The clavicles are a pair of bones that sit at the top the chest on each side and are easily visible under the skin, especially in thin individuals. It is also known as the collarbone since these slender bones form a collar atop the chest cavity. The main function of these bones is to connect the upper arms to the torso. Clavicles are strong bones that provide sturdy attachments to various muscles and ligaments and bear the weight of the upper arms. The weight-bearing functions of the clavicles are facilitated by their attachments to the sternum (breast bone) in the front (via the sternoclavicular joint) and the scapula (shoulder blade) at the back (via the acromioclavicular joint).
What are swollen clavicles?
Swollen clavicles refer to the appearance of a visible swelling or mass over the clavicular region. This swelling could be due to an inflammation, which occurs as the body’s response to tissue injury. Sometimes a swelling may actually be due to a mass, like a tumors. The swelling can arise from the bone itself or from the overlying soft tissue including the skin.
Typically with inflammation which is the more common cause of swelling of the collarbone, the swelling may extend to the area surrounding the clavicle. Generally this may be described as upper chest swelling. It is important to differentiate swelling or a mass from fat accumulation in the area which is more likely to occur with obesity and certain disorders where fat accumulation is prominent, like in Cushing’s disease.
What are the symptoms of a swollen clavicle?
Swelling of the collar bone is a symptoms of some underlying problem. It can occur on its own but is often accompanied by other symptoms, such as:
- Restricted shoulder and arm movements
- Reddish skin, which is warm to the touch
- Numbness or tingling in the arm of the affected region
What causes swollen clavicles?
Swollen clavicle is not a disease in itself. It is a manifestation of some underlying injury or disease. The primary defect could either be in the clavicles or in the surrounding tissues. Following are some of the diverse conditions that can cause visible swelling in the clavicular region:
Direct physical injury to the bones or to the attached muscles and ligaments is one of the most common reasons for swollen clavicles. These injuries can happen in cases of automobile accidents, falls, and blows to the shoulder region. Physical contact sports constitute a common avenue for acquiring such injuries. Surgeries can also sometimes result in inadvertent injury to the clavicular region.
High impact injuries could result in fractured clavicles, and swelling in the region could occur in the aftermath of such a fracture. However, even low intensity injuries can result in swollen clavicles. Soft tissue injuries affecting the muscles, ligaments and other connective tissues near the clavicles contribute to the swelling in these cases.
Infections of the clavicles or the adjacent tissues could also result in a swollen appearance of the clavicular region. Usually, these infections affect both the clavicles and the surrounding tissues and organs. It is rare to find only the clavicles being infected. Infections can result from piercing injuries to the overlying skin and consequent entry of pathogenic microbes through it. Infections can also spread to the clavicles from nearby organs such as lungs, or from distant tissues via the blood.
Once the bone becomes infected, the condition is known as osteomyelitis. In some cases, swelling could also arise in the absence of any infection in the bone. In these cases, infection in the surrounding subcutaneous tissues and skin cause the swollen appearance, a condition termed as cellulitis. Although rare in the torso region, cellulitis could result in severe, and sometimes fatal, complications if the infection spreads to the internal organs. Swollen clavicles are also a feature of the later stages of syphilis, a sexually transmitted disease.
Bone Growth Disorders
Swollen clavicles could also be one of the characteristics of bone growth and remodeling disorders. An example is Paget’s disease, in which abnormalities in the processes of bone growth and breakdown lead to malformed bones, including swollen clavicles. The cause of Paget’s disease is not clear.
Bone tumors that affect the clavicles and lead to their swollen appearance are rare. They are also mostly benign in nature. Sometimes, these bone tumors could result from metastasized tumors from other regions such as the lungs and their pleural coverings.
The classical nutritional deficiency that is characterized by deformed bones is caused by insufficient vitamin D in the body. This disease, termed rickets in children and osteomalacia in adults, results from defects in mineralization of the bones and causes severe bone brittleness. Bones all over the body are affected, including the clavicles. Deficiency of calcium and phosphorus, which are essential minerals for bone formation, also results in bone deformities.
Inflammation of the two joints in which the clavicles participate could also result in a swelling of these regions. The joint between the clavicle and the shoulder blade is the most likely to get inflamed. However, any swelling at this joint is least likely to be detected since it is covered by muscles. Swelling is more commonly visible when the joint between the clavicle and the sternum gets inflamed.
Muscles and Ligaments
Another cause of swollen clavicles is inflammation of the muscles and ligaments that connect to the clavicles. The inflammation might occur in conditions like bursitis and tendonitis. Tear in the muscles or ligaments could also be contributing factors to a swollen clavicular region. For example, sprain in the acromioclavicular ligament that connects the clavicles to the shoulder blades results in swollen clavicles.
Swollen Lymph Nodes
The region around the clavicles is rich in lymph nodes. A swelling in these lymph nodes could result in a swollen clavicular region. Such lymph node enlargements are seen in conditions such as dental infections, infections of the airways, and systemic viral infections such as HIV/AIDS. Tumors of the lymphoid tissue (such as lymphoma or leukemia) also cause the lymph nodes to swell. A swollen clavicular region in these conditions has nothing to do with the clavicles or the nearby muscles and ligaments.