InfoSheet – Acromioclavicular Separation David M. Klein, MD – Kennedy-White Orthopaedic Center

together. are soft tissue WHAT IS A SEPARATION? structures that connect bone to bone. One set of ligaments surround the A shoulder separation is a fairly and make up the joint capsule. Two common injury, especially in an athletic other ligaments hold the down, population. A shoulder separation is and attach the clavicle to a bony knob actually a dislocation of the on the called the coracoid acromioclavicular (AC) joint, the joint process. between the scapula (shoulder blade) and the clavicle (collarbone). Some people mistake this for a shoulder dislocation, and vice versa. This is a very different injury than a shoulder dislocation. Let's look at what structures are involved in this injury. ANATOMY

The AC joint can be injured in varying degrees. The simplest type injury is a simple of the ligaments around the joint (grade 1). A more severe injury can result when the ligaments around the joint (AC ligaments) are actually torn (grade 2). If the ligaments around the joint are torn and the ligaments that attach the clavicle to the coracoid process (CC ligaments) are torn, then the injury results in an obvious bump on the shoulder (grade 3). The shoulder is made up of three bones: CAUSES the scapula (shoulder blade), the The most common cause of an humerus (upper bone) and the acromioclavicular (AC) joint separation clavicle (collarbone). The part of the is a fall on the shoulder. As the shoulder scapula that makes up the roof of the strikes the ground, the force from the fall shoulder is called the . The pushes the scapula down. The joint where the acromion and the collarbone, because it is attached to the clavicle join is known as the rib cage, cannot move down enough to acromioclavicular (AC) joint . follow the motion of the scapula. Ligaments hold these two bones Something has to give, and the Separated Shoulder Page 2 ligaments around the acromioclavicular The treatment of Grade 3 AC (AC) joint begin to tear - separating, or separations is somewhat controversial. dislocating, the joint. You may hear a Many studies show no difference in the tear or snap at the time of injury. Pain outcomes for surgically treated and swelling will develop in the joint separations versus doing nothing. A area. significant portion of people who undergo surgery will need another SYMPTOMS operation later as the injury causes the The symptoms may range from simply joint to degenerate and become painful. tenderness over the joint, to a complete Other physicians feel that some patients dislocation of the acromioclavicular (AC) benefit from surgical repair. One case joint as seen in the grade 3 separation. where repairing the ligaments may be There may be a considerable amount of best is in the case of the highly swelling if the separation is grade 2 or 3. functioning throwing athlete. Some A bluish discoloration of the skin due to would argue that these athletes perform bruising may occur several days after better following repair than without the the injury. In the grade three separation repair. you may feel a popping sensation due to In some grade 3 shoulder separations, the loose joint shifting. There is usually surgery may be suggested. Surgery a noticeable bump on the shoulder if the involves relocating the joint and joint has completely dislocated. This repairing the torn ligaments. A screw or deformity or bump will be permanent, some other type of fixation may be used while the pain will disappear. to hold the joint together while the DIAGNOSIS ligaments heal. This surgery is done Diagnosis is usually made on physical through a 4-5 inch incision over the examination. X-rays may show the acromioclavicular (AC) joint. If a screw acromioclavicular (AC) joint to be is used to hold the clavicle in place while dislocated, and may be necessary to the ligaments heal, it will usually be make sure there is not a fracture of the removed six or eight weeks after the clavicle. In some cases, x-rays are surgery. If not removed, the screw will taken while holding a weight in each probably break, but usually will not hand to stress the joint and determine cause problems. how much instability in the joint is Several studies have been done looking present. at what happens to the TREATMENT acromioclavicular (AC) joint after this injury. It appears that many people, Treatment for a Grade 1 or Grade 2 whether they had the joint repaired shoulder separation usually consists of surgically or not, will need an operation a sling and pain medication until the at some time in the future. The injured sprain, or tearing, of the ligaments joint degenerates faster than normal and heals. In most cases, the shoulder over time becomes arthritic and painful. becomes relatively pain free within 3 This process may take years to develop, weeks. Since there is not a danger of but sometimes this happens within 1-2 making the condition worse, activity can years. be determined by the symptoms. You can usually do whatever you can tolerate.