There are three primary bones that make up the shoulder complex. The clavicle (or collarbone) connects the sternum and the main part of the skeleton to the scapula (or shoulder blade). The scapula is only held in place by the acromioclavicular (AC) joint between the clavicle and scapula and muscles that attach it to the chest wall. Suspended from the scapula is the humerus. It is only held to the scapula by thin ligaments and muscles/tendons that compress the humeral head (ball) into the glenoid (socket). Fractures of any of these bones or a separation of the AC joint can affect the attachment of the arm to the rest of the body. This can potentially limit mobility and use of the shoulder.
Clavicle fractures
Fractures of the clavicle are one of the more common fractures (4% of all fractures) and are frequently in young active people. Because of its suspension between the arm and chest wall, it can easily break from a fall on the point of the shoulder or outstretched arm. The clavicle is also not covered by muscles and is easily felt directly under the skin. This makes it susceptible to a direct blow and subsequent fracture. Many fractures have some amount of displacement. The weight of the arm pulls the outer part of the clavicle down. This causes the top of the fractured bone to be prominent and the shoulder to droop.
Treatment and Recovery
Despite the displacement of the fracture in many people, the fracture is often managed without surgery. The fracture will not remain in place if reduced. The weight of the arm and pull of the muscles will cause the fracture to return to its original position. Therefore, either the fracture is allowed to heal in the current position or it is surgically reduced and held with a metal plate or screws. Up to 2 cm (almost one inch) of displacement can be accepted in younger patients. Despite the lack of direct contact between the bones, the body is able to bridge the gap and heal the fracture in most circumstances. However, the bony prominence at the fracture site may persist. The clavicle is the last bone in the body to stop growing around age 21 and can remodel or straighten itself as it grows. In pediatric patients, surgery is rarely necessary. Despite significant displacement, the fracture will heal and the deformity will remodel with growth. A sling is worn for approximately 4 weeks.
