Shoulder

Glenohumeral joint dislocations are the most common major joint dislocation encountered, and are generally the result of an indirect blow with the arm in abduction, extension, and external rotation [7]. Anterior dislocations are the most common and can be identified clinically in the field with some reliability. In general, the patient will present guarding the affected arm with mild abduction and external rotation. Posterior dislocations are rare, usually the result of a mechanism of injury such as a seizure, electrical shock, or direct anterior blow to the shoulder, and while carrying a similar associated fracture rate they are less likely to have neurovascular injury. Inferior and superior dislocations are even less common.

When examining a suspected shoulder dislocation, close attention should be paid to the axillary nerve. Vascular injuries are rare but when they do occur, will generally involve the axillary artery [8]. Associated fractures occur in 15–35% of shoulder dislocations and can include the humeral head (Hill–Sachs lesion), anterior glenoid lip, and greater tuberosity. Although these fractures generally do not change management, prereduction x-rays are recommended, and field reduction should typically not be attempted [9]. There are exceptions to this rule, in particular for patients with known recurrent dislocations and athletes on the field with appropriately trained staff [10,11]. Providers should splint the extremity in the position found with a sling and swathe. A short board splint can be placed along the medial upper arm for extra stability, particularly in the presence of a suspected humeral head fracture [9]. In the event of a spontaneous reduction, providers should still splint and transport, as radiographs and follow-up will be needed.

Rotator cuff injuries may be associated with shoulder dislocations or may present independently. Complete evaluation of the rotator cuff could become more commonplace prehospital practice, particularly within a community paramedicine setting. However, no validated rules currently exist to exclude fracture or dislocation, and a patient with an acute shoulder injury would likely benefit from transport to the hospital [9].

Humerus

Fractures of the humerus can be divided into three categories: proximal, midshaft, and distal. Axillary nerve and artery injuries have been recognized in up to 50% of displaced humeral fractures. Humeral shaft injuries are most common in active young men and elderly osteoporotic patients and can be associated with radial nerve injuries or vascular injuries to the brachial artery or vein [7]. Field management is the same as for other shoulder injuries.

Elbow

The elbow joint is composed of the articulations of the distal humerus, proximal radius, and ulna. The brachial artery and the nerves of the forearm and hand travel in close proximity. It is the third most commonly dislocated joint after the shoulder and knee. Supracondylar fractures are among the most common fractures in children [12]. The primary fracture patterns in adults include flexion and extension, the latter being more common. The majority of elbow dislocations (90%) are posterolateral, with the mechanism of injury being fall on an outstretched hand. Commonly associated neurovascular injuries include entrapment of the ulnar nerve and the brachial artery [13].

It is difficult to differentiate an elbow fracture from a dislocation in the field without x-rays, and as such, it is recommended that EMS providers splint all suspected fractures or dislocations in the position found. However, gentle reduction is recommended in a severely angulated fracture or one with significant neurovascular compromise. If reduction is attempted, the elbow then should be splinted at 90° with the forearm in supination with a posterior moldable splint and a sling and swathe placed.

Forearm

While the unique fracture and dislocation patterns of the forearm are of interest to the emergency physician in determining definitive management, they are less important to the prehospital provider. Field management involves splinting with a posterior mold or short boards in the position found. Indications for attempted field reduction are similar to other fractures, although neurovascular compromise in these fractures is less common than in injuries of the humerus or elbow. Fractures to the proximal ulnar, olecranon, and radius are treated similarly to other fractures and dislocations about the elbow.