Shoulder Dislocation: Causes, Diagnosis and Treatment
Shoulder dislocation is the most common dislocation because the shoulder joint is made of a very
shallow glenoid cavity and a large head of the humerus. Natural bony stability of the shoulder is less than other joints. Due to this it is more prone to dislocate.
Please see the shoulder anatomy to get a better understanding of this condition. (skip this if you have already done so)
Dislocation can be of two types
- anterior in which the humeral head dislocates in front of the glenoid cavity
- posterior in which the humeral head dislocates in behind the glenoid cavity
Causes of dislocation include
- congenitally lax shoulders
- injury to the shoulder
- direct by a blow to the shoulder
- indirect by a injury causing abduction, extension and external rotation (scratching in between your shoulder blades by taking
your hand over head reproduces this position)
Most common type of dislocation is the anterior dislocation that is usually caused by indirect injury.
Epileptic fits and electrical shocks usually cause a posterior dislocation.
Symptoms of shoulder dislocation include
- history of injury, electric shock, fall or epileptic fit
- pain in the region of the shoulder
- loss of the normal roundness of the shoulder area
- movements of the shoulder are painful and limited
People with congenitally lax joints can voluntarily dislocate and relocate their shoulders.
Diagnosis can be confirmed by x rays of the shoulder joint. X ray will show the head of the humerus out of the glenoid cavity
and will help in deciding the type of dislocation.
At times x rays in special positions are required to diagnose a dislocation. Posterior dislocations are particularly
deceptive on routine x rays.
Fractures of the head of humerus and the glenoid cavity can also be visualized on x rays.
Treatment includes relocation of the head of humerus into the glenoid cavity as soon as possible. I prefer to reduce the dislocation
under complete relaxation with anaesthesia given by a anaesthetist. This makes the reduction rapid, painless and least traumatic.
Various manoeuvres described include
- Hippocratic method in which the surgeon puts his foot in the arm pit of the patient and applies traction with his hands.
- Kocher's method in which the surgeon first applies traction to the limb followed by external rotation then adduction and lastly internal
rotation. The dislocation should reduce at the point of adduction and then only should the limb be internally rotated. If this is not
followed then fracture of the humerus can occur.
- Stimson's method in which the patient is made to lie on his belly and the dislocated limb is allowed to hand down by the edge of
the table by a weight.
- Traction and counter traction method is similar to Hippocratic method except for the surgeon using his foot, an assistant provides counter traction
by a sheet of folded cloth across the arm pit and chest wall.
After manipulation the reduction is confirmed by x rays.
Now the limb is immobilized in a position of adduction and internal rotation in anterior dislocations by strapping the arm to the front of the chest.
In posterior dislocations the position is of slight external or neutral rotation by a handshake cast.
The duration of immobilization lasts for three weeks after which physiotherapy is started to regain strength and range of motion.
- recurrence of the dislocation with normal day to day activity
- injury to the blood vesseles (more common in old age)
- injury to the nerves
In Kocher's method the arm is pulled (traction) in the direction of the red arrow.
Now the limb is externally rotated. (red arrow)
Next the arm is brought close to the body (adduction; red arrow). The shoulder relocates at this moment and a pop like sensation is felt. If this is not felt or the shoulder does not relocate at this moment then internal rotation should not be done or else a fracture of the humerus may occur.
Lastly the limb is internally rotated (red arrow) to stabilize the dislocation.
In the hippocratic method the limb is gently rotated along with simultaneous traction.
Here is a photograph of a 40 year male who has a right shoulder dislocation. He is supporting his right limb with his left hand. You can also see the loss of contour of the right upper arm.
His shoulder re-located with in 5 seconds of giving an anaesthetic agent. I only applied moderate traction to the limb. In this photograph, chest arm strapping has been done after re-location of his shoulder.
Frequently Asked Questions
How long does it take for completely recovery?
Complete recovery can take 3 to 6 months.
When can I suspect that I have dislocated my shoulder?
If after trauma you have
- severe pain in the shoulder
- you can not take your arm over head
- you have to support your limb with the opposite hand
then you probably have a shoulder dislocation.
What causes recurrent shoulder dislocation?
Recurrent Dislocation is more common in young adults. Damage of the labrum of the glenoid cavity is the common pathology seen
in these patients.
I hope the information provided was helpful. If you have any query
you can ask me at the contact me page.
This page was last updated on 1st April 2009.
Other causes of shoulder pain...
Rotator Cuff Tendinitis
Recurrent Shoulder Dislocation
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