Separated shoulder

A Type I AC separation involves direct trauma to the shoulder causing the injury to ligaments that form the joint, but no severe tearing or fracture. It is commonly referred to as a sprain.[9] For a type 1 AC separation, the joint does not lose stability.[5]

A Type II AC separation involves complete tearing of the acromioclavicular ligament, as well as a partial tear (but not a full tear) of the coracoclavicular ligaments.[5] This often causes a noticeable bump on the shoulder and partial or incomplete dislocation.[10][5] This bump is permanent. The clavicle is unstable to direct stress examination.[5] On radiographs, the lateral end of the clavicle may be slightly elevated by pressing on the sternal aspect of the clavicle forcing the acromial end down, and by releasing, it may pop back up eliciting a piano key sign due to the tearing of the AC.

Type 3 AC joint separation on plain X ray

In a Type III AC separation both acromioclavicular and coracoclavicular ligaments are torn without significant disruption of the deltoid or trapezial fascia.[10] A significant bump, resulting in some shoulder deformity, is formed by the lateral end of the clavicle. This bump, caused by the clavicle's dislocation,[5] is permanent. The clavicle can be moved in and out of place on the shoulder. A radiographic examination will show the results as abnormal.

This is a type III injury with avulsion of the coracoclavicular ligament from the clavicle, with the distal clavicle displaced posteriorly into or through the trapezius and may tent the posterior skin.[10] A displaced clavicle is easily seen on a radiograph. It is important to evaluate the sternoclavicular joint also, because there can be an anterior dislocation of the sternoclavicular joint and posterior dislocation of the AC joint. This injury is generally acknowledged to require surgery.[5]

This is a more severe form of a type III injury, with the trapezial and deltoid fascia stripped off of the acromion as well as the clavicle. This is type III but with exaggeration of the vertical displacement of the clavicle from the scapula. Distinguishing between Type III and Type V separations based on radiographs is difficult and often unreliable between surgeons.[11] Type V is manifested by a 2- to 3-fold increase in the coracoclavicular distance.[10] The shoulder manifests as a severe droop, secondary to downward displacement of the scapula and humerus due to loss of the clavicular strut.[10] This injury generally requires surgery.[5]

This is type III with inferior dislocation of the distal end of the clavicle below the coracoid. This injury is associated with severe trauma and frequently accompanied by multiple other injuries.[10] The mechanism is thought to be severe hyperabduction and external rotation of the arm, combined with retraction of the scapula. The distal clavicle is found in 2 orientations, either subacromial or subcoracoid. With the subcoracoid dislocation, the clavicle becomes lodged behind the intact conjoined tendon. The posterior superior AC ligaments, which often remain attached to the acromion, get displaced into the AC interval, making anatomic reduction difficult. The tissue needs to be surgically cleared and then reattached after reduction. Most patients with type VI injuries have paresthesia that resolves after relocation of the clavicle [10] It is extremely rare and generally only involved with motor vehicle collisions. This requires surgery.[5]

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  Classification type 1 is the most common type
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  Classification type 2
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  Classification type 3
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  Classification type 4
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  Classification type 5 is rare
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  Classification type 6 is rare

Type I and type II shoulder separation are the most common types and rarely need surgery.[5] However, the risk of arthritis with type II separations is greatly increased. If it becomes severe, the Mumford procedure or distal clavicle excision can be performed.

Most non-surgical treatment options include first immobilizing the arm with a sling for approximately 2 weeks followed by gradually improving shoulder movement using physical therapy to build up the muscles and help stabilize the joint.[5]

Literature regarding long-term follow-up after surgical repair of type III injuries is scarce, and those treated nonoperatively generally do quite well.[12][5] Many studies have come to the conclusion that non-surgical treatment is as good as or better than surgical treatment, or that anything attained because of surgery is quite limited.[13][5] It appears that after a while, the body "remodels" the joint, either expanding the distal clavicle or causing it to atrophy.[14] There may also be the potential that surgical repair may be less painful in the long run.

Once the pain has eased, range-of-motion exercises can be started followed by a strength training program. The strength training will include strengthening of the rotator cuff, and shoulder blade muscles. With most cases, the pain goes away after three weeks. Although full recovery can take up to six weeks for type II and up to twelve weeks for type III.

Those who do have a separated shoulder will most often return to having full function, although some may have continued pain in the area of the AC joint. With the continued pain there are some things that maybe causing it. It may be due to an abnormal contact between the bone ends when the joint is in motion, the development of arthritis, or an injury to a piece of the cushioning cartilage that is found between the bone ends of this joint.[15]

Surgical interventions including repositioning of the shoulder joint and repairing torn ligaments may be necessary for severe injuries in which the shoulder is discolated.[5] Medical device implants including coracoclavicular screws, a hook plate, fixation pins, and surgical wire may be necessary for repair of the joint.[5] Most of these devices need to be surgically removed after the shoulder has healed. Allografts, biological grafts, and arthroscopic-assisted coracoclavicular ligament reconstruction may also be considered.[5]

Type IV, V, and VI shoulder separations are very uncommon but require surgery. There is some debate among orthopedic surgeons, however, about the treatment of type III shoulder separation.[5] Many with type III shoulder separation who do not undergo surgical treatment recover just as well as those who do receive it, and avoid the added risks that surgery may present.[5] Those with type III injuries who opt out of surgery often have faster recovery times, avoid hospitalization, and are able to return to work or sports sooner.[5] Some studies suggest early surgical treatment of type III separation may benefit laborers and athletes who perform overhead motions. The potential benefit of surgical treatment for type III remains unproven.[5]

There have been many surgeries described for complete acromioclavicular separations, including arthroscopic surgery. There is no consensus on which is best. There has been a focus on attempting to restore horizontal, as well as vertical, instability. A review found that although horizontal stability can be more reliably restored with additional acromioclavicular joint reconstruction (in addition to coracoclavicular ligament reconstruction), there is no clear advantage with respect to outcomes.[16]

A common surgery is some form of modified Weaver-Dunn procedure, which involves cutting off the end of the clavicle portion, partially sacrificing the coracoacromial ligament and suturing the displaced acromial end to the lateral aspect of the clavicle for stabilization, then often some form of additional support is introduced to replace the coracoclavicular ligament(s). Variations of this support includes grafting of tendons from the leg[17] or the use of synthetic sutures or suture anchors.[18] Other surgeries have used a Rockwood screw that is inserted initially and then removed after 12 weeks. Physical therapy is always recommended after surgery, and most patients get flexibility back, although possibly somewhat limited.

After one does have surgery, a sling should be worn to support and protect the shoulder for a few days. For the first couple physical therapy visits, the treatment will focus on controlling the pain and swelling. Type of treatment can include, ice and electrical stimulation, massage, or other hand on treatment to help ease the pain and muscle spasm. After about four weeks range of motion exercises can be started. Passive exercises are done which the shoulder joint is moved but the muscles stay relaxed. After about six to eight weeks active therapy is started. Such exercises can include isometric strengthening which works the muscles without straining the healing of the joint. After about three months, more active strengthening will be incorporated which focus on improving the strength and control of the rotator cuff muscles and the muscles around the shoulder blade. The exercises that the therapist gives the patient to be done at home should be done to be able to get a better recovery in the long run.[19]

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  Strengthening the shoulder joint.
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  Passively moving the shoulder joint
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  Side-lying external rotation start
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  Side-lying external rotation end

Some physical therapy exercises that can be performed to help rehab the shoulder are: While standing and using a theraband you can perform Y, T, and I’s, Internal shoulder rotation, External shoulder rotation, Shoulder extensions, and Scapula squeezes While lying on your side you can perform internal rotation and external rotation with a light weight. The light weight can be any type of object such as a 1-5 lb dumbbell weight, or a soup can. Also you can foam roll the pectorals. With the foam roller you can also lie on your back on top of it and do snow angels.

In Italy 1.8 out of 10,000 people are estimated to experience an acromioclavicular joint discolation per yer, and this type of injury is the most common in injury experienced by adults who participate in sports that include body contact.[5]

In the United States, an estimated 41% of football players at the collegiate level and 40% of quaterback football players from the National Football League level experience acromioclavicular dislocations.[5]