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Elbow and Forearm

Terms in this set (102)

What are the routine radiologic views of the elbow?
-AP view
-lateral view
What is an optional view of the elbow?
oblique view(s)
What are routine radiologic views of the forearm?
-AP view
-lateral view
What is the patient position for the AP view of the elbow?
-sitting
-Shoulder: full ER and 90° abduction
-Elbow: extension (if possible)
-Forearm (FA): supination
Why is FA supination important in the AP view of the elbow?
to avoid overlapping of radius on the ulna
What is the central ray for the AP view of the elbow?
perpendicular to the elbow joint
What bony observations are seen on the AP view of the elbow?
-distal humerus
-olecranon process
-trochlea of humerus
-radial head, neck, tuberosity
-ulna
-HRJ, HUJ, PRUJ spaces
What is the olecranon process superimposed on in the AP view of the elbow?
trochlea of the humerus
What is the radial head (portion), neck, and tuberosity superimposed behind in the AP view of the elbow?
ulna
How is the HUJ space observed on the AP view of the elbow?
as a subtle joint line as the ulna superimposes it
What is an angle that is observed on the AP view of the elbow?
varus or valgus angle
What two bones form the intersecting line to determine varus/valgus of the elbow?
humerus and ulna
What is the patient position for the lateral view of the elbow?
-sitting
-Shoulder: 90° abduction
-Elbow: 90° flexion
-FA: neutral
Where is the image receptor located for the lateral view of the elbow?
medial side of the elbow
What is the central ray for the lateral view of the elbow?
perpendicular to the elbow through HRJ
What is the direction of the central ray for the lateral view of the elbow?
lateral to medial
What are bony observations in the lateral view of the elbow? (long)
-olecranon process
-coronoid process superimposed behind radial head
-anterior portion of radius easily viewed
-distal humerus
-epicondyles
-trochlear sulcus
-inner concentric arc formed by the capitulum and trochlea
What are potential fracture sites observed in lateral view of the elbow?
-olecranon process
-coronoid process
What is the terrible triad of the elbow?
-elbow dislocation
-radial head fracture
-coronoid process fracture
T/F
The posterior portion of the radius is easily viewed on the lateral view of the elbow.
False.
The posterior portion of the radius is superimposed
T/F
The radial tuberosity is superimposed on itself in the lateral view of the elbow.
True.
What do the epicondyles look like on the the lateral view of the elbow?
superimposed teardrop shape
What does the trochlear sulcus look like on the lateral view of the elbow?
white circular appearance
What else can be observed on the lateral view of the elbow?
fat pads of HRJ and HUJ
What do the fat pads look like on the lateral view of the elbow?
superimposed together as a thin triangular lucency anterior and posterior to distal humerus
If the fat pads of the HRJ and HUJ are displaced, what may that indicate?
intra-articular swelling
There is an increased suspicion of a __________ with intra-articular swelling in the fat pads of the HRJ and HUJ.
fracture
What is the patient position for an IR oblique view of the elbow?
-Shoulder: 90° abduction and slight IR
-Elbow: full extension (or close to)
-FA: max pronation
What is the central ray for the IR oblique view of the elbow?
perpendicular to the elbow passing through the elbow joint
How is the radius and ulna observed with the IR oblique view of the elbow?
this view crosses radius over ulna creating superimposition of many structures
What are bony observations for the IR oblique view of the elbow?
-coronoid process without superimposition
-articulation of coronoid process in olecranon fossa
-posterior HUJ space
-medial epicondyle
-trochlea
What does the olecranon fossa look like on an IR oblique view of the elbow?
generally cartilagenous (black/dark on rads)
T/F
With the IR oblique view of the elbow, the supracondylar ridge on the medial side is slightly smaller than the lateral side.
True.
What is the patient position for the ER oblique view of the elbow?
Shoulder: 90° abduction and slight ER
Elbow: full extension (or close to)
-FA: max supination
What is the central ray for the ER oblique view of the elbow?
perpendicular to elbow passing through the elbow joint
What bony observations are seen without superimposition on the ER oblique view of the elbow?
radial head, neck, and tuberosity
What two bony observations are seen in profile on the ER oblique view of the elbow?
-capitulum
-lateral epicondyle
What patient population frequently uses the ER oblique view of the elbow?
children/adolescents (esp. little league)
What 3 joint spaces are visible on the ER oblique view of the elbow?
-HUJ
-HRJ
-PRUJ
What is the patient position for the AP view of the forearm?
-sitting
-Shoulder: full ER and 90° abduction
-Elbow: extension (if possible)
-FA: supination
What is the central ray for the AP view of the forearm?
perpendicular to FA at the midpoint of the FA
What bone is difficult to see on the AP view of the FA but can still be viewed?
distal humerus
What joints are visible on the AP view of the forearm? Which ones are the more important joints to observe in this view(**)?
-HRJ
-HUJ
-PRUJ**
-DRUJ**
What bones are seen in its entirety on the AP view of the FA?
-radius
-ulna
--can look for fracture or bowing
What is important to observe related to the diaphysis in the FA?
observe the contour of the diaphysis
The ___________ is superimposed on the trochlea in the AP view of the FA.
olecranon
What is the patient position for the lateral view of the FA?
-sitting
-Shoulder: 45° abduction
-Elbow: 45-90° flexion
-FA: slight supination (45°)
What is a good study tip when reviewing the patient position for the lateral view of the FA?
Think of everything at 45° for the lateral view of the FA
What is the central ray for the lateral view of the FA?
perpendicular to FA at the midpoint of the FA
What are observations for the lateral view of the FA?
-olecranon process seen in profile
-distal humerus is superimposed
-epicondyles
Why is it important to look at the radius and ulna in the lateral view of the FA?
to look for changes in shaft angulation and potential fractures
Why is the lateral view of the FA not an ideal view to observe the elbow and wrist joints?
due to the location of the central ray (since it is located at the midpoint between the two joints)
T/F
There are many guidelines to help with decision making for pathologies related to the elbow.
False.
There are limited guidelines related to the elbow.
What radiographs should be used with trauma to the elbow/FA?
routine radiographs
-elbow (AP and lateral)
-FA (AP and lateral)
When is advanced imaging typically used with a trauma to the elbow/FA?
if a fracture is highly suspected but not visible on radiographs
What 2 advanced imaging modalities are typically used to view osteochondral fractures?
CT or MRI
What type of imaging modality should be used with high suspicion of ST involvement (UCL)?
advanced imaging (MRI)
What type of advanced imaging modality is used to look at tendon involvement (LE) or stress views as in UCL involvement?
DUS
T/F
Many times you won't see a fracture line on an x-ray, so it is important to look at other factors that may lead to suspicion of a potential fracture.
True.
What are important factors to look for when a fracture line is not visualized but there is still a suspicion of a fracture?
-(+) fat pad sign
-abnormal supinator line
-capitulum displaced
T/F
Anterior and posterior fat pads are easily visualized on a normal radiograph.
False.
Posterior fat pad is difficult to see on a normal radiograph
What does a (+) fat pad sign look like on a lateral radiograph of the elbow?
flat, black lucent stripe that extended out from the bone
T/F
Advanced imaging is helpful when viewing fat pads.
True.
What does an abnormal supinator line look like on a lateral radiograph of the elbow?
can present as slightly convex and wavy
T/F
The abnormal supinator line is easily visualized.
False.
The abnormal supinator line is NOT easily visualized
What can you suspect if an abnormal supinator line is visualized on lateral radiograph of the elbow?
suspect an occult fracture on the lateral side (radius, capitulum)
How can you tell on a radiograph if the capitulum is displaced?
draw 2 lines (I think this is what he said):
-anterior to humerus running caudally intersecting the middle third of the capitulum
-perpendicular running through the radius
** if the lines are off --> may indicate a subtle fracture is present
T/F
Children have many ossification centers. It is important to know the order of ossification to determine potential for OCD lesions.
True.
What is the mnemonic to determine the order of ossification?
CRITOE
What is the order of the ossification centers (from first closed to last closed)?
1. capitulum
2. radial head
3. (internal) medial epicondyle
4. trochlea
5. olecranon process
6. (external) lateral epicondyle
What are radial head fractures also known as?
mason fractures
What is the description of a type 1 radial head fracture?
non-displaced
What is the description of a type 2 radial head fracture?
displaced with separation or angulation
What is the description of a type 3 radial head fracture?
comminuted (usually displaced)
What is the description of a type 4 radial head fracture?
fracture with dislocation
What is the most common MOI for a radial head fracture?
FOOSH
What is the most common type of radial head fracture seen in the clinic?
type 1
What types of radial head fractures are usually treated conservatively?
types 1 and 2
What types of radial head fractures are usually treated surgically?
types 3 and 4
What is the description of a type 1 olecranon fracture?
-consists of proximal 1/3 of olecranon
-extra-articular or intra-articular
What is the description of a type 2 olecranon fracture?
-consists of the middle 1/3 of olecranon
-may have 1 or 2 fracture lines
What is the description of a type 3 olecranon fracture?
-consists of the distal 1/3 of olecranon
-rare
What type of olecranon fracture is more serious and can potentially result in instability?
type 3
T/F
A type 1 olecranon fracture is typically treated surgically.
False.
Type 1 is typically treated conservatively.
An intra-articular olecranon fracture has a ________ (increased, decreased) prognosis compared to an extra-articular olecranon fracture.
decreased
T/F
It is important to look for an abnormal supinator sign, (+) fat pad sign, and/or sign of capitulum displacement because a radiograph of a child/adolescent can have a growth plate that is not closed. This results in a non-pathological radiograph.
True.
What are 2 types of FA fractures?
-distal radius fracture (Galeazzi's fracture)
-ulnar shaft fracture (Monteggia's fracture)
What is a general description of a Galeazzi's fracture?
usually displaced and often associated with dislocation
What is a general description of a Monteggia's fracture?
fracture of proximal 1/3 of ulna with displacement of radial head
What was the helpful tip he gave to help us remember the Galeazzi's fracture and Monteggia's fracture? (I think this is right, but he went through it quickly in class)
GRUesome MURder
-Galeazzi; Radial fracture; Ulnar dislocation
-Monteggia; Ulnar fracture; Radial dislocation
How is a FA dislocation characterized?
by the direction of the radius or ulna displaced in relation to the distal humerus
What is the most common direction of a FA dislocation (80-90% of cases)?
posterior to posterolateral dislocation of both radius and ulna
What is another fracture/dislocation of the elbow/FA?
Essex-Lopresti fracture
What does a Essex-Lopresti fracture consist of?
-distal widening of DRUJ
-Proximal radial head fracture
What might a fracture to the interosseous membrane limit?
pronation/supination of the FA
When a radiograph comes back negative for a diagnosis of medial/lateral epicondylitis, what advanced imaging option is best to use next?
MRI
When is DUS helpful with medial/lateral epicondylitis?
According to ACR guidelines (7/9 variant 5): chronic elbow when radiograph is nondiagnostic
What 2 bony structures of the elbow are the most common sites to look for osteochondritis dissecans (OCD)?
-radius
-capitulum (most commonly anterior capitulum)
What type of imaging is first used to look for OCD?
routine radiographs
What advanced imaging modality is appropriate to use if the patient is symptomatic but not picked up on normal radiographs or re-evaluation demonstrates joint surface irregularities?
MRI
T/F
There are a lot of ACR guidelines for the elbow, so it is important to utilize them when appropriate.
False.
There are not a lot of ACR guidelines for the elbow.
Make sure to review pictures, labs, case studies, and book for additional information on the elbow and FA.
:)
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