Arm held in adduction and internal rotation.
Anterior shoulder squared-off, flat with prominent
coracoid process. Shoulders may look identical in
bilateral dislocation (commonly missed).
Posterior shoulder full when humeral head is palpable
beneath the acromion process.
Patient resists external rotation and abduction.
Neurovascular deficits are infrequent.
Inferior Shoulder Dislocation (luxatio erecta):
Arm fully abducted with elbow commonly flexed on or
behind head.
Humeral head may be palpable on the lateral chest
wall.
Causes:
Anterior shoulder dislocations usually result from abduction,
extension and external rotation, as in preparation for a
volleyball spike. Falls on an outstretched hand are a common
cause in older adults. During anterior shoulder dislocation, the
humeral head is forced out of the glenohumeral joint thus
rupturing or detaching the anterior capsule from its attachment
to the head of the humerus or from its insertion to the edge of
the glenoid fossa. This occurs with or without lateral
detachment.
Posterior dislocations are caused by severe internal rotation
and adduction. This usually occurs during a seizure, a fall on
an outstretched arm or electrocution. Occasionally, a severe
direct blow may cause a posterior dislocation. Bilateral
posterior dislocation is rare and almost always results from
seizure activity.
Rare but serious inferior dislocations (luxatio erecta) may be
due to axial force applied to an arm raised overhead, as in a
tumbling motorcycle collision victim. More commonly, the
shoulder is dislocated inferiorly by indirect forces
hyperabducting the arm. The neck of the humerus is levered
against the acromion and the inferior capsule tears as the
humeral head is forced out inferiorly. This injury is always
accompanied by fracture and/or serious soft tissue injury.
DIFFERENTIALS
[Acromioclavicular injury]
Fractures,
Humerus
Other Problems to be Considered:
Humeral
fractures most commonly involve the greater tuberosity,
head
and neck.
WORKUP
Lab Studies:
None are needed specifically for shoulder dislocation but they
may be appropriate for associated trauma.
Imaging Studies:
Shoulder Trauma Series:
AP and scapular Y or axillary views
Anterior dislocation is characterized by subcoracoid
position of the humeral head in the AP view. The
dislocation is often more obvious in a scapular Y view
where the humeral head lies anterior to the Y. In an
axillary view, the golf ball (humeral head) is said to
have fallen anterior to the tee (glenoid).
In posterior dislocation, the AP view may show a
normal “walking stick” contour of the humeral head, or
it may resemble a light bulb or ice cream cone
depending upon the degree of rotation. The scapular Y
view reveals the humeral head behind the glenoid (the
center of the Y). In an axillary view, the golf ball
(humeral head) falls posteriorly off the tee (glenoid).
Pre-reduction films document the nature of the
dislocation and associated pathology, such as a
Hill-Sachs lesion or other humeral fractures.
Post-reduction films confirm relocation of the humerus
and may reveal new or previously obscured pathology.
Immobilization prior to rentgenography is imperative.
Other Tests:
Arteriography may be used to evaluate suspected arterial
injury.
EMG may be used to later characterize neural injuries.
Procedures:
The key to successful reduction is slow and steady
application of a maneuver with adequate analgesia and
relaxation.
Successful reduction is evidenced by a palpable or audible
relocation, marked reduction in pain and an increased range
of motion. The patient may be asked to touch the uninjured
shoulder to safely demonstrate a successful reduction.
Some recommend orthopedic consultation prior to reduction
of posterior and inferior dislocations.
After all reductions, a shoulder immobilizer is applied and
neurovascular and radiographic examinations are performed.
Reduction of Anterior Dislocation:
Leverage methods such as the Kocher and
Hippocratic techniques are discouraged because of
increased incidence of humeral shaft fractures and
capsule or axillary nerve injuries.
Stimson echnique:
Patient lies prone on the bed with the dislocated arm
hanging over the side. Traction is provided by up to 10
kg of weight attached to the wrist or above the elbow.
Gentle internal/external humeral rotation may be
applied. May take 20-30 minutes.
External Rotation Method:
While supine, the arm is adducted and flexed to 90
degrees at the elbow. The arm is slowly rotated
externally, pausing for pain. The shoulder should be
reduced before reaching the coronal plane. Often
successful, this procedure requires only one physician
and little force (see Special Concerns).
Traction-Countertraction:
While supine, axial traction is applied to arm with a
sheet wrapped around forearm and the elbow bent 90
degrees. Countertraction is applied by an assistant
using sheet wrapped under the arm and across the
chest.
Zahiri, et. al., recently described a new technique
based on optimal anatomic positioning while avoiding
complications. The dislocated arm is grasped just
above the humeral condyles and, while traction is
applied, the elbow is flexed to 120 degrees. The distal
forearm is grasped overhand with the opposite hand
and a wrestling-type hold is established by passing the
hand from the condyles through the acute angle of the
arm grasping the physician’s own wrist. The shoulder
is then flexed to 90 degrees while distal traction is
continued. The shoulder is externally rotated then
slowly brought over the chest. Finally, the shoulder is
internally rotated with a lift over the anterior glenoid.
The scapular rotation and Milch maneuvers are also
good methods of atraumatic reduction.
Reduction of Posterior Dislocation:
Gentle, prolonged axial traction applied on the
humerus.
Gentle anterior pressure applied while coaxing the
humeral head over the glenoid rim.
Slow external rotation may be needed.
Reduction of Inferior Dislocation:
Gentle axial traction maintained on the humerus while
gentle abduction applied.
Counter traction applied across the ipsilateral shoulder.
Following reduction, arm is slowly adducted.
Buttonholing of the humeral head through the capsule
usually requires open reduction.
TREATMENT
Prehospital Care:
Stabilize and treat associated trauma as indicated.
Allow the patient to assume a position of comfort while
maintaining cervical spine immobilization if necessary.
A pillow placed between the patient’s arm and torso may
help.
Emergency Department Care:
Opiates titrated to decrease pain.
Pre and post-reduction radiographic and neurovascular
examination
Conscious sedation helps relax surrounding musculature
making reduction easier.
Reduction (see Procedures)
Consultations:
Orthopedic surgeon
MEDICATION
Opiate
analgesia should be given as needed for pain. Conscious
sedation
is generally required to achieve adequate muscle relaxation
for
reduction. Some orthopedic surgeons advocate relaxation and
analgesia
with intraarticular anesthetics.
Drug
Category: Analgesics - Analgesics may be used for the
relief
of pain and relaxation of shoulder muscles.
Drug Name
Fentanyl - Fentanyl is the drug of choice
because of its rapid onset (almost
immediate) and short duration (30-60
min). It can be easily reversed by
naloxone 2 mg IV as needed for
respiratory depression. Useful for office
visit only -- not intended to be given as a
take-home med.
Adult Dose
Titrated to pain in 50 mcg IV increments
Pediatric
2-3 mcg/kg IV titrated to pain.
Contraindications
Allergy
Interactions
Additive effects with other CNS
depressants
Pregnancy
C - Safety for use during pregnancy has
not been established.
Precautions
Watch for respiratory depression, nausea
and vomiting and rare hypotension.
FOLLOW-UP
Further Inpatient Care:
Following conscious sedation, the patient should be observed
for at least one hour before being discharged in the care of
family or friends.
Patients requiring operative reduction and repair will require
admission by the orthopedic surgery service.
Further Outpatient Care:
Arrange for orthopedic follow-up in 5-7 days.
The patient’s shoulder should remain in the immobilizer until
her/his orthopedic clinic appointment.
In/Out Patient Meds:
NSAID's (e.g., ibuprofen) may be taken as needed for pain
and inflammation.
Deterrence:
The patient should remain in the immobilizer until under the
care of an orthopedic surgeon.
To prevent recurrent dislocation, patients should avoid
activities that involve abduction and external rotation of the
arm (combing their hair).
Complications:
Recurrence (see Prognosis)
Fractures and soft tissue injuries
Hill-Sachs lesion occurs when the edge of the glenoid
causes an impaction fracture in the posterolateral
aspect of the humeral head during anterior dislocation
and the anterolateral aspect in posterior dislocation.
This lesion is reported in 11-50% of anterior
dislocations.
Fracture of anterior or posterior glenoid rim may also
occur, and significant displacement necessitates
operative management. The greater tuberosity,
acromion, coracoid, clavicle and humeral neck and
shaft are also common sites of fractures.
Bankart lesion is a detachment of the anterior part of
the glenoid labrum and capsule.
Rotator cuff traction injury is more common after age
40 and with inferior dislocation. In an ongoing
prospective study of patients older than 40 sustaining
an initial dislocation, all treated with arthroscopic
evaluation, 86% had rotator cuff tears. This is
commonly missed and Neviaser, et. al., found an
average time of over seven months from injury to
diagnosis of rotator cuff rupture in patients over 40.
Brachial Plexus Traction Injury:
Particularly occurs to the axillary nerve (5-18%). May
resolve spontaneously or require surgical exploration
and possible nerve grafting.
Does not change initial treatment but pre- and
post-reduction neurologic exam is important.
Vascular Injury:
Axillary artery most common
Decreased radial pulse
Axillary mass or hematoma with possible bruit may be
observed, and lateral chest bruising is common.
Prognosis:
Approximately 90% of patients under 20 at the time of the
initial dislocation will develop a recurrence; however
dislocation recurs in only 14% of patients over 40. Many
orthopedic surgeons consider more than one complete
anterior dislocation justification for considering surgical repair.
MISCELLANEOUS
Medical/Legal Pitfalls:
Posterior dislocations are commonly missed, so careful
examination and radiographic evaluation are imperative.
Hawkins found an average interval of one year between
injury and diagnosis of posterior dislocation in a series of 40
patients.
Associated fractures and neurovascular injuries must be
thoroughly sought and documented.
Special Concerns:
Pregnant Patient:
Patients in the third trimester should be placed in the
left lateral decubitus position to avoid compression of
the inferior vena cava by the uterus.
The abdomen should be shielded during
roentgenography.
Relocation techniques placing the patient in a prone
position may be problematic.
Pediatric Patient:
As mentioned above, the epiphyseal plate is prone to
fracture, so a gentle relocation technique should be employed
(see Geriatric patient).
Geriatric Patient:
Fractures can easily occur with vigorous manipulation,
so a gentle relocation technique should be chosen. The
Hippocratic and Kocher techniques should be
avoided. The external rotation method also uses
leverage primarily and although reported complications
are extremely rare, choice of another technique would
be prudent.
Towels or sheets used for traction or countertraction
can cause friction injury to the fragile skin of older
adults./
[search] [notes] [papers] [articles] [zine] [links] [forum] [chat] [about] [disclaimer] [main]