Approach Considerations
Reduction techniques can vary in terms of required force, time, equipment, and staff. [7] No single reduction method is successful in every instance; therefore, the clinician should be familiar with several reduction techniques.
Techniques commonly used to reduce anterior shoulder dislocations include the following [34, 35, 36, 37, 38, 39] :
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Stimson maneuver
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Scapular manipulation
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External rotation
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Milch technique
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Spaso technique
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Davos technique
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Traction-countertraction
Posterior shoulder dislocations are typically reduced by means of traction-countertraction.
Techniques commonly used to reduce inferior shoulder dislocations include the following:
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Axial (inline) traction
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Two-step reduction
Adequate pain control and muscle relaxation, in conjunction with smooth atraumatic technique, are the keys to a successful reduction. Slow, consistent movements by the operator prevent pain and associated muscle spasm; quick pulling or release of tension is sure to cause resistance and pain. Most techniques are facilitated by the following two maneuvers:
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Flexion of the elbow 90° to relax the biceps tendon
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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:
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Palpable or audible clunk
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Return of rounded shoulder contour
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Relief of pain
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Increase in range of motion (eg, the patient can touch the opposite shoulder with the palm of the affected arm)
Before any attempts at reduction, it is essential to explain the procedure, benefits, risks, and complications to the patient or the patient’s representative and to obtain informed consent.
Most neurovascular injuries are caused by the dislocation itself, but they can be induced or exacerbated by attempted reduction. A conscientious neurovascular examination, both before and after reduction, is important for documenting the presence and alteration of these injuries.
For complex dislocations and failed initial attempts, orthopedic consultation in the emergency department (ED) is recommended.
Stimson Maneuver
The patient is placed in the prone position on an elevated stretcher. The affected shoulder should be 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.
To prevent the patient from sliding off the stretcher, he or she is tightly strapped down with a sheet, and 5-10 lb (2.25-4.5 kg) of weight is securely fastened to the wrist of the affected arm to provide continuous traction. If weights are unavailable, two to four 1-L containers of normal saline and a stockinette can be used (see the image below). The patient is instructed 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 (see below). [7, 40]
The advantages of the Stimson maneuver are as follows:
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No assistance is required
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The shoulder is reduced with minimal force (gravity and weights)
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Success rates are high - Scapular manipulation, with proper analgesia, has a success rate of 96% [41]
The disadvantages are as follows:
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The patient may slip off the elevated stretcher (a belt or wrap may be placed around the bed to prevent this)
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The patient must be monitored at all times
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Equipment is necessary
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Sufficient premedication may be necessary
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The time required for reduction is relatively long
Scapular Manipulation
With the patient prone or seated and the back exposed, the affected arm is placed in 90° of forward flexion at the shoulder, and slight traction is applied.
If the patient is prone, weights are used (as in the Stimson technique; see above), or manual downward traction is applied by an assistant. If the patient is seated, an assistant should 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 (see the image below).
The treating physician then stands lateral to the affected shoulder and stabilizes the scapula by placing the palm of one hand on the lateral aspect of the shoulder with the thumb securely on the superior lateral border, then placing the other palm over the inferior tip of the scapula and positioning the thumb on the inferior lateral border of the scapula (see the image below).
The physician then uses 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 the correct anatomic position. [7, 40] To facilitate reduction, the assistant may apply, along with traction, slight external rotation of the humerus, elbow flexion in 90°, or both.
The advantages of scapular manipulation are as follows:
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This reduction is tolerated well by patients
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Reduction can be performed without premedication
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Minimal force is required
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Success rates are high - Pishbin et al obtained success rates of 87.5% without medication; this figure rose to 97.3% with the addition of intravenous (IV) midazolam [42]
The disadvantages are as follows:
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The borders of the scapula are difficult to locate in obese patients
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Assistance is needed for traction if the patient is prone and weights are unavailable or if the patient is seated
External Rotation
The patient is placed supine on a stretcher. The treating physician adducts the affected arm tightly to the patient’s side with one hand, then, with the other hand, grasps the patient’s wrist, bends the elbow to 90° of flexion, and gently rotates the upper arm externally, using the forearm as a lever, without force or traction (see the video below).
If the patient experiences pain, a short pause should be taken to allow the muscles of the upper arm to relax. After the pain has subsided, rotation continues until the forearm is in the coronal plane. Reduction typically takes place between 70° and 110° of external rotation; sometimes, it takes place during return on internal rotation. [7, 40]
The advantages of external rotation are as follows:
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This reduction is tolerated well by patients [43]
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The procedure can be performed by a single operator
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Premedication is not necessary
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The reduction can be done quickly and easily
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No force or traction is necessary
The main disadvantage is a success rate that may be lower than those obtained with other methods. Previously documented success rates were approximately 80%; however, some reports cited first-attempt success rates of 89-90%, mostly without the use of sedation. [43, 44]
Milch Technique
The patient may be supine or prone, with the shoulder close to the edge of the stretcher. The affected arm is placed in full abduction overhead, or the patient is instructed to raise the arm laterally and behind the head. The operator may assist abduction gently.
With the patient’s arm in full abduction, the physician gently applies longitudinal traction and external rotation with one arm (see the video below). If reduction is not completed, the physician uses the thumb or fingers to push the humeral head up into the glenoid fossa, with gradual adduction of the extended arm still held in traction. [7, 40]
The advantages of the Milch technique are as follows:
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This reduction is tolerated well by patients
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Procedural sedation is not necessary
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The reduction can be performed by a single operator
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Minimal force is required
This technique has no significant disadvantages.
Spaso Technique
With the patient supine on a stretcher, the physician grasps the affected arm around the wrist or distal forearm and lifts it vertically to the ceiling, applying upward traction and gentle external rotation (see the video below). If the patient experiences pain, the physician should stop and wait until the muscles relax; this may take several minutes. Once the muscles have relaxed, the physician may continue gently. If an audible or palpable clunk is not heard, direct pressure should be applied to the humeral head with the other hand. [7, 40, 46]
An alternative to the standard Spaso technique is the Waldron variation. In this approach, while the elbow is maintained in a flexed position, the physician firmly holds the epicondyles and applies vertical traction on the humerus while moving the forearm through an arc extending from 10° of external rotation to 10° of internal rotation.
The advantages of the Spaso technique are as follows:
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This reduction can be performed by a single operator
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Minimal force is required.
This technique has no significant disadvantages.
Davos Technique
The Davos (Boss-Holzach-Matter) technique, described in 1993 at Davos hospital in Switzerland, [39] allows for self-reduction in appropriately selected patients, with a high success rate and without the need for sedation. Analgesia is recommended.
The patient is seated with the ipsilateral knee and hip in maximal flexion. The patient clasps his or her fingers below the flexed knee, or, commonly, a wrap such as an elastic bandage is placed around the wrists, also below the flexed knee. The patient's foot can be stabilized by the physician or assistant if available. The patient relaxes the shoulder, scapular, and arm muscles while leaning back and extending the neck slightly, pulling the shoulder into reduction.
Traction-Countertraction
The patient is supine on a securely locked stretcher, with the bed elevated to the height of the operator’s ischial tuberosities; this positioning is critical for ensuring smooth application of force. One sheet or strap is placed over the patient’s upper chest, under the axilla of the affected shoulder and underneath the back, so that the two 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. [9]
While maintaining the affected arm in 90° of flexion at the elbow, with both hands around the forearm, the physician applies traction by leaning backward with fully extended arms. It is important to use body weight, not upper arm muscles (eg, biceps), to provide traction along the axis of dislocation while the assistant applies countertraction.
Alternatively, to facilitate traction and reduce fatigue, the clinician can wrap another sheet around his or her proximal forearm and tie it around the back, letting the continuous loop sit at the level of the ischial tuberosities (see the images below). The affected extremity is flexed at the elbow and is placed inside the loop. With the elbow maintained in flexion, the clinician steps back to make the sheet taut and then leans back—again, using body weight to apply traction. The operator’s hands thus are free to guide and stabilize the extremity. [9]
Traction should be applied in a gentle, smooth, firm manner for several minutes, until reduction is attained. Patience is rewarded; yanking, placing the operator’s foot in the patient’s axilla, or other impatient maneuvers will only increase the likelihood of complications. At reduction, the affected arm is usually lengthened and relaxed, with an audible clunk. Slight external rotation may ease reduction. [7]
In a patient with a posterior dislocation, an assistant may apply additional gentle pressure to the humeral head in the posterior [7, 9] and lateral [9, 49] directions to disengage it from the posterior glenoid. When the head of the humerus disengages, the arm may be externally rotated. However, the operator must exercise extreme caution here because external rotation can cause a fracture of the humerus if the head is not disengaged from the glenoid. [50]
If the joint is stable, the patient may be placed in a sling and swathe; if it is unstable, the patient may be splinted in slight abduction and neutral rotation. [49, 7]
The advantages of the traction-countertraction technique are as follows:
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This traditional method is familiar to most clinicians
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The success rate is high; thus, the procedure is useful in patients with severe muscle spasm or pain and in those who cannot relax
The disadvantages are as follows:
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Procedural sedation is typically required; accordingly, this method usually is not the initial method of choice
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More than one operator is required
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This reduction requires prolonged force and endurance
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Equipment is needed
Axial (Inline) Traction
The patient is placed supine on a sturdy immobile surface (eg, a wheel-locked gurney). The physician, standing on the affected side at the patient’s head, [7] applies axial traction in line with the abducted arm. To facilitate the procedure, an assistant can apply parallel countertraction by using a sheet wrapped diagonally over the affected shoulder. During the application of axial traction, increasing the degree of abduction (if possible) and applying cephalad pressure to the displaced humeral head can aid in reduction (see the image below).
Reduction of shoulder dislocation: axial traction and countertraction. Axial traction is applied to arm, and parallel countertraction is applied with sheet wrapped over shoulder. Increasing degree of abduction (if possible) and applying cephalad pressure to displaced humeral head (star) can aid in reduction.
After successful reduction of the humeral head, the arm should be fully adducted against the chest wall and supinated and immobilized in that position (see the image below).
Reduction of shoulder dislocation: axial traction and countertraction. After inferior dislocation is reduced, arm is adducted, supinated, and immobilized for postreduction radiography.
Two-Step Reduction
In 2006, Nho et al described a two-step method for the reduction of inferior shoulder dislocation (ie, luxatio erecta humeri). [51] In this technique, the inferior dislocation is converted to an anterior dislocation (step 1), which is subsequently reduced (step 2).
The patient is placed supine on a sturdy immobile surface (eg, a wheel-locked gurney). The clinician, standing on the affected side near the patient’s head, places one hand (the hand nearer the patient) on the lateral aspect of the midhumerus and places the other hand on the medial condyle.
Step 1 of the reduction may be divided into two parts. In part 1, the clinician pushes anteriorly with the hand on the midhumerus and pulls posteriorly with the hand on the medial condyle (see the first image below). This motion brings the humeral head to a position anterior to the glenoid (ie, the humeral head is now anteriorly rather than inferiorly dislocated). In part 2, the clinician adducts the arm and moves the hand on the medial condyle to grasp the wrist (see the second image below).
Reduction of shoulder dislocation: two-step reduction. Step 1, part 1. Push anteroinferiorly on midhumerus with hand A while pulling posteriorly on medial condyle with hand B.
Reduction of shoulder dislocation: two-step reduction. Step 1, part 2. After conversion of inferior dislocation to anterior dislocation, adduct arm and grasp patient's wrist.
In step 2 of the two-step reduction, the clinician, while holding the arm in adduction against the chest wall, externally rotates the shoulder by pulling on the wrist (see the image below).
Reduction of shoulder dislocation: two-step reduction. Step 2. Hand A holds patient's arm in adduction while hand B externally rotates arm to reduce now anteriorly dislocated humeral head.
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Ultrasound probe placement for viewing glenohumeral joint via posterior approach.
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Ultrasound image of normal (right) and anteriorly dislocated shoulder (left). Arrow points to humeral head. Image courtesy of Michael A Secko, MD, RDMS.
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Reduction of shoulder dislocation: Stimson maneuver.
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Reduction of shoulder dislocation: Stimson maneuver.
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Reduction of shoulder dislocation: scapular manipulation. Hand placement.
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Reduction of shoulder dislocation: scapular manipulation. Sitting position.
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Reduction of shoulder dislocation: external rotation.
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Reduction of shoulder dislocation: Milch technique.
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Reduction of shoulder dislocation: Spaso technique.
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Reduction of shoulder dislocation: traction and countertraction.
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Reduction of shoulder dislocation: traction and countertraction.
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Classic presentation of inferior shoulder dislocation. Affected arm is hyperabducted, with elbow flexed and forearm resting on top of head.
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"Regimental badge" area. Examine pinprick sensation to this area to assess axillary nerve sensory function.
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Reduction of shoulder dislocation: axial traction and countertraction. Axial traction is applied to arm, and parallel countertraction is applied with sheet wrapped over shoulder. Increasing degree of abduction (if possible) and applying cephalad pressure to displaced humeral head (star) can aid in reduction.
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Reduction of shoulder dislocation: axial traction and countertraction. After inferior dislocation is reduced, arm is adducted, supinated, and immobilized for postreduction radiography.
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Reduction of shoulder dislocation: two-step reduction. Step 1, part 1. Push anteroinferiorly on midhumerus with hand A while pulling posteriorly on medial condyle with hand B.
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Reduction of shoulder dislocation: two-step reduction. Step 1, part 2. After conversion of inferior dislocation to anterior dislocation, adduct arm and grasp patient's wrist.
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Reduction of shoulder dislocation: two-step reduction. Step 2. Hand A holds patient's arm in adduction while hand B externally rotates arm to reduce now anteriorly dislocated humeral head.
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Anteroposterior radiograph of left shoulder shows posterior glenohumeral dislocation. Impaction of humeral head on posterior glenoid results in reverse Hill-Sachs defect (trough sign) on anterior aspect of humeral head. Image courtesy of Dr M A Png, Singapore General Hospital.
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Axial spin-echo T1-weighted magnetic resonance arthrogram of right shoulder shows tear of posterior glenoid labrum (arrow) and reverse Hill-Sachs defect (arrowhead). Patient had previous posterior dislocation.
