Anterior Shoulder Dislocation

Where is Anterior Shoulder Dislocation painful? (Body Chart)

Anterior Shoulder Dislocation

What are the classical features of Anterior Shoulder Dislocation?

Age: younger athletic populations // increased engagement in high-risk activities

Gender: males > females however prevalent in both populations

Sport: throwing athletes, football, hockey, skiing, snowboarding, gymnastics

Where is Anterior Shoulder Dislocation painful?

– Anterior shoulder however can be hard to localise initially as will be intense pain from multiple sites implicated in the injury
– Deep in the joint
– Localised to the shoulder // unless they have subsequent injury
– Sensory disturbance in shoulder patch region (axillary nerve)
– Can have distal circulatory symptoms and should be examined

Characteristics of symptoms for Anterior Shoulder Dislocation

– Intense deep ache
– Heavy arm
– A feeling of instability or apprehension with movement
– Will get instant relief once relocated

Typical activity capability/restriction for clients with Anterior Shoulder Dislocation

– Very disabling
– Will not be able to perform much activity in the upper limb if any
– Will require a minimum of 3-4 days of immobilisation even if not for surgical management
– More restrictive in positions that cause stress on the anterior structures of the shoulder ( above head movements especially if there are any moments for external rotation)

Behaviour of symptoms for Anterior Shoulder Dislocation

Aggravating factors:
– External rotation, abduction, contraction of muscles that cross the shoulder joint, holding the weight of the arm

Easing factors:
– Relocation, immobilisation, analgesics, ice, NSAIDs

24-hour pattern:
– Depends on trauma and the amount of concurrent injury
– Mechanical in nature

Typical history of a client with Anterior Shoulder Dislocation

– Sport-related trauma when considering dislocation
– Common mechanisms for dislocation include a fall onto an outstretched arm or an external rotation moment on the arm of an abducted shoulder
– If dislocated arm might be stuck in an externally rotated and abducted position or held by the patient supported in internal rotation
– Palpable/observable depression of the space under the acromion due to the translation of the humerus
– If dislocated there is disruption of the inferior glenohumeral ligament complex
– Between 5 and 60% of patients sustain nerve damage
– 40-90%% of patients sustain a rotator cuff tear
– Constant pain should resolve with a couple of days
– Should be asymptomatic after this time if in an adequately supported position

Pathobiological mechanisms behind Anterior Shoulder Dislocation

– Primarily nociceptive as an acute mechanism of injury
– If recurrent likely to get nociplastic changes in the presentation
– Normal for patients to guard/protect the shoulder following injury
– Apprehension could be considered a nociplastic mechanism to tell the body it is in a vulnerable position

Proposed pathology underlying Anterior Shoulder Dislocation

– Results from failure of the anterior structures of the shoulder to stabilise the humeral head in the glenoid cavity
– 95% of shoulder dislocations occur anteriorly out of the glenoid cavity
– Typically tears the inferior glenohumeral ligament and labrum (Bankart injury)
– Nearly all first-time dislocations have a compression fracture behind the humeral head (Hill Sachs lesion)
– Muscle spasm will occur shortly after the injury to compensate for the failure of the passive structures
– Once injured the passive stability of the anterior shoulder stabilisers will not return to preinjury levels // stretched
– Rehabilitation attempts to get the active stabilisers to compensate for the passive insufficiency

Physical impairments & associated structure/tissue sources (ie P/E findings)

Local
– Humeral head translated anteriorly
– Arm held in abducted and externally rotated position
– Loss of normal contour at the deltoid
– Acromion prominent posterolaterally
– Loss of contractile function (especially into ER)
– Reduced range of motion (greatest into abduction and ER)
– Muscle guarding
– Apprehension with movement
– Positive apprehension test (Sn 65.6, Sp 95.4)
– Positive relocation test (Sn 64.6, Sp 90.2)
– Positive release/surprise test (Sn 81.8, Sp 86.1)
– Increased translation on load shift test (low-level evidence and no reported Sn and Sp)

Remote
– vascular changes in the upper limb
– sensory changes in the should patch region or greater if brachial plexus

Typical contributing factors to Anterior Shoulder Dislocation

– History of a previous dislocation
– History of previous shoulder trauma
– Genetics (predisposed to laxity)
– Hypermobility
– Gender (males > females)
– Age (after childhood the younger the higher the prevalence)
– Engage in repetitive overhead movement (laxity and high-risk behaviour)

Relevant precautions/ contraindications to P/E and treatment

– Fracture of head of the humerus, greater trochanter and the anterior glenoid
– Axillary nerve compromise 10 %
– Brachial plexus compromise
– Axillary artery compromise 3%

Relevant diagnostic imaging for Anterior Shoulder Dislocation

– Imaging is recommended if suspicion of dislocation
– Fracture of the greater trochanter occurs in 5-13% of cases
– 3-10 % of cases have a fracture of the anterior glenoid
– Compression fracture of the humeral head is normal for first-time dislocations
– If there is a greater than 5mm displacement then surgical referral is advised
– Arthroscopic visualization is considered the gold standard however recognise the limitations (having surgery, general anesthetic, infection ect)
– MRI has a 95% accuracy
– CT is less accurate than MRI however still provides valuable insight
– X-ray is adequate for bone health however insufficient for other potential lesions and therefore isn’t commonly recommended

Typical prognosis for Anterior Shoulder Dislocation

– Once dislocated there is a 40-90% chance of recurrence in young athletes
– Recurrent dislocations are a risk factor for the development of OA (⅓ of patients)
– If the patient opts for conservative management recommended a minimum of 12 weeks rehab prior to return to sport

Management/treatment selection for Anterior Shoulder Dislocation

Relocation
– Not within a physiotherapists scope of practice
– Send to hospital for relocation and further investigation
– Early reduction is easier as there is less muscle spasm
– Stimson method most common (patient in prone, arm hanging over the edge of the bed, traction force applied in a downward direction, should be done slowly, it can take 5 to 10 minutes for relocation to occur)

Surgery
– Reduction immediately if displacement
– Early reduction is easier as there is less muscle spasm
– If there is no displacement, not necessarily for surgery. Should consider the type of athlete and if reoccurrence is likely. If the sport requires stability at the ends of ranges (throwing athlete) may opt for surgery sooner compared to an athlete that had a one-off fall (ie horse riding)
– Some debate on the most effective method as some surgeons prefer the arthroscopic repair (which is less invasive) to the open repair (much more invasive). Evidence has suggested that arthroscopic has a higher failure rate hence the open repair is still considered the gold standard for the outcome.

Immobilisation (high-level evidence)
– After a dislocation, a minimum of 3-4 days of immobilisation is required
– Is shown to reduce recurrence rate but up to 35%

Rehabilitation: (lacks evidence)

Phase 1 – immobilisation
Phase 2 – shoulder/scapular mobilisation and stabilisation
Phase 2 – strengthening
Phase 4 – return to activity

Local
– Scapula control and range of motion exercises
– GHJ control and range of motion exercises
– Muscle balance // emphasis on the active stabilisers of the joint to assist impaired passive structures (rotator cuff), ensure to incorporate into functional tasks in phase 4
– Strengthening of the muscles that cross the shoulder joint

Remote
– Optimise thoracic mechanics

General
– Review technique // can we redistribute forces elsewhere in the kinetic chain
– Minimise risk factors

Taping (low-level evidence)
– Rigid anterior block restricting ER/Ab

Return to criteria (low-level evidence)
– Left = right range of motion
– Left = right strength
– Negative apprehension relocation test
– Less than 12 weeks of rehab is a risk factor for recurrence

Differential diagnosis for Anterior Shoulder Dislocation

– Anterior laxity // history and nil trauma
– Inferior dislocation // sulcus sign and inferior draw
– Posterior dislocation // posterior draw
– Multidirectional instability // history, multidirectional laxity
– Labral tear // labral tear tests
– Fracture // imaging
– Subacromial pain syndrome // SAIS cluster (hawkins kennedy, neer, jobes, painful arc and resisted ER at 0 degrees)
– Cervical referral // AROM, PAIVMs, spirlings
– Axillary nerve // sensory testing

References

Bahr R. The IOC manual of sports injuries. 1st ed. Sweden: International Olympic Commitee; 2012.

Brukner P, Khan K. Clinical sports medicine (volume 1 injuries). 5th ed. Australia: McGraw-Hill Education; 2017.

Cutts, S., Prempeh, M. and Drew, S., 2009. Anterior shoulder dislocation. The Annals of The Royal College of Surgeons of England, 91(1), pp.2-7.

Deitch, J., Mehlman, C.T., Foad, S.L., Obbehat, A. and Mallory, M., 2003. Traumatic anterior shoulder dislocation in adolescents. The American journal of sports medicine, 31(5), pp.758-763.

Hasebroock, A.W., Brinkman, J., Foster, L. and Bowens, J.P., 2019. Management of primary anterior shoulder dislocations: a narrative review. Sports medicine-open, 5(1), pp.1-8.

Karatsolis, K. and Athanasopoulos, S., 2006. The role of exercise in the conservative treatment of the anterior shoulder dislocation. Journal of Bodywork and Movement Therapies, 10(3), pp.211-219.

Olds, M., Ellis, R., Donaldson, K., Parmar, P. and Kersten, P., 2015. Risk factors which predispose first-time traumatic anterior shoulder dislocations to recurrent instability in adults: a systematic review and meta-analysis. British journal of sports medicine, 49(14), pp.913-922.