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28 Cards in this Set
- Front
- Back
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Which direction is the most common for shoulder dislocations?
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Most shoulder dislocations are anterior; this occurs between eight and nine times more frequently than posterior dislocation, the second most common direction of dislocation.
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What is the the critical angle of scapular inclination?
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Scapular inclination: for >90% of shoulders, the critical angle of scapular inclination is between 0 and 30 degrees, below which the glenohumeral joint is considered unstable and prone to inferior dislocation.
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This is the primary restraint to inferior translation of the adducted shoulder.
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Superior glenohumeral ligament
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This is variable, poorly defined, or absent in 30%. It limits external rotation at 45 degrees of abduction.
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Middle glenohumeral ligament
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This consists of three bands, the superior of which is of primary importance to prevent anterior dislocation of the shoulder. It limits external rotation at 45 to -90 degrees of abduction.
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Inferior glenohumeral ligament
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Refers to avulsion of anteroinferior labrum off the glenoid rim.
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Bankart lesion
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A posterolateral head defect is caused by an impression fracture on the glenoid rim; this is seen in 27% of acute anterior dislocations and 74% of recurrent anterior dislocations.
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Hill-Sachs lesion
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What percentage of people older than 40 have a rotator cuff injury associated with a shoulder dislocation?
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>40 years of age: 35% to 40%
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What percentage of people older than 60 have a rotator cuff injury associated with a shoulder dislocation?
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>60 years of age: may be as high as 80%
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How does a patient with an anterior shoulder dislocation present?
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The patient typically presents with the injured shoulder held in slight abduction and external rotation
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How would one assess the integrity of the musculocutaneous nerve?
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Musculocutaneous nerve integrity can be assessed by the presence of sensation on the anterolateral upper arm.
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What initial imaging should be ordered?
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Trauma series of the affected shoulder: Anteroposterior (AP), scapular-Y, and axillary views taken in the plane of the scapula
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How long should one be immobilized after a shoulder dislocation?
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Postreduction care includes immobilization for 2 to 5 weeks. A shorter period of immobilization may be used for patients older than 40 years of age because stiffness of the ipsilateral hand, wrist, elbow, and shoulder tends to complicate treatment. Younger patients with a history of recurrent dislocation may require longer periods of immobilization.
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What are the indications for surgery in an anteriorly dislocated shoulder?
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Indications for surgery include:
1. Soft tissue interposition. 2. Displaced greater tuberosity fracture. 3. Glenoid rim fracture >5 mm in size. 4. Selective repair in the acute period (e.g., in young athletes). |
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What is the most common complication after dislocation?
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The most common complication after dislocation is recurrent dislocation.
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What is the incidence of recurrent dislocation in the 20s?
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Incidence:
Age 20 years: 80% to 92% (lower in non-athletes) |
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What is the incidence of recurrent dislocation in the 30s?
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Age 30 years: 60%
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What is the incidence of recurrent dislocation in the 40s?
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Age 40 years: 10% - 15%
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What artery can be involved in what population of patients as a result of an anterior dislocation?
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Vascular injuries: These typically occur in elderly patients with atherosclerosis and usually involve the axillary artery. They may occur at the time of open or closed reduction.
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What nerves can be involved in what population of patients as a result of an anterior dislocation?
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Nerve injuries: These involve particularly the musculocutaneous and axillary nerves, usually in elderly individuals; neurapraxia almost always recovers, but if it persists beyond 3 months it requires further evaluation with possible exploration.
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These injuries represent 10% of shoulder dislocations and 2% of shoulder injuries.
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Posterior dislocations
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What position is the shoulder typically in when a posterior dislocation occurs?
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The shoulder typically is in the position of adduction, flexion, and internal rotation.
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What position does a posteriorly dislocation shoulder typically present in?
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Clinically, a posterior glenohumeral dislocation does not present with striking deformity; the injured upper extremity is typically held in the traditional sling position of shoulder internal rotation and adduction.
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What is the Trough sign and what does it suggest?
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Trough sign: impaction fracture of the anterior humeral head caused by the posterior rim of glenoid (reverse Hill-Sachs lesion). This is reported to be present in 75% of cases. Posterior shoulder dislocation.
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What are the three classification of a posterior shoulder dislocation?
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Subacromial (98%): Articular surface directed posteriorly with no gross displacement of the humeral head as in anterior dislocation; lesser tuberosity typically occupies glenoid fossa; often associated with an impaction fracture on the anterior humeral head
Subglenoid (very rare): Humeral head posterior and inferior to the glenoid Subspinous (very rare): Humeral head medial to the acromion and inferior to the spine of the scapula |
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What are inferior shoulder dislocations called?
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LUXATIO ERECTA
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How do inferior shoulder dislocations typically present?
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Patients typically present in a characteristic "salute" fashion, with the humerus locked in 110 to 160 degrees of abduction and forward elevation. Pain is usually severe.
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What typically is a complication of an inferior shoulder dislocation?
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Neurovascular compromise: This complicates nearly all cases of inferior glenohumeral dislocation, but it usually recovers following reduction.
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