The AC joint functions to allow an increase in elevation and abduction of the arm. Two ligaments provide stability at this joint: the AC and the CC ligaments. The CC ligament is divided into the conoid and the trapezoid ligaments, which function together to anchor the distal clavicle to the coracoid process (Fig. 16–3).
Subluxations and dislocations of the AC joint, “shoulder separation,” are common injuries presenting to the ED and account for 10% of all dislocations.23 These injuries are divided into three types that represent progressive amounts of ligamentous injury—first-degree, second-degree, and third-degree (Fig. 16–35). A first-degree injury to this joint is commonly called a sprain of the AC ligament and involves an incomplete tear of that structure. A second-degree injury involves a subluxation of the AC joint and is always associated with disruption of the AC ligament; however, the CC ligament remains intact. In patients with third-degree AC joint separation, there is disruption of both the AC and CC ligaments resulting in upward displacement of the clavicle.
Acromioclavicular (AC) separation. A. A first-degree “sprain” with intact ligaments. B. A second-degree separation with tear of the AC ligament. C. A third-degree sprain with tear of both the AC and coracoclavicular (CC) ligaments.
AC separations have been further classified according to the Rockwood Classification based on the direction of displacement of the clavicle (Table 16–1). Type 4 injuries exist when the clavicle is displaced posteriorly into or through the trapezius muscle. Type 5 injuries involve disruption of all ligaments above the joint, and the clavicle is displaced far superiorly toward the base of the neck. In type 6 injuries, the clavicle is displaced inferiorly with the lateral end under the acromion or the coracoid process. This injury is often associated with clavicle fractures, rib fractures, or brachial plexus injuries. Types 4, 5, and 6 AC dislocations are rare. Treatment of these injuries is operative.24
TABLE 16–1The Rockwood Classification for Acromioclavicular Injuries ||Download (.pdf) TABLE 16–1 The Rockwood Classification for Acromioclavicular Injuries
|Type ||Pathology ||Clinical Findings ||Radiographic Findings ||ED Management ||Definitive |
|Type I ||AC sprain, CC intact ||AC tenderness ||Normal ||Sling 7–10 d, pain control ||Conservative |
|Type II ||AC torn, CC sprain ||AC tenderness ||AC >3 mm ||Sling 2–3 wk, pain control ||Conservative |
|Type III ||AC torn, CC torn, D and T torn ||AC tenderness, deformity ||AC >3 mm |
CCD >13 mm
|Sling, pain control ||Controversial, nonoperativea |
|Type IV ||AC torn, CC torn, D and T torn, posterior displacement of clavicle through trapezius ||Prominent acromium ||AC >3 mm |
CCD >13 mm
Posterior displacement of clavicle on axillary lateral
|Sling, pain control, neurovascular assessment ||Surgical |
|Type V ||AC torn, CC torn, D and T torn, severe superior displacement of clavicle ||Deformity ||AC >3 mm |
CCD >13 mm
|Sling, pain control ||Surgical |
|Type VI ||AC torn, CC intact, inferior displacement of clavicle subcoracoid ||CCD decreased ||Associated trauma AC >3 mm ||Sling, pain control ||Surgical neurovascular assessment |
The mechanisms by which these injuries occur are either as a result of a direct force, usually a fall with the arm adducted to the side, or a force from above the acromion that strikes the bony prominence and dislodges it from its attachments to the clavicle. An indirect mechanism by which this injury occurs is a fall on the outstretched arm with the force transmitted to the AC joint. Most injuries of the AC joint are caused by a direct fall onto the point of the shoulder (Fig. 16–36).24 A more horizontally directed force (i.e., fall to the lateral side of the shoulder) may result in intra-articular damage with no significant injury to the ligaments. This may account for many cases of late degenerative joint disease and pain following a seemingly mild AC sprain.
A fall onto the shoulder is the most common mechanism for sustaining an AC separation.
The examination of the AC joint starts with inspection. In patients with significant ligamentous disruption (i.e., third-degree injury), a deformity at the top of the shoulder will be apparent in the upright position (Fig. 16–37). This deformity represents a prominence of the distal clavicle, indicating a tear of the AC and CC ligaments. The upward displacement of the clavicle is due to the loss of the suspending CC ligament combined with the downward pull of the shoulder laterally caused by the weight of the arm.
AC separation is noted on the right (arrow). This deformity represents prominence of the distal clavicle as it separates from the acromion.
In patients with first-degree injuries, there will be minimal swelling, but pain with palpation of the AC joint or when performing the AC cross-arm adduction test. This test is performed by bringing the arm across the body (Fig. 16–38).16,24 Localization of pain to the AC joint confirms that it is the source. The patient with second-degree injury experiences tenderness to mild palpation and moderate swelling is noted.
Technique for testing for injury or inflammation of the AC joint.
The O’Brien test of active compression can also be performed. In this test, the affected arm is brought into 90-degree forward flexion and 10-degree adduction. The arm is resisted from further forward flexion in both full internal rotation (thumb down) and external rotation (thumb up). Pain in internal rotation is suggestive of labral pathology, pain in external rotation is suggestive of AC pathology.16 It is imperative to match physical examination findings in the context of the clinical picture as the specificity of these tests are limited in isolation.25
Routine shoulder x-rays in a patient whom one suspects has an AC joint injury should detect significant AC injury (Fig. 16–39). Simultaneous imaging of both sides on one large cassette is recommended in order to compare the injured with the normal side. Tilting the beam 10 to 15 degrees toward the head will avoid superimposing the scapular spine and allow for more subtle detection of injuries.11 Three measurements should be taken and compared to the opposite side (Fig. 16–40).24,26
AC separation on AP radiograph. A. Second-degree injury. B. Third-degree injury.
Radiographic measurements to determine the degree of AC separation. AC joint width (normal is <3 mm); CC distance (normal is <13 mm); and CE, clavicular elevation (inferior aspect of the acromion and clavicle should be level).
AC joint width (normal is <3 mm).
Clavicle–coracoid distance (CCD): This is defined as the perpendicular distance from the clavicle to the superior portion of the coracoid process (normal is <13 mm).
Clavicle elevation: The degree of superior displacement of the clavicle compared with the acromion.
Patients with first-degree injury will have normal radiographs. The radiographic findings of second-degree injuries are subtle and may be misinterpreted as normal. The AC joint width is increased (≥3 mm or >50% increase when compared with the uninjured side), but the CCD is normal (<13 mm or similar to the opposite side). In addition, the lateral end of the clavicle may be slightly elevated, but the separation from the acromion is no more than one-half its diameter.
In patients with third-degree injury, the inferior border of the distal clavicle is above the midpoint of the acromion. In addition, the CCD is greater than 13 mm. Alternatively, a CCD of 5 mm greater than the CCD on the contralateral normal side is also suggestive of injury.
Stress views may be taken in the AP position with 5 to 10 lb of weight suspended from the arm. Once widely obtained to differentiate second- and third-degree AC separations, the necessity of stress films has been questioned and the authors no longer use them. They can be painful to obtain and of limited accuracy. In one study, stress films provided a significant difference to unmask a third-degree injury in only 4% of cases.26
The treatment of first-degree injuries is rest, ice, and a sling, with early range of motion.
Second-degree injuries are treated conservatively in a similar fashion to first-degree injuries. The sling should be continued for 2 weeks or until the symptoms resolve, followed by physical therapy and rehabilitation. Early motion will help reduce the development of adhesive capsulitis. Heavy lifting and contact sports are avoided initially while the ligaments heal so as not to convert a partial injury into a complete dislocation. Earlier return to contact sports is acceptable if the joint is covered with a protective pad.
Treatment of third-degree injuries in the acute setting is similar to second-degree injuries with the additional measure of early referral. There is no definitive proof that an AC support (Kenny–Howard harness) makes any difference in terms of long-term function as compared with a sling and ice.27–29
The definitive treatment of third-degree AC joint dislocations is controversial. Although operative intervention has historically been performed for this injury, nonoperative management has been increasingly preferred by orthopedic surgeons. In a 2007 survey of orthopedic surgeons, 81% recommended conservative treatment.30 Several studies support conservative treatment for third-degree injuries with equivalent rates of functional recovery and pain control.31–33 Overhead athletes may be candidates for operative repair. Anatomic fixation may avoid potential complications such as impingement or neurovascular symptomatology. However, surgical intervention is often performed in a delayed time frame.34
Late symptoms of post-traumatic degenerative joint disease may occur after AC joint injury. Persistent pain in the AC joint after first- and second-degree injuries occurs in 8% to 42% of patients.16,35 If conservative measures fail, operative management with distal clavicular resection may be necessary.
Sternoclavicular Joint Dislocation
The SC joint is stabilized by the SC ligament and the costoclavicular ligament (Fig. 16–2). The SC ligament has both an anterior and posterior portion. Maximum motion of this joint occurs during internal rotation with the arm elevated above 110 degrees.
A mild sprain of the SC joint involves microscopic, incomplete ligamentous tears of the SC and the costoclavicular ligaments (Fig. 16–41A). A moderate sprain involves subluxation of the clavicle from its manubrial attachment and signifies complete rupture of the SC ligament and partial rupture of the costoclavicular ligament (Fig. 16–41B).
Sternoclavicular joint injuries. A. Mild sprain occurs when microscopic tears are present in the sternoclavicular and costoclavicular ligaments. B. Moderate sprain with tear of the sternoclavicular ligament. C. Dislocation with disruption of both the sternoclavicular and costoclavicular ligaments.
A dislocation of the SC joint involves complete rupture of the SC and costoclavicular ligaments (Fig. 16–41C), permitting the clavicle to be removed from its manubrial attachment. This injury is rare and accounts for less than 1% of all dislocations.23 Dislocations at this joint are either anterior or posterior. Posterior dislocations are also referred to as retrosternal because the clavicle displaces medially as well as posterior to the sternum. Anterior dislocation of the SC joint is much more common due to the greater strength of the posterior SC ligament. In patients younger than 25 years of age, the injury is typically a physeal fracture rather than a true dislocation.24
The most common mechanism of injury is a force that thrusts the shoulder forward. It usually involves a tremendous force and most commonly follows a motor vehicle collision (40%), athletics (20%), or falls and other trauma (40%).36 An anterior dislocation occurs indirectly, when a shoulder is laterally compressed (against the ground) and then rolled backward. Conversely, a posterior dislocation is created when a laterally compressed shoulder is rolled forward. A direct anterior force may also produce a posterior dislocation.36 In the absence of trauma, an infectious process within the SC joint, although rare, should be considered.37,38
A patient with a mild sprain experiences minimal swelling and complains of tenderness over the joint. Pain is increased by elevation of the arm above 110 degrees. The patient with a moderate sprain experiences pain on abduction of the arm, and swelling is noted over the joint.
A patient with a SC joint dislocation experiences severe pain, which is increased by any motion of the shoulder or when the patient is placed in a supine position. The affected shoulder appears shortened and thrust forward. On inspection, one will note the obvious deformity of an anterior dislocation (Fig. 16–42). Palpation may find that the clavicle is fixed or quite mobile. A patient with a posterior dislocation may present with significant anterior swelling that may mislead the physician into thinking the dislocation is anterior (Fig. 16–43A).36
Anterior sternoclavicular joint dislocation on the patient’s right (arrow).
Posterior sternoclavicular joint dislocation on the left. A. Clinical photograph. Swelling is noted over the joint and obscures the diagnosis (arrow). B. CT demonstrating posterior sternoclavicular joint dislocation with the medial clavicle in proximity to the mediastinal structures (arrow). C. CT reconstruction in the same patient. (From Beecroft M, Sherman SC. Posterior displacement of a proximal epiphyseal clavicle fracture. J Emerg Med. 2007;33(3):245–248, with permission from Elsevier Scientific Publications.)
Patients with posterior dislocations may constitute a true orthopedic emergency if they present with breathing difficulties secondary to tracheal compression, tracheal rupture, or a pneumothorax. Venous congestion may also be seen. These injuries are often associated with fatal injuries to the mediastinum including the great vessels.39 Subclavian vein compression may lead to numbness and edema in the extremity. Esophageal compression causes dysphagia. CT angiography can evaluate major vascular injuries.39,40 These injuries, if present, may necessitate emergency reduction by the physician in the ED.
Although anterior dislocations are not a direct cause of secondary injuries, they may be a marker of significant injuries due to the amount of force required to create them. Greater than two-thirds of patients with anterior dislocations have significant associated injuries that include pneumothorax, hemothorax, pulmonary contusion, and rib fractures.41
A nonrotated AP radiograph may suggest dislocation if the difference in the height of the medial clavicles is greater than 50% of their width. Lateral views are difficult to interpret due to superimposition of other structures.41 A Rockwood serendipity view with the beam tilted 40 to 45 degrees cephalad and centered on the sternum is the best plain film for detecting dislocation.42 A CT scan of the chest is often required to diagnose an SC dislocation and its associated injuries (Fig. 16–43B).43
A mild sprain is treated with ice three to four times daily for a period of 24 hours and a sling for 3 to 4 days. Moderate sprains and subluxations of the joint are treated with a figure-of-eight clavicle strap and a sling to hold the clavicle in its normal position and permit ligamentous healing. This protection should be continued for 6 weeks and the patient should be advised that problems in the joint may develop that may require operative intervention.44
In patients with a posterior dislocation with a stable airway and no symptoms of vascular compromise, workup of associated injuries should occur before reduction is attempted because the posteriorly displaced clavicle may be functioning to occlude a vascular injury.36 Procedural sedation is frequently needed to reduce a posterior dislocation of the SC joint. Consultation with an orthopedic surgeon and a thoracic surgeon should be obtained.42
Axiom: In patients with a posterior SC dislocation with a stable airway and no symptoms of vascular compromise, emergent ED reduction is not indicated because the posteriorly displaced clavicle may be functioning to occlude a vascular injury
Dislocations are reduced in the following manner (Fig. 16–44): A folded sheet is placed between the shoulders while the patient is supine, which serves to separate the clavicle from the manubrium. The arm is abducted and traction is maintained. In anterior dislocations, the assistant pushes a downward, posterior-directed force on the clavicle toward its normal position. For posterior dislocations, the assistant attempts to pull the clavicle anteriorly. In more difficult posterior dislocations, the clavicle can be grasped with a towel clip (Fig. 16–45).
Reduction of a displaced sternoclavicular joint injury. The arm is abducted and traction is applied. With traction maintained, an assistant pushes the clavicle back into its normal position for anterior dislocations or pulls back on the clavicle for posterior dislocations.
In difficult cases of posterior dislocation, the clavicle can be grasped with a towel clip and replaced.
Anterior dislocations are often unstable. Immediately following reduction of an anterior dislocation, place a pressure bandage (e.g., a roll of gauze) over the SC joint to ensure that it does not redislocate.
Reduction of a posterior dislocation is usually mechanically stable. If it cannot be performed by closed methods, surgical repair is indicated.45 If reduction of an anterior dislocation is successful, and no other injuries are present, the patient should be placed in a figure-of-eight harness, which should remain for a period of 6 weeks followed by protected motion for another 2 weeks. Anterior dislocations are often unstable and may dislocate again. These injuries are not treated operatively because the complications of the procedure outweigh any benefits.36
Although anterior dislocations of the SC joint often remain unstable, they generally do not cause functional impairment. The most common complication of an anterior dislocation is cosmetic, with chronic swelling noted around the joint. Posterior dislocations are less frequent, but are fraught with more serious complications including pneumothorax, laceration of the superior vena cava, occlusion of the subclavian artery or vein, and rupture or compression of the trachea. Up to 25% of all posterior dislocations of the SC joint are associated with tracheal, esophageal, or great vessel injury, which emphasizes the need for early reduction and consultation.46
Anterior Shoulder Dislocation
The shoulder, with its wide range of motion and shallow glenoid, is inherently unstable. As a consequence, shoulder dislocation is a common joint dislocation presenting to the ED, representing approximately 50% of all major dislocations seen by the emergency physician. The most frequent location of a glenohumeral joint dislocation is anterior, accounting for 95% of cases. Approximately 70% of all anterior dislocations of the shoulder occur in patients younger than 30 years.
Posterior dislocations are seen in the remaining 5%, with inferior dislocations (luxatio erecta) being extremely rare.
There are three types of anterior dislocation: subclavicular, subcoracoid, and subglenoid (Fig. 16–46). In 90% of cases, the humeral head is in a subcoracoid location. A subclavicular dislocation is rare. Subclavicular and subglenoid dislocations have either an associated rotator cuff tear or a greater tuberosity fracture. The humeral head can interchange from one position to the next, but it usually remains in one of the three.
The three types of anterior dislocations of the shoulder.
The mechanism by which this injury occurs is usually abduction accompanied by external rotation of the arm, which disrupts the anterior capsule and the glenohumeral ligaments.47 Subcoracoid dislocations are often secondary to “hyper” external rotation. Less commonly, they can be seen after convulsions or a direct blow to the posterior aspect of the proximal humerus, displacing it anteriorly. Subglenoid dislocations are usually associated with more abduction than external rotation. A small percentage (4%) of dislocations are atraumatic, occurring while raising an arm or moving during sleep.47
The patient presents with the arms held to the side. In a thin patient, the acromion is prominent, providing the classic “squared off” appearance to the shoulder. The absence of the humeral head can be quite obvious (Fig. 16–47A). In other patients, the only finding may be loss of the normal rounded contour of the shoulder (Fig. 16–47B). On palpation, the examiner will note the absence of the humeral head in its usual location while palpating inferior to the acromion. Fullness in the anterior shoulder may be noted, indicating the presence of the humeral head. In most cases, the patient will resist any movement of the arm, only occasionally permitting some abduction and external rotation. Internal rotation and adduction will be quite painful, and therefore, the patient will be unable to use the affected arm to touch the opposite shoulder (Video 16–1).
Video 16-1: Intraarticular lidocaine injection is used for pain relief prior to shoulder dislocation reduction.
Anterior shoulder dislocation. A. In a thin individual, absence of the humeral head is straightforward. B. In a larger patient, the normal, rounded appearance of the left shoulder compared with a more “squared off” appearance of the dislocated right shoulder.
A full neurovascular examination of the upper extremity should be performed. Associated neurologic injury occurs in 13.5% of anterior glenohumeral dislocations, with the axillary nerve being the most commonly affected.48 Injury to the axillary nerve can be assessed by testing motor strength and pinprick sensation over the lateral aspect of the arm and comparing it with the other side. Some authors have reported that sensory testing is unreliable and motor weakness (i.e., abduction) is a better indicator of nerve injury.48,49 However, testing deltoid muscle strength is impractical to assess during the initial evaluation.
Standard shoulder radiographic views (AP and scapular Y views) are typically obtained before reduction is attempted to both confirm the diagnosis and exclude concomitant fractures, which occur in approximately 20% to 25% of cases.50,51 Factors associated with a fracture include age over 40, first-time dislocation, presence of humeral ecchymoses and a traumatic mechanism. When none of these features are present and the clinician is clinically certain with their diagnosis, prereduction radiographs can be omitted.51–54
The diagnosis is usually apparent on AP radiographs (Fig. 16–48A). The humeral head will be displaced from the glenoid fossa and fixed in external rotation. In external rotation, the greater tuberosity will be located along the lateral aspect of the humeral head. Any attempt to obtain an internal rotation AP view will be unsuccessful and should be a clue to the diagnosis. Pseudodislocation occurs when a hemarthrosis causes widening of the joint space. This is seen most commonly in patients with proximal humerus fractures (Fig. 16–16).
Anterior shoulder dislocation. A. AP view. B. Scapular Y view.
The scapular Y view will demonstrate anterior dislocation of the humeral head from the glenoid (Fig. 16–48B). Occasionally, a false-negative scapular Y view will occur, so if question still exists, an axillary view of the scapula should be obtained. To perform an axillary view, it should be noted that the patient does not need to abduct the arm to 90 degrees as this will be quite impossible in the setting of an anterior dislocation. Approximately 15 degrees of abduction or just enough to get the x-ray tube between the arm and the body is usually sufficient. If the patient is ambulatory, and has difficulty fully abducting the arm due to pain, a Velpeau axillary view will be much easier for the patient and provides similar information (Fig. 16–49). A true AP (Grashey) view in which the beam is directed at a 45-degree angle in a medial to lateral direction is also helpful to assess subtle joint incongruity.55
The Velpeau axillary view can be used to diagnose shoulder dislocations in patients who are unable to abduct the arm.
In evaluating the radiographs in patients with suspected anterior dislocations of the shoulder, one should look for a defect in the posterior lateral portion of the humeral head. This defect, known as a Hill–Sachs defect, is present in up to 40% of cases of anterior shoulder dislocation (Fig. 16–50A).56 It occurs as a result of impaction of the soft base of the humeral head against the anterior glenoid. The longer the humeral head is out of the glenoid fossa, the larger is the defect. This defect commonly occurs with recurrent anterior dislocations. If one suspects a Hill–Sachs deformity, an internal rotation view can be obtained after the shoulder has been reduced that will delineate the defect more clearly.
A. Hill–Sachs impaction fracture following an anterior shoulder dislocation (arrow). B. Glenoid rim (Bankart) fracture (arrow).
Associated fractures other than the Hill–Sachs defect include the greater tuberosity and glenoid rim (i.e., Bankart lesion) (Fig. 16–50B). Fractures of the greater tuberosity occur in 15% of patients with anterior shoulder dislocations (Fig. 16–51).47 In approximately 40% of cases they occur in patients older than 45 years. Glenoid rim fractures occur in approximately 5% of patients.47
Anterior shoulder dislocation with associated fracture of the greater tuberosity.
Soft-tissue injuries also occur. In the young, the common site of capsular tear is between the superior and middle glenohumeral ligaments. In addition to capsular tears, the labrum may be torn from the glenoid by the displacing humeral head. This injury, known as the soft-tissue Bankart lesion occurs in approximately 90% of patients younger than 30 years who suffer an anterior shoulder dislocation.47,57
Rotator cuff tears occur in 35% to 86% of patients older than 40 years of age.48 Inability to abduct the arm following reduction of an anterior shoulder dislocation is a sensitive indicator of a rotator cuff tear. This test is not specific, however, because it may occur in patients with an axillary nerve injury. Rotator cuff tears are important to diagnose early because early surgical repair improves outcome.48 Biceps tendon injuries may also be seen.
Brachial plexus injury or damage to the axillary nerve occurs in 5% to 14% of cases.50 An axillary nerve injury is usually a neurapraxia and full recovery can be expected in most instances.58
Before performing shoulder reduction, the clinician should consider appropriate analgesia. In cooperative patients with recent, recurrent, and relatively atraumatic dislocations, reduction can be achieved without procedural sedation. Reduction without analgesia is most effective when reduction techniques that do not require a significant amount of traction are used (e.g., scapular manipulation).59 If the patient is anxious and in a significant amount of pain, procedural sedation should be administered as described in Chapter 2. Without adequate analgesia and muscle relaxation, anterior shoulder dislocation reduction can be difficult.
Alternatively, an intra-articular injection of 20 mL of 1% lidocaine using a 20-gauge spinal needle is another method to achieve reduction that has been shown to shorten the time to discharge (Video 16–2).60–62 The site of injection is approximately 1 cm inferior to the lateral edge of the acromion (Fig. 16–52). The needle is directed medially and inferiorly to a depth of 2.5 to 3 cm. Comparison studies with procedural sedation have shown equivalent success rates with lower complication rates, lower cost and shorter ED length of stays.61–64 Intra-articular injection is more effective when the patient presents within 6 hours of dislocation.65
Video 16-2: A patient with an anterior shoulder dislocation will be unable to touch the opposite shoulder
Lateral approach to intra-articular injection of lidocaine. A spinal needle is inserted perpendicular to the adducted arm approximately one inch below the lateral border of the acromion.
Several methods have been described for reducing anterior shoulder dislocations (Table 16–2). No clear evidence supports the superiority of any one technique and the method used is frequently based on the clinician’s experience. The ideal method is quick, simple, and requires the least amount of force.66 With this goal in mind, we prefer the external rotation or the scapular manipulation techniques as the methods of first choice; and in the appropriate setting, reduction is attempted before preparing the patient for procedural sedation.
TABLE 16–2Techniques for Reduction of Anterior Shoulder Dislocation ||Download (.pdf) TABLE 16–2 Techniques for Reduction of Anterior Shoulder Dislocation
|Technique ||Operators ||Position ||Description ||Disadvantages ||Success rate (%) |
|Modified Hippocratic (Traction–Countertraction) ||Two ||Supine ||One operator provides a longitudinal traction force with the arm slightly abducted. Second operator provides countertraction (typically with a bedsheet wrapped around the thorax in the axilla) ||Requires significant force. ||86 |
|FARES ||One ||Supine ||Starting position: Arm adducted with elbow straight and forearm in neutral. Gently apply longitudinal traction while taking the arm into abduction using a vertical oscillatory movement to help with muscle relaxation. Add external rotation after 90-degree abduction and continue abduction, vertical oscillation until reduction achieved ||None ||88–95 |
|Kocher ||One ||Seated ||Starting position: Arm should be adducted at the side with elbow flexed. Gently adduct the arm further and externally rotate the elbow. When resistance is felt, the arm is forward flexed upward and then internally rotated. ||Higher incidence of fracture ||72–100 |
|Milch ||One ||Supine ||Starting Position: Arm fully abducted above the head with extended elbow. Apply Longitudinal traction and external rotation of arm ||None ||70–89 |
|Scapular Manipulation ||Two ||Prone ||One operator provides downward traction to arm forward flexed 90 degrees. Second operator attempts to adduct and medially rotate inferior border of scapula ||Difficult to monitor sedation, operator dependent ||79–90 |
|External Rotation ||One ||Supine/seated ||Starting position: Arm fully adducted at side with elbow flexed. Perform slow passive external rotation of arm ||None ||80–90 |
|Stimson ||One ||Prone ||Arm hangs off stretcher in 90-degree forward flexion and 5–10 lb weights attached to affected arm. (can combine with scapular) ||Equipment, |
Difficult to monitor sedation
|Snowbird ||Two ||Seated ||Starting position: Patient seated in chair with arm adducted and flexed at elbow. Operator applies downward traction by placing foot in a loop of stockinette wrapped around the patient’s forearm. ||None ||97 |
|Spaso ||One ||Supine ||Starting position: Arm forward flexed 90 degrees toward the ceiling. Apply longitudinal traction toward ceiling and passive external rotation. ||Operator back discomfort (rare) ||67–91 |
A description of several techniques for reducing anterior shoulder dislocations are provided below.
Scapular Manipulation Technique
The patient lies prone on the table with the affected arm hanging off of the table suspended with approximately 5 to 10 lb of weight in a similar fashion to the Stimson technique. The physician then rotates the tip of the scapula medially and the superior aspect of the scapula laterally (Fig. 16–53 and Video 16–3). This technique is quick, has a high rate of success, and is associated with few complications.56,67,68 Alternatively, the patient sits upright with the unaffected shoulder leaning up against a stretcher that is placed at 90 degrees. While one person performs scapular manipulation from behind the patient, another individual provides gentle downward traction on the patient’s affected, flexed arm (Fig. 16–54 and Video 16–4).69,70
Video 16-4: Scapular manipulation with downward arm traction in the upright patient.
Scapular manipulation. The inferior border of the scapula is rotated medially, while the superior border is rotated laterally.
In the upright patient leaning the unaffected shoulder against the stretcher, scapular manipulation is performed with gentle downward traction.
External Rotation Technique
This technique was described by Leidelmeyer and popularized at Hennepin County Emergency Medicine Center.71,72 External rotation of the shoulder acts to overcome internal rotator muscle spasm and unwind the joint capsule, allowing the external rotators of the rotator cuff to pull the humerus back into position. The technique requires little manipulation and permits the shoulder muscles to reduce the dislocation with little or no analgesia. In one case series, 81% of patients were reduced with no sedation.73 Only one person is required to perform the reduction. Success rates for this maneuver are between 80% and 90%.73
To perform the external rotation technique, the patient is supine, upright, or at 45 degrees. The patient’s elbow is supported by one hand and the other hand is used to slowly and gently externally rotate the arm. Gradually, the arm is externally rotated to 90 degrees (Fig. 16–55 and Video 16–5A and Video 16–5B).If the patient experiences any discomfort during external rotation, the examiner should stop and wait a moment until the muscles relax. During this procedure, it is important that the patient be completely relaxed and that the rotation be done gradually and slowly. Reduction is frequently subtle and the “clunk” of the humerus rearticulating with the glenoid is not heard.
Video 16-5a: External rotation technique.
Video 16-5b: External rotation technique.
External rotation technique (i.e., Hennepin technique) for the reduction of anterior shoulder dislocations.
The authors use this technique when external rotation to 90 degrees using the external rotation technique described earlier has not reduced the shoulder spontaneously. The arm is slowly abducted and the humeral head is lifted into the glenoid if it does not spontaneously reduce on elevation alone (Fig. 16–56 and Video 16–6). Elevation of the arm (i.e., abduction) is thought to aid reduction of the shoulder by eliminating the cross-stresses of the shoulder muscles that normally prevent reduction.74,75 The modified Milch maneuver incorporate some longitudinal traction if reduction is not successful at 90 degrees abduction and external rotation with 30 degrees forward flexion.76 Success rates are between 70% and 89%.59,76,77
Video 16-6: If external rotation is unsuccessful, the arm is lifted above the head in a technique described by Milch.
Milch technique for reduction of anterior shoulder dislocations.
The patient is supine and the examiner applies gentle vertical traction and external rotation to reduce the dislocation (Fig. 16–57).78,79 This technique is rapid and success is usually achieved within 1 to 2 minutes.
Spaso technique for reduction of anterior shoulder dislocations.
The Stimson technique is a safe procedure to reduce an anterior dislocation of the shoulder. The patient is placed in the prone position with the arm dependent over a pillow or folded sheets (Fig. 16–58). A strap is added to the wrist or distal forearm and 10 to 15 lb of weights are applied for a period of 20 to 30 minutes.80,81 Procedural sedation is difficult to administer in the prone patient, leaving intra-articular lidocaine as a good alternative anesthetic method. Success rates range from 91% to 96%.56 If unsuccessful, the examiner may rotate the humerus gently, externally, and then internally with mild force, which usually reduces the dislocation. Alternatively, the examiner may apply scapular manipulation with the patient in the prone position with excellent success rates.80
Stimson technique for reduction of anterior shoulder dislocations.
Traction and Countertraction
This method has been advocated for those anterior dislocations that are difficult to reduce by other techniques (Fig. 16–59A). In this method, an assistant applies countertraction with a folded sheet wrapped around the upper chest, and the examiner applies traction to the arm in an inferolateral direction (Video 16–7). This maneuver dislodges the humeral head and will reduce the dislocation. Lateral traction during traction and countertraction can also be employed in patients with good muscle relaxation. Lateral traction involves a perpendicular force to the longitudinal axis of the humerus applied by a second assistant to the proximal humerus in the axilla (Fig. 16–59B and Video 16–8). Lateral traction should be used with some caution. If it is applied before the humeral head is safely below the glenoid rim, fracture to the rim may occur.
Video 16-7: Traction and countertraction.
Video 16-8: Traction and countertraction with slight axillary pressure.
A. Traction–countertraction technique for reducing anterior shoulder dislocations. B. If a few minutes of traction–countertraction is unsuccessful, gentle lateral traction on the arm may aid the reduction. Using excessive lateral traction should be avoided so as not to produce a proximal humerus fracture.
The FARES (fast, reliable, and safe) method can be done safely with or without analgesia with successful reduction achieved in 88% to 95% of cases.82,83 To perform this method, the patient should be placed supine on the cart. The examiner uses both hands to grasp the wrist of the affected arm to apply longitudinal traction with the elbow extended and the forearm in neutral position. Slowly abduct the affected arm while using brief 2 to 3 second bursts of a vertical oscillating motion (approximately 5 cm above and below the neutral position) to promote muscle relaxation. Once 90-degree abduction has been achieved, gently externally rotate the arm while maintaining the longitudinal traction and oscillatory movements. Continue abduction and the shoulder is generally reduced by 120-degree abduction (Figure 16–60 and Video 16–9). This newer method has shown promising results in two small randomized control trials with greater success than External Rotation, Kocher’s and Hippocratic methods.82,83
FARES Method. A. Examiner hold the arm with longitudinal traction with the elbow extended and forearm in neutral. Gently abduct the arm while applying a vertical oscillating motion as shown. B. Once 90-degree abduction has been reached, externally rotate the arm and continue abduction and vertical oscillation. C. Reduction is typically achieved before 120-degree abduction.
Several other methods have been described to reduce anterior shoulder dislocations. These include the chair technique, Eskimo technique, Hippocratic technique, Cunningham, and Kocher’s technique.24,84–87 The Kocher maneuver, particularly when modified to include traction, is fraught with many complications and should be used with great caution by the emergency physician in reducing anterior dislocations of the shoulder.88 In our opinion, the Hippocratic technique should never be used under any circumstances in reducing these dislocations.
Successful reduction is frequently signaled by an audible clunk as the humeral head relocates. The shoulder returns to its normal contour and fullness is felt again below the acromion. The ability to place the hand of the affected extremity on the opposite shoulder further confirms reduction.
A shoulder dislocation is more likely to be irreducible the longer it has been in this position. Should the dislocation be irreducible by the methods listed earlier, then general anesthesia is considered and reduction attempted in the operating room. Irreducible dislocations constitute 5% to 10% of cases treated in the ED and are usually due to soft-tissue interposition.
Immobilization and Rehabilitation
Following reduction, the shoulder should be immobilized and the patient sent for postreduction radiographs. The traditional method of immobilization is adduction and internal rotation, typically with a sling and swathe or a shoulder immobilizer (Appendix A–13). In an effort to reduce the long-term rate of recurrent dislocation, several authors have proposed immobilization in 10 degrees of external rotation.89–92 This position has been shown in a few studies to reduce redislocation rates.89,93 In MRI studies, external rotation provides better anatomic reduction of the detached labral lesions.94–96 The most common method is with a wire-mesh splint covered with sponge that is bent such that half of the splint fits over the anterior trunk and the second half extends forward and is attached to the arm. Commercially available splints are also available to immobilize the shoulder in external rotation. Although seemingly awkward for patients, studies have found this immobilization to be surprisingly well tolerated with good compliance rates.93
Recent studies have not shown benefit to external rotation over a typical internal rotation sling.97,98 Further research is needed to determine the optimal mode of immobilization after primary shoulder dislocation.
The duration of immobilization is also unclear, but is generally longer in younger patients due to the higher rates of recurrence. In patients younger than 30 years, 3 weeks of immobilization is advocated. A German study showed equivalent results with 3 weeks of immobilization compared to 5 weeks.99 After this, gentle active range-of-motion exercises can be instituted; however, the patient should be cautioned against abduction and external rotation. External rotation and abduction should be prohibited for an additional 3 weeks after immobilization has been discontinued. During the time the patient is immobilized, exercises of the wrist, hand, and elbow should be instituted.
In patients older than 30 years, we advocate immobilization for 7 to 10 days with circumduction (Codman) exercises, to begin within 4 to 5 days of injury to reduce stiffness (Fig.11–13).100 The patient should avoid abduction and external rotation of the shoulder. Exercise should be performed within a pain-free range of motion following the period of immobilization. Too little movement following a dislocation may result in tightening of the structures around the shoulder and a prolonged time to regain full range of motion.100
Following the initial recovery period, strengthening of the subscapularis muscle is advocated to prevent future redislocation (Fig. 16–61). Exercises can be initiated 2 months after injury. The external rotators can be strengthened by the opposite maneuver. By strengthening these muscles, the capsule, which is a static stabilizer of the joint, is further enhanced by the dynamic muscular stabilizers.
Internal rotation exercise using rubber tubing strengthens the subscapularis muscle and helps prevent recurrent dislocations of the shoulder. The elbow is held as close to the chest wall as possible.
There are several indications for surgery in an acute anterior dislocation of the shoulder besides soft-tissue interposition. In a subglenoid or subclavicular dislocation there is often complete disruption of the cuff. Fracture of the greater tuberosity that is displaced greater than 5-mm postreduction or a glenoid rim (Bankart) fracture that is displaced greater than 5 mm are also indications for surgery.
Arthroscopic repair of a labral tear (i.e., soft-tissue Bankart lesion) is sometimes recommended in young patients with physically demanding occupations after a first-time dislocation.57,101–105 Surgery in these patients will significantly reduce the rate of recurrent dislocation.106 Most agree, however, that unless there is a complication requiring surgery most patients do not benefit from surgical intervention to stabilize these dislocations.107–109
The most common complication of anterior dislocation is recurrence, which is seen in 60% of patients younger than 30 years and drops off to an incidence of approximately 10% to 15% in patients older than 40 years.107,110 Operative repair is indicated in patients who have sustained multiple dislocations. Most of the literature demonstrates that patients with recurrent dislocations have extensive capsular tears and at least partial labral detachment resulting in some instability. Bankart lesions have been found at the time of repair in 90% of cases.111
Anterior glenohumeral instability may complicate an anterior shoulder dislocation or occur independently in the absence of a previous dislocation. This condition, in which subluxation of the humeral head occurs due to a loss of ligamentous and labral support, is a common and often missed problem in the ED. Subluxation is characterized by sudden sharp pain when the shoulder is forcibly moved into external rotation during abduction. The shoulder apprehension test is usually positive. To perform this test, the arm is rotated externally and abducted. Anterior pressure is then applied to the posterior aspect of the humeral head (Fig. 16–62). This causes sudden pain and may cause anterior displacement of the humeral head. When performed 6 to 9 weeks after the initial dislocation, it may be suggestive of an increased risk for recurrent dislocation. However, the exam test cannot be used as a definitive predictor of recurrence alone and has relatively poor sensitivity.112 When this is a recurrent problem, the patient should be referred for further evaluation as many of these cases require surgical intervention to stabilize the shoulder.
Technique for performing shoulder apprehension test.
Posterior Shoulder Dislocation
Posterior dislocations are far less common than anterior dislocations, but are the most commonly missed major dislocations of the body. These dislocations are missed in up to 60% to 70% of cases.113–115 The most frequent cause is suboptimal radiographic evaluation, but also because they present with less pain than anterior dislocations and the radiographic findings are subtle. The diagnosis of a posterior shoulder dislocation should be suspected in a patient whose shoulders are blocked to external rotation.
There are three types of posterior dislocations: subacromial, subglenoid, and subspinous, the majority of which are subacromial.
There are several mechanisms by which this injury occurs. A blow to the anterior aspect of the shoulder and axial loading of the arm when it is adducted and internally rotated are two possible mechanisms. A violent internal rotational force such as would occur during a fall on the forward flexed internally rotated arm is another mechanism. A seizure or an electric shock is a common precursor to posterior shoulder dislocation and occurs because the internal rotators are twice as strong as the external rotator muscles.114
The cardinal sign of a posterior dislocation of the shoulder is that the arm is held in adduction and internal rotation. Abduction is severely limited and external rotation of the shoulder is blocked (Video 16–10). On palpation of the shoulder girdle, the examiner will note a prominence in the posterior aspect of the shoulder accompanied by an anterior flattening of the normal shoulder contour. The coracoid process is usually more obvious than its counterpart on the normal side. Blocking of external rotation and limitation of abduction occur in all cases of posterior dislocations. In the subglenoid and subspinous type, the arm is held in 30 degrees of abduction and is internally rotated. A subacromial dimple may be present with a posterior dislocation, representing the posteromedial portion of the deltoid.116
Video 16-10: Blocked external rotation of the left shoulder due to a posterior shoulder dislocation.
Evidence of a posterior shoulder dislocation on the standard AP view of the shoulder is not always apparent, causing this dislocation to be missed on this view in up to 50% of cases.117 A lateral projection is essential.
However, there are several radiographic features that will aid the emergency physician in making this diagnosis on a standard AP view.
This is the loss of the normal elliptical pattern produced by overlap of the medial aspect of the humeral head and the anterior glenoid rim (Fig. 16–63). Both superimposition of these two structures or widening of the joint space (>6 mm) suggests a posterior dislocation.
Rim sign. A. The normal distance between the medial aspect of the humeral head and the anterior glenoid rim. B. Normal radiograph. C. In the patient with a posterior dislocation, this distance is abnormal. D. Superimposition (i.e., Rim sign) seen on a radiograph of a posterior shoulder dislocation.
Internal rotation of the humeral head that occurs with a posterior shoulder dislocation results in rotation of the greater tuberosity so that it is no longer in its normal lateral position (Fig. 16–64). This is referred to as the “lightbulb” or “ice cream cone” sign because the humeral head appears rounded, as though it sits on top of a cone—the humeral shaft.118
Lightbulb sign indicating a posterior shoulder dislocation.
When the humeral head dislocates behind the glenoid, an impaction fracture occurs to its articular surface referred to as the “reverse Hill–Sachs lesion.” On the AP radiograph, two parallel lines of cortical bone representing the medial cortex of the humeral head and the base of the impaction fracture on the anterior articular surface are called the trough line sign (Fig. 16–65).117,119 This was found in 75% of posterior dislocations in one case series.117
Trough sign indicating a posterior shoulder dislocation.
If there remains a question about dislocation, a lateral projection such as a scapular Y or axillary view should be obtained (Fig. 16–66). A CT scan will be diagnostic and also reveals the size of the impaction fracture, aiding the orthopedic surgeon in choosing the best definitive treatment (Fig. 16–67).114,120
Axillary view of a posterior shoulder dislocation.
CT scan demonstrating a posterior shoulder dislocation. Note the articular impaction fracture.
Axiom: A scapular Y view or axillary lateral view is essential to exclude a posterior shoulder dislocation, which may be missed in 50% cases.
This dislocation is commonly associated with fractures of the humerus and the posterior aspect of the glenoid rim.114 An isolated fracture of the lesser tuberosity should lead one to suspect a posterior dislocation until proven otherwise. A reverse Hill–Sachs lesion is an impression defect on the anteromedial part of the humeral head due to compression by the glenoid. It is seen in up to 80% of these patients.113 Rotator cuff tears are present in up to 20% of cases.121 Neurovascular complications with this injury are uncommon.
Axiom: An isolated fracture of the lesser tuberosity should lead one to suspect posterior dislocation of the shoulder until proven otherwise.
Consultation with an orthopedic surgeon is advised. Closed reduction using axial traction on the flexed and adducted shoulder is usually successful and can be performed in acute dislocations (<3 weeks) when there is a less than 25% articular surface defect.114 Direct pressure on the posteriorly displaced humeral head may facilitate the reduction. Indications for surgical intervention include significant displacement of the lesser tuberosity that is irreducible on reduction of the dislocation, an articular defect greater than 25%, or a chronic dislocation (>3 weeks).
Inferior Shoulder Dislocation (Luxatio Erecta)
Inferior dislocations of the shoulder are uncommon, accounting for 0.5% of shoulder dislocations (Fig. 16–68). These injuries are more common in men than women and can occur at any age.122 The term luxatio erecta means “to place upward,” which refers to the characteristic presentation of the arm in this injury.
Luxatio erecta. The mechanism by which this injury occurs is hyperabduction. This dislocation is always accompanied by both disruption of the rotator cuff and tear through the inferior capsule.
The mechanism by which this injury occurs is forceful hyperabduction.123
This injury is unlikely to be missed because the patient holds the arm elevated 180 degrees and cannot adduct it, as if they are “asking a question” (Fig. 16–69A). These patients usually present with significant pain. The arm appears to be shortened when compared with the normal side. On palpation, the humeral head is felt along the lateral chest wall.
A. Patient with an inferior shoulder dislocation (luxatio erecta). B. Radiograph.
Standard shoulder radiographs are diagnostic and reveal the inferior location of the humeral head with the humeral shaft raised upward (Fig. 16–69B).
Luxatio erecta may concurrently cause damage to the rotator cuff. In a review of 80 published cases of luxatio erecta, rotator cuff tears were noted in 12% of cases.122 Patients commonly have neurovascular compression; however, they usually recover function following reduction. The axillary artery and brachial plexus are commonly injured because the humeral head tears through the inferior capsule rather than the anterior capsule as with an anterior dislocation of the shoulder. Vascular injury is not common, but is more common in luxatio erecta than in any of the other types of shoulder dislocation.122 Greater tuberosity fractures are the most common associated fracture. Reduction of the dislocation often reduces the fracture fragment as well.
Early reduction is necessary in luxatio erecta in order to prevent neurovascular sequelae that are quite common.123 Reduction is not difficult in most cases, unless the humeral head has torn a small defect in the inferior glenohumeral capsule. In these cases, closed reduction may not be successful and open reduction may be required.122 To perform the reduction, the physician applies traction in the longitudinal axis of the humerus while an assistant applies countertraction with a folded sheet wrapped around the supraclavicular region (Fig. 16–70 and Video 16–11). While traction is maintained, the arm is rotated inferiorly in an arch as shown.
Video 16-11: Luxation erecta (inferior) shoulder dislocatoin reduction
Reduction of a luxatio erecta dislocation. Traction is applied by the physician in the longitudinal axis of the humerus while an assistant applies countertraction with a folded sheet. While traction is maintained the arm is rotated inferiorly in an arc as shown.
Another reduction technique is the two-step closed reduction maneuver in which the inferior dislocation is converted to an anterior location prior to full reduction.124 To perform this maneuver, the physician should stand on the affected side with the patient in the supine position. One hand (PUSH hand) should be placed on the lateral aspect of the mid-humerus with the second hand (PULL hand) positioned over the medial epicondyle. The physician will provide pressure to the humerus with the push hand while gently pulling at the elbow. This should reduce the humeral head to an anterior location. Ability to adduct the arm against the body confirms the conversion. At this point, the physician may use their preferred technique for reduction of an anterior glenohumeral dislocation.
After reduction, immobilize the shoulder for 2 to 4 weeks. Postinjury, the patient must be followed closely for evidence of rotator cuff tears.122
Impingement syndrome involves mechanical compression of the rotator cuff tendons as they pass between the acromion, the rigid coracoacromial ligament, and the head of the humerus (Fig. 16–4).125 The end result is acute inflammation, edema, and hemorrhage of the rotator cuff tendons. If untreated, fibrosis and tendinosis occur, and eventually the condition progresses to tearing of the rotator cuff tendons. The supraspinatus tendon is most commonly affected because of its proximity to the coracoacromial arch and poorer blood supply.
The condition most commonly affects elderly individuals and young athletes whose sport involves overhead motions (e.g., tennis, swimming). It has also been described in patients with whiplash injury secondary to a seatbelt.126
Many anatomical variables contribute to impingement, including a hooked acromion, osteophyte formation, subacromial bursal fibrosis, and coracoacromial ligament thickening. A hook shaped acromion has been associated with a greater extent of rotator cuff tears.127,128
The clinical findings of impingement are characterized by pain that is referred to the lateral aspect of the upper arm in the region of the deltoid and its insertion. Characteristically, the pain is worse at night and is typically exacerbated with overhead activities because the outlet narrows with shoulder abduction (Fig. 16–71). The painful arch is between 60- and 120-degree abduction, which indicates a disorder of a structure in the subacromial region.129
In the painful arch syndrome, as the patient elevates and abducts the arm, the tuberosity encroaches upon the coracoacromial arch. This causes maximal pain between 60 and 120 degrees.
Tenderness is maximal below the lateral edge of the acromion. The rotator cuff outlet is further compromised when the shoulder is placed in forward flexion and internal rotation (Fig. 16–72A). Pain may be cleared by external rotation of the humerus during abduction. Pain may also occur with passive forward elevation of the pronated arm to 180 degrees (Fig. 16–72B). High-resolution ultrasonography is useful in diagnosing this condition, as is magnetic resonance imaging (MRI).126 In situations where the pain increases at a point beyond 120 degrees of abduction up to full elevation, disorders of the AC joints should be suspected.
A. Hawkins sign—internal rotation of the forward flexed arm with elbow flexion reproduces subacromial impingement. B. Neer test—Painful forward flexion of the internally rotated arm results in impingement.
Treatment with a local anesthetic and steroid injection may provide immediate relief and support the diagnosis if the pain resolves. Have the patient sit with the arm relaxed at the side. The needle is inserted underneath the anterior edge of the acromion and the coracoacromial ligament at the site of maximal tenderness (Fig. 16–73 and Video 16–12).
Video 16-12: Injection technique for impingement (painful arch) syndrome.
Injection along the coracoacromial arch. Injection should be concentrated under the arch, which is palpable through the needle tip.
Supraspinatus Tendonitis and Subacromial Bursitis
The pathogenesis, clinical presentation, and treatment of these two conditions are similar, and they will therefore be considered together.
Supraspinatus tendonitis is the most common cause of shoulder pain and is usually caused by degenerative changes in that tendon with advancing age and impingement, as stated previously. Impingement is the cause of approximately three-fourths of the cases, followed by chronic overuse (10%) and acute strains (5%).
The tendons of the supraspinatus, infraspinatus, teres minor, and subscapularis muscles come together and attach on the greater and lesser tuberosities to form the rotator cuff. Tendonitis can occur in any one of these tendons but is much more common where the supraspinatus tendon comes in close proximity with the coracoacromial arch (Fig. 16–74).
The relationship of the supraspinatus tendon and the subdeltoid–subacromial bursa.
The pathogenesis of supraspinatus tendonitis is along a continuum that will ultimately lead to subacromial bursitis. As the supraspinatus tendon traverses under the acromion and the coracoacromial arch, small tears occur. The repair process is associated with inflammatory cells that lead to tendonitis. The patient seen at this stage usually complains of a deep ache in the shoulder with increasing pain on abduction and internal rotation. The inflammatory cells cause significant swelling, and eventually calcium deposits within the tendon.130 The swelling of the tendon causes worsening impingement on the subacromial bursa that forms the roof of the supraspinatus tendon. At this stage, the tendon becomes an obstacle to pain-free abduction and the patient complains of increasing pain in the shoulder. Attempts to abduct the arm to 70 degrees cause significant pain.
As the process continues, a severe inflammatory reaction occurs within the bursa, leading to bursitis. As the subacromial bursa swells, partial abduction and adduction is restricted. The arm is held at approximately 30 degrees of abduction. Further adduction or abduction causes increasing pain, and the patient resists any attempt to elevate the arm beyond this point. If the process is allowed to continue, the patient may experience a chronic bursitis leading eventually to adhesive pericapsulitis or bursitis.
This condition usually occurs between the ages of 35 and 50 years. It appears to be more common in sedentary people. Patients usually complain of a deep ache in the shoulder referred to the deltoid region and the pain may radiate to the entire limb. There is often point tenderness at a “critical point” between the acromion and the greater tuberosity. The pain is increased on abduction and internal rotation of the arm. The onset is usually gradual, but may be acute after overuse of the shoulder, especially in an overhead position. Within 2 to 3 days the pain becomes increasingly intense at the point of the shoulder.
Radiographic findings include calcification and cystic changes along the greater tuberosity accompanied by sclerosis. These do not occur, however, until the process has become more chronic. Calcification is sometimes seen in asymptomatic patients.
Treatment consists of avoidance of the inciting activity, nonsteroidal anti-inflammatory medications, ice, and exercises that prevent muscle atrophy. The patient should be encouraged to initiate range of motion, starting with pendulum (Codman) exercises (Fig. 16–12). Continued motion is essential to reduce the risk of adhesive capsulitis in patients older than 40 years. Physical therapy referral is appropriate.
Treatment with a local anesthetic and steroid injection may provide immediate relief. A lateral approach in which the needle is inserted directly under the acromion is used (Video 16–13). A longer needle directed medially and anteriorly under the acromion provides the best results.131 Move the needle back and forth through the tendon sheath as this releases the fluid in the bursa and reduces pain. Ultrasound is very useful in both making the diagnosis and aiding in placement of steroid injections.132 Methylprednisolone (40 mg, 1 mL) and bupivacaine (5–10 mL) are generally effective. The condition may require repeat injections before relief is obtained, so the patient should be referred for follow-up care. Local corticosteroid injections have been commonly performed for this condition with unclear benefit. Some studies have shown a marginal decrease in pain but long-term improvement has not been demonstrated in the limited published literature.133 In patients with calcific tendonitis/bursitis, which can lead to frozen shoulder syndrome, optimal outpatient treatment includes multiple punctures in the calcific deposits to break up the calcium and treat the condition.126
Video 16-13: Injection technique for subacromial bursitis.
Tears of the rotator cuff are more common in the elderly because of degenerative changes that occur with advancing age, particularly after the fifth decade of life. In patients older than 60 years, full-thickness rotator cuff tears occurred with a reported incidence of 28% in asymptomatic individuals.134,135 Only 25% of rotator cuff tears are symptomatic.134
Disruption of the rotator cuff can occur at any point; however, it is more common in the anterosuperior portion of the cuff near the attachment of the supraspinatus muscle (Fig. 16–75).136 In this location, the tendon is worn down by impingement occurring between the humeral head and the coracoacromial arch. Other causes include intrinsic degeneration, chronic overuse, or acute overload.125
A rotator cuff tear is shown. The rotator cuff usually tears along the supraspinatus tendon insertion.
When this injury is seen in the young, it requires a greater degree of trauma. Prior to the fifth decade, rotator cuff tears are more likely to avulse bone.136 The mechanism by which one disrupts the rotator cuff is usually a sudden powerful elevation of the arm against resistance in an attempt to cushion a fall. It can also occur secondary to heavy lifting or a fall on the shoulder. In a patient older than 50 years, this injury may occur with minimal or no trauma (e.g., during sleep).
The patient presents with complaints of pain aggravated by activity that radiates to the anterior aspect of the arm. There is no relationship between the size of the tear and the level of pain and disability.137 The most severe pain occurs when one compresses the tendon beneath the coracoacromial arch with passive abduction between 70 and 120 degrees.138 Abduction is painful and weak. Although no singular examination maneuver is definitive, the rotator cuff can be evaluated in the ED with a comprehensive physical examination including range of motion, strength testing, and provocative maneuvers as described earlier in the section.
Weakness in abduction of greater than 50% compared to the unaffected arm is suggestive of a large or massive tear.139 Up to 40 degrees of abduction may occur by the “shrugging” mechanism alone in which the patient compensates for glenohumeral motion with scapulothoracic motion. The patient cannot initiate abduction if large tears of the supraspinatus occur (Video 16–14). Strength testing of the supraspinatus, infraspinatus, and subscapularis muscles is also helpful in the acute evaluation of rotator cuff tears (Fig. 16–8).
Video 16-14: In this patient with a rotator cuff tear, abduction of the arm cannot be initiated.
The drop arm test is frequently positive in patients with significant tears.25,140 This test is performed by laterally elevating the arm to the 90-degree position, and asking the patient to hold the arm in this position (Fig. 16–76 and Video 16–15). A slight pressure on the distal forearm or wrist applied by the examiner will cause the patient to suddenly drop the arm. In addition, the patient is unable to bring the arm from the abducted position to the side in a slow fashion, but rather, drops it suddenly. Lidocaine may be infiltrated around the cuff in patients unable to abduct the arm to perform the drop arm test. Injection will also allow the examiner to differentiate a significant tear from tendonitis, as patients with tendonitis will be able to perform better after injection.
Video 16-15: A positive drop arm test is indicative of a rotator cuff tear.
The drop arm test is shown. A. The patient or examiner abducts the arm to 90 degrees. B. With minimal pressure over the abducted arm, the patient cannot sustain abduction and drops the arm to the side.
All physical examination findings should be interpreted with caution and incorporated into the context of the clinical picture as no singular physical examination maneuver has sufficient predictive value. Multiple studies have shown that physical examination alone has relatively low sensitivity at picking up even moderate tears.25,137,141 However, the combination of age older than 65, night pain, and weakness in external rotation was found to have a specificity of 95% in the diagnosis of rotator cuff tears.138
When tears are localized to the posterosuperior aspect of the cuff, pain is elicited on abduction and internal rotation, whereas tears of the anterosuperior cuff cause pain on abduction and external rotation. A defect may be palpable in early cases (i.e., before swelling occurs) of acute rotator cuff rupture below the acromion. Crepitation may be palpated on examination in this region.
Although often not definitive, plain radiographs are the first-line in the evaluation of suspected rotator cuff injuries. One may see the acromial morphology and signs of degenerative changes in the rotator cuff, including the following: erosion and periosteal reaction of the greater tuberosity, alterations of the inferior aspect of the acromion, humeral osteophytes, and subchondral erosion in the greater tuberosity. A true AP (Grashey view) is more sensitive than traditional AP views of the shoulder.142
The sensitivity of MRI for the diagnosis of full-thickness rotator cuff tears is 100% and the specificity is 95%.143 MRI is able to differentiate partial cuff tears from intact tendons with a sensitivity of 82% and a specificity of 85%. It is also highly predictive of the size of the full-thickness rotator cuff tear.144 MR arthrography is an excellent means of detecting the degree of tear.145 High-resolution, real-time ultrasound has been shown to be a good examination technique for rotator cuff tears.144 Some studies have shown equal accuracy with ultrasound and MRI.146–148
Conservative measures remain the mainstay of initial treatment for most rotator cuff tears. Conservative therapy will result in a good outcome in 50% of patients.149 Passive range-of-motion exercises should be instituted as soon as possible in elderly patients. In the initial period, rest, ice, and NSAIDs should be accompanied by modified activity and physical therapy. With partial-thickness tears, range-of-motion exercises are important to reduce stiffness.150
In the young, early surgical repair is indicated for complete tears of the rotator cuff.151–153 Arthroscopic rotator cuff repair leads to satisfactory results in more than 90% of cases.153–155 In a large study involving more than 400 patients, arthroscopic repairs for moderate tears was the mainstay of treatment with excellent results and open repair was reserved for massive tears.156 More recent studies suggest that arthroscopic repair can be considered even in large or massive tears as clinical outcomes are good despite higher incidence of recurrent tear.157 In the elderly, with more sedentary lifestyles, repair may not be beneficial.
The long head of the biceps traverses between the greater and lesser tuberosities within the bicipital groove and inserts on the glenoid rim. In this location, it is ensheathed by the capsule of the glenohumeral joint. This position makes the tendon subject to constant trauma and irritation from motions of the shoulder and impingement as described previously. Inflammation around the tendon increases until it moves reluctantly. Bicipital tendinosis rarely occurs in isolation and is commonly a marker for underlying impingement or labral pathology, such as the superior labrum anterior to posterior (SLAP) tear.24,158
The patient complains of pain in the biceps region and anterior aspect of the shoulder that radiates down toward the forearm. Abduction and external rotation are the most painful motions and snap extension of the elbow increases the pain markedly. On examination, there is tenderness to palpation in the bicipital groove (Video 16–16). This irritative process increases with abduction of the shoulder with the elbow fixed in an extended position.A reliable test for diagnosing tenosynovitis of the long head of the biceps is the Yergason test (Fig. 16–77).159 In performing this test, the patient’s elbow is held at 90 degrees of flexion. The patient is asked to supinate the forearm as the examiner resists this attempt. This causes pain along the intertubercular groove and is a reliable test to indicate tenosynovitis of the long head of the biceps.
Video 16-16: Tenderness in the bicipital groove suggests bicipital tendinosis
The Yergason test. Although this test was originally described for dislocation of the bicipital tendon, it can be used to diagnose tenosynovitis of the long head of the biceps as well. In performing this test, the patient is asked to supinate the forearm against resistance as the elbow is held in flexion.
This condition may progress to complete adhesion of the tendon and either shoulder motion will be restricted or the biceps will rupture proximal to the groove.
The treatment includes immobilization in a sling and injection of the bicipital canal with an anesthetic and steroid solution (Fig. 16–78 and Video 16–17).158 One must be careful not to inject the tendon itself. The injection is usually carried out at several points along the route of the tendon within the bicipital groove. Analgesics and anti-inflammatory agents may be administered as well.
Video 16-17: Injection technique for bicipital tendonitis.
Injection of the bicipital tendon sheath along the intertubercular groove.
Bicipital Tendon Subluxation
The bicipital tendon can subluxate or dislocate out of its groove between the greater and lesser tuberosities (Fig. 16–79). This condition is more likely when there is a congenitally abnormal, shallow bicipital groove. A tear of the subscapularis tendon where it attaches to the lesser tuberosity and extends over the bicipital groove is another predisposing factor. The most common mechanism by which this condition occurs acutely is forced external rotation of the arm with the biceps contracted.
Dislocation of the bicipital tendon out of the intertubercular groove.
The patient usually complains of a painful snap felt in the anterior aspect of the shoulder during forced external rotation of the arm while the biceps is contracted. With rotation, the tendon slips back and forth, in and out of the groove. Pain is usually felt in the anterior and lateral aspect of the shoulder and is referred distally and along the anterior aspect of the arm. The pain is typically worse at night; in the acute phase, spasms of the deltoid and subscapularis muscles are common accompanying features. The Yergason test should be performed. The stability of the biceps tendon is determined by subluxation of the tendon from its normal position in the intertubercular groove. When supination against resistance is tested, the bicipital tendon will pop out of the groove and the patient will experience pain.
Treatment is usually operative. Both anchoring the tendon to bone (i.e. tenodesis) and releasing the tendon (i.e., tenotomy) are possibilities and the specific procedure performed depends on a variety of factors including the age of the patient, activity level, presence of an accompanying rotator cuff tear and the condition of the tendon itself.160
Acute Traumatic Synovitis
This is common secondary to sprains of the glenohumeral ligaments or slight tears in the capsule occurring in young athletes. The patient complains of pain over the shoulder joint, and there is tenderness elicited to palpation of the capsule and motion of the shoulder. The anterior/inferior portion of the capsule is the most commonly affected site, usually secondary to abduction–external rotation injuries. The treatment for this condition is immobilization in a sling and the application of warm moist packs. One should begin active range-of-motion exercises as soon as pain will permit.
Adhesive capsulitis, or “frozen shoulder,” usually occurs in women older than 40 years. It may be insidious in onset or occur after an injury.161 Pain is projected to the anterolateral aspect of the shoulder and to the arm. Nighttime pain is often severe interfering with sleep.162 Risk factors include diabetes, trauma, hypertriglyceridemia, and thyroid disease. Diabetes, in particular, is a major risk factor as 20% diabetics will experience adhesive capsulitis. Furthermore, in a small study, 30% of patients with adhesive capsulitis were diagnosed with diabetes or prediabetes.163 Due to the strong association, emergency physicians should consider screening for diabetes or referring for diabetic testing in patients in whom adhesive capsulitis is suspected.
Symptoms typically progress through three traditional phases over the course of several months.164 The initial “freezing” stage occurs with progressive pain from the synovitis and development of limited range of motion. The middle phase is the “frozen stage” in which the range of motion becomes very limited with a rigid feel. The third phase is the “thawing phase” in which slow improvements in range of motion and pain can occur.
Loss of external rotation is greater than abduction and internal rotation. In most cases, palpation over the bicipital tendon groove elicits pain.165,166 Although the etiology of frozen shoulder in many cases remains unclear, increasingly calcific tendonitis of the rotator cuff and bicipital tendon complexes are being implicated.126,166
Treatment is not the same in all cases and consists of physical therapy, NSAIDs, corticosteroid injections, and surgery. Exercises to improve the range of motion should be done in the painless arc of motion.165,166 Corticosteroids have been shown to improve results, but require multiple injections.161 Simple excision of the calcified material will initiate a sequence of events leading to recovery in many cases.166 Arthroscopically, multiple punctures through these deposits lead to good results.
Scapulocostal Syndromes and Bursitis
The syndromes in this category are a group of conditions with a common course and clinical presentation. They are usually caused by inflammation of the bursae around the scapula or strains of the muscles that insert onto the scapula. Pain in the scapular region is usually secondary to poor posture and occurs more commonly at the end of the day. These conditions can also be seen when the arm has not been used for a protracted length of time because of fractures or other conditions.
The onset of bursitis and muscle strains around the scapula is usually insidious and is characterized by exacerbations and remissions. The most common sites for bursitis to occur in this region are the superior and inferior angles of the scapula. The patient usually experiences pain on any motion of the scapula, and the examiner may elicit crepitation when he or she instructs the patient to bring the arm across the chest. To diagnose this condition, the physician should retract the scapula by asking the patient to place the hand on the opposite shoulder. A trigger point usually at the superior angle or near the base of the spine can be palpated. Lidocaine injection should give the patient relief if the condition is secondary to a bursitis of one of the scapular bursae.
Local injection of a trigger point affords prompt relief and should be attempted in those cases with significant pain. Heat in the form of ultrasound twice a day for 20 minutes each day and diathermy (electrically induced heat treatments) provides good relief for patients with muscle strains. Patients with bursitis in the scapular region can be treated with local injection, heat, and rest.
Long Thoracic Nerve Palsy
Injury of the long thoracic nerve results in paralysis of the serratus anterior muscle. This nerve is injured due to its length and superficial course. Clinically, this injury is noted by an unusual prominence of the medial and inferior borders of the scapula, commonly referred to as the “winged scapula” (Fig. 16–80). The most common cause of this injury is overuse. Other causes include acute trauma, either blunt or penetrating, and the improper use of axillary crutches. The cause is idiopathic in 17% of cases.167
Long thoracic nerve palsy on the right creating the classic appearance of the “winged scapula.”
Treatment is conservative in most cases, including analgesics and referral for physical therapy. A full range of motion should be encouraged. Recovery may take 12 to 18 months. One-fourth of patients do not recover following conservative management and should be considered for surgical repair.167
A number of extrinsic disorders can present as shoulder pain. The astute clinician should consider a referred source of pain when the patient presents with shoulder pain and minimal findings on physical examination. Serious underlying pathology, such as an acute myocardial infarction or an inflammatory process under the diaphragm, may refer pain to the shoulder. Cervical spine disease, brachial plexus neuropathy, neoplastic disease, and thoracic outlet syndrome cause shoulder pain and will be considered subsequently.
Cervical spine problems including disk degeneration, herniation, and osteoarthritis can cause shoulder pain. The examiner will find restricted range of motion of the neck and the shoulder pain is often reproduced by neck movement. Neurologic findings, such as a radiculopathy, may be present and can be assessed with the spurling test. This test can be performed by lateral bending of the neck to the affected extremity and applying a downward axial load on the cervical spine. The addition of neck extension with lateral bending may improve the sensitivity.168 It is important to examine the cervical spine carefully and order radiographs of the neck if this condition is suspected.169 Treatment consists of analgesics and referral. Shoulder pain that radiates beyond the elbow should prompt evaluation of the cervical spine.
Brachial Plexus Neuropathy
This is an uncommon cause of shoulder pain that can present with vague symptoms that are either localized or diffuse throughout the upper extremity. Brachial plexus neuropathy can occur due to allergic conditions, infectious disorders (viral syndromes), or may be idiopathic.
The predominant symptom is pain, which may be localized to the shoulder area or may be generalized. Within a few weeks, the patient usually develops weakness in the shoulder girdle. This condition usually has a good prognosis.169
Neoplastic disease particularly of the apical lung may present with shoulder pain. This may involve the chest wall and brachial plexus producing local pain or radicular pain.
This syndrome includes a number of disorders including neurologic and vascular compression. In neurologic thoracic outlet syndrome, portions of the brachial plexus can be compressed as the plexus traverses the supraclavicular area and passes through the axilla to the arm. Compression may be due to the scalene muscle, the first rib, the coracoid process, or the tendinous insertion of the pectoralis minor muscle.169 Patients present with pain noted during certain motions. Thrusting of the shoulders back with the arms dependent at the side while the patient is taking a deep breath may produce pain. The medial trunk of the brachial plexus is the area most commonly affected by compression. Thus, pain may radiate down the forearm along the ulnar nerve distribution and weakness of grasp may be noted.170
The treatment for neurologic thoracic outlet syndrome consists of physical therapy and shoulder muscle strengthening, which provides symptomatic relief. Occasionally, surgery is necessary to relieve the area of compression.168,170
Vascular compression may also occur but is less common. Activity related compression of the venous outflow may result from repetitive shoulder abduction such as performed by overhead athletes. This is commonly referred to Paget–Schroetter Syndrome and requires urgent evaluation by a vascular surgery for consideration of thrombolysis.170