(See also Overview of Fractures.)
Etiology
Clavicle fractures usually result from a fall on the lateral shoulder or, less often, a direct blow.
Classification
Traditionally, treatment has been based on the following classification.
Class A fractures involve the middle third of the bone and account for about 80% of clavicle fractures. The proximal fragment is often displaced upward because it is pulled by the sternocleidomastoid muscle. Subclavian vessels are rarely damaged.
Class B fractures involve the distal third of the bone and account for about 15% of clavicle fractures. They usually result from a direct blow. There are 3 subtypes:
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Type I: Extra-articular and nondisplaced, generally indicating a functionally intact coracoclavicular ligament (a strong and structurally important ligament)
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Type II: Extra-articular and displaced, generally indicating rupture of the coracoclavicular ligament, with the proximal fragment typically displaced upward because it is pulled by the sternocleidomastoid muscle
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Type III: Involving the intra-articular surface of the acromioclavicular joint, thus increasing the risk of osteoarthritis (see figure Class B clavicular fractures)
Class C fractures involve the proximal third of the bone and account for about 5% of clavicle fractures. These fractures usually result from great force and thus may be accompanied by intrathoracic injuries or sternoclavicular joint damage.
Symptoms and Signs
The area over the fracture is painful, and patients may sense movement of the fracture fragments and instability. Some patients report pain in the shoulder. Arm abduction is painful.
Class A fractures and extra-articular class B fractures usually cause visible and palpable deformity. Widely displaced fractures may significantly tent the skin.
Diagnosis
Treatment
Many fractures are minimally displaced and can be treated with a sling for comfort for 4 to 6 weeks. Figure-of-eight braces are not recommended anymore because a simple sling is just as effective and often more comfortable.
Usually, reduction is not necessary, even for greatly angulated fractures.
However, if the skin is significantly tented (usually in class A fractures), immediate consultation with an orthopedic specialist may be needed. Usually, such fractures are still successfully managed with a sling, but if they are not treated promptly, the bone may pierce the skin, causing an open fracture.
In class B type II fractures, the ruptured coracoclavicular ligament usually requires surgical repair by an orthopedic surgeon. For example, if patients have a distal clavicle fracture with superior displacement of the proximal fragment, they should be referred to an orthopedic surgeon for consideration of surgical repair of the coracoclavicular ligament.
For class B type III fractures, early mobilization may help decrease the risk of osteoarthritis.
Displaced class C fractures require reduction by an orthopedic surgeon.
