Shoulder
Page Index: Tips | Anatomy |AC distance | CC distance | Hill-Sachs defect | Bankart lesion | Dislocations
Tips:
Assess AC Joint (<7 mm)
Assess coraoclavicular distance (<13 mm)
Check for Hill-Sachs lesion and bankart lesion
Normal: Frontal, external rotation
Normal: Frontal, internal rotation
1. anatomical neck of humerus 2. greater tuberosity 3. lesser tuberosity 4. surgical neck of humerus 5. humeral shaft 6. humeral head 7. glenoid fossa 8. acromion 9. acromioclavicular joint 10. coracoid process 11. clavicle 12. superior angle of scapula 13. medial border of scapula 14. inferior angle of scapula 15. ateral border of scapula 16. scapula
Axial
1. anatomical neck of humerus 2. greater tuberosity 3. lesser tuberosity 4. surgical neck of humerus 5. humeral shaft 6. humeral head 7. glenoid fossa 8. acromion 9. acromioclavicular joint 10. coracoid process 11. clavicle 12. superior angle of scapula 13. medial border of scapula 14. inferior angle of scapula 15. ateral border of scapula 16. scapula
Scapular Y view
Acromioclavicular distance
The acromioclavicular joint space normally measures 1-6 mm (females) and 1-7 mm (males) 4, decreasing with age - a joint space of <0.5 mm can be considered normal in patients >60 years old.
When the AC distance is >7 mm (males) and >6 mm (females) is abnormal and can be from:
acromioclavicular injury, effusion, distal clavicular erosion, prior surgery
Coracoclavicular distance
A normal coracoclavicular distance is between 11-13 mm and there should be no greater than 5 mm difference between the left and right sides. It is relevant for the determination of the Rockwood type of acromioclavicular joint injury.
Hill-Sachs defect
Hill-Sachs defects are a posterolateral humeral head depression fracture, resulting from the impaction with the anterior glenoid rim, and indicative of an anterior glenohumeral dislocation. It is often associated with a Bankart lesion of the glenoid.
Bankart lesion
Bankart lesions are injuries specifically at the anteroinferior aspect of the glenoid labral complex and represent a common complication of anterior shoulder dislocation. They are frequently seen in association with a Hill-Sachs defect.
Anterior Shoulder Dislocation
Anterior and inferior dislocations are usually simple diagnoses, with the humeral head and outline of the glenoid being incongruent.
Where the humeral head is displaced medially and overlies the glenoid, the dislocation is anterior.
Posterior Shoulder Dislocation
Posterior dislocation may be missed initially on frontal radiographs in 50% of cases, as the humeral head appears to be almost normally aligned with the glenoid. An axillary view is a preferred view for diagnosis.
lightbulb sign: fixed internal rotation of the humeral head which takes on a rounded appearance
trough line sign: dense vertical line in the medial humeral head due to impaction of the humeral head
loss of normal half-moon overlap sign, in which the glenoid fossa appears vacant due to the lateral displacement of the humeral head
rim sign: widened glenohumeral joint >6 mm
Shoulder radiograph (an approach)
Rockwood classification
