AC Shoulder Separation

An Overview of the AC Joint

AC Joint Function

The AC joint is classified as a synovial joint. Located where the collarbone meets the shoulder blade, the shoulder AC joint allows the arm to raise above the head. It also allows the transmission of forces from the upper arm to the rest of the skeleton. The joint itself does not have its own musculature, so movement is initiated elsewhere. For instance, when the arm is raised or rotated, the AC joint moves to accommodate the action.

AC Joint Anatomy

The acromioclavicular joint’s articular surfaces are lined with fibrocartilage, much like those of the sternoclavicular joint. The cavity of the AC joint is partially divided by an articular disc that is classified as a wedge of fibrocartilage suspended from the capsule’s upper portion.

The shoulder AC joint capsule is composed of a loose fibrous layer which encloses the two articular surfaces. As a synovial joint, the joint capsule is lined by a synovial membrane that releases synovial fluid into the joint cavity.

The acromioclavicular joint is stabilized by three ligaments and two sets of muscles. The acromioclavicular ligament runs horizontally from the shoulder blade to the collarbone. The two coracoclavicular ligaments connect the coracoid process, portion of the scapula, to the collarbone. The two sets of muscles responsible for assisting with the support of the AC joint include the trapezius muscle and deltoid muscle.

Injuries related to the AC joint are fairly common and often result from a hard fall or other trauma. Some examples of these injuries include:

• AC Joint Injury
• AC Joint Separation
• AC Arthritis
• AC Joint Sprain
• AC Fracture

Dr. Millett will perform a thorough physical examination to assess a patient’s shoulder AC joint injury, and then will discuss appropriate treatments that are available for patients from Vail, Aspen and the surrounding Denver, Colorado communities.

For additional resources on the AC joint, please contact the orthopedic practice of Dr. Peter Millett.

Are you suffering from an AC joint injury?

There are two ways to initiate a consultation with Dr. Millett:

You can provide current X-rays and/or MRIs for a clinical case review ($250).

You can schedule an office consultation with Dr. Millett.

An Overview of an AC Joint Sprain

An AC joint sprain is a fairly common shoulder injury among active individuals. A shoulder sprain in the AC joint is typically caused by a direct blow to the “point” of the shoulder or a fall onto the shoulder joint. An AC joint sprain is characterized by the tearing of the connective tissue and ligaments of the acromioclavicular (AC) joint. Dr. Peter Millett, serving patients from Vail, Aspen and the surrounding Denver, Colorado communities, specializes in diagnosing and treating shoulder pain associated with a shoulder sprain in the AC joint.

The AC joint is responsible for connecting the shoulder blade to the clavicle. The joint allows for a small range of shoulder movement compared to the shoulder joint. When the AC joint is put under extreme stress during sports or work activity, it has the potential to tear. When a tear occurs, it is known as an AC joint sprain. A shoulder sprain in the AC joint can range from a small sprain, causing minimal shoulder pain, to a severe sprain causing extreme pain, instability and deformity.

What are the Symptoms of an AC Joint Sprain?

Many individuals who sustain an AC joint sprain will experience a sudden onset of shoulder pain located at the top of the shoulder joint. The pain may increase during certain activities such as overhead lifting, pushing and pulling movements and when moving the arm across the body. In a minor AC shoulder sprain, an individual may be able to perform daily activities with limited pain, swelling and stiffness. In more severe cases, a deformity may be visible from the tearing of the connective tissue holding the AC joint together.

Have you sustained an AC joint sprain?

There are two ways to initiate a consultation with Dr. Millett:

You can provide current X-rays and/or MRIs for a clinical case review ($250).

You can schedule an office consultation with Dr. Millett.

How is an AC Joint Sprain Diagnosed?

In order to diagnosis a shoulder sprain of the AC joint, Dr. Millett will perform a thorough physical examination. He will ask questions regarding the patient’s medical history as well as what led to the injury. Dr. Millett will also move the affected shoulder to determine areas of shoulder pain and weakness. X-rays and an MRI may also be performed to determine the extent of the AC joint sprain and to rule out any other possible shoulder injuries.

How is an AC Joint Sprain Treated?

Active individuals can recover from an AC shoulder sprain in a few weeks without the need of surgical intervention. Dr. Millett typically begins with conservative treatment options to alleviate shoulder pain such as rest, activity modifications, shoulder immobilization, ice and a physical therapy program.

Dr. Millett may recommend surgical treatment if conservative treatments do not alleviate the symptoms. Surgery may also be recommended for athletes and workers that require a full recovery to perform necessary, everyday movements. There are numerous procedures designed to treat an AC joint sprain, including arthroscopic shoulder surgery for AC repair. Dr. Millett will explain the different treatment options to his patients and will suggest the best course of action.

For additional information on an AC joint sprain, or to learn more about treatment options shoulder pain and other shoulder conditions, please contact the office of Dr. Peter Millett.

AC Joint Separation Overview

An AC separation injury can range from a mild separated shoulder to a complete tear of both the AC ligament and CC ligaments. Many physicians range the injuries on a Grade I-III scale.

What are the Symptoms of a Separated Shoulder?

An AC joint separation has a wide range of symptoms dependent on the grade of injury.

• Grade I: A slight stretch or partially torn AC ligament may cause joint tenderness, bruising and minor shoulder pain.
• Grade II: A completely torn AC ligament and intact CC ligaments may cause moderate to severe shoulder pain, swelling and a small bump on the top of the shoulder.
• Grade III: Completely torn AC ligament and CC ligaments may cause swelling, severe shoulder pain, shoulder deformity, and instability. Often a popping sound is heard at the time of injury.

How is a Separated Shoulder Treated?

AC joint separation treatment depends on the injury grade. Many patients will experience a full recovery with non-operative treatment which includes rest, ice, shoulder immobilization, pain and anti-inflammatory medications, and physical therapy.

Surgery may be recommended by Dr. Millett if the AC separation is too severe or if non-operative treatment measures do not alleviate the separated shoulder symptoms. A variety of surgical measures may be used. The most common technique involves the reconstruction of the CC ligaments and performing a distal clavicle resection. During this procedure, Dr. Millett removes a tiny part of the collarbone, then transfers the AC ligament from the bottom of the shoulder blade to the end of the prepared collarbone, replacing the torn ligament. Dr. Millet can discuss the different surgical options individually, depending on the specific injury.

For additional information on an AC joint separation, or to learn more about treatment options for this shoulder condition, please contact Dr. Peter Millett.

Have you sustained an AC joint separation?

There are two ways to initiate a consultation with Dr. Millett:

You can provide current X-rays and/or MRIs for a clinical case review ($250).

You can schedule an office consultation with Dr. Millett.

AC Joint Grading System Overview

An acromioclavicular (AC) joint separation is the medical classification for the separation of the collarbone from the shoulder blade. An AC joint separation is a common injury in the active population and typically occurs from a hard fall or direct hit to the AC joint. AC joint separation grading helps physicians properly diagnosis and plan for proper treatment based on the extent of injury. The AC joint grading system includes a scale of six grades, and is determined by the level of separation found in the diagnostic x-ray and MRI. The most common AC separations are grade 1 through grade 3. Dr. Peter Millett specializes in diagnosing and treating AC joint injuries, helping patients return to the athletic activities they love.

AC Joint Separation Grading Scale

During an injury to the AC joint, soft tissues may become torn, leading to a varying amount of damage. An AC joint separation is graded by the extent of damage sustained to the ligaments. An AC joint separation grading scale includes:

• Grade 1 – AC joint separation is a mild shoulder separation where the AC ligament is stretched or partly torn.
• Grade 2 – AC joint separation is a partial separation of the AC joint where the AC ligament is completely torn but the coracoclavicular (CC) ligaments are intact.
• Grade 3 – AC joint separation is a complete separation of the joint where the AC ligament and CC ligaments are completely torn, as well as the joint capsule.
• Grades 4, 5 and 6 – AC separations are extremely rare and occur when there is significant posterior movement of the clavicle (collar bone) in relation to the acromion (bony process on the shoulder blade).

What are the symptoms of AC joint separation?

The symptoms of an AC joint separation vary based on the extent of the injury. Treatment treatment options are dependent on the extent of the injury based on the AC joint grading system.

• Grade 1 – A grade 1 injury typically causes mild tenderness, bruising and minor pain.
• Grade 2 – A grade 2 injury typically causes moderate to severe pain, swelling and a small bump may be present on the top of the shoulder where the clavicle ends.
• Grade 3 – A grade 3 AC joint separation injury causes severe pain, swelling, instability and visible deformity.

Have you sustained an AC joint injury and would like information on the severity?

There are two ways to initiate a consultation with Dr. Millett:

You can provide current X-rays and/or MRIs for a clinical case review ($250).

You can schedule an office consultation with Dr. Millett.

AC Joint Separation Grading MRI and AC Joint Separation Grading X-Ray

In order to diagnose an AC joint injury and determine the injury level based on the AC joint grading system, Dr. Millett will perform a complete medical review and physical examination. He typically moves and feels the injured joint to get a better understanding of injury and to identify areas of pain and weakness. In many cases, Dr. Millett will perform an AC joint separation grading MRI and AC joint separation grading x-ray. Both diagnostic tests will help determine injury grade and an appropriate treatment plan.

The treatment of an AC separation depends on the injury grade. Grades 1-3 are commonly treated with non-operative measures such as rest, ice medication and arm stabilization in a sling.

Certain patients with a grade 3 AC joint separation will need a surgical treatment to fully recover. The surgical technique most commonly performed by Dr. Millett involves the reconstruction of the CC ligaments and the removal of a small piece of the clavicle at the shoulder. Using a screw or suture loop, he will stabilize the joint which allows for a full recovery in most patients.

For more resources on the AC joint separation grading scale, or to determine your grade of injury with an AC joint separation grading x-ray and MRI, please contact the orthopedic office of Dr. Peter Millett.