A 16 year-old boy is brought to the Emergency 
Department by ambulance complaining of pain in his 
right shoulder.  He was at a shopping center in a 
crowded video arcade when he turned suddenly and 
struck his shoulder on the edge of a door.  He felt his 
shoulder pop out.
     Exam:  He is alert, cooperative, and moderately 
anxious in moderate pain.  He is of light body build.  His 
right upper extremity is internally rotated.  The head of 
the humerus is noted to be protruding anteriorly, 
obscuring the deltopectoral groove.  There is moderate 
tenderness on palpation of the shoulder.  No crepitus is 
noted.  His clavicle is non-tender.  His mid and distal 
humerus are non-tender.  His elbow and forearm are 
non-tender.  His sensation and pulses are intact distally.  
His axillary nerve function is intact (note the method of 
testing this).

View axillary nerve assessment.

     In addition to routinely checking distal sensation and 
major nerve function, the axillary nerve dermatome 
should be routinely tested (by lightly brushing it or 
testing pin prick sensation) and documented since it 
may be injured during a shoulder dislocation.
     He is given some intravenous morphine and is sent 
to the imaging department for radiographs of his right 
shoulder.

View shoulder radiographs.



     Because of this patient's discomfort, he is unable to 
fully cooperate with obtaining the proper radiographic 
views.  Thus, typically, the radiographic evaluation of a 
dislocated shoulder involves the interpretation of less 
than ideal views of the shoulder.  AP and lateral views 
should be ideally obtained.  The structures are labeled 
in the next set of images.

View labels on radiographs.

     The position of the humeral head relative to 
the glenoid is the most important criterion for 
dislocation.  Note that the humeral head is medial to 
the glenoid and inferior to its normal position, since it 
should overlie the glenoid in this view.  However, the 
humeral head is not entirely below the glenoid itself.  
This radiograph is dark, making the visualization of the 
clavicle, acromion (acr) and coracoid (co) process 
difficult to see.  They are outlined here to show their 
positions.  Note that the humeral head is just inferior to 
the coracoid, but not totally inferior to the glenoid.  This 
"subcoracoid" type of anterior shoulder dislocation is 
the most common type.

     This view again shows the position of the 
humeral head relative to the glenoid.  The humeral 
head should be overlying the glenoid, but it is clearly 
medial to the glenoid and inferior to its normal position.  
The acromion (acr) and clavicle are dark.  They are 
outlined to show their position.  This view again 
demonstrates the subcoracoid dislocation.

     This lateral view may be difficult to interpret 
at first unless you can tell how to locate the glenoid.  
The glenoid is located by following the lateral border of 
the scapula upward.  This will lead to the inferior margin 
of the glenoid as noted in this labeled view.  The 
humeral head should be articulating with the glenoid in 
this view.  However, it is clearly dislocated inferiorly 
(relative to its expected position).

     Try examining another set of shoulder radiographs 
to apply these landmark identifications.
 
View second set of shoulder radiographs.


View labels on the above radiographs.

      The acromion (acr), the clavicle, the 
acromioclavicular joint (ac), and the coracoid (co) are 
better seen in this radiograph.  The glenoid is outlined 
in black dots.  The humeral head should be overlying 
the glenoid.  However, the humeral head is medial to 
the glenoid and inferior to its expected position.  The 
humeral head is below the coracoid (co) but not 
entirely below the glenoid.  This is a another example of 
a subcoracoid dislocation.

     On this lateral view, locate the glenoid by 
following the lateral margin of the scapula upward 
(white dots) to the inferior margin of the glenoid (oval 
white dots).  The humeral head should be articulating 
with the glenoid.  However, the humerus is slightly 
inferior to its expected location.  The positions of the 
clavicle, acromion (acr), coracoid (co), and sternum (st) 
are marked.

     Such anterior dislocations of the shoulder commonly 
present to an emergency department.  Shoulder 
dislocations are often associated with capsular tears 
and, in older patients, avulsion fractures may also be 
seen.
     The three types of anterior shoulder dislocations: 
subclavicular, subcoracoid (most common), and 
subglenoid, are diagrammed below compared to the 
normal shoulder anatomy.

View shoulder diagrams.

     The dislocated humerus is labeled as "D" while the 
expected normal location of the humerus head drawn in 
a broken line is labeled as "N". 
    Both sets of radiographs displayed above show 
subcoracoid dislocations.  Note that while the humeral 
head is inferior to its expected position articulating with 
the glenoid (subcoracoid), the humeral head is not 
entirely inferior to the glenoid (a subglenoid dislocation).

     Many textbooks will recommend that radiographs of 
the shoulder be obtained for all dislocations.  In older 
adults, associated fractures are not uncommon.  
Fractures are less common in teenagers.  A typical 
history and a cooperative teenager would generally 
indicate that no fracture is present.  Loss of the normal 
delto-pectoral groove is indicative of an anterior 
dislocation since the humeral head commonly 
protrudes anteriorly into this space.

View delto-pectoral groove.

     This model shows a normal delto-pectoral groove 
(arrows).  This groove is normally not visible in an 
anterior shoulder dislocation.  The non-affected side 
can be compared clinically.

     In younger children with shoulder deformities, 
radiographs are mandatory since a dislocated 
shoulder is uncommon (fractures are more common).
     Thus, are radiographs necessary in a teenager with 
a typical anterior shoulder dislocation?  It would seem 
that such a patient is at low risk for fracture.  Obtaining 
radiographs may be an unnecessary delay that would 
prolong the discomfort for such patients.  Since poor 
radiographs are often obtained initially, perhaps it would 
be better to obtain radiographs following closed 
reduction if clinical factors suggest this to be beneficial.  
Higher quality radiographs would be obtained, the 
patient would not suffer as long, and any complications 
can be identified more definitively (because of better 
radiographs) to receive appropriate care.  Decisions on 
when to obtain radiographs are not without controversy.  
Understanding the pros and cons of obtaining 
radiographs can assist you in deciding on whether to 
obtain radiographs pre-reduction, post-reduction, both 
pre- and post-reduction, or not at all.
     Following closed reduction, the axillary nerve should 
be reassessed.  The joint should be palpated for any 
signs of fracture.  Range of motion should be 
documented.  The patient should feel as though their 
shoulder is "back to normal".  The patient should be 
placed in a shoulder immobilizer.  Follow-up with their 
primary care physician or an orthopedic surgeon should 
be arranged.  Recurrent dislocations are common, and 
these should be referred to an orthopedic surgeon to 
consider corrective surgery (for ligament laxity).  
     Complications of an anterior shoulder dislocation 
include:  rotator cuff tears, avulsion of the greater 
tuberosity, brachial plexus injury, axillary nerve injury, 
humeral head fracture, glenoid rim fracture, etc.  Most 
of these complications are more common in older 
patients (adults).  Occasionally, soft tissue (rotator cuff, 
capsule, muscle, or tendon) will be interposed in the 
joint, making closed reduction difficult or impossible.  
Orthopedic surgery is indicated for these patients.
     Posterior shoulder dislocations are less common 
and beyond the scope of this discussion.  Posterior 
dislocations should generally be referred to an 
orthopedic surgeon.
     We will review four popular methods of closed 
reduction of an anterior shoulder dislocation; 1) external 
rotation, 2) Stimson (dangling weights) technique, 3) 
traction-countertraction, and 4) scapular manipulation.

External rotation method:
     This method is highly effective and is conceptually 
the simplest since it does not require diagrams to 
understand.  This is the preferred reduction method of 
one text (1) and my favorite as well.

View external rotation method.

     With the patient's back (both shoulders) against the 
gurney in the supine position, the affected upper 
extremity is adducted against the torso.  The elbow is 
flexed to 90 degrees so that the long axis of the forearm 
points to the ceiling (as noted in the photo).  The upper 
arm is externally rotated slowly and gently, using the 
forearm as an external rotation lever.  No traction 
(pulling) is required.  The rotation is halted as pain is 
produced, then continued as muscle spasm and pain 
subside.  Reduction occurs spontaneously as the 
forearm is rotated externally from the sagittal plane 
(vertical in the supine patient) to the coronal plane 
(horizontal in the supine patient).  This maneuver can 
also be performed with the patient sitting up or at 45 
degrees.
     While this method is almost always successful, one 
text recommends that if reduction does not occur 
spontaneously after external rotation, the arm should be 
slowly elevated and the humeral head should be lifted 
into the socket.

Stimson (dangling weights) technique:
     This technique involves the use of weights attached 
to the wrist/forearm.

View Stimson technique.

     The patient is positioned prone.  5 to 10 kg (10 to 20 
pounds) of weight are strapped to the wrist or forearm 
of the affected upper extremity.  A special velcro wrist 
brace can be used to attached the weights to the wrist, 
or a soft restraint can also be used.  The weighted arm 
dangles, placing constant traction on the shoulder, 
which gradually overcomes muscle spasm, and 
reduction occurs spontaneously after about 20 to 30 
minutes.  Analgesia and/or muscle relaxation is 
recommended.  If reduction does not occur 
spontaneously, reduction may be achieved by gently 
rotating the humerus externally and then internally with 
mild force.
     There are three things that I don't like about the 
Stimson technique.  1) It is slow.  2) Most teenagers are 
tall and our gurneys cannot be raised high enough to 
prevent the dangling weights from touching the floor.  
Note this in the photo.  Additionally, patients tend to roll 
toward their affected shoulder lowering the weights 
further.  3) Since these patients are usually sedated, 
and reduction occurs after some delay, a nurse must 
watch the patient continuously to prevent the patient 
from falling asleep and rolling off the gurney.

Traction-countertraction methods:
     There are several variations on this method.  All of 
them involve inferior and/or lateral traction of the upper 
extremity.

View traction method #1.

     In this traction-countertraction method (#1), two 
persons are required.  One person pulls downward on 
the affected arm (traction).  The other person provides 
counter traction in the opposite direction by pulling on a 
sheet wrapped around the upper chest under the axilla 
of the affected shoulder.

View traction method #2.

     This method #2 is similar to traction method #1, 
except that upward lateral traction is added by a third 
person using another sheet as shown.  This method is 
not routinely recommended.

View traction method #3.

     This method #3 was recently described in the 
American Journal of Sports Medicine by sports 
medicine clinics serving skiers in Utah.  This report 
refers to it as the Snowbird reduction technique.  With 
the patient sitting upright on a fixed chair (without 
wheels), a one-meter loop of 10 cm (4-inch) cast 
stockinette is hung from the patient's elbow of the 
affected arm.  The elbow is flexed.  Downward traction 
is provided by gradually applying downward tension on 
the loop using your foot.  The operator should assist the 
patient in maintaining this elbow flexion to prevent the 
loop from slipping.  Countertraction is provided by the 
chair, however, an assistant can be helpful by clasping 
his hands around the chest in the axilla of the affected 
shoulder to prevent the patient from tilting toward the 
downward traction.  The operator providing downward 
foot traction can use his/her hands to apply rotation if 
necessary.

View traction method #4.

     This method #4 is known as the Hippocratic method.  
While many clinicians use this method, several 
textbooks indicated that this method should NOT be 
used.  There are more effective methods than this one.

Scapular manipulation method:
     This method is intriguing and is reported to be highly 
effective.  Forward traction is provided by pulling on the 
forearm with countertraction over the clavicle as noted 
in the photograph.

View scapular manipulation method.

     As one operator provides the forward traction, a 
second operator from the patient's back manipulates 
the scapula by pivoting it clockwise for a right shoulder 
and counter clockwise for a left shoulder.  This is done 
by pushing the inferior tip medially (adducting it) with 
both thumbs as shown, while supporting the top of the 
scapula.
     An alternative way of doing this is to have the 
patient prone with forward traction provided by weights 
attached to the affected arm as in the Stimson 
technique.  The scapula is then manipulated in the 
same fashion.

Which method is the best to try first?
     Only four methods would qualify to be considered 
here.  The external rotation method, the Stimson 
technique, the Snowbird technique (traction method 
#3), and scapular manipulation.  I have only tried the 
external rotation method and the Stimson technique 
myself.  Of these two, I find the external rotation 
method to be preferable.  The problems with the 
Stimson technique limit its use.  The best 
traction-countertraction method seems to be the 
Snowbird technique (traction method #3).  However, it 
is not as "elegant" as the external rotation method or 
the scapular manipulation method.  The external 
rotation method is the simplest.  The Snowbird 
technique requires a somewhat elaborate set-up.  The 
scapular manipulation method has been shown to be 
less successful when performed by inexperienced 
operators.  Thus, it is not the simplest method here.  
However, all of these methods have been reported to 
be highly effective overall.

Which method is the least painful?
     The two recently described techniques in the 
literature, the Snowbird technique and scapular 
manipulation, were reported to be less painful 
compared to other methods.  This was concluded 
because only a small fraction of the patients required 
narcotic analgesics and/or benzodiazepines.  While 
most texts recommend narcotic analgesics and/or 
benzodiazepines routinely, this often is not done.  I 
generally recommend IV narcotic analgesics and/or 
benzodiazepines to patients prior to reduction.  
However, in my experience, more than half the 
teenagers decline this (when the patient is empowered 
to make this decision) because it will delay reduction 
which is what they really want.  In these instances 
where IV medications are declined, reduction using the 
external rotation is achieved quickly and patients 
tolerate it well.  However, it is intriguing that the 
scapular manipulation method is reported to be the 
least painful in an uncontrolled study.  Because of this, 
it should be considered after identifying the anatomic 
landmarks and practicing the technique on a colleague 
(without a dislocated shoulder of course).

References
     1.  The Shoulder and Upper Arm.  In:  Simon RR, 
Koenigsknecht SJ.  Emergency Orthopedics:  The 
Extremities, second edition.  Norwalk, CT, Appleton & 
Lange, 1987, pp. 323-332.
     2.  Lyman JL, Ervin ME.  Management of Common 
Dislocations.  In:  Roberts JR, Hedges JR (eds).  
Clinical Procedures in Emergency Medicine.  
Philadelphia, W.B. Saunders Company, 1985, pp. 
606-615.
     3.  Westin CD, Gill EA, Noyes ME, Hubbard M.  
Anterior Shoulder Dislocation:  A Simple and Rapid 
Method for Reduction.  Am J Sports Med 
1995;23(3):369-371.
     4.  Kothari RU, Dronen SC.  Prospective Evaluation 
of the Scapular Manipulation Technique in Reducing 
Anterior Shoulder Dislocations.  Ann Emerg Med 
1992;21(11):1349-1352.
     5.  McNamara RM.  Reduction of Anterior Shoulder 
Dislocations by Scapular Manipulation.  Ann Emerg 
Med 1993:22(7):1140-1144.