Can a shoulder dislocation occur spontaneously in an elderly patient without a history of trauma?

Can Shoulder Dislocation Occur Spontaneously in Elderly Patients Without Trauma?

Yes, shoulder dislocations in elderly patients can occur with minimal or seemingly "spontaneous" trauma due to underlying rotator cuff pathology that compromises the posterior stability mechanism of the shoulder. 1, 2

Mechanism in Elderly Patients

The pathophysiology differs fundamentally from younger patients:

• Elderly patients develop anterior shoulder dislocations through rotator cuff tears affecting the posterior stability mechanism, which is well-accepted in the literature 3
• Large or massive rotator cuff tears can create combined pathology with anterior capsulolabral injuries (Bankart lesions or glenoid rim fractures), disrupting both anterior and posterior stability mechanisms simultaneously 3
• The prevalence of rotator cuff tears in patients over 60 years with shoulder dislocation reaches approximately 70%, making this the dominant pathology rather than labral injuries seen in younger patients 2

Clinical Presentation Patterns

Two distinct patient populations are most commonly affected:

• Elderly women sustaining dislocation from simple falls represent one of the two most common groups experiencing shoulder dislocations with neurological complications 4
• These "low-energy" mechanisms can produce dislocations because the underlying rotator cuff pathology has already compromised shoulder stability, making what appears "spontaneous" actually trauma-induced but with disproportionately minimal force 4

Associated Pathology Requiring Assessment

Older patients are more likely to have rotator cuff tears in association with shoulder dislocation compared to younger patients who predominantly have labroligamentous injuries 1

Key findings to evaluate:

• Rotator cuff tears are the predominant soft tissue injury in patients over 60 years (approximately 70% prevalence) 2
• Bony Bankart and Hill-Sachs lesions remain constantly distributed across age groups, but soft tissue patterns differ markedly 2
• Neurological complications occur in 5.4-55% of all dislocations, with elderly patients being a high-risk group 4

Diagnostic Approach

Standard radiographs including AP views in internal and external rotation plus an axillary or scapula-Y view should be obtained first 5, 6

For further evaluation:

• MR arthrography is the gold standard (rated 9/9 appropriateness) for evaluating shoulder instability and associated rotator cuff pathology 5
• MRI without contrast may be preferred in acute dislocation settings and is rated 7/9 when MR arthrography is unavailable 1, 5
• Post-reduction radiographs are necessary to confirm successful reduction and evaluate for fractures 6

Critical Pitfalls

• Failure to recognize that "minimal trauma" in elderly patients often reflects underlying rotator cuff pathology rather than true spontaneous dislocation can lead to incomplete treatment 3, 2
• Overlooking associated rotator cuff tears in older patients impacts outcomes and can lead to secondary osteoarthritis and persistent symptoms 6, 2
• Vascular assessment is critical, especially with proximal humeral fractures, as axillary artery injury can occur 6
• Neurological complications require systematic control, with surgery indicated within 3-6 months if no recovery signs are present 4