The sternoclavicular joint (SCJ) is the joint between the clavicle (collarbone), and the sternum (chest bone). You might be able to feel the end of the clavicle as a bump to the side of the dip at the base of your throat. The actual joint is just below this bump. The end of each bone is covered with smooth, slippery, cartilage, which allows them to move against each other with minimal friction.
The SCJ supports the shoulder and is the only joint that connects the arm and shoulder to the main skeleton. It is an inherently unstable joint, but there are four different types of very strong ligaments, attaching bone to bone, which help to reinforce it and to keep the bones in their correct positions.
Types of sternoclavicular joint injury:
Sternoclavicular joint injuries are uncommon but not unknown, and are usually caused by a strong blow to the clavicle that tears or ruptures one or more ligaments, thereby damaging the joint to a greater or lesser degree.
The ligaments of the joint can be sprained, which causes pain but does not destabilize the joint further.
An injury to one or more of the ligaments is rare, but extremely painful. Most SCJ injuries are caused when something, a steering wheel, for example, or a tackling football player, hits the clavicle very hard. This can cause the ligaments to be torn or even ruptured, forcing the bones of the joint out of position. Fifty per cent of such dislocations are caused by car accidents and a further twenty per cent are the result of sports injuries, usually contact sports.
Up until about the age of 25, part of the clavicle is still cartilage and not yet bone. This area is called the physis, or growth plate. A fracture to this area can look very similar to a dislocation.
Degenerative arthritis, also known as osteoarthritis, tends to get worse with age and can cause pain and stiffness in the sternoclavicular joint. An old injury to the joint can also eventually cause problems.
Sternoclavicular joint injury risk factors:
Being young and male. Young men tend to suffer more injuries of this type, probably because they play more contact sports and also are involved in more car accidents.
Sternoclavicular joint injury symptoms:
Pain and stiffness are the main symptoms of an injury to the sternoclavicular joint. A clicking, popping, or grating sensation might be felt in the event of a sprain. In the case of dislocation, the pain can be very severe, especially when attempting any movement of the arm. A dislocation can be termed anterior or posterior, depending on the direction in which the clavicle has been pushed. In the case of anterior dislocation, the clavicle has been pushed forward, in front of the sternum. The end of the clavicle can usually be felt, and often seen, as a hard lump in the middle of the upper chest.
A posterior dislocation is potentially very serious, as the clavicle has been forced backwards and may be endangering vital organs and blood vessels in the chest. Possible symptoms include having trouble breathing or swallowing, or a feeling of choking. Sometimes the voice becomes hoarse. Fortunately a posterior dislocation is extremely uncommon.
Sternoclavicular joint injury diagnosis:
Your health care provider will take a medical history from you and perform a careful and thorough physical examination, including assessing the range of motion of your arm. Any swelling, bruising or other signs of inflammation will be noted, and a comparison of both shoulders made. All of the joints in the shoulder will be gently pressed and felt. Muscle strength might be tested, and your pulse taken to ensure that blood flow is good.
X-rays from different angles will be taken, to look at the bones. You may have a CT (computed tomography) scan, as these show the soft tissues of ligaments and tendons as well as bones, and are therefore more informative.
Sternoclavicular joint injury treatment:
A sprain will be treated with ice and NSAIDs (non-steroidal anti-inflammatory drugs) such as Advil, Motrin or others, plus over-the-counter pain medications. A sling will be worn for between one and six weeks, depending on the severity of the sprain, to immobilize the joint and allow for healing.
Both anterior and posterior dislocations are treated by a procedure called closed reduction, unless the injury is so severe that surgery is required. As any movement of a dislocated sternoclavicular joint is extremely painful, sedation or a general anesthetic will be administered. The joint will then be manipulated back into its proper position. Following the procedure, the joint must be kept immobile, so a figure-of-eight strap, or clavicle harness, is worn, along with a secure sling, for about six weeks. Pain medication will be prescribed.
If surgery is considered necessary, because initial treatment has not worked, the clavicle will be attached to the ribs instead of the sternum. The joint remains unstable, but danger to the internal organs is minimized.
Growth plate fracture:
This usually heals without treatment, as bone growth tends to straighten out the clavicle, especially in younger children who have less bone in the physis at the time of injury.
Rest, ice, physiotherapy and anti-inflammatory medication are the usual treatments for arthritis-related pain of the SCJ. If these fail to resolve the problem, surgery might be considered.
Treatment for any injury to the SCJ will probably include physiotherapy. Ice treatment, electrical stimulation and perhaps massage, will help to reduce pain and swelling. Once the pain has lessened, an exercise regime will be developed with the initial aim of improving range of motion. Exercises to strengthen the muscles of the shoulder blade and rotator cuff will gradually be added.
What to look for in a sling, to help with a sternoclavicular joint injury:
You will need to wear a sling or shoulder support for at least one week and possibly up to six, so two main criteria are comfort and the required amount of immobilization. Some shoulder supports include a pocket for inserting cold or heat packs.
If partaking in contact sports, wear proper padding and other protective gear.
Do exercises to strengthen the muscles of the shoulder and rotator cuff.
Exercises to strengthen rotator cuff muscles:
Be sure to warm up carefully before doing any exercise, and do not exercise if there is any pain. Use light weights (2-3 pounds) and more repetitions for best results. Start with 15 repetitions for 1 set. Gradually increase number of sets and repetitions.
Lie on one side with the upper arm resting on the stomach. Place a small towel under the elbow and upper forearm. Keeping the elbow on the towel, slowly rotate the arm until it is just above horizontal. Slowly lower again.
Lie on the stomach on a table or firm bed. With your arm hanging over the side and your thumb facing forwards, slowly raise the arm straight out to the side. Do not raise your arm higher than the level of your body.