Wilderness and Rescue Medicine 7th Edition Jeffrey Isaac, PA-C and David E. Johnson, MD

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Section IV: Trauma

of an evolving ischemia to infarction problem; the main reason for early reduction in the field. Occasionally, a shoulder dislocation can be con- fused with a shoulder separation. In a shoulder dislocation, the proximal end of the upper arm (humerus) is displaced from its socket (glenoid) in the shoulder blade (scapula). This glenohumeral dislocation results in gross deformity and com- plete loss of active range of motion of the arm. A shoulder separation is a disruption of the joint between the distal end of the clavicle (collar bone) and the acromion process of the scapula (shoulder blade). The usual mechanism of injury is a direct blow to the top of the shoulder during a forward fall. This is a common skiing and over the handle- bars bike accident. This acromioclavicular joint lies directly above the shoulder joint and, when unstable, can have a similar step-off appearance caused by the dis- placed and elevated distal end of the clavicle. However, the shoulder joint itself remains intact with the rounded deltoid contour, and the arm retains active internal and external rotation. An acromioclavicular separation does not require field treatment other than pain management and a sling for comfort. If there are no other problems, non-urgent medical follow-up is sufficient.

Dislocations

General Principles

Treatment: Immediate field reduction if: • Simple dislocation from indirect force • Shoulder, patella, digits • Wilderness context • Patient consents WILDERNESS PROTOCOL “The damage to the joint and surrounding soft tissue due to ischemia will increase significantly after a couple of hours.”

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Shoulder Dislocations Shoulder dislocations can be extremely painful and acute stress reaction is common, leading to unwarranted high speed and high-risk rescue efforts. However, this is one emergency that you can often fix in the field. The usual mechanism is external rotation and abduction by indirect force, such as high-bracing with a kayak paddle or catching a fall on an outstretched arm while skiing. The velocity is usually low, and the mass is restricted to the weight of the patient. Fractures are uncommon, and generally do not interfere with treatment.

Shoulder Dislocation

General Principles

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AC Joint

Glenohumeral Joint

Normal

Dislocation

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The shoulder itself loses the contour of the del- toid muscle and becomes a step-off deformity, with a hollow area where the shoulder is normally full and rounded. The patient will lose active range of motion (i.e., be unwilling to move the shoulder joint without help). There is often some degree of impaired circulation to the arm as part

Acromioclavicular separation (shoulder separation)