The clavicle (also known as the collar bone) is an elongated bone that sits between the shoulder and sternum at the top of the ribcage. The bone also joins the scapula or shoulder blade to form two joints on either end of the bone, which are:
- Acromioclavicular (AC) joint – The acromioclavicular joint forms between the acromion of the scapula and clavicle at the top of the shoulder, held together by the acromioclavicular ligament.
- Sternoclavicular joint – The sternoclavicular joint forms between the sternum and clavicle at the front of the chest.
The sternoclavicular joint is a synovial saddle joint that connects the sternum with the clavicles. It is the only joint that connects the appendicular skeleton of the upper limb with the axial skeleton of the trunk. The overall function of the sternoclavicular joint is to help coordinate the movements of the upper limb with the core of the body, thus allowing the upper limb to perform its full range of motion. More specifically, the movements of the sternoclavicular joint are sorted into three degrees of freedom, which are:
- Depression & protraction
- Axial rotation
A sternoclavicular joint injury (SC joint injury) is often due to a direct blow or blunt force trauma that occurs to the collarbone. These injuries can also result from a traumatic landing to the shoulder area, such as in football. A sternoclavicular joint injury is usually associated with a disruption of the supporting ligaments. Generally, a sternoclavicular joint injury is relatively uncommon, but when it occurs, the affected ligaments are stretched or torn (partially or completely) causing the joint to become disrupted. Sprains to the SC joint are often referred to as shoulder sprains. However, shoulder sprains can affect various structures within the shoulder joint. A sternoclavicular joint sprain is a distinct injury that isn’t as common as other sprains that can occur within the joint. An SC joint injury is also graded into 3 degrees of severity, such as described below:
- Grade 1 sprain – A grade 1 sprain of the SC joint indicates a minor tear within the ligaments. This tear can only be seen under a microscope and all other structures remain connected. This injury causes pain, but can easily be remedied with ice, anti-inflammatory medications, a sling, and physiotherapy.
- Grade 2 sprain – A grade 2 sprain of the SC joint shows a tear between the collarbone and breastbone that is more visible to the naked eye. While the tear itself is larger and presents an increase in symptoms, the ligaments surrounding this area still remain connected. Conservative treatment is also used to treat a grade 2 sprain of the SC joint, however, physiotherapy will be required so strength and range of motion can be regained.
- Grade 3 sprain – A grade 3 sprain of the SC joint indicates all of the ligaments within this region of the shoulder have suffered trauma. When this type of sprain occurs, in most cases, the ligaments become so damaged the joint may become separated. Arthroscopic shoulder surgery will usually be the most recommended course of treatment in order to repair the damaged ligaments.
Causes & Symptoms
Some of the most common examples of sternoclavicular joint injuries include:
- Sternoclavicular joint separation – An SC joint separation is usually caused by a direct hit to your breastbone or collarbone. It may also be caused by a fall onto your shoulder or onto your outstretched hands that put pressure on your collarbone.
- Sternoclavicular joint arthritis – Osteoarthritis of the SC joint is prevalent, but mostly asymptomatic disorder. It is the most common condition to affect the sternoclavicular joint. Most examinations of the joint report degenerative changes present in all patients over the age of 50.
- Sternoclavicular joint dislocation – An SC joint dislocation most often results from a fall onto the shoulder. Anterior or forward dislocations are the most common and can sometimes occur with minimal trauma in patients with generalized looseness in their joints. Posterior dislocation of the SC joint is less common than the anterior type but is potentially much more serious.
- Sternoclavicular joint fracture – A fracture to the SC joint is an injury that takes place when a break occurs in the clavicle bone or in the sternum. The break can occur at either end of the clavicle, but most often, the middle-third of the clavicle bone is affected as this is the area that represents the thinnest part of the bone.
- Sternoclavicle joint subluxation – A sternoclavicular joint subluxation takes place when two bones are pulled apart from their regular position, causing a displacement that will lead to severe pain, weakness, and loss of mobility. Subluxations and dislocations often mirror one another, however, in the case of subluxation, the joint is only partially dislocated with articular surfaces still remaining intact.
Different SC joint injuries have different symptoms, such as:
- Dislocation – A dislocation of the SC joint may cause severe pain that worsens with any arm movements. In an articular dislocation, the end of the clavicle juts out near the sternum. This later causes a hard bump in the middle of the chest. In posterior dislocation, a bump is usually less obvious.
- Sprains – Sometimes force may only sprain the SC joint. Mild sprains cause pain, but the joint is still stable. In moderate sprains, the joint becomes unstable.
- Ligament injury – In rare cases, patients have a stable joint by a painful clicking, grating, or popping sensation.
- Degenerative arthritis – Injury to a joint can result in the development of osteoarthritis. In addition, osteoarthritis eventually causes pain and stiffness.
Who gets a Sternoclavicular Joint Injury?
The sternoclavicular joint is one of the least commonly injured joints in the body. Therefore, vehicle accidents cause nearly half of all SC joint injuries. Sports injuries cause about 20% of injuries to the joint as well (affected by certain sports activities such as football, basketball, skiing, skating, and soccer). These sorts of traumatic injuries can also cause injuries to the physis in people under the age of 25.
How does it affect you? How serious is it?
Oftentimes, a closed reduction for a posterior dislocation of the SC joint does not work, or SC joint problems become chronic. In these cases, a patient may need to undergo surgery. Therefore, the risk of harm to your heart, lungs, and other organs behind the sternum is extremely high. Posterior dislocations have been known to cause a ruptured esophagus, laceration of major veins, and pressure on major arteries, among other complications. These problems can all decrease your chance of surviving.
Posterior dislocation of the SC joint has also been known to cause hoarseness, a sudden onset of snoring, and voice changes with arm movement. Most of the time the goal of surgery is to stabilize the SC joint. When the ligaments are too severely damaged, the clavicle is surgically attached to the rib instead of the sternum. The joint will still probably be unstable, but the displaced clavicle no longer compresses the organs behind the sternum.
Recommended Treatment & Rehabilitation
A sternoclavicular joint injury can be difficult to see on a regular X-ray, although there are other ways to visualize the joint by modifying the way the X-ray is performed. If the SC joint appears to be injured, a CAT scan is often performed to better evaluate the type of injury.
Symptoms of a sternoclavicular dislocation depend on whether or not it is an anterior or posterior dislocation. In the case of an anterior SC dislocation, you can typically see the dislocated end of the clavicle. Patients with posterior SC joint dislocation may have a subtle dimpling of the skin over the SC joint, as well as pain and swelling. Additionally, patients can have difficulty breathing, painful swallowing, and abnormal pulses caused by compression of the trachea, esophagus, and blood vessels.
After a diagnosis has been done, physiotherapy may be necessary to boost your recovery for your SC joint. Therefore, the following treatment plans your physiotherapist will depend on the type of injury to your joint:
A mild sprain usually gets better by resting the joint for 2-3 days. Ice packs can be placed on the sore joint for up to 15 minutes at a time during the first few days after the injury. Moderate sprains may require some assistance to get the joint back into position. Your physiotherapist may recommend a set figure-eight strap wraps around both shoulders to support the sternoclavicular joint. If you are experiencing a moderate sprain, you may need to wear this type of strap for 4-6 weeks. The strap protects the joint from another injury and lets the injured ligaments heal and become strong again.
Osteoarthritis of the SC joint typically responds well to treatments instructed by your physiotherapist, including rest, ice, and anti-inflammatory medications (NSAIDs). If the symptoms of osteoarthritis do not respond to basic treatments over 6-12 months, your therapist may refer you for surgical evaluation. However, if surgery isn’t needed, your physiotherapist will start you on range-of-motion exercises as pain eases, followed by a program of strengthening. In addition, your therapist will give you tips on controlling your symptoms, which may include using tape to help hold the SC joint in place.
Growth plate injury rehabilitation
Injuries to the growth plate of the clavicle usually heal without treatment. In younger children, the growth of the bone will remodel the fractured bone. Remodeling actually causes the collarbone to straighten as the child grows. In young adults, there is less of this straightening effect because their bone growth is nearly complete.
Below are some exercise examples for you to try…performing these stretches will help improve your symptoms and decrease the chances of re-injury:
- Shoulder rolls – Begin by sitting comfortably with your feet shoulder-width apart (you can also perform this exercise while standing). Next, roll your shoulders up, then back, and then down in a smooth, circular motion. Repeat this exercise 2-4 times a day.
- Neck rotation – Sit in a firm chair or stand up straight. Keeping your chin level, turn your head to the right, and hold for 15-30 seconds. Turn your head to the left, and hold for 15-30 seconds before repeating 2-4 times a day to each side.
- Shoulder blade squeeze – While standing with your arms at your sides, squeeze your shoulder blades together. Do not raise your shoulders as you are squeezing. Afterward, hold for 6 seconds, then repeat 8-12 times a day.
- Goalpost stretch – Lie on your back with your knees bent. Next, hold a wooden wand in your hands with your palms facing your knees. Rest your elbows on the floor, holding your hands about shoulder-width apart with the wand above your chest. Move the wand back over your head as far as possible without pain. Hold this position for 15-30 seconds, then repeat 2-4 times a day.
Alternative & Homeopathic Treatment
While your sternoclavicular joint is healing, there are some home remedies can do to help prevent collarbone and shoulder pain and ease your pain. Most homeopathic treatments include:
- Rest – Avoidance of activity or activities that increase pain may boost your SC joint recovery. Deep breathing or coughing may exacerbate the pain but need to continue to avoid developing lung issues.
- Ice – Apply an ice pack to your injured area immediately and regularly for several days to reduce pain and local inflammation.
- Compression – A contentious issue in the early treatment of a sternoclavicular joint injury due to concerns that wrapping the upper chest in a bandage, corset, or strap may exacerbate breathing issues. There is still a role for strapping following SC joint pain but only with specialist supervision.
- Pain medications – Taking non-steroidal anti-inflammatory drugs (NSAIDs) may help reduce further swelling and inflammation.