div class=”ChapterContextInformation”>
36. Radiology Case 7
Keywords
Anterior shoulder dislocationsHumeral headAnteriorlyInferiorlyMediallyCase 7a Indication for Exam
19-year-old male wrestler presents with shoulder pain during a match. The right shoulder is painful with a low lying humeral head and the arm held in slight abduction and internally rotated.
Radiographic Findings
Humeral head is displaced anteriorly, medially, and inferiorly compatible with anterior subcoracoid glenohumeral dislocation.
Diagnosis
Anterior Shoulder Dislocation
Case 7b Indication for Exam
26-year-old male presents with shoulder pain after an assault. The left shoulder is painful, deformed, and fixed in internal rotation.
Radiographic Findings
The AP view shows widening of the glenohumeral joint. The scapular Y view shows posterior displacement of the humeral head relative to the glenoid compatible with posterior dislocation.
Diagnosis
Posterior Shoulder Dislocation
Learning Points
Priming Questions
How are anterior and posterior dislocations different?
What are the common associated injuries?
Does the management differ for anterior vs. posterior dislocations?
Introduction
Anterior shoulder dislocations account for 95% of shoulder dislocations. In those cases, the humeral head is displaced anteriorly, inferiorly, and medially. The peak age is 15–25 years, and it is more common in males. The four types of anterior dislocation are subcoracoid, subclavicular, subacromial, and intrathoracic. [1]
Posterior shoulder dislocations account for 2–4% of glenohumeral dislocations. The humeral head usually dislocates straight posteriorly (subacromial). Rarely, the humeral head may dislocate subglenoid or subspinous. The peak age is 35–55 years, and it is more common in males. It can occasionally be bilateral depending on the mechanism [2].