Humerus and Shoulder Girdle Notes

Radiographic Anatomy

Review Exercise A: Humerus and Shoulder Girdle

The shoulder girdle consists of:
- Clavicle
- Scapula
- Proximal Humerus
Figure 5.1 and 5.2 Parts Identification
- A. Greater tubercle (tuberosity)
- B. Intertubercular groove (bicipital)
- C. Head
- D. Anatomic Neck
- E. Lesser tubercle (tuberosity)
- F. Surgical Neck
- G. The projection represented is a Neutral rotation of the proximal humerus.
The three aspects of the clavicle are:
- Acromial extremity
- Sternal extremity
- Body
The male clavicle tends to be thicker and more curved in shape.
The three angles of the scapula include the:
- Medial
- Superior
- Lateral
The anterior surface of the scapula is referred to as the Costal surface.
The anatomic name for the armpit is Axilla.
The two fossae located on the posterior scapula are:
- Infraspinous
- Supraspinous
All of the joints of the shoulder girdle are classified as being Diarthrodial (freely movable).
Movement types for the following joints:
- Scapulohumeral: Ball and Socket or Spheroidal
- Sternoclavicular: Plane or gliding
- Acromioclavicular: Plane or gliding
Matching Anatomic Structures with Location:
- Greater tubercle - Proximal humerus
- Coracoid process - Scapula
- Crest of spine - Scapula
- Sternal extremity - Clavicle
- Acromial extremity - Clavicle
- Intertubercular groove - Proximal humerus
- Glenoid cavity (fossa) - Scapula
- Surgical neck - Proximal humerus
Figures 5.3 and 5.4 Structures
- A. Neck
- B. Scapulohumeral joint (glenohumeral)
- C. Acromion
- D. Coracoid process
- E. Scapular notch
- F. Body
- G. Medial (Vertebral) border
- H. Lateral (Axillary) border
- I. Costal (Ventral) surface
- J. Dorsal (Posterior) surface
- K. Spine of scapula
- L. Acromion
- M. Coracoid process
- N. Body (Blade)
- O. Inferior angle
Figure 5.5 Structures
- A. Coracoid process
- B. Scapulohumeral joint
- C. Acromion
- D. Greater tubercle
- E. Lesser tubercle
- F. Lateral border
- G. Internal rotation anteroposterior (AP) projection of the proximal humerus and shoulder
- H. Lateral perspective of the proximal humerus
- I. Epicondyles of the distal humerus are perpendicular to the IR on this projection.
Figure 5.6 Structures
- J. Body of scapula
- K. Acromion and Spine
- L. Coracoid process
- M. Body of humerus
- N. Scapular Y-lateral (Posterior oblique projection)
Figure 5.7 Structures
- A. Coracoid process
- B. Glenoid cavity
- C. Spine
- D. Acromion
- E. Inferosuperior axial projection
- F. Affected arm be abducted from the body for this projection at $90^{\circ}$ .

Radiographic Positioning

Review Exercise B: Positioning of Humerus and Shoulder Girdle

Proximal humerus rotation:
- Greater tubercle profiled laterally: External rotation
- Humeral epicondyles angled 45 degrees to image receptor (IR): Neutral rotation
- Epicondyles perpendicular to IR: Internal rotation
- Supination of hand: External rotation
- Palm of hand against thigh: Neutral rotation
- Epicondyles parallel to IR: External rotation
- Lesser tubercle profiled medially: Internal rotation
- Proximal humerus in a lateral position: Internal rotation
- Proximal humerus in position for an AP projection: External rotation
Figures 5.8-5.10 Proximal Humerus Rotation
- Fig. 5.8: Neutral rotation.
- Fig. 5.9: External rotation.
- Fig. 5.10: Internal rotation.
Positioning and Technical Considerations:
- False: The use of a grid is not required for shoulder studies that measure less than 4 inches (10cm).
- False: The kVp range for adult shoulder projections is between 100 and 110 kVp.
- False: Low mA with long exposure times should be used for adult shoulder studies.
- False: Large focal spot setting should be selected for most adult shoulder studies.
- True: Shoulder projections are best performed erect when possible.
- False: A 72-inch (180-cm) source image distance (SID) is recommended for most shoulder girdle studies.
- True: Selection of the center cell if using the AEC.
kVp ranges for a shoulder series on an average adult using a grid: 80-90 kVp.
Device permits good visualization of soft-tissue and bony anatomy for adult shoulder radiography: Wedge compensating filter.
If physical immobilization is required, the individual that should be asked to restrain a child for a shoulder series: A Parent or guardian.
True: It is recommended to perform shoulder positions on bariatric patients in the erect position when possible.
True: CT arthrography of the shoulder joint often requires the use of iodinated contrast media injected into the joint space.
True: Magnetic resonance imaging (MR) can be used to evaluation soft tissue injuries.
True: Nuclear medicine bone scans can demonstrate signs of osteomyelitis and cellulitis.
False: Radiography is more sensitive than nuclear medicine for demonstrating physiologic aspects of the shoulder girdle.
True: Diagnostic medical sonography (DMS) can provide a functional (dynamic) evaluation of joint movement that MR cannot.
Matching Clinical Indications to Definition:
- Compression between the greater tuberosity and soft tissues on the coracoacromial ligamentous and osseous arch: Impingement syndrome
- Injury of the anteroinferior glenoid labrum: Bankart lesion
- Inflammatory condition of the tendon: Tendonitis
- Superior displacement of the distal clavicle: Acromioclavicular joint dislocation
- Compression fracture of the articular surface of the humeral head: Hill-Sachs defect
- Traumatic injury to one or more of the supportive muscles of the shoulder girdle: Rotator cuff tear
- Atrophy of skeletal tissue: Osteoporosis
Matching Radiographic Appearances to Pathology:
- Subacromial spurs: Impingement syndrome
- Fluid-filled joint space: Bursitis
- Thin bony cortex: Osteoporosis
- Abnormal widening of acromioclavicular joint space: Acromioclavicular joint separation
- Calcified tendons: Tendonitis
- Avulsion fracture of the glenoid rim: Bankart lesion
- Narrowing of joint space: Osteoarthritis
- Closed joint space: Rheumatoid arthritis
- Compression fracture of humeral head: Hill-Sachs defect
Clinical indications requires a decrease in manual exposure factors: Osteoporosis.
True: The shoulder is the most common joint to develop bursitis due to repetitive motion.
False: Rheumatoid arthritis is more prevalent in men over women.
The most common injury to the rotator cuff is to the Supraspinatus tendon.
Two shoulder projections that are taken routinely for a shoulder (with no traumatic injury) and proximal humerus: AP external.
Specifically, where is the central ray placed for an AP projection of the shoulder: 1 inch inferior to Coracoid process.
Which lateral projection can be performed to demonstrate the entire humerus for a patient with a midhumeral fracture: Transthoracic.
To best demonstrate a possible Hill-Sachs defect, which additional positioning technique can be added to the inferosuperior axial (Lawrence method) projection: Rotate affected arm externally approximately 45 degrees.
What type of central ray angulation is required for the inferosuperior axial projection (Lawrence method) for the shoulder: 25-30 degrees medially.
The anterior oblique projection of the shoulder produces an image of the glenoid process in profile. This projection is also referred to as the Grashey method.
Which of the following projections produces a tangential projection of the intertubercular sulcus (groove): Fisk modification.
The CR for the superoinferior transaxillary projection is directed to the Glenoid cavity.
Which of the following projections is best for demonstrating a possible dislocation of the proximal humerus: Posterior oblique (scapular Y) projection.
The Tangential projection is the special projection of the shoulder that best demonstrates the acromio-humeral space for possible subacromial spurs, which create shoulder impingement symptoms (more than one answer possible).
What type of CR angle is required for the apical AP axial shoulder projection: 30 degrees caudad.
Which of the following nontrauma projections can be performed erect to provide a lateral perspective of the proximal humerus in relationship to the scapulohumeral joint: Anterior oblique position (Grashey method).
How much is the CR angled for the inferosuperior axial projection (Clements modification) if the patient cannot fully abduct the arm 90 degrees: 5-15 degrees.
What CR angle is required for the AP axial projection (Zanca method) for acromioclavicular (AC) joints: 10-15 degrees cephalad.
False: The PA axial transaxillary projection (Bernageau method) requires no CR angle.
True: The transthoracic lateral projection can be performed for possible fractures or dislocations of the proximal humerus
True: The use of a breathing technique can be performed for the transthoracic lateral humerus projection.
False: The affected arm must be placed into external rotation for the transthoracic lateral projection.
True: A central ray angle of 10-15 degrees caudad may be used for the transthoracic lateral shoulder projection if the patient is unable to elevate the uninjured arm and shoulder sufficiently.
False: The scapular Y lateral (posterior oblique) position requires the body to be rotated 25-30 degrees anteriorly toward the affected side.
Which two landmarks are placed perpendicular to the IR for the scapular Y lateral projection: Superior angle of Scapula & AC joint articulation.
Which special projection of the shoulder requires that the affected side be rotated 45 degrees toward the cassette and uses a 45 degrees caudad central ray angle: AP apical oblique axial projection.
A posterior dislocation of the humerus projects the humeral head Superior to the glenoid cavity with the special projection described in the previous question.
An asthenic patient requires more CR angle for an AP axial clavicle projection than a hypersthenic patient.
What must be ruled out before performing the weight-bearing study for AC joints: Fracture of Clavicle.
Matching Projections with Method Name:
- Inferosuperior axial: Bernageau method
- Anterior oblique for glenoid cavity: Grashey method
- Tangential for intertubercular (bicipital) sulcus: Fisk modification
- Supraspinatus outlet tangential: Neer method
- PA axial transaxillary: Bernageau method
- AP apical oblique axial: Garth method
What is the most common clinical indication to perform the Alexander method for the AC joints: Suspected AC joint separation.
What type of CR angle is required for the Pearson method for AC joints: None.
Where is the CR centered for the AP scapula projection: Midscapula.
What type of CR angle is required for the lateral scapula position: None.
True: Orthostatic (breathing) technique is recommended for the transthoracic lateral projection.
False: The lateral scapula and posterior oblique (scapular Y) projections are the same projection.

Problem Solving for Technical and Positioning Errors

Review Exercise C

Lateral humerus radiograph overexposed, lesser tubercle not in profile: Increase kVp to 80, decrease mAs to 10, ensure humeral epicondyles perpendicular to IR.
AP axial clavicle, clavicle projected below superior border of scapula: Increase cephalic angle based on body habitus.
AP recumbent scapula in lung field, difficult to see: Abduct affected arm 90°, use breathing technique.
AP shoulder (external rotation), neither tubercle profiled: Supinate hand, ensure epicondyles parallel to IR.
Lateral scapula not true lateral: Increase body rotation, ensure midscapula perpendicular to IR.
AP oblique (Grashey), glenoid cavity borders not superimposed, broad shoulders: Increase rotation toward IR (35°-45°).
Possible right shoulder dislocation, transthoracic lateral attempted, patient unable to raise left arm: Angle CR 10°-15° cephalad to separate shoulders.
Possible right proximal humerus fracture, patient unable to stand/sit: AP of right shoulder and humerus, no rotation and a supine, beam, right transthoracic shoulder.
Chronic shoulder dislocation, suspect Hill-Sachs defect: Inferasuperior axial, Clements modification, and Garth method.
Possible Bankart lesion: (A. Ap apical oblique axial B. Scapular Y lateral C. Grashey Method).
Possible rotator cuff tear: MR
Clinical history of tendon injury, functional study needed: Diagnostic medical sonography (DMS)
AP internal rotation shoulder, neither tubercle profiled: Humeral epicondyles weren't + to IR
Transthoracic lateral, lung markings/ribs superimposed over proximal shoulder: Orthostatic (breathing) technique.
Midhumerus fracture, patient unable to stand: Transthoracic lateral for humerus
AP apical oblique axial (Garth), proximal humeral head below glenoid cavity: Anterior dislocation of the proximal humerus

Critique Radiographs of the Shoulder Girdle

Review Exercise D

(A) AP clavicle (Fig. 5.11)
- Possible errors:
  - 2 (rotation), 36 incorrect centering), 56missing markers)
(B) AP shoulder-external rotation (Fig. 5.12)
- Possible errors:
  - ROTATION
(C) AP scapula (Fig. 5.13)
- Possible errors:
  - 1 (anatomy), 2 (positioning), 36 centering), 4 (exposure), and 56marker)
(D) AP humerus (Fig. 5.14)
- Possible errors:
  - Canatomy) and 3(contering)
  - Which projection (AP, lateral, or oblique) and which rotation (internal, external, or neutral) of the proximal humerus are evident? AP, External rotation

Laboratory Exercises

SELF TEST

Term(s) that correctly describe(s) the shoulder joint: B and C
- Scapulohumeral
- Glenohumeral
Specific joint found on the lateral end of the clavicle: Acromioclavicular
Not an angle found on the scapula: Medial angle
Structure of the scapula extends most anteriorly: Coracoid process
False: The male clavicle is shorter and less curved than the female clavicle.
Bony structure separates the supraspinous and infraspinous fossae: Scapular spine
Structure is considered the most posterior: Acromion
Type of joint movement for the scapulohumeral joint: Ball and socket
Fig. 5.15 represent an AP projection with: (B) external
The labeled structures are:
- A. Spine of scapula
- B. Lesser tubercle
- C. Coracoid process
- D. Lateral (axillary) border of scapula
- E. Scapulohumeral joint
- F. Clavicle
- G. Intertubercular sulcus
- H. Acromion of scapula
- I. Neck of scapula
- J. Greater tubercle
- L. Lateral extremity of clavicle
- M. Head of humerus
- N. Glenoid cavity
Fig. 5.16:
- Inferosuperior axial projection.
Technical considerations does not apply for adult shoulder radiography: Nongrid
False: If a virtual grid is used, a physical grid is not needed.
False: The greatest technical concern during a pediatric shoulder study is voluntary motion.
Imaging modalities or procedures assesses physiologic aspects instead of anatomic: Nuclear medicine
Imaging modalities or procedures provides a functional, or dynamic, study of the shoulder joint: DMS
Clinical Indications Definitions:
- Disability of the shoulder joint caused by chronic inflammation in and around the joint: Idiopathic chronic adhesive capsulitis
- Injury to the anteroinferior glenoid labrum: Bankart lesion
- Chronic systemic disease with arthritic inflammatory changes throughout the body: Rheumatoid arthritis
- Superior displacement of distal clavicle: AC joint dislocation
- Compression fracture of humeral head: Hill-Sachs defect
- Traumatic injury to one or more muscles of the shoulder joint: Rotator cuff tear
- Reduction in the quantity of bone: Osteoporosis
Projections and/or positions best demonstrates signs of impingement syndrome in the acromiohumeral space: Apical AP axial projection
Pathologic conditions often produces narrowing of the joint space: Osteoarthritis
Pathologic conditions results in systemic inflammatory changes to connective tissues: Rheumatoid arthritis
Alternative CR centering technique for an AP shoulder projection on a bariatric patient if unable to palpate the coracoid process: Center 2 inches (5 cm) below level of vertebra prominens
Type of compensating filter is recommended for use on an AP shoulder projection for a hypersthenic patient: Boomerang
Routine projection of the shoulder requires that the humeral epicondyles be parallel to the IR: Neutral rotation
Where is the central ray centered for an AP projection-external rotation of the shoulder: 1 inch (2.5 cm) inferior to coracoid process
Position of the shoulder and proximal humerus projects the lesser tubercle in profile medially: Internal rotation
Type of central ray angle should be used for the inferosuperior axial projection for the scapulohumeral joint space: 25-30 degrees medially
To best demonstrate the Hill-Sachs defect on the inferosuperior axial projection, which additional positioning maneuver must be used: Use exaggerated external rotation
How are the humeral epicondyles aligned for a rotational lateromedial projection of the humerus: Perpendicular to IR
Special projection of the shoulder places the glenoid cavity in profile for an "open" scapulohumeral joint: Grashey method
Type of CR angle is required for the apical AP axial shoulder (Garth method) projection: 30 degrees caudad
For the erect version of the tangential projection for the intertubercular sulcus, the patient leans forward 10-15 degrees from vertical.
Major advantage of the supine, tangential version of the intertubercular sulcus projection over the erect version: Ability to use automatic exposure control
Projections best demonstrates the supraspinatus outlet region: Tangential projection (Neer method)
Projections which an orthostatic (breathing) technique can be used: Transthoracic lateral for humerus
Central ray angulation is required for the tangential projection-supraspinatus outlet (Neer method): 10-15 degrees caudad
Clinical indication is best demonstrated with the Garth method: Scapulohumeral dislocations
Anatomy of the shoulder is best demonstrated with superoinferior transaxillary projection: Coracoid process of the scapula on end
If the patient cannot fully abduct the affected arm 90 degrees for the inferosuperior axial transaxillary projection (Clements modification), the technologist can angle the CR 5--15 degrees toward the axilla.
Projections requires the CR to be centered 2 inches (5 cm) inferior and medial from the superolateral border of the shoulder: Posterior oblique (scapula Y lateral projection)
Anatomy is best demonstrated by the Alexander method: AC joints
Type of injury must be ruled out before the weight-bearing phase of an AC joint study: Fractured clavicle
Minimal amount of weight a large adult should have strapped to each wrist for the weight-bearing phase of an AC joint study: 8-10 lb (3-4kg)
False: A PA axial projection of the clavicle requires a 35- to 45-degree caudal central ray angle.
False: A 72-inch (180-cm) SID is recommended for adult AC joint studies.
Two positioning landmarks are aligned perpendicularly to the IR for the lateral scapula projection: Superior angle and AC joint
A radiograph of an anterior oblique (Grashey method) shows that the anterior and posterior glenoid rims are not superimposed: Rotate body more toward affected side
Situation: A patient with a possible shoulder dislocation enters the emergency room. A neutral AP projection of the shoulder has been taken, confirming a dislocation. Which additional projection should be taken? CAP apical oblique axial (Garth method)
Situation: A patient is referred to radiology for an AC joint series. The routine calls for an AP axial projection (Zanca method) to be included. Perform the position AP erect with 10- to 15-degree cephalic angle
AP axial clavicle taken on an asthenic patient shows that the clavicle is projected in the lung field below the top of the shoulder: Increase central ray angulation
Situation: A patient with a possible right-shoulder separation enters the emergency room. AC joint series: non-weight-bearing and weight-bearing projections
Situation: A patient comes to the radiology department with a history of tendonitis of the bicep tendon: Tangential projection (Fisk modification)
AP apical oblique axial (Garth method) radiographic image demonstrates poor visibility of the shoulder joint. Wrong direction of CR angle
Situation: A patient enters the ER with a proximal and midhumeral fracture.:AP and transthoracic lateral of humerus