How to Manage an Acute Anterior Shoulder Dislocation – Tips for Safe, Fast & Effective Reduction

The glenohumeral or shoulder joint is a multi-axial synovial joint which is responsible for facilitating movement in the arms. The shoulder is classified as an enarthrosis or ball and socket joint, however due its small interface area and its large range of motion, it is one of the less stable joints in the body. This lack of stability results in a high incidence of shoulder dislocation and recurrent instability. A Swedish study reported an average of between 8.5 and 17 cases of shoulder dislocation per 100 000 subjects in a population aged between 18 and 70 years old. (Hovelius, 1982)

The shoulder generally dislocates as a result of a traumatic force applied to the arm, compromising the supporting structures of the joint. This style of traumatic dislocation is common in contact sports or as the result of a fall with an outstretched arm. Once the supporting structures are compromised the humeral head will separate from the glenoid socket and rest either anteriorly or posteriorly to the socket.

Ninety-six per cent of shoulder dislocations are classified as anterior. While a posteriorly directed dislocation should be suspected following a fall, seizure or electric shock. Due to the movement of the humeral head away from its socket, patients presenting with shoulder dislocation will usually have an obvious visual deformity of the glenohumeral joint. (Goss, 1988) But this is not always the case and some posteriorly dislocated shoulders are much harder to diagnose. So it is usual practice to order specific X-ray views to properly diagnose the direction of dislocation and management required.

Anterior dislocations are by far the most common

Once dislocated, the shoulder will need to be mobilised back into its original position using a variety of reduction techniques. Techniques for reducing the shoulder originated with Hippocrates in 460 BC and are constantly being revised and improved. The ideal technique is one which is quick, effective, simple to perform and requires minimal force, analgesia and assistance. Each therapist will have favoured methods of reduction for each individual injury. (See Dala-Ali et al. for techniques)

Care must be taken when reducing a dislocated shoulder as improper or insufficient diagnosis and treatment can result in a number of side effects, ranging from increased risk of future dislocation, to loss of blood supply, internal bleeding and bone necrosis. Fractures are a common complication of shoulder dislocation and need to be diagnosed and taken into consideration when reducing the humeral head. It is recommended that medical imaging is sought before treatment occurs in all first-time dislocations, patients aged over 40 and in dislocations resulting from high energy trauma.

Once the shoulder has been reduced a follow up x-ray is recommended to check for fractures that may only be visible post-reduction and to ensure that the humeral head is securely and correctly placed in the glenoid socket. The affected arm should then be immobilised using a sling to improve healing and stability. Traditionally the shoulder is immobilised in an adducted and internally rotated position, however recent studies have found improved healing of torn cartilage to bone, reduced bleeding into the joint capsule and increased joint stability when the shoulder is immobilised in an externally rotated position. (Itoi E, 2010)

Regardless of the reduction technique used in treating a dislocated shoulder, it is important to ensure that the muscles supporting the shoulder joint are sufficiently relaxed during reduction, to allow the humeral head to easily enter the glenoid socket. It is important to be mindful of potential fractures or other complications before reduction of the shoulder occurs. Post reduction imaging is recommended and the affected arm should be immobilised potentially in an externally rotated position to maximise healing and stability. Due to the high recurrence rate, it is certainly prudent in the younger (first time) active population to suggest a surgical opinion with consideration given towards a stabilisation procedure to reconstruct any disrupted bone, labral or capsular tissue.

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References:
Dala-Ali, B., McConnell, J., & Penna, M. (2012). Management of acute anterior shoulder dislocation. British Journal of Sports Medicine, 1-8.

Goss, T. P. (1988). Anterior glenohumeral instability. Orthopedics, 87–95.

Hovelius, L. (1982). Incidence of shoulder dislocation in Sweden. Clinical Orthopaedics and Related Research, 127-31.

Itoi E, S. R. (2010). Is external rotation the correct immobilisation for acute shoulder dislocation? An MRI study. Orthopaedics & Traumatology: Surgery & Research journal, 329–33.

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