Chapter 13 - Upper Limb and Shoulder Gridle

Question 1

carpal bones

Answer 1

Beginning with the proximal row on the lateral aspect (thumb side), they are named scaphoid, lunate, triquetrum, and pisiform. The scaphoid is the most frequently fractured carpal bone. Continuing back toward the thumb, the distal row consists of the trapezium, trapezoid, capitate, and hamate. The capitate is the largest of the carpal bones.

Question 2

olecranon process

Answer 2

sometimes called the funny bone or crazy bone.

Question 3

There are two distal articular surfaces on the humerus:

Answer 3

the rounded capitulum (also called the capitellum), which articulates with the head of the radius, and the trochlea, a spool-shaped process that articulates within the semilunar notch of the ulna.

Question 4

shoulder girdle

Answer 4

They include the scapula (shoulder blade), the clavicle (collar bone), and the proximal portion of the humerus.

Question 5

Hand - posteroanterior (PA), PA oblique-lateral rotation, and lateral projections

Answer 5

Body position

Seated at end of table with elbow flexed 90 degrees and arm resting on the table.

Part position

PA

Hand open, fingers extended, with palmar surface in contact with IR, fingers moderately separated (Fig. 13.12).

PA oblique

From the PA, the hand is rotated laterally to place the anteromedial aspect in contact with IR. Coronal plane of hand forms a 45-degree angle with IR. Stair-step sponge is used to support and maintain position of fingers so that IP joints are clearly visualized (Fig. 13.14). Alternatively, without stair-step sponge, “modified teacup” position (named for position of hand when holding a teacup) is used when fingers are not of interest (Fig. 13.16).

Lateral

Medial aspect of hand is in contact with IR with coronal plane of hand perpendicular to IR. Thumb is positioned as for PA projection and is supported on a radiolucent sponge. Wrist will be slightly pronated (Fig. 13.18A). Fingers may be separated (fanned) to prevent superimposition, if desired (see Fig. 13.18B).

Central ray

PA and PA oblique

Perpendicular to third MCP joint.

Lateral

Perpendicular to second MCP joint.

Structures seen

Anatomy of entire hand (including fingertips), carpus, and distal radius and ulna.

PA

No overlap of metacarpals or digits (Fig. 13.13).

PA oblique

No or minimal overlay of metacarpal shafts, with some overlap of metacarpal heads and bases. IP joint spaces open (stair-step sponge, Fig. 13.15) or not well demonstrated (“modified teacup,” Fig. 13.17).

Lateral

Superimposition of second through fifth metacarpals. Superimposition of second through fifth phalanges (extension, Fig. 13.19A) or phalanges individually demonstrated (fanned, Fig. 13.19B). Thumb is seen in PA projection.

Question 6

Finger - PA, PA oblique-lateral rotation, and lateral projections

Answer 6

Body position

Seated at end of table with elbow flexed and arm resting on table.

Part position

PA

Hand is open with palmar surface in contact with IR. Fingers are moderately separated (Fig. 13.21).

PA oblique

From the PA, hand is rotated lateral to place anteromedial (palmar/ulnar) surface in contact with IR. Coronal plane of fingers is at a 45-degree angle to IR. Fingers are supported by stair-step sponge (Fig. 13.23). (The alternative to the use of a stair-step sponge is the “modified teacup” position, as shown for examination of the hand.)

Lateral

Medial or lateral surface of hand may be in contact with IR, depending on which brings finger of interest nearest to IR. Other fingers are flexed or extended as necessary to leave affected finger free of superimposition. Affected finger is supported parallel to IR (Figs. 13.25, 13.27 to 13.29).

Central ray

Perpendicular to proximal IP joint.

Structures seen

Entire digit and distal portion of metacarpal with IP and MCP joint spaces open and clearly visualized (Figs. 13.22, 13.24, and 13.26). Department protocol may require including an adjacent digit in each image.

Question 7

Thumb - AP, PA oblique, and lateral projections

Answer 7

Body position

AP

Seated at end of table, leaning forward, arm abducted 90 degrees, with forearm rotated internally into exaggerated degree of pronation.

PA oblique and lateral

Seated at end of table with elbow flexed 90 degrees, arm fully supported, and palm resting on the IR.

Part position

AP

Dorsal surface of thumb is in contact with IR. Coronal plane of thumb is parallel to IR. Plane of palm of hand is perpendicular to IR (Fig. 13.30).

PA oblique

Palmar surface of hand is in contact with IR as for PA projection of hand. Coronal plane of thumb will be 45 degrees to plane of IR (Fig. 13.32).

Lateral

Beginning with hand positioned for PA oblique thumb, patient flexes MCP joints 2 through 5 with the fingers extended, “tenting” hand until thumb is in lateral position (Fig. 13.34).

Central ray

Perpendicular to first MCP joint.

Structures seen

Entire thumb and first metacarpal with all joint spaces open and clearly visualized (Figs. 13.31, 13.33, and 13.35).

Question 8

Wrist - PA, PA oblique-lateral rotation, and lateral projections

Answer 8

Body position

Seated at end of table with elbow flexed 90 degrees and forearm resting on table.

Part position

PA

Anterior surface of wrist is in contact with IR. Fingers are flexed to form a loose fist, placing wrist in firmer contact with IR and opening intercarpal joints (Fig. 13.38).

PA oblique

Anteromedial surface of wrist is in contact with IR so that coronal plane of wrist forms a 45-degree angle with IR. Position may be supported by wedge sponge, stair-step sponge, or patient’s thumb (Fig. 13.40).

Lateral

Medial surface of wrist is in contact with IR. Coronal plane of wrist is perpendicular to IR (Fig. 13.42).

Central ray

Perpendicular to the midcarpal area.

Structures seen

Distal portion of radius and ulna, carpal bones, and proximal halves of metacarpals (Figs. 13.39, 13.41, and 13.43).

Question 9

Forearm - AP and lateral projections

Answer 9

Body position

Seated at end of table with axilla (armpit) at table level; this may be achieved by lowering seat or by having patient lean toward table.

Part position

AP

Arm is fully extended with hand supinated and posterior surface in contact with IR. Both wrist and elbow are supinated with coronal plane of arm parallel to IR (Fig. 13.52). This is achieved by adjusting the coronal plane of the humeral epicondyles parallel to the plane of the IR. A small sandbag in palm of hand can aid in maintaining position.

Lateral

Elbow is flexed 90 degrees with medial surface in contact with IR. Wrist is in lateral position (Fig. 13.54).

Central ray

Perpendicular to midpoint of the forearm.

Structures seen

Entire forearm, including both elbow and wrist joints (Figs. 13.53 and 13.55).

Question 10

Elbow - AP and lateral projections

Answer 10

Body position

Seated at end of table with axilla at level of table, as for AP forearm.

Part position

AP

Arm is fully extended with hand supinated and posterior surface in contact with IR. Coronal plane of humeral epicondyles parallel to IR (Fig. 13.56). If patient is unable to fully extend arm, substitute alternate positions for AP projection with flexed elbow.

Lateral

Elbow is flexed 90 degrees with medial surface in contact with IR. Coronal plane of humeral epicondyles perpendicular to IR. Wrist is in lateral position to degree patient can achieve (Fig. 13.58).

Central ray

Perpendicular to elbow joint. For AP projection, joint is midway between humeral epicondyles. For lateral projection, it is at lateral epicondyle.

Structures seen

Elbow joint with portions of distal humerus and proximal forearm (Figs. 13.57 and 13.59).

Question 11

Humerus - AP and lateral projections

Answer 11

Body position

Seated or standing with back to upright Bucky or grid cabinet. The body position, whether oblique or facing toward or away from the IR, is not critical as long as the epicondyles are oriented appropriately for the projection.

Part position

Adjust the height of the IR to place its upper margin about 1.5 inches (3.8cm) above the head of the humerus.

AP

Arm slightly abducted with palm of hand supinated. Coronal plane of humeral epicondyles parallel to IR (Fig. 13.68).

Lateral

Elbow flexed approximately 45 degrees and palm of hand against hip so that fingertips point down and elbow is lateral with coronal plane of humeral epicondyles perpendicular to IR (Fig. 13.69).

Central ray

Perpendicular to midhumerus.

Structures seen

Entire humerus, shoulder joint, and elbow joint (Figs. 13.72 and 13.73).

Question 12

Shoulder - AP projections with both internal and external humerus rotation

Answer 12

Body position

Standing or seated with back to upright Bucky or grid cabinet or supine on table; coronal plane of body parallel to IR.

Part position

External rotation

Arm slightly abducted with palm of hand supinated. Arm adjusted to place coronal plane of humeral epicondyles parallel to IR (Figs. 13.74 and 13.76).

Internal rotation

Humerus and arm rotated internally until back of hand is against thigh. Arm adjusted to place coronal plane of humeral epicondyles perpendicular to IR (Figs. 13.75 and 13.77).

Central ray

Perpendicular to a point 1 inch inferior to coracoid process.

Structures seen

Entire clavicle and scapula and proximal third of humerus. External rotation demonstrates greater tubercle in profile (Fig. 13.78); internal rotation demonstrates lesser tubercle in profile (Fig. 13.79).

Question 13

Shoulder - AP Oblique Projection (Grashey Method)

Answer 13

Body position

Patient upright or recumbent. Coronal plane of body aligned 35 to 45 degrees with respect to IR (Fig. 13.80).

Part position

Posterolateral aspect of shoulder in contact with upright Bucky or table; scapular body parallel to IR; arm in internal, external, or neutral rotation.

Central ray

Perpendicular through glenohumeral joint, at a point 2 inches (5cm) medial and 2 inches (5cm) inferior to superolateral border of shoulder.

Structures seen

Glenohumeral joint with open joint space and glenoid process in profile; coracoid process will usually obscure superior aspect of joint space (Fig. 13.81).

Question 14

Shoulder - AP and transthoracic lateral or PA oblique (scapular Y) projections

Answer 14

Body position

Standing or seated at upright Bucky or grid cabinet.

Part position

AP

With back to upright Bucky and without moving arm. Coronal plane of body is parallel to IR (Fig. 13.82).

Transthoracic lateral

Coronal plane of body is perpendicular to IR with affected side against upright Bucky. Unaffected arm is raised above head (Fig. 13.84).

PA oblique (scapular Y)

Anterolateral aspect of shoulder against upright Bucky. Coronal plane of body 45 to 60 degrees to IR. Body rotation adjusted to place scapular body perpendicular to IR (Fig. 13.86).

Central ray

Perpendicular to center of IR, with top of IR 1.5 inches to 2 inches above top of shoulder.

Patient instruction

AP and PA oblique

Stop breathing. Do not move.

Transthoracic lateral

Use “breathing technique.” (Exposure is made during slow, deep breathing. This technique effectively blurs superimposing rib and lung structures, improving visualization of humerus.)

Structures seen

Proximal half of humerus and portions of scapula and clavicle (Figs. 13.83, 13.85, and 13.87).

Question 15

Clavicle - upright PA and PA axial projections, or recumbent AP and AP axial projections

Answer 15

Body position

Upright

Standing or seated facing Bucky with coronal plane parallel to IR. Head turned away from side of interest. Arm at side (Figs. 13.88 and 13.89).

Recumbent

Supine (Figs. 13.90 and 13.91).

Part position

See body position.

Central ray

PA or AP

Perpendicular to midclavicle.

PA axial

15 to 30 degrees caudad to midclavicle.

AP axial

15 to 30 degrees cephalad to midclavicle.

Structures seen

Entire clavicle and its articulations (Figs. 13.92 and 13.93).

Question 16

Scapula - AP and lateral projections

Answer 16

Body position

Standing or seated at upright Bucky or grid cabinet, or recumbent on table.

Part position

AP

Arm abducted so that humerus is perpendicular to long axis of body. Elbow flexed 90 degrees. When patient is upright, patient may support position by grasping a pole (Figs. 13.94 and 13.97).

Upright lateral

Anterior oblique body position with affected side nearest IR. Adjust rotation of body (45 to 60 degrees) so that blade (body) of scapula is perpendicular to IR. Patient’s forearm is positioned behind back with elbow flexed 90 degrees (Fig. 13.96). Alternatively, arm may be positioned over head or across chest, depending on structures of interest and patient’s ability to comply (Fig. 13.95).

Recumbent lateral

Posterior oblique body position with unaffected side in contact with table. Rotation of body adjusted (45 to 60 degrees) so that blade (body) of scapula is perpendicular to IR. Patient’s arm may be positioned across chest (Fig. 13.98).

Central ray

Perpendicular to midscapula. For the AP, this point is approximately 2 inches (5cm) inferior to the coracoid process. For the lateral, this point is the middle of the medial border of the scapular body.

Structures seen

Entire scapula and its articulations with clavicle and humerus. AP projection demonstrates portions of scapula not obscured by ribs and clavicle (Fig. 13.99). Lateral projections demonstrate body of scapula free of superimposition by ribs, acromion, and coracoid process. Position of arm will determine portion of scapula obscured by proximal humerus (Fig. 13.100).

Question 17

AC Joints - bilateral AP projections, both with and without weights

Answer 17

Body position

Standing with back to IR(s).

Part position

First exposure (no weights)

Back of shoulders against lower half of IR(s). Arms relaxed at sides in neutral position (Fig. 13.101).

Second exposure (weights)

Back of shoulders against upper half of IR(s). Arms at sides with 5- to 10-lb sandbag attached to each wrist (Figs. 13.102 and 13.104).

Central ray

Perpendicular to midline at level of acromion processes. Exposure field collimated to cover half of the IR (see Fig. 13.101).

Structures seen

Both AC joints for comparison to evaluate ligament integrity (Fig. 13.105).

Question 18

boxer’s fracture

Answer 18

The boxer’s fracture is a common fracture of the fifth metacarpal, usually caused when the patient strikes a solid object with a closed fist (Fig. 13.106).

Question 19

Colles fracture

Answer 19

A Colles fracture (Fig. 13.109) is a common fracture of the distal radius, accompanied by posterior and medial displacement.

Question 20

Monteggia fracture

Answer 20

A Monteggia fracture consists of a fracture of the ulna and dislocation of the radial head (Fig. 13.110).

Question 21

joint effusion

Answer 21

increased fluid in the joint capsule

Question 22

bursitis

Answer 22

Chronic irritation to a bursa may lead to a condition called bursitis, inflammation of the bursa. Bursitis may cause calcific (calcium) deposits in the soft tissue of the joint region that are visible on radiographs. The shoulder is a very common site for calcific bursitis

Question 23

tendinitis

Answer 23

Inflammation of a tendon, called tendinitis or tendonitis, may occur at any tendon attachment in the body. It is common at the shoulder and in the wrist. Tendinitis may also produce calcific deposits in the soft tissues.

Question 24

Rheumatoid arthritis

Answer 24

Rheumatoid arthritis (see Fig. 12.40) is a crippling disease that often involves the hands and is a common reason for radiography.

Question 25

osteoarthritis

Answer 25

The most common type of arthritis is a degenerative joint disease called osteoarthritis (Fig. 13.116). It is a chronic condition that causes hypertrophy of the bone.

Question 26

Osteomyelitis

Answer 26

Osteomyelitis (Fig. 13.117) is inflammation of bone, especially the marrow, caused by a pathogenic organism.

Question 27

Bone infection

Answer 27

Bone infection may be caused by a number of different bacteria, including Staphylococcus and Mycobacterium tuberculosis.