What is the Collarbone?

The collarbone (clavicle) is the s-shaped bone that runs horizontally between the neck and shoulder region. It varies largely in size and shape; predominantly as a result of carrying heavy loads or shear stress.  A variation in the use of hands, based upon dominance (as in, which hand an individual uses more often compared to the other), is often responsible for asymmetry in features of the collarbone. The human clavicle is subjected to an extended growth period when compared to all other long bones of the skeleton. This growth period can continue up to the age of 30 years. The collarbone is fundamentally suspended through attachments to muscular and ligamentous tissues, making it extremely vulnerable to injuries and subsequent pain.¹ 

Causes of collarbone pain

Collarbone pain can be distressing and uncomfortable. It may be accompanied by swelling or bruising, a change in shape or size, pain moving down into the chest, difficulty in breathing, and an inability to move your arm. The most common causes of pain are:

• Injury
• Sleeping position
• Infection or inflammation
• Repetitive strain injuries
• Neurological issues
• Systemic causes

Types of collarbone injuries

Dislocated or fractured collarbone 

A broken or dislocated collarbone is the most common cause of clavicle pain in 25-year-olds and over 70-year-olds, usually as a result of a fall onto the shoulder or on an outstretched arm, as well as from direct trauma to the clavicle. Other causes include injury from vehicle accidents, sporting injuries, and as a consequence of a traumatic birth (infant injury). It is associated with immense pain and deformation to the localised area, injury to the surrounding ligaments, nerves, or blood vessels, and in rare cases, it can lead to air accumulation around the lungs.²

Fractures to the collarbone are classified based on location and vary in severity. While all of these injuries require intervention, they often do not require surgery unless located within the mid-section of the clavicle. These fractures require surgical intervention to pin the bone back together. In particularly traumatic injury cases, when the clavicular bone breaks, the force of breaking may also cause penetration of the fragment through the skin. This is classified as an open fracture can increase the risk of infection.³

Joint injury 

Joints are crucial structures that attach two parts of the skeleton together. Injuries to joints are usually caused by sporting events or direct trauma. They can be associated with immense pain, swelling, deformity in the shoulder area, and an inability to lift the arm. Injuries are classified on a severity scale, with grades 1-6 determining the extent of joint rupture. Those that are grade 1 or 2 often require no surgical intervention and are treated predominantly through joint isolation using a sling. Grades 3 to 6 may require surgery.⁴

Soft tissue injury

When bone and ligaments remain intact after injury, damage to the surrounding soft tissues is often the cause of collarbone pain. This is usually characterised by pain surrounding the clavicle rather than direct pain to the bone structure. Bruising and hematomas may also be noted due to blood vessel damage occurring upon injury.⁴

Repetitive strain injury 

Repetitive strain injuries are common in individuals in manual labour jobs and those who participate in sports (particularly rugby, ice hockey, etc.). These lifestyles are associated with repetitive muscle strain and a knock-on effect on the collarbone and can lead to poor posture.

Rotator cuff injury

The rotator cuff is a group of muscles and tendons, which are cords that attach muscles to bones, that surround the shoulder joint, allowing us to move our arms freely around the body and above our head. Injuries of the rotator cuff are associated with muscular and tendinous damage, which can extend to the collbarone. They are usually in combination with other shoulder injuries, however, they can also occur due to the wearing down of the tendon, causing degeneration of the rotator cuff tissues. Repetitive overhead lifting or activity is a risk factor alongside micro repetitive trauma in athletes.⁵

Inflammatory conditions that cause collarbone pain

Arthritis

Arthritis is associated with pain and stiffness in the affected areas. It can be classified as osteoarthritis (degeneration of the protective cartilage at the ends of the collarbone) and rheumatoid arthritis (inflammation of the joints). Cases of rheumatic arthritis are associated with wide breakdown of bone and cartilage across the body and it may even cause issues with organs and other tissues. 

The symptoms of arthritis are largely similar to many other causes of collarbone pain, including:

• Pain
• Stiffness
• Tenderness to touch or move
• Inflammation
• Restricted movement
• Weakness
• Muscle wastage
• The affected area is red and warm to the touch

Unfortunately, arthritis is incurable, however, medication, physiotherapy, and, in extreme cases, surgical intervention can help to resolve some signs and symptoms.

Osteomyelitis

Osteomyelitis is a bone infection that causes swelling inside the bone shaft. This can initiate from an infection that originated somewhere else in the body and travels to the collarbone, and, if left untreated, it can cause serious problems. The infection may cause a buildup of pus in the bone that can spread to other tissues, initiating the breakdown of other body structures. If the bone itself decays, it will become brittle and require reconstruction. As this is an infection, it is often accompanied by a high temperature. Osteomyelitis is usually rectified with antibiotics if treated on time.

Costochondritis 

Costochondritis is an inflammatory condition of the rib bones that is commonly associated with pain in the collarbone and shoulders when moving or breathing. It is often caused by an injury or repetitive lifting or coughing, but may also be a result of underlying conditions such as rheumatoid arthritis or an infection. Painkillers and rest are the most common courses of treatment for this condition.

Neurological problems that can cause collarbone pain 

Nerve compression

Thoracic outlet syndrome is a condition that occurs when nerves and blood vessels within the neck and chest become compressed. It most commonly happens to people between the ages of 20 and 50. It can be caused by the presence of an extra rib, injury to the area, significant muscle gain in a short time and poor posture. Thoracic outlet syndrome can be recognised by a number of symptoms including:

• Tenderness and swelling
• Weakness in the little finger
• Pins and needles down the arm
• Excess blood drainage from the palm when raising a hand above the head (hand can turn pale or blue)
• Cold hands

Referred pain 

Collarbone pain can sometimes be caused by referred pain from other injuries or conditions. For example, cervical radiculopathy is classified as neck pain caused by the compression of a spinal nerve root. This pain can radiate outwards from the neck, into the shoulders and down the chest. It is associated with:

• Muscle weakness
• Impaired reflexes
• Pain or tenderness⁶

Systemic causes that cause collarbone pain

Osteoporosis

Osteoporosis is a condition that causes bone weakness, including the collarbone, making them brittle or fragile and more susceptible to breakage. It can be caused by: 

• Sustained steroid use
• Medical conditions
• Family history
• Low BMI
• Eating disorders
• Lack of exercise

Cancerous causes

Bone cancer mainly affects long bones, such as the collarbone. The tumour may be a primary or metastatic mass, the classification of which often determines prognosis. If diagnosed early however, the prognosis of bone cancer is much better than many other cancers as there are available cures. Symptoms for this condition may include:

• Bone pain 
• Swelling 
• Redness of the localised area
• A lump 
• Trouble with movement 
• Bone weakness

Infections that can cause collarbone pain

Bacterial infections

Tuberculosis is a condition that primarily affects the lungs, however in cases of prolonged infection then an individual may be susceptible to spread to the bones such as the collarbone. It is caused by the Mycobacterium tuberculosis bacterium and is often associated with the manifestation of septic arthritis. The bacteria become lodged in the bone, embedding themselves into the web of blood vessels available at the tip of bones such as the collarbone. An infection amounts, causing abscesses and a build-up of pus which prevents movement and causes pain by initiating swelling within the bone and joint.⁷

Viral infections

Epstein-Barr virus, a member of the human herpes virus family, is often associated with early bilateral shoulder, upper chest and arm pain that persists. The cause of the pain originates from an infection of the respiratory system and inflammation of the heart caused by the virus. Common other symptoms include:

• Fatigue
• Sore throat
• Weakness
• Reduced appetite⁸ 

Diagnosis 

Diagnosing collarbone pain is initiated by a physical examination, usually followed by an X-ray to identify deformities and damage caused to the bone. If this is inconclusive, an MRI scan may be ordered, which is able to identify damage to the tendons, ligaments and muscles. In instances where there is concern surrounding cancer, an MRI may also be used to image tumours. A CT scan can be used to identify damage to the bones or muscles and can provide a more detailed imaging of these structures, including blood vessels.⁹

If imaging strategies and physical examinations are unable to uncover a cause and the pain persists, then laboratory tests may be ordered. A blood test may be taken as a standard to identify autoimmune diseases, neurological causes and inflammatory conditions. They can also be used in the identification of infectious agents that may be causing disease. If a tumour is identified at the local site then a biopsy may also be ordered, this is run through the laboratory to assess whether it is malignant (cancerous) or benign.¹⁰

Summary 

Pain associated with the collarbone can be indicative of a number of different injuries, infections or diseases. Most causes can be managed and it is important to consider any events that may have caused this pain within the days prior to its commencement. In the event of the pain source being unexplainable, then it is key that you consult a healthcare professional for diagnosis. It could be a simple fix, however it could be indicative of something more sinister and in this case timely diagnosis and treatment is of the utmost importance. You know your body best so if you’re concerned, seek medical advice!