Wrist Forearm Elbow Positioning
What is seen best on the PA oblique lateral rotation of the wrist?
1. Carpals on lateral side of wrist 2. Trapezium and distal half of the scaphoid without superimposition
What is seen best on the PA oblique medial rotation of the wrist?
1. Carpals on medial side of wrist 2. Triquetrum, hook of hamate, and pisiform free of superimposition and in profile
What do we need to see in the lateral elbow projection?
1. Elbow joint open and flexed 2. Superimposed humeral epicondyles 3. Olecranon process in profile
What should we see in a AP forearm projection?
1. NO ROTATION 2. No elongation or foreshortening of the humeral epicondyles 3. Open radioulnar spaces
Why do we flex the elbow in the Lateral Projection (Lateromedial)?
1. Olecranon process can be seen in profile 2. Elbow fat pads are the least compressed
What do we need to see on the Proximal forearm AP projection partial flexion?
1. Proximal radius and ulna without rotation or distortion 2. Radial Head and Coronoid Process
What do we need to see in the AP Oblique Projection with lateral rotation of the elbow?
1. Radial head, neck and tuberosity projected free of the ulna. 2. Capitulum
What do we need to see on an AP Elbow?
1. Radial head, neck, and tuberosity slightly 2. No rotation of humeral epicondyles. (coronoid and olecranon fossae equidistant)
What should we see in a lateral projection of the forearm?
1. Superimposition of the radius and ulna at their distal end 2. Superimposition of the radial head over the coronoid process 3. Superimposed humeral epicondyle 4. Elbow flex 90 degrees
What is the evaluation criteria for a PA wrist?
1. distal radius and ulna 2. carpals 3. proximal half of metacarpal 4. open radioulnar joint space
What is a "trauma elbow" series?
1.distal humerus 2. proximal forearm
In the elbow, how many articulations are enclosed in a common capsule?
3 (the proximal radioulnar joint, humeroulnar joint, and the humeroradial joint)
On an AP oblique projection of the elbow in lateral rotation, the plane of the humeral epicondyles are positioned in...
45 degree angle with lateral epicondyle closer to IR
Which positioning maneuver ensures that the radial head, neck, and tuberosity will be free of superimposition?
45-degree lateral rotation of the elbow
If you want to see medial carpals what projection do you use?
AP Oblique Projection
What oblique of the elbow closes the joint space?
AP oblique with medial rotation
How is arm positioned?
All in same plane
What is the purpose of performing an AP oblique projection of the elbow with lateral rotation?
Allows the radial head and neck to be free of the ulna. The radius is more commonly hurt.
How is the CR positioned with the tangental projection?
Directed to the palm of the hand 1 inch distal to the base of the 3rd metacarpal angle of 25 to 30 degrees to the long axis of the hand.
How is the arm positioned in the AP elbow?
Extend the elbow, supinate the hand and center the IR to the elbow joint
What is something you do not do when taking a lateral projection of the humerus?
Externally rotating the limb to place the humeral epicondyles parallel to the image receptor
In the PA/PA axial projections scaphoid radiographic series (Rafert-Long method), the wrist is positioned:
In extreme ulnar deviation
Which carpal bones are seen to best advantage on the PA oblique projection with lateral rotation?
Lateral Side Carpals
What is the large prominence on the proximal posterior aspect of the ulna?
Olecranon Process
What may the patient need to do during the AP elbow?
Patient lean laterally until the humeral epicondyles and anterior surface of the elbow are parallel with the plane of the IR.
How is the CR for the Proximal Forearm AP Projection Partial Flexion?
Perpendicular to the elbow joint and long axis of the forearm.
For the PA projection of the proximal forearm with the elbow in acute flexion, the central ray is directed
Perpendicular to the flexed forearm
How is the CR placed for the distal humerus AP Projection Partial flexion?
Perpendicular to the humerus, transversing the elbow joint.
How is the hand and wrist positioned for the Scaphoid PA axial projection?
Place on end of the IR on a support and adjust the IR so that the finger end of the IR is elevated 20 degrees.
What happens if we do not supinate the hand in a AP forearm projection?
Pronation of the hand crosses the radius over the ulna at its proximal 3rd and rotates the humerus medially, resulting in an oblique projection of the forearm.
How is the hand positioned for the AP Oblique Projection with Lateral Rotation of the elbow?
Rotate the hand laterally (Externally) to place the posterior surface of the elbow at 45 degree angles.
What should we see in ulnar deviation?
Scaphoid with adjacent articulations open
What needs to be in the same plane for the AP Elbow projection?
Shoulder joint, humerus, and elbow joint in the same plane.
What method looks at the scaphoid?
Stecher
Which method is the Scaphoid PA Axial Projection?
Stecher Method
What projection and method of the wrist is used if the ulnar deviation cannot be performed?
Stecher Method PA Axial Projection
How is the arm positioned for an AP forearm projection?
Supinate the hand, extend the elbow and place the dorsal surface of the forearm against the IR. Ensure that the joint of interest is included.
Which positioning maneuver prevents the radius and ulna from crossing over each other in the AP projection of the forearm?
Supinating the hand
Why do we position the arm in the same plane when performing radiographic procedures?
To open joint space and reduce distortion.
Why do you supinate the hand on a AP forearm?
To prevent superimposition of the radius on the ulna.
When do we use the Distal Humerus AP Projection Partial Flexion?
When the patient cannot completely extend the elbow, the lateral position is easily performed; however, two AP projections must be obtained to avoid distortion. Separate AP projections of the distal humerus and proximal forearm are required.
What is changed in the PA projection (ULNAR DEVIATION) of the wrist?
Without moving the forearm turn the hand outward until the wrist is in extreme ulnar deviation.
What can you see better on a AP wrist verses a PA wrist?
carpal interspaces
What two fossa creates the illusion of a hole in the middle of the distal end of the humerus?
coronoid and olecranon fossa
What do we do to the digits on an AP projection of the wrist?
elevate them in order to place wrist in close contact to the IR
What is the prominence on the proximal lateral humerus called?
greater tubercle
What prevents rotation on an AP projection of the wrist?
having the patient lean laterally
What need to be in the same plane for the lateral elbow projection?
humerus and elbow joint
Which carpal bone is immediately medial to the scaphoid?
lunate
What is located at the distal posterior aspect of the humerus?
olecranon fossa
How is the CR placed for a PA wrist?
perpendicular to the midcarpal area
How is the hand positioned for a PA projection of the wrist?
pronated with fingers flexed
What does the capitulum articulate with?
radial head
Which side of elbow is hurt more often?
radial head
How is the arm and hand for an AP projection of the wrist?
supinated
What is the purpose for performing the PA projection of the wrist with ulnar deviation?
to make the scaphoid look straighter, and stretch it out allows fractures to be shown in the waist or middle of the scaphoid
Which carpal bone is located in the distal row most laterally?
trapezium
What is the angle of the PA Axial Projection?
20 degrees chephalad
How is the arm positioned for a Lateral Projection (Lateromedial) of the forearm?
Flex the elbow 90 degrees and place the medial aspect of the forearm against the IR Thumb side of the hand up.
How do you achieve a lateral wrist?
bend elbow to 90 degrees and rotate ulna to lateral potion
What does the patient need to do for a AP forearm projection?
Have the patient lean laterally until the forearm is in a true supinated position.
What oblique of the elbow opens the joint space?
AP oblique with lateral rotation
What do you see with an AP oblique wrist?
Carpals on the medial side
What does ulnar deviation achieve?
Reduces foreshortening of the scaphoid
What is the position of the styloid process for the lateral projection of the wrist?
superimposed and perpendicular to the IR
What should you see in a lateral wrist?
superimposed distal radius and ulna metacarpals
When do we use the Scaphoid PA axial projection?
when patients can't do ulnar deviation
What is a Collie's Fracture?
fracture of the distal radius with posterior displacement
How many projections are in a forearm series?
2
Why do we flex the fingers on a PA wrist?
to reduce OID
