Msk -- Shoulder

Front 1

What are the phases of throwing?

Back 1

1. Wind up
2. Early cocking
3. Late cocking
4. Acceleration
5. Follow through

Front 2

What are the Allman stages of acromioclavicular joint separation-dislocation?

Back 2

TYPE 1 SEPARATION:
- radiographs appear normal.
- MRI demonstrated soft-tissue swelling about the joint and effusion
may be evident and indicate a mild strain of the AC and coracoclavicular ligaments.
TYPE 2 SEPARATION:
- disruption of the AC ligament and partial disruption of the coracoclavicular ligaments
- clavicle migrates superiorly less than 5 mm or 50% of the width of the clavicle on weight-bearing views.
TYPE 3 INJURY:
- AC and coracoclavicular ligaments are completely disrupted
- clavicular migration exceeds 5 mm or 50% of the bone width.

Front 3

What are the injuries associated with an anterior shoulder dislocation?

Back 3

1. Impaction fracture of the posterolateral aspect of the humeral
head (Hill-Sachs lesion)
2. Avulsion of the labrum from the
glenoid rim (Bankart's lesion)
3. Labrum erosion and tear
4. Capsular stripping
5. Rupture of the subscapularis tendon

Front 4

1. What is impingement syndrome?
2. What are some common locations of impingement?

Back 4

1. Impingement syndrome is related to a loss of space between the proximal humerus and the structures that compose the coracoacromial arch.
2.
- Critical zone of the supraspinatus tendon: most vulnerable area of the rotator cuff. Subacromial spurs cause mechanical trauma to the musculotendinous junction of the supraspinatus muscle.
- Rotator cuff interval: Impingement in this location is frequently associated with a hooked acromion process.
- Beneath a degenerated acromioclavicular joint: look for inferior osteophytosis.

Front 5

1. What is the most common location of calcific tendinitis?
2. What structure is most commonly involved?
3. What is the pathophysiology of disease from hydroxyapatite crystal deposition?

Back 5

1. Shoulder
2. Distal aspect of the supraspinatus tendon. Hydroxyappatitie crystals may become extruded from the tendon into the surrounding bursa causing bursitis.
3. Hydroxyapatite crystals are released into the synovial fluid which becomes engulfed by synovial cells which subsequently release collagenase and pretease leading to destruction of articular cartilage and periarticular tissues including teh rotator cuff.

Front 6

1. What is the etiology of posterior shoulder dislocation?
2. What are the radiographic findings of a posterior shoulder dislocation?

Back 6

1. Electrocution, seizure. Uncommonly = direct trauma or FOOSH.
2.
- Shoulder is locked in internal rotation (light bulb sign)
- Lesser tuberosity fracture
- Trough sign (vertical compression fracture of hte anterior humeral head)
- Absent half moon (loss of humeral head and glenoid rim overlap)

Front 7

1. What is Milwaukee shoulder?
2. What are the radiographic findings?
3. Where are calcifications associated with hydroxyapatite crystal deposition seen?

Back 7

1. Structural damage caused by deposition of hydroxyapatite crystals in the shoulder.
2. Radiographic findings include loss of joint space, destruction of bone, subchondral sclerosis, intra-articular debris, and joint disorganization and deformity.
3. Capsular, tendinous, ligamentous, and bursal calcification are common in patients with HA crystal deposition disease.

Front 8

1. In what locations do nerve entrapment occur in the shoulder?
2. What are the signs of denervation?
3. What is Parsonage Turner syndrome?
4. Wha anatomical lesions result in neve compression?

Back 8

1.
- Supraspinatus notch: leads to Supraspinatus and infraspinatus muscle injury.
- Spinoglenoid notch: leads to isolated infraspinatus injury.
- Quadrilateral space: affects the axillary nerve leading to deltoid muscle injury.
2. Acutely (< 2 weeks) leads to increased T2SI. Chronic changes characterized by fatty atrophy occur after 2 weeks.
3. Denervation of the shoulder muscles without anatomical cause. It is thought to be related to viral infection.
4. Ganglion, perilabral cyst, and tumors.

Front 9

1. What are the two types of tendinous dislocations?
2. Which is more common?

Back 9

1.
- Extra-articular dislocation: anteromedial displacement of the tendon associated with an intact subscapularis muscle and tendon.
- Intra-articular dislocation: a defect in the subscapularis attachment on the lesser tuberosity allowing displacement of the tendon into the gleno humeral joint.
2. Extra-articular dislocation is more common.

Front 10

Milwaukee Shoulder

Back 10

1. complete rotator cuff tear
2. osteoarthritis
3. effusion with CPPD crystals