What is a shoulder separation?
separation is the partial or complete separation of two
parts of the shoulder : the collarbone (clavicle) and the end of the shoulder
blade (acromion). See a picture of
shoulder separation injuries .
The collarbone and the shoulder blade
(scapula) are connected by the
acromioclavicular (AC) joint, which is held together
primarily by the acromioclavicular (AC) and the coracoclavicular (CC)
ligaments. In a shoulder separation (also called an
acromioclavicular joint injury), these ligaments are partially or completely
torn. A shoulder separation is classified according to how severely these
ligaments are injured:
- In a type I injury, the AC ligament is
partially torn, but the CC ligament is not injured. See a picture of a
type I injury .
- In a type II injury, the AC ligament is completely
torn, and the CC ligament is either not injured or partially torn. The
collarbone is partially separated from the acromion. See a picture of a
type II injury .
- In a type III injury, both the AC and CC ligaments
are completely torn. The collarbone and the acromion are completely separated.
See a picture of a
type III injury .
There are three further classifications, types IV through
VI, which are uncommon. These types of shoulder separations may involve tearing
of the muscle that covers the upper arm and shoulder joint (deltoid muscle) and the one that extends from the back
of the head, neck, and upper back across the back of the shoulder (trapezius muscle).
What causes a shoulder separation?
blow to the top of the shoulder or a fall onto the shoulder, such as
a fall from a bicycle, can cause a shoulder separation.
What are the symptoms?
Signs and symptoms of a
shoulder separation include:
- Pain at the moment the injury
- Limited movement in the shoulder area (because of pain,
- Swelling and bruising.
- Tenderness over
the AC joint on top of the shoulder.
- Possible deformity. The outer end of the collarbone
may look out of place, or there may be a bump on top of the shoulder.