Shoulder Dislocation

Clinical
Examination Pearls
Management
Options for reduction
Most Common Techniques
Special Cases
Disposition

• The glenohumeral joint (GHJ) is the most commonly dislocated major joint in the body. 
• The lack of intrinsic bony stability in conjunction with its wide range of motion predisposes the joint to dislocations. 
• Anterior dislocations account for 95-97% of all glenohumeral dislocations. 
• Posterior dislocations account for most of the remainder, while inferior and superior dislocations are rare. 

The most common mechanism of injury of anterior dislocations consists of an indirect force transferred to the anterior capsule from a combination of :

1. abduction 
2. extension 
3. external rotation. 

In younger the injury is usually sustained during athletic activities involving rapid movements; a characteristic pathological feature is avulsion of the antero-inferior glenohumeral ligament with capsulolabral detachment – Bankart Lesion. 

In older patients, a fall onto the outstretched arm is the more common mechanism of injury and there is often an accompanying rotator cuff tear. 

Clinical 

• The dislocated arm is held in slight abduction and external rotation by the opposite extremity. 
• The lateral edge of the acromion process is prominent, and the normally rounded shoulder assumes a “squared-off” appearance. 
• The coracoid process is indistinct, and the anterior shoulder appears full. 
• The patient cannot adduct or internally rotate without pain. 

Examination PEARLS 

• A neurovascular examination must be performed to identify associated injuries of the brachial plexus, axillary nerve, radial nerve, or axillary artery. 
• The incidence of axillary nerve injuries increase with age and reports range between 5-54% 
• Other injuries associated with shoulder dislocations are Hill’s Sachs deformity, Bankart lesion and an avulsion fractures of the greater tuberosity. 

Management 

• Perform closed reduction of the dislocation expeditiously because neurovascular complications increase with time and reduction success decreases due to local swelling. 
• Good muscle relaxation is often the key to a successful reduction. 
• Procedural sedation vs. local anaesthetic can be used for reduction and the clinician should assess the availability of resources at his / her specific institution. 

Options for reduction 

1. Leverage techniques – Liedelmeyer – Place the patient in the supine position, the involved arm is slowly and gently adducted to the side. The elbow is flexed to 90 degrees and slow, gentle external rotation is applied to achieve reduction. 

2. Traction techniques - Gentle traction in various directions (forward flexion, abduction, overhead, lateral) is used to overcome the muscle spasm that holds the humeral head in its dislocated position. – Stimson, Milch. Stimson place the patient prone on a stretcher and hang 3-5kgs weight from the patient’s wrist. Apply gentle internal and external rotation with traction if needed; reduction should occur within 20 minutes. 

3. Scapular Manipulation uses re-positioning the glenoid fossa rather than the humeral head to achieve reduction. The patient is placed in the prone position with the affected arm hanging off the table as for the Stimson technique. After the application of downward traction (manual or hanging weights), the scapula is manipulated by rotating the inferior tip medially while simultaneously stabilising the superior and medial edges with the opposite hand. 

The most common techniques 

Hippocratic 

The Hippocratic method was performed with the injured arm being placed in slight abduction. A downward traction force was then exerted by the clinician performing the reduction (accompanied by slight rotational movements when needed) while an assistant exerted counter-traction by holding a sheet wrapped around the patient’s chest and under the patient’s axilla and pulling it toward the patient’s contralateral shoulder. 

Kocher 

The Kocher method was performed with the elbow flexed to 90 and the arm then pressed (adducted) against the side of the body. After that, the forearm was slowly rotated outward until resistance was felt (at around 75 degrees) and then it was lifted forward in the sagittal plane as far as possible. Finally, reduction was achieved by internally rotating the arm. 

Special Cases 

Posterior dislocation 

• Posterior dislocations are rare and account for 2% of all glenohumeral dislocations 
• Common cause is epileptic patient presenting with a seizure with a shoulder with limited abduction and external rotation is completely blocked. 
• Dislocation is often missed due to clinicians reliance on radiology and the “benign” appearance of the AP film – specific signs are the light bulb or drumstick (humeral head internally rotated), rim sign (show abnormal overlap of the glenoid fossa with the humeral head. 
• Closed reduction may be attempted in the ED under procedural sedation. The technique of reduction incorporates axial traction in line with the humerus, gentle pressure on the posteriorly displaced head, and slow external rotation. 

Inferior dislocations (Luxatio erecta) 

• Luxatio erecta is a rare type of glenohumeral dislocation in which the superior aspect of the humeral head is forced below the inferior rim of the glenoid fossa. 
• Typically, the patient presents with the arm locked overhead in 110-160 degrees of abduction. The elbow is usually flexed with the forearm resting on top of the head. The inferiorly displaced humeral head may be palpable along the lateral chest wall and any attempted movement is very painful. A completed neurovascular examination is essential to evaluate for associated injuries. 
• When possible, obtain orthopedic consultation before attempting closed reduction in the ED; it should then be performed under procedural sedation using a traction-counter-traction manoeuvre. Apply traction in line with the humeral shaft while an assistant applies counter-traction across the shoulder. Gentle abduction usually reduces the dislocation, and the arm can then be brought down into an adducted position. 
• Complications are common not only neuropraxic lesions of the brachial plexus are very common. Aneurysm or thrombosis of the axillary artery as well as thrombosis of the axillary vein have also been associated with luxatio erecta. 

Due to the higher complication rate in the above two dislocations orthopedic consultation is advised. 

Disposition 

• Discharge patients with adequate analgesia and appropriate follow-up. 
• Primary dislocations and complicated cases (associated fracture, rotator cuff tear, axillary nerve injury) should receive prompt orthopaedic follow-up (institution dependant). 
• In uncomplicated cases, immobilise the shoulder for three to six weeks in younger patients and one to two weeks in patients older than 40 years of age. 
• If immobilisation is used, early initiation of shoulder exercises can help reduce the risk of adhesive capsulitis. 
• This should be followed by a meticulous rehabilitation program aimed at restoring the static and dynamic stabilisers of the glenohumeral joint. 

References 

1. Riebel GD, McCabe JB. Anterior shoulder dislocation: a review of reduction techniques. Am J Emerg Med. 1991;9:180-8. 
2. Ufberg JW, Vilke GM, Chan TC, Harrigan RA. Anterior shoulder dislocations: beyond traction-countertraction. J Emerg Med. 2004;27:301-6. 
3. Rockwood CA Jr, Green DP, Bucholz RW, eds. Rockwood and Green's Fractures in Adults. 4th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 1996:971-85.