A 65-year-old woman presented to the ED with shoulder pain after
falling down. She was pushed and fell onto her outstretched right
arm and shoulder. There were no other injuries.
On examination, her vital signs were normal. She was in moderate
distress and resisted any attempt to move her shoulder, which had
been immobilized in a sling by the ambulance crew in the field.
There was loss of the normal shoulder contour with a prominent step-off
deformity at the acromion and a palpable concavity of the deltoid
region. Neurovascular function was intact.
Parenteral analgesia was administered and radiographs were obtained
(Figure 1). (A metal clip from the shoulder sling is seen on the
- Why obtain x-rays on a patient with
a shoulder dislocation that can be diagnosed by clinical examination?
- How would you reduce this shoulder dislocation?
- What are the significant findings on these
The standard AP view of the shoulder,
in conjunction with the findings on physical examination, is usually
sufficient to diagnose an anterior dislocation (Figure 2A).
Anterior shoulder dislocation.
view: The humeral head is in external rotation (greater tuberosity
is lateral, arrow) and in a subcoracoid
location. Asterisk = coracoid
Y view: Interpretation of this view can be difficult when it
is slightly oblique and overlying soft tissues obscure the image,
as in this patient. The humeral head overlies the ribs (arrowheads). Arrow = glenoid
view: There is a large linear deformity (arrowheads)
representing an impacted fracture of the humeral head (Hill-Sachs deformity). This was not
evident on the initial radiographs. This common fracture does not
alter emergency management. If large, it predisposes to recurrent
dislocation and may need surgical repair.
findings include an abrupt step-off deformity due to a prominent
acromion (arrow), palpably empty glenoid
fossa, and the arm held in external rotation and abduction.
[D from: Knoop KJ, Stack LB, Storrow AB: Atlas of Emergency Medicine, 2nd ed.,
McGraw-Hill, 2002, with permission.]
Although an AP radiograph does not allow direct determination
of whether the dislocated humeral head is anterior or posterior
to the glenoid fossa, anterior dislocation can be surmised by making
two observations. First, with an anterior dislocation, displacement
of the humeral head is much greater than is possible with a ...