What is a shoulder separation?
The clavicle, or “collarbone” is connected to the shoulder blade at the top of the shoulder blade. This region is called the acromion. The joint between the collarbone and the acromion is called the AC joint (acromioclavicular joint). Three sets of important ligaments hold the AC joint together. When part or all of these ligaments are injured, this is called a shoulder separation. This most commonly occurs by a direct fall onto the shoulder.
What is the role of the clavicle?
The clavicle is the only bone connecting the shoulder blade and the arm to the central skeleton. In essence, the clavicle is like a suspension bridge between the spines central skeleton and the shoulder blade (scapula) and arm. The shoulder blade and arm are actually suspended from the distal end of the clavicle. The ends of the clavicle are held in place by very strong ligaments.
The inside end of the clavicle (medial) creates the sternoclavicular joint (SC joint) at the central skeleton (the sternum). The outside end (lateral or distal) creates the acromioclavicular joint (AC joint). Injuries to the clavicle and or the AC joint will result in a disruption of the connection between the central skeleton and shoulder blade/arm. This results in a loss of position of the shoulder blade/arm.
When this happens, the shoulder blade/arm are dropping down away from the clavicle. Muscles attached to the clavicle will now pull unopposed by the weight of the shoulder blade/arm. The result of the arm dropping down and away and the muscles pulling the clavicle up creates the typical deformities seen with clavicle fractures and AC joint injuries.
Will it heal on its own?
Fortunately, most of the injuries from Grade 1 to 3 will heal on their own. This is because the ligaments can generate scar tissue. This scar tissue can hold the torn ligaments together. This can restore the normal function to the ligaments that were torn. Once the ligaments are back to normal function, the shoulder will return to normal function.
These injuries occur in four degrees of severity.
Grade 1: Injury to only the ligaments at the AC joint itself.
Grade 2: Injury to the ligaments of the AC joint and a partial injury to the CC ligaments. There is a partial displacement of the collarbone upwardly.
Grade 3:Injury to both sets of ligaments. There is a complete displacement of the collarbone upwardly.
Grade 4+:Injury to both sets of ligaments. There is a complete displacement of the collarbone through the trapezius muscle and it is stuck up and behind the AC joint. Or it could even be displaced below and in front of the AC joint.
When is surgery needed?
In certain cases, the function of the shoulder can be affected by a shoulder separation. Usually, surgery is reserved for injuries that involve all three sets of ligaments (Grade 3), in patients who put very high demands on their shoulders. For example, a quarterback with a Grade 3 injury is a patient who puts high demand on his shoulder and may need surgery. A recreational tennis player with a Grade 3 injury usually does not need surgery. All patients with Grade 4 injuries or higher will need surgery. The type of surgery performed varies with the situation and the severity of the injury.