INTRODUCTION​

• As its name suggests, shoulder instability is characterized by the loss of stability of the shoulder joint

• Most commonly, shoulder instability occurs when patients dislocate or subluxate their shoulder after an injury

• The anatomic structures most commonly injured are the shoulder labrum (bankart lesion) and the inferior glenohumeral ligament

• Injury to the bone of the shoulder joint (hill-sachs lesion) can also contribute to instability

• Chronic or repetitive shoulder dislocations and instability can lead to attrition of the shoulder socket (glenoid bone loss)

• The vast majority of shoulder instability cases involve the front (anterior) shoulder

• Older patients with shoulder dislocations often sustain rotator cuff tears as a result  of their dislocation

• Patients under 20 who sustain a shoulder dislocation have a 90% chance of recurrence.

 

CAUSES

• The vast majority of shoulder instability episodes occur after a traumatic injury, usually from a fall or a force applied to a shoulder in the abducted externally rotated position

SIGNS AND SYMPTOMS

• Pain in the front of the shoulder 

• Sensation of instability with certain shoulder motions

TREATMENT​​

• Treatment of shoulder instability depends on multiple factors, most importantly recurrence rate. Factors that contribute to recurrence are younger age, male gender, participation in contact sports, large hill-sachs lesion, multiple dislocations, etc. 

• In patients with a low recurrence risk for dislocation, a period of sling use followed by a course of physical therapy is usually recommended. The goal of therapy is strengthening the dynamic stabilizers of the shoulder to confer stability to the shoulder joint

• In patients with recurrent instability episodes, surgery is often recommended. Surgery is almost always arthroscopic and consists of an arthroscopic labral repair (bankart repair) and capsular shift. Other associated procedures may also be done depending on pathology

• For patients with chronic shoulder instability and bone loss, a latarjet procedure can be done where the coracoid bone is transferred to the socket of the shoulder

PREVENTION​

• The best way to prevent shoulder instability episodes is to maintain strength of the dynamic shoulder stabilizers, the rotator cuff muscles.