Humerus And Shoulder Flashcards
Identify the structures of the humerus
What are the routine projections for the humerus?
AP and lateral
What is the SID and kVp (both grid and non-grid) for the humerus?
SID= 40” kVp= 80 grid and 60 non-grid
Where should the height of the IR be for an AP humerus?
Upper edge should be 1-2 inches above head of humerus
How do you position a patient for an AP projection of the humerus?
Patient upright with arm straightened and hand supinated
What does the patient being positioned upright with arm straightened and hand supinated do?
Put the humeral epicondyles parallel to the IR
Where do you direct the CR for an AP humerus?
Over the humerus to the midpoint of IR
What does the AP projection of the humerus demonstrate?
Demonstrates the entire length of the humerus with greater tubercle in profile pointing laterally
How do you position a patient for a lateral humerus?
From AP position, have patient flex elbow and rotate arm internally, then place back of hand on hip
What is perpendicular to the IR when the patient is positioned for a lateral humerus?
Epicondyles
What is perpendicular to the IR once the patient is positioned for an lateral humerus?
Epicondyles
What does a lateral humerus demonstrate?
Entire length of humerus with lesser tubercle in profile pointing medially
If a patient is unable to rotate arm for a lateral view, what method can be used instead?
Transthoracic lateral or Lawrence method
What does the transthoracic lateral/Lawrence method demonstrate?
Demonstrates anterior/posterior displacement of fracture or anterior/posterior dislocation of head of humerus
Where should the upper edge of IR be for transthoracic lateral/Lawrence method?
Upper edge of IR 1-2 inches above head of humerus.
How is the patient placed for the transthoracic lateral/Lawrence method?
Patient in lateral position with affected arm against IR and uninjured arm raised to forearm on head (to elevate shoulder of uninjured arm)
Why is the affected arm against the IR for the transthoracic lateral/Lawrence method?
To minimize magnification
What should be in the center of the IR for a transthoracic lateral/Lawrence method?
The affected humerus
Where should the CR be directed for a transthoracic lateral/Lawrence method?
Direct CR through humerus to midpoint of IR
When is the exposure taken for a transthoracic lateral/Lawrence method? Why?
Taken on full inspiration to improve contrast and decrease exposure necessary to penetrate body
Identify the structures of the shoulder joint
Between the acromion and coracoid process in the scapula, which one is more anterior? Which one is more posterior?
Anterior- coracoid process
Posterior- Acromion
What are the routine projections for a shoulder x-ray?
AP neutral, AP internal, AP external oblique, axillary view, and scapular Y
What is the SID and kVp (grid and non-grid) for shoulders?
SID= 40” kVp= 80 grid and 60 non-grid
How do you position the patient for an AP neutral shoulder?
Patient’s arm should hang down by their side with palm of hand against thigh
Where should the CR be for an AP neutral shoulder?
1 inch inferior to coracoid process (which is medial to head of of humerus)
What will the AP neutral shoulder demonstrate?
Demonstrate the humerus in neutral position, placing the humeral epicondyles at an angle of about 45° with plane of IR
How is a patient positioned for an AP internal?
Have patient flex elbow, rotate arm internally, and rest back of hand on hip
How does the AP internal position of a shoulder place the humerus?
Places humerus in a lateral position so that lesser tubercle will be in profile pointing medially and the epicondyles will be perpendicular to the plane of IR
Where is the CR directed for an AP internal shoulder?
CR directed 1 inch inferior to coracoid process and center IR to CR
An AP external oblique of the shoulder is also known as…
Grashey method
How do you position the patient for an AP external oblique?
Patient externally rotates arm or rests hand across belly
How is the patient rotated for AP external oblique of shoulder/Grashey method?
35-45° toward affected side
In the AP external oblique shoulder/Grashey method, _________ will be in profile pointing laterally and _____ will be parallel to plane of IR.
In the AP external oblique shoulder/Grashey method, GREATER TUBERCLE will be in profile pointing laterally and EPICONDYLES will be parallel to plane of IR.
What will an AP external oblique of shoulder/Grashey method demonstrate?
Demonstrates an open joint space between humeral head and glenoid cavity
How do you position the patient for an axillary view of shoulder?
Have patient sit at end of table with affected arm abducted and leaning over IR and have the patient tilt their head forward to their chin or opposite side of shoulder being radiographed
How is the tube angled for an axillary view of shoulder?
5-10° towards elbow
Where is the CR directed to for an axillary view of shoulder?
Through top of shoulder/shoulder joint
What does the CR directed through top of shoulder for an axillary view of shoulder demonstrate?
Demonstrates glenohumeral joint space
In what positions can you take the scapular Y projection?
AP or PA
Where should the upper edge of IR be for a scapular Y projection?
1-2 inches above shoulder
How do you position a patient for a scapular Y PA projection?
For PA, patient is upright facing grid. Patient is rotated 45-60° towards affected side (shoulder at center of IR, direct CR to midpoint of IR)
How do you position a patient for a scapular Y AP projection?
For AP, patient stands at vertical grid obliqued 45-60° With affected side up (direct CR through shoulder joint)
What does the scapular Y projection demonstrates?
Demonstrates whether a dislocation of humeral head is anterior or posterior
How do you collimate for the scapular Y projection?
Collimate to shoulder while still including length of scapula
What positions (RAO, PRO, LAO, LPO) can the patient be in to demonstrate right shoulder?
RAO or LPO
What positions (RAO, PRO, LAO, LPO) can the patient be in to demonstrate left shoulder?
LAO or RPO
What forms the vertical component of the Y shape? What forms the upper limbs of the Y?
- Body of scapula forms vertical component of Y shape
- Acromion and coracoid process forms upper limbs of Y
In a normal shoulder, what is directly superimposed over the junction of the Y?
The humeral head
In anterior dislocations, where is the humeral head is situated?
Beneath coracoid process
In posterior dislocations, where is the humeral head situated?
Beneath acromion process
