Doctor evaluating patient symptoms for AC Joint Injury diagnosis at Mountain Spine & Orthopedics
Condition/Condition Details

AC Joint Injury

An AC (acromioclavicular) joint injury—often called a shoulder separation—occurs where the collarbone meets the shoulder. It commonly happens after a fall onto the shoulder or contact sports.

Experiencing AC Joint Injury Pain?

Get expert relief — we'll call you to schedule

Free consultation • Same-day callbacks • No obligation

About AC Joint Injury

An AC (acromioclavicular) joint injury—often called a shoulder separation—occurs where the collarbone meets the shoulder blade (acromion). It commonly happens after a fall onto the shoulder or contact sports. Severity ranges from a mild sprain (Grade 1-2) to complete ligament tears causing a visible bump (Grade 3-6).

What Are the Symptoms of AC Joint Injury?

Pain at the top of the shoulder, swelling or bruising after a fall/collision, pain with cross-body movement (reaching across chest), a visible 'bump' in higher-grade injuries, and difficulty lifting the arm overhead.
AC Joint Injury
An AC (acromioclavicular) joint injury—often called a shoulder separation—occurs where the collarbone meets the shoulder. It commonly happens after a fall onto the shoulder or contact sports.

Are There Specific Risk Factors for AC Joint Injury?

Common after falls onto the shoulder, contact sports injuries (football, hockey, rugby), cycling crashes, and collisions. Risk increases with high-impact activities and prior shoulder trauma.

Diagnosing AC Joint Injury?

Exam focuses on pinpoint AC joint tenderness and cross-body pain. X-rays evaluate alignment and grade the separation (Grades 1-6); MRI is used selectively if other injuries (rotator cuff, labrum) are suspected.

Treatment for AC Joint Injury?

Most cases (Grades 1-2) improve with rest, short-term immobilization in a sling, ice, anti-inflammatories, and structured rehabilitation. Injections can help persistent AC joint inflammation. Surgery is reserved for higher-grade separations (Grades 4-6, sometimes Grade 3), ongoing pain despite 3-6 months of rehab, or functional limitation after non-surgical care. Surgical options include AC joint reconstruction or distal clavicle excision.

Does AC Joint Injury Cause Pain?

AC joint pain is typically focused at the top of the shoulder where the collarbone meets the shoulder blade. Pain often worsens with cross-body movement, reaching overhead, or lifting. In higher-grade injuries, a visible bump and bruising are common. Our specialists differentiate AC joint pain from rotator cuff or labral issues and tailor treatment to your grade and goals.

What Can Patients Do to Prevent It?

Reducing risk of AC joint injury involves avoiding direct impact to the shoulder when possible: use proper technique and padding in contact sports, wear protective gear when cycling or in high-risk activities, and strengthen the shoulder and upper back for better stability. Safe falling techniques (e.g., tucking the arm rather than landing on an outstretched hand) can also lower the chance of separation.

Schedule a Consultation Today

See a specialist if pain persists beyond 2–3 weeks, there is a visible deformity, or you can't use the arm normally. Schedule an appointment today.

Locations Offering Evaluation

Our board-certified specialists offer ac joint injury evaluation and treatment at locations across Florida, New Jersey, New York, and Pennsylvania. Schedule a consultation at a clinic near you.

View All LocationsFlorida LocationsNew Jersey LocationsNew York LocationsPennsylvania Locations

Frequently Asked Questions

Is an AC joint injury the same as a shoulder dislocation?

No, they are different injuries. AC joint injury (shoulder separation) affects where the collarbone meets the shoulder blade. Shoulder dislocation occurs when the ball of the upper arm comes out of the shoulder socket. They require different treatments.

Will the bump on my shoulder go away after AC joint injury?

In higher-grade injuries (Type 3-6), a permanent bump may remain even after symptoms resolve. This cosmetic change doesn't always correlate with function—many people return to full activity despite the visible deformity.

Do all AC joint separations need surgery?

Most do not. Grades 1-2 (sprains) almost always heal with conservative care. Grade 3 is controversial—often treated non-surgically first. Grades 4-6 or Grade 3 in overhead athletes may require surgery for optimal function.

When can I return to sports after AC joint injury?

Timeline depends on grade and sport. Low-grade injuries may allow return in 2-4 weeks with proper protection. Higher grades or surgical cases typically need 3-6 months. Contact sports require full strength and pain-free range of motion before clearance.

Can AC joint arthritis develop later after injury?

Yes, post-traumatic AC joint arthritis can occur years after injury, causing localized pain and tenderness at the top of the shoulder. It's treatable with activity modification, injections, or in severe cases, distal clavicle excision surgery.