Anterior shoulder dislocation

Anterior shoulder dislocation is by far the commonest type of dislocation and usually results from forced abduction, external rotation and extension ¹. 

Epidemiology

Broadly speaking, anterior shoulder dislocations a bimodal age distribution. The first, and by far the largest group are young adult men who have sustained high-energy injuries to the shoulder. The second group are older patients who have been injured with a much lower level of violence. In older patients, the dislocation usually proves to be an isolated event ³.

Radiographic features

Anterior dislocations can be further divided according to where the humeral head comes to lie:

• sub-coracoid - most common
• subglenoid
• subclavicular
• intrathoracic - very rare

In anterior dislocations the humeral head comes to lie anterior, medial and somewhat inferior to its normal location and glenoid fossa.

Treatment and prognosis

Anterior shoulder dislocations are usually managed with closed reduction and a period of immobilisation (e.g. 6 weeks) to allow adequate capsular healing, although whether this significantly changes the likelihood of recurrent dislocation is not certain ⁴. Key to successful healing and normal eventual function is a structured course of physical therapy aimed at reducing muscle wasting and maintaining mobility. The emphasis, especially early on, is on isometric exercises, which the glenohumer joint remains immobilised ⁴.   

Surgical repair is not required for dislocation per se, but rather to treat complications and associated injuries which include: 

• shoulder instability due to damage to the inferior glenohumeral ligmament (IGHL) 
• Hill-Sachs lesion
• Bankart lesion or other anterior glenolabral injuries
• damage to the axillary artery, or brachial plexus
• intraarticular loose body

See also

• upper extremity dislocations
  • shoulder dislocation
    • posterior shoulder dislocation
    • inferior shoulder dislocation