Shoulder/Arm

Protocols

Key Facts

• Routine radiography

Shoulder	Routine views include anteroposterior (AP), true AP (40-degree posterior oblique), axillary, and scapular “Y” views
Special views	Apical oblique, 30-degree angled AP view
Scapula	AP and lateral
Clavicle	AP and 40-degree (cephalad) angled AP

• Arthrography

Indications:	Rotator cuff tears, loose bodies, adhesive capsulitis, biceps tendinopathy, shoulder arthroplasty
Technique:	Single contrast: 6 to 10 mL of contrast medium Double contrast: 4 mL of contrast and 10+ mL of air Views: AP internal and external rotation; abduction with internal and external rotation; axillary; scapular “Y”; upright weight-bearing AP in external rotation

Computed tomography (CT)
- Axial 3-mm sections with bone and soft tissue settings for conventional studies.
- Axial 1.0-mm sections at 0.5-mm intervals for coronal or sagittal reformatting or three-dimensional reconstruction
Magnetic Resonance Imaging (MRI) (Table 7-1)
- Shoulder: shoulder coil
- Arm: license plate phased array coil
- Brachial plexus: torso coil, prefer both sides for comparison
- Magnetic resonance (MR) arthrography: Injection monitored fluoroscopically; 10- to 15-mL mixture of gadolinium dilutes in 50% iodinated contrast and 50% bupivacaine (Marcaine, AstraZeneca, Wilmington, DE) is injected.

Suggested Reading

Berquist TH. MRI of the musculoskeletal system, 5th ed. Philadelphia: Lippincott Williams & Wilkins; 2006:557–656.

TABLE 7-1 MAGNETIC RESONANCE IMAGING PARAMETERS FOR THE SHOULDER, ARM, AND BRACHIAL PLEXUS

Image Plane	Pulse Sequence	Thickness/Skip	FOV	Matrix	Acquisitions
Shoulder
3-plane scout	Fl 15/5	Three 1-cm sections	24	256 × 192	1
Axial	SE 634/16	4 mm/0.5 mm	14	256 × 256	1
Axial	GRE 613/19, 20 degrees	4 mm/0	14	256 × 256	1
Oblique coronal	FSE PD 2000/19	4 mm/0.5 mm	14	256 × 256	1
Oblique coronal	FSE T2 3500/91*	4 mm/0.5 mm	14	256 × 256	1
Oblique sagittal	FSE PD 3050/26*	4 mm/0.5 mm	14	256 × 256	2
Arthrography
3-plane scout	Fl 15/5	Three 1-cm sections	24	256 × 192	1
Axial	SE 500/12*	4 mm/0.5 mm	14	256 × 256	1
Sagittal	SE 544/12*	4 mm/0.5 mm	14	256 × 256	1
Oblique coronal	SE 525/12*	4 mm/0.5 mm	14	256 × 256	1
Oblique coronal	FSE PD 2000/19	4 mm/0.5 mm	14	256 × 256	1
Oblique corona	FSE T2 4140.91*	4 mm/0.5 mm	14	256 × 256	1
ABER	SE 500/12*	4 mm/0.5 mm	14	256 × 256	1
Arm
3-plane scout	Fl 15/5	Three 1-cm sections	30–48	256 × 192	1
Axial	FSE PD 3050/26	5 mm/0.5 mm	24	256 × 256	1
Axial	FSE T2 3500/91	5 mm/0.5 mm	24	256 × 256	1
Coronal or Sagittal	SE 634/13	4 mm/0.5 mm	24	256 × 256	1
Brachial Plexus
3-plane scout	Fl 15/5	Three 1-cm sections	30–48	256 × 192	1
Coronal bilateral	FSE T1 400/17	1.5 mm/0	36	256 × 256	1
Coronal bilateral	FSE T2 3500/91	5 mm/1.5 mm	36	256 × 256	1
Axial (right and left)	SE 419/17	5 mm/1.5 mm	18	256 × 256	2
Sagittal (right and left)	SE 500/13	5 mm/1.5 mm	22	256 × 256	1
Axial bilateral	FSE T2 3500/91	5 mm/1.5 mm	36	256 × 256	1
GRE, gradient-recalled echo; FSE, fast spin-echo; SE, spin-echo; ABER, abducted and externally rotated; PD, proton density; FOV, field of view. *fat suppression

Fractures/Dislocations: Proximal Humeral Fractures

Key Facts

Fractures of the proximal humerus usually occur in the elderly.
Proximal humeral fractures account for 5% of all skeletal fractures.
Fractures in the elderly usually are caused by a fall.
Fractures tend to follow the physeal lines dividing the humerus into four parts: humeral head, greater tuberosity, lesser tuberosity, and shaft.
Fragments are considered displaced if separated by 1 cm or angulated 45 degrees or greater (Table 7-2).
The majority of fractures (85%) are undisplaced.
Undisplaced fractures are treated conservatively. Displaced, especially comminuted or four-part fractures, require surgery or hemiarthroplasty.
Complications:
- Adhesive capsulitis
- Neurovascular injury
- Malunion, nonunion
- Avascular necrosis

TABLE 7-2 NEER CLASSIFICATION

Fracture Type	Description
One part (80% of cases)	No fragment displacement >1 cm or angulated >45 degrees
Two part (13% of cases)	One fragment displaced >1 cm or angulated >45 degrees
Three part (3% of cases)	Two fragments displaced or angulated as in “two part”
Four part (4% of cases)	Three fragments displaced or angulated as above

FIGURE 7-1 The four parts of proximal humeral fractures.

FIGURE 7-2 AP (A) and axillary (B) views of a comminuted impacted proximal humeral fracture. The fracture is angulated (lines) greater than 45 degrees.

FIGURE 7-3 Four-part fracture with marked displacement of the fragments. The patient was treated with a shoulder prosthesis. AP (A) and axillary (B) views.

Suggested Reading

Berquist TH, De Orio JK. The shoulder. In: Berquist TH, ed. Imaging atlas of orthopedic appliances and prostheses. New York, Raven Press; 1995:661–727.

Neer CS II. Displaced proximal humeral fractures. Part I: Classification and evaluation. J Bone Joint Surg 1970;52A:1077–1089.

Fractures/Dislocations: Glenohumeral Dislocations

Key Facts

Dislocations of the glenohumeral joint are the most common dislocation (50% of all dislocations).
Dislocations may be anterior (96%), posterior (2%–4%), or less frequently superior or inferior.
Anterior dislocations usually are the result of falls with the arm abducted and externally rotated.
- The humeral head frequently is impacted against the labrum, resulting in a posterolateral impaction fracture (67%–76%) or Hill-Sachs lesion.
- The anterior inferior labrum or glenoid also may be injured in 50% (Bankart lesion).
- Most anterior dislocations are obvious on routine radiographs.
Posterior dislocations occur with seizures, shock therapy, or falls with the arm abducted and internally rotated. The patient’s arm is internally rotated, and external rotation is blocked.
- Radiographic features may be subtle.
- Humeral head fixed in internal rotation (100%)
- Joint may appear widened
- Overlap of humeral head and glenoid absent or distorted
- “Trough line” in humeral head caused by anteromedial impaction fracture
- Lesser tuberosity fracture (25%)
  - Scapular “Y” view makes diagnosis most obvious.
  - Treatment of dislocations is closed reduction unless there are significant associated fractures.
Complications of dislocations:
- Associated fractures: lesser tuberosity, coracoid, greater tuberosity, subscapularis avulsion
- Recurrent dislocation
- Degenerative arthritis
- Neurovascular injury

FIGURE 7-4 Anterior dislocations. (A) AP radiograph shows an anterior dislocation with fracture fragments laterally. (B) AP postreduction radiograph shows the tuberosity fracture (arrow) and Bankart lesion (open arrow) adjacent to the inferior glenoid. (C) AP radiograph demonstrates an impaction fracture (arrows) or Hill-Sachs lesion in a patient with a prior dislocation.

FIGURE 7-5 Posterior dislocations. (A) AP radiograph showing overlap of the glenoid and humeral head with an anteromedial impaction fracture (arrowheads). The humerus is fixed in internal rotation. (B) Scapular “Y” view clearly showing the posterior dislocation of the humeral head. Axial (C) and sagittal (D) CT images demonstrate the position of the head and the humeral head fracture (arrow).

Suggested Reading

Robinson M, Aderinto J. Recurrent posterior shoulder instability. J Bone Joint Surg 2005;87A:883–892.

Turkel SJ, Pinto MW, Marshall JL, et al. Stabilizing mechanisms preventing anterior dislocation of the glenohumeral joint. J Bone Joint Surg 1981;63A:1208–1217.

Fractures/Dislocations: Acromioclavicular Dislocation

Key Facts

Dislocations of the acromioclavicular (AC) joint (12%) are less common than glenohumeral (85%) shoulder dislocations.
The injury usually is the result of a fall striking the point (AC joint region) of the shoulder.
Injuries may be partial or complete (Table 7-3).
Routine clavicle radiographs may be normal with incomplete ligament injury. Weight-bearing views are useful to classify injuries (Types I and II).
Closed reduction usually is used for Type I and II injuries. Internal fixation frequently is required for Type III to VI lesions.

TABLE 7-3 ACROMIOCLAVICULAR DISLOCATIONS

Classification	Radiographic Features
Type I, few fibers torn	Normal
Type II, rupture of the capsule and AC ligaments	Joint widened, clavicle may be slightly subluxed
Type III, same as Type II, but coracoclavicular ligaments also disrupted	Elevated clavicle, coracoclavicular space ↑
Type III and V, same as Type III	Same as Type III, but posterior clavicular displacement with Type IV and superior with Type V
Type VI, disruption of all ligaments with anterior entrapment	Clavicle trapped below coracoid

FIGURE 7-6 Acromioclavicular joint injuries. Type I: AC sprain, few fibers torn. Type II: disruption of the acromioclavicular ligaments with coracoclavicular ligaments intact. Type III: disruption of the AC and coracoclavicular ligaments. Type IV: disruption of both ligament complexes with posterior clavicular displacement. Type V: disruption of both ligament complexes with marked superior clavicular displacement. Type VI: disruption of the ligament complexes with anterior entrapment beneath the coracoid.

Fractures/Dislocations: Acromioclavicular Dislocation

FIGURE 7-7 AC separation. (A) Normal coracoclavicular distance (lines) and slight AC joint widening (open arrow). (B) Weight-bearing stress view of both shoulders showing a coracoclavicular distance of 4 cm and a complete (Type III) separation (right). Note the normal relationship (left).

Suggested Reading

Allman FL. Fractures and ligamentous injuries of the clavicle and its articulations. J Bone Joint Surg 1967;49A:774–784.

Fractures/Dislocations: Sternoclavicular Dislocations

Key Facts

Dislocations of the sternoclavicular joint are uncommon (3% of shoulder dislocations).
Injury usually occurs with indirect shoulder trauma. Anterior dislocation is the result of posterolateral forces transmitted medially. Posterior dislocation is the result of direct anterior trauma. Almost all (>90%) dislocations are anterior.
Radiographic evaluation is difficult with routine views because of bone overlap. CT is the technique of choice to evaluate the sternoclavicular joint.
Treatment usually is conservative.
Complications are most common with posterior dislocations: tracheal rupture, arch vessel laceration, neural injury.

FIGURE 7-8 Axial CT image of an anterior sternoclavicular fracture dislocation (arrow).

Suggested Reading

Nettles JL, Linsheid R. Sternoclavicular dislocations. J Trauma 1968;8:158–164.

Fractures/Dislocations: Clavicle Fractures

Key Facts

Clavicle fractures are especially common in children.
Injury occurs after a fall on the outstretched hand.
Fractures most commonly involve the middle third (80%). The distal clavicle is involved in 15% and medial clavicle in 5%.
Routine AP radiographs usually are adequate for diagnosis.
Most clavicle fractures can be treated with closed reduction. Distal fractures involving the AC joint and ligaments may require internal fixation.
Complications include malunion, nonunion (1%–2%), and degenerative arthritis when there is joint involvement.

FIGURE 7-9 (A) AP radiograph of a minimally displaced fracture of the mid-clavicle (arrow). (B) AP tomogram of a medial clavicular fracture. (C) AP radiograph of a distal clavicular fracture with coracoclavicular ligament disruption (double arrow).

Suggested Reading

Neviaser JS. The treatment of fractures of the clavicle. Surg Clin North Am 1963;43:1555–1563.

Fractures/Dislocations: Posttraumatic Osteolysis

FIGURE 7-10 (A) AP radiograph shows widening of the AC joint with irregularity of the distal clavicle. (B) Stress views of the AC joints show irregularity (arrow) with no displacement. (C) T2-weighted MR image shows increased signal intensity in the distal clavicle (arrow) as the result of edema.

Suggested Reading

Quinn SF, Glass TA. Posttraumatic osteolysis of the clavicle. South Med J 1983;76:307.

Fractures/Dislocations: Scapular Fractures

FIGURE 7-11 Scapular fracture. Axial (A,B), coronal (C), and sagittal (D–F) CT images demonstrate a fracture of the scapular wing involving the spine (open arrow) and glenoid neck (arrow), but sparing the articular surface.

Only gold members can continue reading. Log In or Register to continue