Shoulder fractures occur in people of all ages. The shoulder joint is the most mobile in the body, but is also the least stable. Three main bones are included in the shoulder joint fracture category: the humerus, or upper arm bone; the clavicle, or collarbone; and the scapula, or shoulder blade. Shoulder fractures are typically caused by a fall or direct trauma. Diagnostic testing is used to assess fractures of each of these bones.
The shoulder joint is a ball-and-socket joint formed by the head of the humerus and a cup-like structure that is part of the shoulder blade. Another part of the shoulder blade called the acromion extends over the top of the shoulder, forming a "roof" over the head of the humerus. The acromion also joins the end of the clavicle to form the acromioclavicular joint, frequently called the AC joint. Shoulder fractures can involve any of these bones.
Proximal Humerus Fractures
Proximal humerus fractures involve the ball of the shoulder joint. These fractures are common in the elderly population, often resulting from falls. Among younger people, these fractures are commonly caused by high-velocity trauma. Proximal humeral fractures are classified based on the part of the bone that is damaged: the neck or shaft just below the humeral head; the head or "ball" of the humerus; and the greater or lesser tubercles, which are bony projections of the humerus where several tendons attach.
Proximal humerus fractures are diagnosed with x-rays taken from three angles, including front to back, from the side and directly through the underarm area. Bones appear white on the x-rays, and black spaces in the bones indicate gaps, or fractures. CT scans are sometimes used to provide cross-section images of the fractured humerus to better visualize the damaged structures. These images are used to determine whether surgery is required to repair the bones. An MRI scan may be used to detect tendons and ligament damage, which often occurs with a shoulder fracture. MRI scans are much better at detecting this type of damage than x-rays or CT scans.
Proximal humeral fractures are sometimes immobilized with an arm sling to allow the bone to heal, typically for four to six weeks. However, these fractures frequently require surgical repair. Bone fragments are joined by screws, metal wires or plates that hold the pieces in place and allow them to heal.
Clavicle fractures are the most common type of shoulder fracture. They typically occur from falls and are very painful. Clavicle fractures often leave a "bump" where the fracture occurred, which may be permanent. X-rays are used to diagnose these fractures.
Clavicle fractures are commonly treated with a sling or "figure 8" brace worn around the shoulders for three to eight weeks to keep the bone in place as it heals. Active movement of the shoulder is allowed within pain limits. However, return to sports activity is not considered until the bone is fully healed. In some cases, a clavicle fracture is surgically repaired with a plate, rod and screws.
Scapular fractures are the least common type of shoulder fractures, typically occurring from a high-impact injury. These fractures are diagnosed with x-rays taken from three angles, as with proximal humerus fractures. Doctors sometimes order CT scans to evaluate scapular fractures and plan surgery. Scapular fractures are treated based on severity, ranging from a sling for two to four weeks to surgical repair.