What is a shoulder separation?

A shoulder separation occurs in the acromioclavicular (AC) joint where the clavicle (collarbone) connects at the top of the shoulder, with the acromion process of the scapula (shoulder blade). Similar to other joints in the body, the bones of the AC joint are covered in cartilage and has an interior cartilage disk. Reinforced by strong coracoclavicular ligaments, the joint maintains stability through movement of the shoulder. If an athlete is tackled or falls landing directly on the shoulder and it forces the bones to move away from each other, stretching the ligaments, shoulder separation occurs.  Van Nuys, Thousand Oaks and Los Angeles, California orthopedic shoulder specialist, Dr. Mark Getelman is highly trained and experienced at treating shoulder separation and AC joint injuries in athletes.

Which sports cause the most shoulder separations in Los Angeles?

Shoulder separations, or AC joint injuries occur most often in contact sports. Grade I and grade II injuries are very common and are usually managed by team physicians and physiotherapists. Grade III injuries are also frequently seen and are generally referred to a specialist for an opinion. Grade IV and V injuries are less frequent.


Shoulder separations are one of the most frequently occurring shoulder injuries in rugby. They usually result from a fall directly onto the shoulder, typically with the posterosuperior aspect of the shoulder striking the ground. This may result in either a sprain or dislocation of this joint due to rupture of the ligaments stabilizing the joint (i.e., the conoid, trapezoid, and AC ligaments).


Shoulder injuries are the second most common injury for football players.  AC joint separations occur during a game, when a player gets hit and brought to the ground with the tackling force of the ground beneath and the other player on top. If the force of the tackle is substantial, the soft tissue connections can tear, resulting in a shoulder separation.


For a hockey player, a separated shoulder most often occur when a player crashes into the boards shoulder-first. Disruption of the AC joint can result in pain and instability of the entire shoulder and arm – the severity depends on which supporting structures are damaged and the extent of that damage.


A shoulder separation can occur when a wrestler takes a blow to the shoulder region or falls onto the shoulder. This injury results in a tear to multiple ligaments of the shoulder complex often affecting the clavicle.  Often, a raised bump near the top front of the shoulder is visible.


Shoulder separations are the most common injury in cycling. Most commonly riders “endo” (end-over or end-over-end) over the handlebars in an unexpected fall or collision.  Since falls are often very sudden, riders are unable to get their arms in front to brace themselves, so they land on the point of the shoulder. The rider’s momentum carries them forward as the force of hitting the ground pushes down on the shoulder causing ligaments to stretch, partially tear (or sprain) or completely tear leading to several different types of shoulder separations.

Martial Arts

Shoulder separation in martial arts usually happen when opponents are fighting while standing and one falls, landing on an outstretched arm or shoulder.

MMA (Mixed Martial Arts)

Separated shoulder injuries occur when blunt trauma is applied to the side or top of the shoulder. In MMA, this often happen when fighters collide and one lands on their shoulder causing the joint to separate, leading to an AC separation.

What does a shoulder separation feel like?

AC joint separations are accompanied by severe pain at the time of injury. Patients experience pain at the top of the shoulder and pain with movement. The extent of injury will impact the level of pain and the extent of deformity. Mild injuries heal readily but Type III or greater injuries with disruption of the coracoclavicular ligaments as well as the acromioclavicular ligaments will have more deformity and more potential for functional impairment. Sometimes there is a prominent bump on the shoulder, where the injury causes the joint to line up incorrectly.

What are the treatment options for an AC joint injury/separated shoulder?

Treatment for an AC joint injury or separated shoulder depends on the grade of the injury:

  • Grade 1 injury: A mild shoulder separation involves a sprain of the AC ligament but does not move the clavicle and will look normal on X-ray. Grade 1 injuries are treated with conservative measures.
  • Grade 2 injury: A more serious injury which tears the AC ligament and sprains or slightly tears the CC ligament, putting the clavicle out of alignment to some extent. A grade 2 separated shoulder also typically does well with non-operative management but may require surgical intervention if conservative measures fail.
  • Grade 3 injury: The most severe shoulder separation which completely tears both the AC and CC ligaments and puts the AC joint often noticeably out of position. Treatment for a grade 3 injury is based on the activity level, demand of the individual and displacement and many patients can do well with nonoperative management assuming they do not have significant shoulder blade dysfunction and can tolerate the asymmetry to the AC joint appearance. More High demand individuals may require surgical repair, which is typically performed now via an arthroscopic assisted approach.
  • Grade 4, 5 and 6 injury: Are very rare and are typically treated surgically.

What are the non-surgical treatment options for an AC joint injury?

Conservative treatment is recommended when the joint is first injured, certainly in grade I cases and most grade II cases. Medication and frequent icing can help control pain, while immobilization in a shoulder sling will help support the injured joint while it heals. Gentle motion exercises are commonly recommended by Dr. Getelman to prevent stiffness.

How is an AC joint injury or shoulder separation treated surgically?

A surgical procedure is typically reserved for cases where there is lingering pain or unacceptable joint deformity resulting in significant shoulder blade dysfunction after several months of conservative treatment, as well as in more severe grade 3 (or above) separated shoulder which can be classified as a type 5, when the bone is through the muscle which can damage the overlying skin.

Surgery may be done for pain or for instability of the joint. The simplest type of surgery for a painful acromioclavicular joint injury involves resection or removal of the end of the clavicle using an arthroscopic technique, called the Mumford procedure. The Mumford procedure can provide satisfactory results in many patients when the joint becomes painful due to AC joint arthritis or when the separation minor.

When the AC joint is dislocated with a severe separation, a more complex reconstructive procedure is needed to restore the clavicle’s position, with an anatomic reconstruction of the coracoclavicular ligaments. Usually this procedure is performed as an arthroscopic assisted procedure. Dr. Getelman does the preparation arthroscopically and adds a graft through a very small incision over the joint. The graft is then passed beneath the coracoid process and tunneled around or through the clavicle replacing the torn ligaments and restoring the ac joint anatomically.

When can I return to contact sports after an AC joint injury?

Returning to sports depends on the severity of the shoulder separation and if surgery was required. In general, athletes with shoulder separations may be limited from sports participation for several weeks after the injury. After a diagnosis and treatment plan, Dr. Getelman can give athletes an estimated timeline for returning to the sports they love.