When a bone breaks or cracks, the injury is called a fracture. In the collarbone (clavicle), fractures can happen in three separate areas:
The outer third of the collarbone is near the tip of the shoulder. Fractures here usually are caused by an accidental fall or some other type of direct impact (football tackle, hockey check, car collision) that transmits force to the side or top of the shoulder. Fractures in this area account for about 15% of all collarbone fractures.
About 80% of all collarbone fractures occur in the middle third of the bone. A fracture here usually is related to a fall on an outstretched arm. This area also can be fractured by a direct impact to the middle of the collarbone, especially during stick sports, such as hockey or lacrosse.
The third nearest the breastbone rarely fractures. Fractures in this part of the collarbone almost always are caused by a direct blow to the front of the chest, often from a steering wheel impact during a car crash.
The collarbone is one of the most common fractures. In most collarbone fractures, the ends of the fractured bone do not move apart widely, and the area of tissue damage involves only the collarbone. In rare cases, a sharp portion of the fractured bone either will pierce the surface skin (an open fracture), or cut into one of the large nerves or blood vessels that travel through the shoulder. In severe impact injuries, it is also possible for a portion of the fractured collarbone to penetrate the upper part the lung, causing serious breathing problems.