1. Shoulder Instability

2. Normal Anatomy
The fossa is relatively shallow and deepened by the glenoid labrum
The ratio of the humeral head to glenoid fossa is similar to a golf ball on a tee
Glenoid labrum acts to deepen the glenoid fossa to increase static stability
Shoulder relies on dynamic stability

3. Pathophysiology
Excessive movement of the humerus on the glenoid which can result in dislocation or subluxations

4. Mechanism Of Injury Acute Anterior Dislocation
Forceful external rotation in an abducted position
Falling on an outstretched arm
Direct blow to the shoulder in a posterior anterior direction

5. Mechanism Of Injury Acute Posterior Dislocation
Rare and usually missed
Caused by fits, seizures or electrocutions
Falling onto an outstretched arm

6. Mechanism Of Injury Congenital Laxity Connective tissue abnormality
Poor motor control of dynamic stabilisers
Laxity becomes instability as soon as it becomes pathological

7. Mechanism Of Injury Acquired laxity Chronic repetitive stress
Usually on top of laxity

8. Associated Pathologies
Hill Sachs Lesion
Compression fracture of humeral head
Bankart Lesion
Tearing of inferior glenohumeral ligament complex from labrum

9. Associated Pathologies
Internal Impingement
SLAP Lesions
External Impingement

10. Subjective – Acute Anterior Dislocation
Usually traumatic
Mechanism of injury as stated above
Usually attended A&E where relocation was completed and X-rays taken
Immobilisation by A&E

11. Subjective – Acute Posterior Dislocation
Usually traumatic
Mechanism of injury as stated above
Usually attended A&E where X-rays taken
Commonly missed
Immobilisation by A&E

12. Subjective – Congenital Laxity
History of recurrent dislocations
History of hypermobility or connective tissue disease
Vague aching around the shoulder

13. Subjective – Acquired Laxity
Overhead sports or activities
Symptoms consisted with associated pathology

14. Objective – Acute Anterior Dislocation
Step deformity if seen acutely
Protective posturing
Spasm and guarding
Significant pain
Global loss of range of movement
Loss of abduction and external rotation after immobilisation due to capsular scarring

15. Objective – Acute Posterior Dislocation
Anterior flattening if seen acutely
Protective posturing
Spasm and guarding
Significant pain
Global loss of range of movement
Loss of internal rotation and horizontal adduction after immobilisation due to capsular scarring

16. Objective – Congenital Laxity
Excessive ROM Globally
Poor Dynamic Control
Beighton Score 4/9 or greater

17. Objective – Acquired Laxity
Signs consistent with associated pathology
i.e internal impingement, SLAP, external impingement
Scapular Dyskinesis

18. Special Tests Inferior Sulcus Test Apprehension Sign Relocation Test
Load and shift

19. Further Investigation
X- Ray
MRI

20. Conservative – Acute Dislocations
See Wilk et al., 2006 for more detail
Relocation
Sling for comfort
Immobilization to allow scaring of capsule

21. Conservative – Acute Dislocations
Restore Normal Mobility
Pain free passive mobilisations
Immediate Isometrics and Rhythmic Stabilisations
As pain allows
Closed chain more comfortable for anterior dislocations
Restore Normal Strength
Once ROM allows start scapular, external and internal rotation strength

22. Conservative – Congenital Laxity
See Wilk et al., 2006 for more detail
Avoid aggravating activities
Minimal to zero stretching
Restore normal motor control and strength
Closed Chain
Rotator Cuff and Scapular Stabilisers
Restore Proprioception
Return to Sport/Activity Specific Exercises

23. Conservative – Acquired Laxity
See Wilk et al., 2006 for more detail
Avoid aggravating activities
Manage associated pathology
Restore Normal Mobility
Reduced Swelling and Inflammation
Reduce soft tissue trauma
Reduce capsule restrictions if present
Restore Normal Motor Control and Strength
Closed Chain
Rotator cuff, scapular stabilisers
Restore Proprioception
Return to Sport/Activity Specific Exercises

24. Surgical - Management Always dependent on the client and the surgeon
Young sports people with repetitive dislocations usually considered for surgery
Arthroscopic repair
Open Repair
Capsular Shift