Shoulder Radiography

Shoulder anatomy

• 3 bones:– Humerus– Scapula– Clavicle

• 3 joints:– Glenohumeral– Sternoclavicular– Acromioclavicular

Scapula Anatomy

• Scapula:– Glenoid– Acromion– Coracoid

Coracoid

Scapula Lateral (Y) view

Routine (transthoracic) AP view of the shoulder

• AP relative to thorax• Suboptimal view of

glenohumeral joint• Good view of AC joint

Scapular/Glenohumeral AP view (aka Oblique view)

• Better visualize Glenohumeral joint/space

• Suboptimal view of AC joint

Normal AP view

Normal oblique

Glenohumeral space

Lateral Scapula “Y” view

• Evaluate relationship of humeral head with glenoid– Humeral head should be

at bifurcation of the Y

Axillary view

• Not routinely performed

• Good for evaluating anterior-posterior relationship of glenohumeral joint

Quiz time

AP and Y view

Diagnosis?

Anterior dislocation

Anterior dislocation

• Make up 96% of all shoulder dislocations• May be associated with: – Fracture of greater tuberosity (15%)– Bankart lesion • Fracture of anterior glenoid rim

– Hill-Sachs defect (50%) • Impaction fracture of posterolateral humeral head 2/2

impaction of humeral head against glenoid during dislocation

Bankart and Hill-Sachs

Hill Sachs deformity

Diagnosis?

AP view – not too revealing…

Same patient, axillary and Y views

Answer: posterior dislocation

Posterior dislocation

• Makes up about 2-4% of dislocations, may be associated w/ convulsive seizure (boards question)

• Common Xray findings:– Rim sign (66%) = distance between medial border of

humeral head and anterior glenoid rim >6 mm– Lightbulb sign = Humeral head held in internal

rotation, appearing bulb-like on AP view– Trough sign (75%) = "reverse Hill-Sachs" = compression

fracture of anteromedial humeral head

Posterior dislocation

Trough sign

Rim sign

Lightbulb sign

Diagnosis?

Inferior dislocation, “Luxatio Erecta”

Accounts for 1-2% of shoulder dislocations,Arm often held above headResults from severe hyperabduction of arm

Diagnosis?

Acromioclavicular separation, grade III

AC separation

Treatment:Grade I-II: always conservativeGrade III: usually conservative, surgical in few cases (young athlete, laborer who does a lot of lifting, etc)Grade IV-VI: surgical

Diagnosis?

Clavicle fracture

Fracture

80% of fractures in middle third, 15% in distal third, 5% medial thirdTreatment mostly conservativeSurgical mgmt if open fracture, severe skin tenting, neurovascular injury or severely comminuted/displaced fractures

• Great site for x-ray cases:• http://www.feinberg.northwestern.edu/

emergencymed/residency/ortho-teaching/shoulder/