreshortening of the scaphoid
radial deviation
52
Preventing visualization of the scaphoid tuberosity and waist
radial deviation
positions the scaphoid directly next to the radius
53
decreases scaphoid foreshortening, the scaphoid will be elongated
ulnar deviation
54
the MCP is not aligned with the midforearm
ulnar deviation
54
in a oblique wrist *If the image demonstrates the posterior radial margin too far distal to the anterior margin , how was the proximal forearm
the proximal forearm was elevated higher than the distal forearm
55
in an oblique wrist , If the anterior radial margin is demonstrated distal to the posterior margin, how is the proximal forearm
the proximal forearm was positioned lower than the distal forearm
55
Parallel to the anteriorsurface of the distal radiusNormally convexBowing or obliteration mayIndicate subtle radial fracture
pronator fat stripe
56
scaphoid and lunate articulate with
radius
57
anterior margain is more than the posterior for radius
11 degrees difference in the radius
more whiter
58
an open radiolunate and radioscaphoid joint spaces
the proximal forearm was positioned slightly lower 5 to 6 degrees
59
In a lateral wrist there should be contrast and density to adequately demonstrate the
pronator fat stripe and posterior soft tissue should look convex
60
if pronator fat stripe is not convex
there is a subtle radial fracture
61
for lateral wrist elbow should be flexed 90 degrees and abduct humerus until
it is parallel with ir
62
in a lateral wrist what should be aligned
distal scaphoid and pisiform
63
what is aligned parallel with the forearm for lateral wrist
thumb has to be down don't want to obscure the trapezium
long axis of the 1st McP
64
what do you want to make sure you get for lateral wrist in relation to radius and ulna and MCp
1/4 distal of ulna and radius and 1/2 of proximal MCP
64
parallel to the anterior surface of the distal radius
pronator fat stripe
65
how to check for rotation of a lateral wrist
To detect rotation check the relationship between the distal aspect of the scaphoid and the pisiform
66
how should the the distal aspect of the scaphoid and the pisiform be in a lateral wrist
They should superimpose and demonstrate anterior to the capitate and lunate
67
criteria for lateral wrist to make sure that is no rotation
-all mc should all be superimposed
-radius and ulna superimposed
-distal scaphoid and pisiform anterior to capatate and lunate
67
what should be align on top of one another in a lateral wrist
pisiform and scaphoid
68
how is the pisiform when the wrist is externally rotated
a
bringing pisiform forward
69
how should the pisiform in a true lateral wrist be
scaphoid and pisiform should be superimposed
-scaphoid can be slightly anterior but pisiform superimposed over it
70
how is the scaphoid when the wrist is rotated externally for a lateral wrist
*If wrist is rotated externally (supinated) the distal scaphoid is visible posterior to the pisiform
71
5th MCP, pisiform, ulna more anterior in
external rotation of lateralwrist
72
pisiform will go more anterior, radius will go posterior and ulna will go anterior
external rotation of lateral hand
73
If the distal scaphoid and pisiform are not superimposed and the ulna is positioned anterior to the radius
it is externally rotated lateral wrist
74
If wrist is rotated internally( hand pronated)
the distal scaphoid is visible anterior to the pisiform
75
in an internal rotation of the lateral wrisyt
pisiform will go posterior the scaphoid more anterior radius will go anterior and ulna posterior
75
If distal scaphoid and pisiform are not superimposed and the ulna is positioned posterior to the radius,
the wrist was internally rotated
75
scaphoid, radius, 2nd MCP more anterior
internal rotation of lateral wrist
76
if the radial side is placed on the IR
the ulna and pisiform are anterior to the radius and scaphoid
77
align the long axis of the 3rd MC with the midforearm parallel with the IR
neutral lateral wrist
77
when the proximal forearm is higher in a lateral wrist is this radial flexion or extension
radial flexion
78
what view forces the distal scaphoid anteriorly and the pisiform is distal to the scaphoid
Radial deviation of wrist
79
what deviation shifts the distal scaphoid posteriorly
ulnar deviation
79
when the proximal forearm is higher it create radial flexion or radial deviation which
forces the distal scaphoid anterior and tghe pisiform more distal to the scaphoid which foreshrotens the scaphoid
80
The pisiform is proximal to the scaphoid
The proximal forearm may not be level ,but lower
what does this cause
ulnar deviation
81
is this wrist flexion or extension? the lunate and distal scaphoid tilt anteriorly
- foreshortens scaphod (ring)
wrist flexion
82
wrist extension or flexion? the lunate and distal scaphoid tilt posteriorly
- elongates the scaphoid
wrist extension
83
is the elbow is higher, is it radial or ulnar deviation
radial deviation
84
if the elbow is lower, is it radial or ulnar deviation
ulnar deviation
85
if the first MC is not lowered it will be foreshortened and its proximal aspect is superimposed over what carpal bone?
trapezium
85
1st and 2nd MCP should be what
at the same level
86
is this radial deviation or ulnar?
foreshortened scaphoid will go down anterior pushing pisiform distally
radial deviation
87
down from suspected fracture of scaphoid
pa axial ulnar deviation
87
Demonstrate scaphoid fat stripe
*Scaphotrapezium and scaphotrapezoidal joint spaces are open
*These joints are aligned at a 15° angle to the IR when the hand is fully extended
*Ulnar deviation approx. 25°
*Align 1st MC with the radius
Ulnar Deviation PA Axial Projection
88
the distal scaphoid tilts anteriorly approx. 20° and results in foreshortening of the scaphoid
Why does this happen
wrist is non flexed
89
if patient is unable to achieve max ulnar deviation what angle should you use
20 degrees
90
what is the most. common fractured carpal bone?
the waist of the scaphoid
90
what angle best demonstrates the proximal scaphoid
5 to 10 degress
91
what degree best demonstrates the distal scaphoid
25 degrees
91
where is most of the stress on when the hand is hyperexteneded
waist of the scaphoid
91
what degree best demonstrates the waist of the scaphoid
15 degrees
92
what degree do you need when the fracture is more distal on the scaphoid
more angle
93
If the scaphocapitate joint space is closed and the capitate and hamate are demonstrated without superimposition
how was the degree of obliquity
insufficient
94
If the scapholunate joint space is closed and the capitate and hamate demonstrate some degree of superimposition
how was the degree of obliquity
rotated more than needed
94
-tube angled inferior to superior
-tangential view skimming base of 3rd MC
-want to see arch
-good view of hamate
- hyperextend wrist til long axia of MC are close to vertical
-25-30 degree angulation
-rotate hand so 5th MC is perp to IR
Gaynor Hart
94
Pisiform is demonstrated without superimposition
*Hamulus of the hamate and carpal canal is clearly demonstrated
*Carpal canal is center of collimated field
*Trapezium ,distal scaphoid, pisiform and hamulus of the hamate are all included within the field
*Hyperextending (dorsiflex) of wrist until long axis of MC are close to vertical
*Central ray 25 to 30 degrees, rotate hand to the radial side approx. 10 degrees, 5th MC vertical
criteria for gaynor hart
95
why does this happen in a gaynor hart:
the carpal canal will not be fully demonstrated and the carpal bones will be foreshortened
angle between the CR and MC is too great
95
95
why does this happen in a gaynor hart :
the bases of the hamulus process, pisiform and scaphoid are obscured by the MC bases
angle is too small
96
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Image Analysis (mine)
flashcards
Decks in class (5)
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