Shoulder dislocation occurs when the head of the humerus separates from the scapula, primarily manifesting as anterior dislocation in 95% of cases. The document outlines clinical features, investigation methods, and treatment protocols for both anterior and posterior dislocations, including the management of recurrent dislocations and associated complications. It emphasizes the importance of imaging and potential surgical interventions for recurrent cases.

1. SHOULDER DISLOCATION
BY TAMIANJI KASITU

2. INTRODUCTION
• Dislocation is the displacement of the bone from a joint.
• Shoulder dislocation is when the head of the humerous
separates from the scapula at the glenohumeral joint
• Shoulder dislocation is the most common major joint
dislocation
• Shoulder dislocation has two major types:
– Anterior shoulder dislocation which is the most common and
accounts for 95%
– Posterior shoulder dislocation which is less common and
accounts for 2-4%

5. Anterior Shoulder dislocation
• Anterior shoulder dislocation is caused by
either falling on the backward-stretching hand
or by forced abduction and external rotation of
the shoulder
• The head of the humerus is driven forward,
tearing the capsule and usually ends up just
below the coracoid process
• This may occur with an associated fracture of
the proximal end of the humerus

7. Clinical Features
• Pain is severe
• Patient supports the arm with the opposite
hand and is very reluctant to allow any kind of
examination
• On examination, the lateral outline of the
shoulder is flattened
• A small bulge may be seen and felt just below
the clavicle

8. • Looking from above, usual forward bulge is
altered compared with the other shoulder
• The arm must always be examined for nerve
and vessel injury

10. Investigations
• X-ray will show overlapping shadows of the
humeral head and the glenoid fossa with the
head usually lying below and medial to the
socket.
• A lateral view is essential to show whether or
not the head is in the socket.

13. Treatment
• In those with recurrent dislocations, reduction may be
achieved spontaneously by the patient or by the doctor under
sedation
• For those experiencing a dislocation for the first time, prompt
reduction can be achieved under sedation but if muscle
spasm and pain are overwhelming, then a general anesthetic
may be required
• While the patient is waiting, they can be placed in the prone
position with the arm hanging over the side of the bed, the
dislocation may reduce.
• Otherwise, the simplest and safest method is to pull on the
arm in slight abduction and flexion while the body is steadied
by an assistant who has wrapped a towel around the torso for
counter-traction.

14. • An x-ray is taken to confirm reduction and
exclude a fracture.
• When the patient is awake, active abduction is
gently tested to exclude an axillary nerve
injury or rotator cuff tear
• The arm is then supported in a sling

15. Complications
• Fractures of the neck of the humeru, greater tuberosity, lesser
tuberosity
• Hillsach’s lesion: depression on the humeral head in its potero-
lateral quadrant
• Bankart’s lesion: Glenoid labrum tear in the anterior joint
• Rotator cuff’s injuries: patient has an inability to abduct the arm.
(particularly in older people)
• Nerve injury
– Commonest is axillary nerve: patient is unable to contract the deltoid
muscle. Lesion is usually a neurapraxia
– Brachial plexus
• Recurrent dislocations

16. Posterior Shoulder dislocation
• This is much rare than anterior shoulder
dislocation
• It should always be suspected if the patient
had suffered an epileptic fit or severe electric
shock
• It is otherwise caused by forced internal
rotation of the abducted arm or by a direct
blow on the front of the shoulder

18. Clinical Features
• Clinically the shoulder contour is maintained
• The patient comes with arm held in medial
rotation and is locked in that position

19. Investigations
• In the AP projection of x-rays, because the
humeral head is medially rotated, it looks
somewhat globular
• This gives it a classic ‘electric light-bulb’
appearance, hence, light bulb sign

23. Treatment
• The arm is pulled and rotated laterally, while
the head of the humerus is pushed forwards
• After reduction, the management is the same
as for anterior dislocation.

24. Recurrent Dislocation
• Once a shoulder has been dislocated, this may
happen repeatedly, and with increasing ease
over the ensuing months or years
• In these cases the capsule and labrum have
usually been stripped from the margin of the
glenoid and the humeral head may be
indented.

26. • In the vast majority of cases, recurrence is anterior, but
occasionally it is posterior; the distinction is not as easy as it
may seem, because often by the time the patient is examined
the head is back in the socket and there is only the history to
go by.
• With recurrent anterior dislocation, the patient complains
that the shoulder ‘slips out’ when the arm is lifted into
abduction and lateral rotation, as in swimming or dressing or
reaching backwards and upwards.
• At first it has to be ‘put back’ by someone but as time goes by,
reduction becomes easier and often patients learn to do it
themselves.

27. Imaging
• An AP X-ray with the shoulder in internal
rotation will often show a posterolateral
defect of the humeral head (Hiil-Sachs lesion)
where the bone has been damaged by the rim
of the glenoid fossa
• CT or MRI will show the damaged glenoid
labrum (Bankart lesion)

28. classic X-ray sign is a depression in posterosuperior part
of humeral head

29. MRI showing the Bankart Lesion

30. Treatment
• For recurrent anterior dislocation, some form
of anterior capsular reconstruction is usually
successful
• Recurrent posterior dislocation is more
difficult and may require soft-tissue
reconstruction combined with a bone
operation to block abnormal movement at the
back of the shoulder.

31. THE END