MSK: Trauma and Overuse, Shoulder Flashcards
What is the most common type of shoulder dislocation?
Anterior (90%)
Hill-Sachs deformity
What is the best radiographic view to see a Hill-Sachs deformity?
Internal rotation view
Hill-Sachs deformity
A posterolateral humeral head depression fracture resulting from a prior anterior shoulder dislocation
Pts with a Hill-Sachs deformity often also have a…
Bankart lesion (injury to the anterior inferior labrum)
Note: Both result from anterior shoulder dislocations.
Humeral greater tuberosity avulsion fracture
Note: These can be seen after an anterior shoulder dislocation (usually pts over 40).
Anterior shoulder dislocation with avulsion fracture of the greater tuberosity
Anterior shoulder dislocation
Posterior shoulder dislocations are often due to…
Seizure or electrocution
Posterior shoulder dislocation
Note: There is a “trough sign” from an anterior humeral head impaction fracture (i.e. reverse Hill-Sachs lesion) due to impaction of the humeral head on the glenoid rim.
Think posterior dislocation of the shoulder
Note: There is a “rim sign” (when there is no overlap between the humeral head and glenoid fossa due to widening of the glenohumeral joint space).
Why does the humeral head appear abnormal on this frontal radiograph?
There is a posterior shoulder dislocation that has locked the humerus in internal rotation
Note: This is the “lightbulb sign”.
Pt is unable to move their arm out of tis position…
Luxatio erecta humeri, indicating an inferior shoulder dislocation
Inferior shoulder dislocations are associated with…
Neurologic injury (60%), usually the axillary nerve
Which of these is a Hill-Sachs deformity?
B
Note: B is at the level of the coracoid process (arrowhead), which is where you see a Hill-Sachs. A is a pseudo Hill-Sachs (normal flattening of the humeral head below the level of the coracoid process).
How can you tell whether there is a Hill-Sachs deformity or just normal flattening of the humeral head on MRI?
Flattening of the humeral head is abnormal at (B) or above the level of the coracoid process (it is normal below the coracoid, A)
What classification system is used for these fractures?
Neer classification (mostly based for how many fracture fragment parts there are)
Treatment for 3 or 4 part proximal humerus fractures
Reverse total shoulder arthroplasty
What are the 4 major types of shoulder surgery?
- Humeral head resurfacing
- Hemi-arthroplasty
- Total shoulder arthroplasty
- Reverse total shoulder arthroplasty
What type of surgery?
Humeral head resurfacing
What type of surgery?
Shoulder hemi-arthroplasty
What type of surgery?
Reverse total shoulder arthroplasty
(Anatomic) total shoulder arthroplasty
Note: There is a glenoid component in addition to the humeral component.
What type of shoulder replacement is best if the glenoid is deficient and the rotator cuff is trashed?
Reverse total shoulder arthroplasty