Finger, Hand, Wrist, Forearm & Elbow Critiques
When the pt cannot completely extend the elbow for an AP projection, describe what you would do to achieve similar results.
1. Have the humerus parallel to IR 2. Have forearm parallel to IR Both with CR directed to mid elbow
If an angle is required for ulnar deviation, what is the degree and direction?
10-15 degree cephalic w/ long axis of forearm
What is the CR location for the 2nd-5th digits? Thumb?
2nd-5th: Proximal interphalangeal joint (PIP) Thumb: Interphalangeal joint (IP)
When performing the oblique projection, how many degrees is the wrist rotated and in what direction?
45 degrees laterally
When performing the medial oblique elbow projection, what is the relationship of the epicondyles to the plane of the IR? What is the relationship for the lateral oblique projection?
45 degrees parallel
How much should the elbow be flexed for the lateral projection? What is the position for the entire upper extremity for the lateral projection?
90 degree flexion. Posterior hand contact w/ hip. Epicondyles perp w/ IR.
How is the thumb positioned compared to the other digits? Why?
AP - Rotate hand medially, back of the thumb in contact with IR, hold fingers back(2-5 digits) Oblique - Hand pronated, thumb will be in a natural oblique Lateral - Rotate medially slightly
Which projection best demonstrates the carpal interspaces? Why?
AP wrist
Name a fracture and a pathologic process that are relatively common on hand radiographs.
Boxers fracture - 5th metacarpal transverse fracture that extends through the metacarpal neck
2 common fractures of the wrist
Colle's - Fracture of distal radius with posterior displacement Barton's - Fracture & dislocation of posterior lip of distal radius
Define: DIP, PIP, IP
Distal interphalangeal joint Proximal interphalangeal joint Interphalangeal joint
Visualization of the posterior fat pad called the "fat pad" sign is significant on a true lateral projection of elbow.
Essential for evolution of joint pathology. Fat pad posterior visualization indicates elbow trauma
Describe the relationship of the coronoid and olecranon process to their fossae when the elbow is flexed and extended
Extended - olecranon fossa has posterior depression Flexion - coronoid process has anterior depression
An extension and fan lateral hand projection can be performed on a pt. When would each projection be performed?
Fan lateral - align o long axis, true lateral w/ thumb up and piny in contact w/ IR. Fingers slightly separated and digits parallel. Extension - extend finger and thumb. support w. radiolucent block. All fingers & metacarpals are superimposed.
Name anatomy indicated by letters
G - Humeral epicondyle I - trochlear sulcus J - trochlear notch K - ridges of capitulum L - coronoid process M - radial head N - radial neck
What would the tech do if the pt condition prohibited including all of the above structures on the IR?
Include as much as possible, with as many projections possible to include the necessary anatomy.
In order to demonstrate the entire circumference of the radial head free of superimposition, what projections should be done?
Lateral oblique, AP
What exposure factors will provide an optimal image?
Low density, short scale contrast, small focal spot, short exposure time.
When bilateral hand images are ordered, each side should be separately positioned and exposed. For what pathological condition would both hands be positioned and radiographed simultaneously on the IR? What is this method called and how is it obtained?
Norgaard method aka ball catchers view. Both hands extended and supinated, internal rotation 45 degrees, thumbs abducted and fingers separated but parallel.
In what direction is the hand rotate when imaging the 2nd digit in the oblique projection? In the lateral projection? When radiographing the 3rd-5th digits?
Oblique 2nd digit - lateral/external rotation Lateral 2nd digit - medial/internal rotation Oblique 3rd-5th - lateral/external rotation Lateral 3rd-5th - lateral/external rotation (will have OID)
What projection of the hand naturally gives an oblique position of the thumb?
PA hand
What will radial deviation demonstrate?
Pisiform and triquetrum
If the pt cannot rotate their hand, what alternative method can be utilized?
Place pt hand on a sponge and shoot perpendicularly to scaphoid
Explain the phrase: Post-reduction radiograph of wrist
Post op or after resetting of wrist radiographs with cast or sling on
The movements of supination and pronation of the forearm and hand are the result of the combines rotary action of which two joints? What type and classification of these two joints?
Proximal & distal radioulnar joints. Diarthrosis; synovial; pivot joint
In which direction, and to what degree should the tube be angled when performing the "coyle trauma" position for the coronoid process? for the radial head? how much is the elbow flexed for each?
Radial head - toward shoulder, 45 degree CR, flexed 90 degrees Coronoid - away from shoulder, 45 degree CR, flexed 80 degrees
Which bone of the forearm articulates most directly with the carpal bones to form the worst joint? What is another name for the wrist joint?
Radius; Carpometacarpal joint
What aids can be used to help immobilize the extended fingers in the oblique and lateral positions?
Step wedge, tape, or have pt. hold back their other fingers for the lateral position
Define supination and pronation. Why is the hand supinated for the AP projection?
Supination - anterior aspect of hand facing up Pronation - posterior aspect of hand facing up Hand is supinated bc there will be no superimposition of radius and ulna.
Which finger has the least numbers pf phalanges?
Thumb
Why is it imperative to keep the finger completely parallel to the IR when performing lateral and oblique positions of the fingers?
To accurately demonstrate the phalanges and joints
Why is this PA scaphoid method performed?
To fully visualize the scaphoid with no superimposition
Why should the fingers be kept parallel to the IR when doing the oblique and lateral positions?
To minimize distortion and to demonstrate good joint spaces
When performing the PA wrist, why is the hand placed in a loose fist?
To place wrist in contact with IR
Describe the jones method as alternate AP projection of the distal humerus and proximal forearm when the elbow cannot be fully extended.
one w/ CR perp to humerus and another w/ CR perp to forearm. Humerus: Olecranon, medial epicondyle, radial neck and ulna Forearm: olecranon process, medial and lateral epicondyles, radial neck.
What types of accessory devices should be used to prevent motion on extremity work?
tape, step wedge
What is the correct terminology used to refer to the PA projection of scaphoid?
ulnar deviation
When doing a lateral elbow, how many degrees is the arm flexed? 2 reasons.
90 degrees; shows displaced fat pads for trauma. To have the ulnar head superimposing radius
What specific type of joint is the elbow?
Synovial; hinge
Why should the hand be supinated for the AP projection of the elbow?
so the radius and ulna are not superimposed
What does the scaphoid articulate with proximally?
The radius
Which bone of the forearm articulates most directly with the humerus at the elbow joint?
Ulna
Indicate the joint name, classification, and movement on the anatomy lettered A,G,I, and N on the radiograph (in critique book)
A - Carpometacarpal joint; Synovial; Saddle G - Metacarpophalangeal joint; Synovial; Condyloid I - Proximal Interphalangeal Joint; Synovial; Hinge N - Distal Interphalangeal Joint; Synovial; Hinge
What anatomy is best demonstrated by the medial oblique elbow? Lateral oblique elbow?
Medial - coronoid process Lateral - Radial head
What is the most common fractured carpal bone?
Scaphoid