Joint Reduction, Shoulder Dislocation, Anterior 

The shoulder is the most commonly dislocated large joint seen in the emergency department (ED), and anterior dislocations account for 90-98% of cases.^[1] Most dislocations are straightforward and easily reducible in the ED using one of several techniques. However, difficult cases do occur, and clinicians need to be mindful of coincident injuries and complications.

Clinical assessment

The patient typically presents with an obvious squared-off shoulder with the humeral head located inferior and medial to the normal anatomic location. Patients generally hold the injured arm in abduction and resist attempts to adduct or internally rotate the arm.^[2] Trying to place the arm into a sling is often futile, as patients usually find the position of greatest comfort.

The provider should perform a neurovascular examination and assess the probability of a fracture prior to any attempts at reduction, considering the mechanism of injury and physical characteristics of the patient. The axillary nerve is the most commonly injured nerve in shoulder dislocations and can be evaluated by testing for sensation in the lateral upper arm and by palpating for contraction of the deltoid muscle while the patient abducts against resistance. The clinician should also assess for damage to other branches of the brachial plexus.

Arterial injury, though rare, is also possible and can present with paresthesias, diminished pulse, paleness or coolness of affected extremity, pain out of proportion to examination, or paralysis.^[2] Injury to the axillary artery is more common in the elderly population.^[3]

The x-ray panel, when indicated, should include anteroposterior, lateral (Y), and axillary views of the shoulder. Radiographs are generally recommended for first-time dislocations or those caused by direct trauma. Empiric reductions should be limited to young healthy patients with clinically apparent anterior shoulder dislocation if they have a history of recurrent dislocations, if they are neurovascularly intact, and if reduction can be performed easily and rapidly. Clinical factors that have been associated with clinically significant fractures include first episode, patient older than 40 years, or involvement in selected mechanisms of injury (ie, fall from more than one flight of stairs, fight or assault, motor vehicle collision).^[4] Some argue that prereduction films are necessary only in patients with these risk factors, especially those patients aged 40 years and older.^{[5, 6]}

The 4 types of anterior shoulder dislocation are subcoracoid, subglenoid, subclavicular, and intrathoracic. Subcoracoid and subglenoid dislocations account for 99% of anterior shoulder dislocations and are amenable to reduction by the emergency department physician. Subclavicular or intrathoracic dislocations, which are caused by large forces, are not easily corrected and should be referred to an orthopedic surgeon.^[2]

Absolute contraindications

Standard shoulder reduction is absolutely contraindicated if prompt surgical consultation is indicated.^[2]

• Subclavicular or intrathoracic dislocations
• Associated fractures of the humeral neck: Attempts at reduction may result in avascular necrosis.

Relative contraindications

Minor neurovascular injuries and common fractures listed below do not prohibit reduction but require a prompt and atraumatic reduction with avoidance of multiple attempts.

• Nerve injuries

  • The brachial plexus, axillary nerve, or musculocutaneous nerve may be injured.
  • Neurapraxias (contusions of the nerve) usually resolve within weeks.
• Suspicion for major arterial injury: Require urgent angiography.
• Common fractures

  • The Hill-Sachs deformity, a compression fracture of the posterolateral aspect of the humeral head, and Bankart fracture, a detachment of the anterior aspect of the glenoid rim, may occur as the result of the dislocating force as the humeral head presses forcefully against the glenoid rim.^[2]
  • Avulsion fractures of the greater tuberosity of the humeral head tend to heal well but require immediate orthopedic consult if the displacement is more than 1 cm.

Pain control and muscle relaxation are key to an easy reduction. Depending on the patient, one or both of the following methods may be used.

• Intravenous procedural sedation and analgesia

  • Commonly used agents include opiates, benzodiazepines, etomidate, and propofol.
  • Procedural sedation may be necessary in patients who are anxious or uncooperative, those with a high degree of muscle spasm, or those who have undergone unsuccessful attempts at reduction without premedication.^[2]
• Intra-articular anesthetic

  • Under sterile conditions, insert a 35-mm needle (18-20 ga) 2 cm inferior to the lateral edge of the acromion into the glenohumeral joint.
  • After aspirating blood, inject 10-20 mL of 1% lidocaine over 30 seconds. Then, wait 15-20 minutes before performing the procedure.^[2] Intra-articular lidocaine injection.
  • Advantages include draining of hemarthrosis; eliminating the need for intravenous access; and reducing the risks of respiratory depression and cardiac compromise, staff involvement for monitoring, length of emergency department stay, and cost.^{[7, 8, 9]}
  • Disadvantages include the risk of infecting the joint space. However, a recent retrospective review of 6 randomized controlled trials comparing intra-articular lidocaine to procedural sedation found no reported cases of joint infection with intra-articular injection.^[10]
• Ultrasound-guided nerve block

  • Anesthesiologists routinely perform brachial plexus nerve blocks for shoulder surgery with the aid of nerve stimulators and more recently using ultrasound-guidance.^{[11, 12]} Literature suggests that an ultrasound-guided interscalene nerve block of the brachial plexus can be used to provide adequate anesthesia for the reduction of shoulder dislocations.^{[13, 14]} A prospective, randomized study by Blaivas et al demonstrated that an ultrasound-guided interscalene block is not only feasible in the emergency department, but also significantly reduced the emergency department length of stay when compared to procedural sedation.^[14]
  • The authors performed the nerve blocks using a linear array probe to identify the brachial plexus in the neck between the anterior and middle scalene muscles on the side ipsilateral to the dislocated shoulder. The brachial plexus appears as three anechoic circles when viewed in the short axis. A 20- or 21-guage 1.5 cm noncutting spinal needle was used to inject 20-30 mL of 1% lidocaine with or without epinephrine or 0.25% bupivacaine. Full loss of sensory and motor function of the arm was achieved in most patients after 15-30 minutes.^{[13, 14]}
  • Advantages of nerve blocks over procedural sedation include reduced length of stay in the emergency department, no need for hemodynamic monitoring, absence of airway or cardiovascular compromise, and a reduction in the amount of one-on-one health care provider time.
  • Disadvantages include possible complications such as vascular puncture (though the use of ultrasound-guidance decreases this risk substantially as a result of direct nerve and needle visualization) and rarely Horner's syndrome, hoarseness or diaphragmatic symptoms due to possible involvement of either the recurrent laryngeal or phrenic nerves.

The equipment required depends on the technique used. See Technique for details.

The equipment required depends on the technique used. See Technique for details.

New shoulder dislocations generally require a great deal of force abducting and externally rotating the shoulder.^[2] However, in patients with recurrent dislocations, the forces may be relatively moderate.

Reduction techniques can vary in terms of required force, time, equipment, and staff. No single reduction method is successful in every instance, so the clinician should be familiar with several reduction techniques. Adequate pain control and muscle relaxation are key to a successful reduction. Most techniques are facilitated by the following 2 maneuvers:

• Flexion of the elbow 90° to relax the biceps tendon
• External rotation of the humerus, which releases the superior glenohumeral ligament and presents the favorable side of the humeral head to the glenoid fossa

Signs of a successful reduction include the following:

• Palpable or audible clunk
• Return of rounded shoulder contour
• Relief of pain
• Increase in range of motion (eg, patient can touch opposite shoulder with palm of affected arm)

Before attempts at reduction, explain the procedure, benefits, risks, and complications to the patient or the patient's representative and obtain a signed informed consent.

Stimson maneuver

• Equipment

  • Weights, 5-10 lb
  • Weight straps
  • Sheets or extra straps
• Position

  • Position the patient prone on an elevated stretcher. Position the affected shoulder off the edge of the stretcher, hanging downward in 90° of forward flexion.
  • The stretcher should be high enough to allow the patient’s arm to dangle without touching the floor.
• Technique

  • To prevent the patient from sliding off the stretcher, strap the patient tightly with a sheet and then securely fasten 5-10 lb of weight to the patient’s wrist to provide continuous traction. If weights are unavailable, 2-4 1-L containers of normal saline and a stockinette can be used (as demonstrated in the picture).
  • Instruct patient to maintain this position for at least 15-20 minutes or until reduction is accomplished.
  • To facilitate reduction, the physician may apply gentle external rotation of the extended arm, flexion of the elbow 90°, or scapular manipulation (as described below).^{[2, 15]} Stimson maneuver.
• Advantages

  • No assistance is required.
  • Shoulder is reduced with minimal force (gravity and weights).
  • Scapular manipulation, with proper sedation, has a success rate of 96%.^[16]
• Disadvantages

  • Patient may slip off the elevated stretcher.
  • Patient must be monitored at all times.
  • Equipment is necessary.
  • Sufficient premedication may be necessary.
  • Time required for reduction is relatively long.

Scapular manipulation

• Equipment - None
• Position - Prone or seated, with back exposed
• Technique

  • Place affected arm in 90° of forward flexion at the shoulder and apply slight traction.
    • If in prone position, use weights (as in the Stimson technique) or have an assistant apply manual downward traction.
    • If in seated position, have an assistant stand, facing the patient, and use one arm to firmly grasp the wrist of the dislocated arm. The assistant should then apply steady forward traction parallel to the floor while applying countertraction with the other arm, which is outstretched and resting on the patient's clavicle. Sitting position for scapular manipulation.
  • Stand lateral to the affected shoulder and stabilize the scapula by placing the palm of one hand on the lateral aspect of the shoulder with thumb securely on the superior lateral border. Place other palm over the inferior tip of the scapula and position the thumb on the inferior lateral border of the scapula. Hand placement for scapular manipulation.
  • Use both hands to rotate the inferior tip of the scapula medially and the superior aspect laterally with slight dorsal displacement. The goal is to move the glenoid fossa back into anatomical position.^{[2, 15]}
  • To facilitate reduction, the assistant may apply, along with traction, slight external rotation of the humerus, elbow flexion in 90°, or both.
• Advantages

  • This reduction is tolerated well by patients.
  • Reduction can be performed without premedication.
  • Minimal force is required.
  • Success rate with this maneuver is more than 85%.^[15]
• Disadvantages

  • The borders of the scapula are difficult to locate in patients who are obese.
  • Assistance is needed for traction if patient is in prone position (if weights are not available) or if patient is in seated position.

External rotation method

• Equipment - None
• Position – Supine on stretcher
• Technique

  • Using one hand, adduct the affected arm tightly to the patient’s side.
  • With the other hand, grasp the patient’s wrist, bend elbow to 90° of flexion, and then gently rotate the upper arm externally, using the forearm as a lever, without force or traction.
  • If the patient experiences pain, pause momentarily to allow the muscles of the upper arm to relax. After the pain has subsided, continue until the forearm is in the coronal plane. Reduction takes place between 70-110° of external rotation and, sometimes, during return on internal rotation.^{[2, 15]}
    External rotation.
• Advantages

  • This reduction is tolerated well by patients.
  • This reduction can be performed by a single operator.
  • Premedication is not necessary.
  • This reduction can be done quickly and easily.
  • No force or traction is necessary.
• Disadvantages: Previously documented success rates were approximately 80% (lower than other methods). However, a recent study achieved an 89% success rate of reduction.^[17]

Milch technique

• Equipment – None
• Position – Supine or prone, with shoulder close to edge of stretcher
• Technique

  • Place affected arm in full abduction overhead or instruct patient to raise affected arm laterally and behind the head. Operator may assist abduction gently.
  • With arm in full abduction, gently apply longitudinal traction and external rotation with one arm.
  • If reduction is not completed, use the thumb or fingers to push the humeral head upward into the glenoid fossa with gradual adduction of the extended arm still held in traction.^{[2, 15]}
    Milch technique.
• Advantages

  • This reduction is tolerated well by patients.
  • Procedural sedation is not necessary.
  • This reduction can be performed by a single operator.
  • Minimal force is required.
  • Success rates are 70-90%.^[15]
• Disadvantages – None

Spaso technique

• Equipment – None
• Position – Supine on stretcher
• Technique

  • Grasp the affected arm around the wrist or distal forearm and lift vertically to the ceiling with traction upward toward the ceiling and gentle external rotation. If the patient experiences pain, wait until the muscles relax and continue gently. This may take several minutes.
  • If an audible or palpable clunk is not heard, use the other hand to apply direct pressure to the humeral head.^{[2, 15, 18]}
  • As an alternative, try the Waldron variation on the Spaso technique. While the elbow is maintained in a flexed position, firmly hold the epicondyles and apply vertical traction on the humerus while alternating the forearm through an arc of 10° of external rotation to 10° of internal rotation.
    Spaso technique.
• Advantages

  • This reduction can be performed by a single operator.
  • Minimal force is required.
  • Published success rates for this technique range from 67.6%-87.5%. Yuen et al demonstrated a success rate of 87.5% with premedication, while another study reported a 75% success rate without anesthesia or assistance and no complications.^{[19, 18, 20]}
• Disadvantages - None

Traction and countertraction

• Generally requires substantial force, which necessitates procedural sedation
• Equipment – Several sheets or wide straps
• Position – Supine on a securely locked stretcher, with bed elevated to the height of the operator's ischial tuberosities (This is critical positioning to ensure smooth application of force.)
• Technique

  • Place one sheet or strap over the patient's upper chest, under the axilla of the affected shoulder and underneath the back, so that the 2 ends of the sheet are of equal length and open to the unaffected side.
  • Standing on the unaffected side, the assistant takes a firm hold of each end of the sheet with each hand or securely ties the sheet around his or her own waist at the level of the ischial tuberosities. When instructed to start, the assistant leans back to provide countertraction with body weight.
  • While maintaining the affected arm in 90° of flexion at the elbow, with both hands around the forearm, apply traction by leaning backward with fully extended arms. Use body weight, not upper arm muscles (eg, biceps), to provide traction along the axis of dislocation while the assistant applies countertraction.
  • Alternatively, if fatigued, the clinician can wrap another sheet around his or her proximal forearm and tie it around his or her back, letting the continuous loop sit at the level of the ischial tuberosities. While still holding the elbow in flexion, step back to make the sheet taut and lean back, using body weight to apply traction.
  • Apply gentle traction for several minutes until reduction is attained. At reduction, the affected arm is usually lengthened and relaxed, with an audible clunk. Again, slight external rotation may ease reduction.^[2] Traction and countertraction. Traction and countertraction.
• Advantages

  • This traditional method is familiar to most clinicians.
  • This reduction has a high rate of success; therefore, it is useful in patients with severe muscle spasm or pain and in those who cannot relax.
• Disadvantages

  • Procedural sedation is required; therefore, this method is not usually the initial method of choice.
  • More than one operator is required.
  • This reduction requires prolonged force and endurance.
  • Equipment is needed for this reduction.
• Orthopedic consultation in the emergency department is recommended for complex dislocations and failed initial attempts.

Postreduction care

• After reduction, repeat and document the neurovascular examination. Postreduction radiographs to confirm reduction and identify any missed fractures are recommended. Some argue that postreduction films should be obtained only in patients in which a fracture was identified on prereduction films or if the physician is unsure of the reduction.^[5] Recent case reports and one small study suggest that bedside ultrasonography, using a posterior approach to the shoulder, is a useful tool for confirming reduction.^{[21, 22, 23]} This may be especially helpful prior to obtaining postreduction films in cases when procedural sedation was used but the clinician is unsure whether the reduction was successful. Yuen et al propose alternate approaches to the shoulder for this same purpose.^[24]
• The shoulder should be immobilized in a sling and swathe or shoulder immobilizer. The traditional method is to immobilize the shoulder in internal rotation. However, some recent literature suggests that, in first-time shoulder dislocations, immobilizing in external rotation may decrease the risk of recurrence.^{[25, 26, 27]} Refer the patient for orthopedic follow-up.
• For younger patients, especially those who are active, immobilize for 3-6 weeks. Follow up within 1-2 weeks to evaluate for need for early operative joint stabilization.^[2] A recent systematic review that identified studies comparing operative versus nonoperative management of anterior shoulder dislocations demonstrated that surgical intervention in young active patients decreases rates of recurrence.^[28]
• For patients older than 40 years, immobilize the shoulder for 1-2 weeks and follow up in 1 week to reexamine the shoulder. Advise pendular exercises to increase mobility and prevent adhesive capsulitis.^[2]
• Rotator cuff tears, which occur in 10-15% of anterior shoulder dislocations and are usually associated with greater tuberosity fractures that are displaced more than 1 cm, are difficult to evaluate immediately after reduction because of pain and swelling. These injuries are best evaluated at orthopedic follow-up.^[2]
• Explain to the patient that most nerve injuries are neurapraxic and should gradually improve and resolve within a few weeks to months.
• Instruct the patient to decrease the risk of recurrence by avoiding activities that involve abduction and external rotation, such as combing hair.
• Prescribe adequate pain medication, but also inform the patient that severe or escalating pain merits immediate reevaluation.

• Make sure the patient’s pain is well-controlled and muscles are relaxed prior to attempts at reduction.
• When reducing a recurrent dislocation, ask the patient to describe what analgesia and reduction technique has been successful in the past.
• When selecting the technique for reduction, keep in mind the current patient load, staff, and equipment availability.
• Consider intra-articular lidocaine as an alternative, especially for patients who have contraindications to intravenous sedation and analgesia.
• With elderly and pediatric patients, take extra care when applying traction with leverage techniques. Be careful not to cause friction injury to the skin when using sheets or straps.
• As part of the clinical evaluation, remember to consider other diagnoses, such as concomitant cervical spine injuries. In addition, referred pain from acute myocardial infarction or splenic rupture may also present as shoulder pain.

• Failed reduction: If multiple attempts at closed reduction fail or signs of neurovascular injury develop, consult an orthopedic surgeon to evaluate for closed reduction or possible open reduction in the operating room under general anesthesia.
• Reduction injuries: Apply the least amount of force during reduction with traction and leverage techniques to avoid the formation or exacerbation of existing fractures or vascular (eg, hemarthrosis) or nerve injuries (eg, neurapraxia). New fractures rarely appear on postreduction films.
• Recurrence: Recurrence is the most common complication, especially with young active patients. Age at the time of dislocation is inversely related to the rate of recurrence.^[29] Common fractures such as Hill-Sachs deformities or Bankart fractures require prompt orthopedic follow-up because they are associated with increased joint instability and higher risk of redislocation. After evaluation of the shoulder’s range of motion status postreduction, immediate immobilization with a sling and swathe is crucial to prevent recurrence.