IMPORTANT NOTE: JAAPA CME activities consist of 2 articles. To obtain credit, you must also read
Emergency or urgency? How to effectively manage a hypertensive crisis; the post-test will include questions related to both articles. AAPA Fellow members should complete and submit the post-test on the AAPA Web site by going to
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JAAPA post-tests. All others may complete and submit the post-test online at no charge at
www.mycme.com. To obtain 1 hour of AAPA Category I CME credit, PAs must receive a score of 70% or better on each test taken.
KEY POINTS
■ PAs should be aware of proper atraumatic reduction techniques for a dislocated shoulder. Numerous reduction methods are described in the literature, and success rates range from 50% to 94%; however, no single method has a 100% success rate.
■ On examination, a prominent acromion process with a vacant glenoid fossa is represented by the classic sign of a squared-off shoulder.
■ A complete neurovascular examination is important when evaluating shoulder dislocations and should be performed before and after the reduction.
■ Postreduction neurovascular integrity needs to be confirmed as injury may occur during the reduction, even when an atraumatic technique is used. Patients may present with a prereduction neurologic deficit. Nerve function may return with reduction; however, nerve palsy can last for months.
Traumatic shoulder dislocation is a common injury encountered in the emergency department (ED). The shoulder is the most commonly dislocated joint in the body. Approximately 50%
of all joint dislocations occur in the shoulder, 85% of which are anterior dislocations.1,2 Common mechanisms of traumatic injury include excessive shoulder abduction and/or external rotation, fall on an outstretched hand, or a direct posterior blow to the shoulder. Shoulder dislocation, particularly posterior, can also occur during a seizure, as well as accidental electrocution.
The role of the PA as a first responder in an orthopedic trauma case is ever increasing. Therefore, PAs should be aware of proper atraumatic reduction techniques for a dislocated shoulder. Numerous reduction methods are described in the literature, and success rates range from 50% to 94% for various methods. No single method has a 100% success rate; as a consequence, PAs should be familiar with several techniques.3
Shoulder reduction procedures have been performed for centuries. The oldest known technique was described by Hippocrates. The Hippocratic method consists of the operator grasping the wrist and applying longitudinal traction to the arm while placing the heel in the axilla to provide countertraction.4 This technique, as well as the traditional traction-countertraction and Kocher methods, rely heavily on applying extreme forces across the glenohumeral joint and leveraging of the humerus.1 These methods have fallen out of favor because they can be associated with neurologic injury, iatrogenic fracture, and capsular damage, as well as considerable patient discomfort.
The goal of this article is to summarize acute management of anterior shoulder dislocations with an emphasis on atraumatic reduction methods and demonstration of proper reduction technique. This is not intended to be a comprehensive list, but rather a summary of the current, common, atraumatic reduction techniques and the most up-to-date studies regarding their efficacy and safety. Preference for individual reduction techniques remains provider dependent.
SHOULDER ANATOMY
Mechanical advantages that allow the shoulder to have the greatest range of motion in the body also predispose the joint to dislocation. Bony features of the shoulder include the humerus, glenoid fossa, and acromion and coracoid processes. The glenoid fossa is relatively shallow and approximately one quarter the size of the humeral head, which contributes to multiaxial motion of the shoulder joint as well as its relative instability. A commonly used analogy of the shoulder is that of a golf ball on a tee. The ball (humeral head) is a large structure resting on the relatively small surface area of the tee (glenoid fossa). Therefore, the minimal stability inherent in the bone articulation must be supplemented by the soft tissues of the joint.
Soft tissue stabilizers of the glenohumeral joint consist of the capsule, labrum, and rotator cuff (RTC). The fibrous joint capsule is made up of thickenings known as the glenohumeral ligaments. Of these capsular ligaments, the strongest is the inferior glenohumeral ligament (IGHL). It is the principle capsular inhibitor of anterior motion of the humeral head. The dense fibrous labrum also contributes to shoulder stability. The role of the labrum is to deepen the glenoid socket. Both the IGHL and labrum become disrupted in many cases of anterior dislocation, resulting in avulsion of the anteroinferior labrum from the glenoid. Injury to the labrum at this position is known as a Bankart lesion and may influence future shoulder instability.
The RTC is a dynamic stabilizer of the glenohumeral joint and consists of the supraspinatus, infraspinatus, subscapularis, and teres minor musculotendinous structures. The tendons of the supraspinatus and subscapularis muscles are commonly injured in anterior dislocations, particularly in middle-aged to older adult patients. These tendons may be stretched, ruptured, or cause an avulsion fracture at their respective bony insertion sites. Most commonly, the supraspinatus tendon causes an avulsion fracture in the greater tuberosity. An avulsion fracture in the lesser tuberosity caused by the subscapularis tendon may also occur but is much less common.
Neurovascular structures in close proximity to the glenohumeral joint include the axillary artery and nerve. These structures travel near the inferior joint capsule, predisposing them to injury with anterior dislocation. They may become stretched from the tension of a protruding humeral head or even lacerated if the dislocation is associated with a fracture.