At the top of the shoulder the collar bone, or clavicle, meets the top of the shoulder blade, called the acromion. This forms the acromioclavicular joint or AC joint. Several strong AC ligaments help hold this joint together and coracoclavicular, CC, ligaments stabilize the joint by attaching to other parts of the shoulder blade. A sprain to this joint can affect any of the ligaments that help hold the joint together or stabilize the joint. Depending on the severity or grade of the sprain, treatment may be conservative or need surgery immediately.
Grades of Sprain
Sprains are graded from one to three. A grade one sprain is over stretching of the AC ligaments and does not show movement of the collar bone on imaging such as X-ray, according to the American Academy of Orthopedic Surgeons, AAOS. A grade two or more moderate sprain involves more tearing of both the AC and CC ligaments and may show the collar bone to be lifted slightly, or out of alignment on imaging. A grade three tear is a full tear of both the AC and CC ligaments. A grade three tear will show the clavicle out of position, as if it is bulging up out of the skin. Depending on the injury, clavicle fracture may also be associated with a grade three sprain.
Symptoms
Symptoms depend on the grade of sprain. The Athletic Advisor website states a grade one sprain has mild pain and a small decrease in range of motion of the shoulder. Pain will be more noticeable with palpation, or touch, over the area. A grade two sprain will have notable pain with any type of arm movement. The joint itself might feel more loose than normal. A grade three separation will have an obvious deformity of the collar bone and severe pain. Most people with a grade three sprain will not be able to move the arm at.
Causes
This injury is most noted with a blow to the shoulder in contact sports like football, rugby and hockey. Another common way to injure the area is a fall on an outstretched arm or directly on the shoulder, according to the Mayo Clinic. The higher the grade of sprain the more immediate the pain and deformity will be.
Conservative Treatments
Typical treatment for any joint sprain involves resting the joint, icing, compressing the injury and elevating the area higher than the heart, according to Athletic Support. Additional support includes protecting the joint from further injury. In the case of an AC sprain, an arm sling is necessary to use as the weight of the arm will pull on the joint. Even if there is a deformity of the joint many people return to full activity. Grade one sprains usually take a few weeks to heal and return to activity, where a grade two sprain will take around 4 to 6 weeks to fully recover, according to Athletic Support.
Surgical Treatment
Surgical treatment may be recommended in a grade two sprain but more often happens with a grade three sprain, or if the ends of the bones start rubbing on each other due to damage to the protective cartilage in the joint. In cases of surgery, the end of the clavicle may be shaved down to keep it from rubbing on the acromion. Additional options for surgery include reconstruction of the supportive ligaments around the joint, according to the AAOS. Athletic Support states, recovery from surgery will take around 10 to 12 weeks.
