AC Joint Sprain: Guide to Shoulder Recovery

What Is an AC Joint Sprain?

The acromioclavicular (AC) joint is the small joint at the top of the shoulder where the clavicle (collarbone) meets the acromion (part of the shoulder blade). This joint plays a crucial role in shoulder stability and movement, helping the arm lift overhead and across the body.

An AC joint sprain occurs when the ligaments that hold this joint together are stretched or torn, typically due to trauma or overuse. The severity of the sprain can range from mild ligament stretching to a complete separation of the joint.

Causes of an AC Joint Sprain

AC joint sprains are most commonly caused by direct impact or excessive force to the shoulder. The most frequent causes include:

• Falls onto the shoulder: A direct fall onto the top of the shoulder (common in biking, skiing, and football) can put excessive stress on the AC joint.
• Collisions in contact sports: Football, hockey, and rugby players are at high risk for AC joint injuries due to frequent tackles and high-impact collisions.
• Weightlifting injuries: Lifting heavy weights, particularly with improper form, can strain the AC joint, leading to ligament sprains or tears.
• Overuse and repetitive stress: Athletes who frequently use overhead motions, such as baseball pitchers or swimmers, may develop AC joint irritation and instability over time.

Symptoms

The symptoms of an AC joint sprain vary depending on the severity of the injury. Common signs include:

• Pain at the top of the shoulder, especially when lifting the arm or carrying objects
• Swelling and bruising around the joint
• Visible bump or deformity at the top of the shoulder (in moderate to severe cases)
• Limited shoulder movement, especially with overhead or cross-body motions
• Weakness or instability when using the affected shoulder
• Pain when sleeping on the injured shoulder

If you suspect an AC joint sprain, it’s important to seek medical evaluation, especially if the pain is severe or if you notice a visible deformity in the shoulder.

Grading the Severity of an AC Joint Sprain

Doctors classify AC joint sprains into six grades based on the extent of ligament damage and joint separation:

• Grade 1: Mild sprain with minor ligament stretching, no joint separation
• Grade 2: Partial ligament tear with slight joint misalignment
• Grade 3: Complete ligament tear and visible separation of the AC joint
• Grade 4-6: Severe joint separation with clavicle displacement (less common)

Grades 1-3 typically heal with non-surgical treatments, while Grades 4-6 may require surgery to restore shoulder stability.

How Is an AC Joint Sprain Diagnosed?

At Motion Orthopaedics, diagnosing an AC joint sprain begins with:

• Physical Examination: Your doctor will check for swelling, tenderness, and range of motion in the shoulder. Specific tests, such as the cross-body adduction test, help assess pain and instability.
• X-rays: Imaging is often used to determine the severity of the sprain and assess any misalignment of the AC joint.
• MRI (in some cases): If soft tissue damage needs further evaluation, an MRI may be ordered to examine ligament integrity.

Proper diagnosis ensures that your treatment plan is tailored to your specific injury and recovery needs.

Treatment Options for an AC Joint Sprain

The treatment approach for an AC joint sprain depends on the severity of the injury. Most cases heal with non-surgical treatments, but severe cases may require more advanced interventions.

Non-surgical Treatment for AC Joint Sprains

1. Rest and Activity Modification

• Avoid overhead movements and activities that put pressure on the joint.
• Modify workouts and daily tasks to prevent aggravation of the injury.

2. Ice and Anti-inflammatory Medications

• Apply ice packs for 15-20 minutes, several times a day, to reduce swelling and pain.
• Use NSAIDs (like ibuprofen) to manage inflammation and discomfort.

3. Immobilization (for moderate sprains)

• A shoulder sling may be recommended for 1-2 weeks to support healing and prevent further strain.
• Avoid prolonged immobilization to prevent stiffness.

4. Physical Therapy

Once the initial pain and swelling subside, rehabilitation exercises help restore range of motion, strength, and stability. Therapy typically includes:

• Gentle stretching to prevent stiffness
• Rotator cuff and deltoid strengthening exercises
• Postural training to avoid shoulder compensation patterns

Physical therapy is essential to ensure full recovery and prevent long-term weakness.

When Is Surgery Necessary?

Surgery may be considered for Grade 4-6 sprains or for athletes with chronic pain and instability after conservative treatment. Surgical options include:

• AC Joint Reconstruction: Uses grafts or sutures to stabilize the joint.
• Distal Clavicle Resection: In some cases, removing a portion of the clavicle relieves pain and restores function.

Recovery from surgery typically requires several months of rehabilitation, but most patients return to full activity with proper post-op care.

Recovery Timeline

Recovery time depends on the severity of the sprain:

• Grade 1: 1-2 weeks (mild pain, minimal swelling)
• Grade 2: 3-6 weeks (moderate pain, some joint instability)
• Grade 3: 6-12 weeks (severe pain, joint separation)
• Grade 4-6 (surgical cases): 4-6 months (recovery includes post-op rehab)

Following a structured rehabilitation plan is key to regaining full function and avoiding chronic pain.

Preventing AC Joint Sprains

While some AC joint injuries are unavoidable (especially in contact sports), there are steps you can take to reduce your risk:

• Strengthen your shoulder muscles: A strong rotator cuff and upper back help stabilize the AC joint.
• Practice proper technique in sports and weightlifting: Avoid excessive stress on the shoulder joint.
• Wear protective gear: If you play contact sports, shoulder padding can help absorb impact.
• Improve flexibility and posture: Stretching and maintaining good posture prevent unnecessary strain on the AC joint.

When to See a Specialist for AC Joint Pain

If you experience persistent shoulder pain, swelling, or instability, it’s time to seek medical evaluation. Ignoring an AC joint sprain can lead to chronic pain and weakness, making everyday activities and sports more difficult.

At Motion Orthopaedics, our team specializes in diagnosing and treating orthopedic injuries like AC joint sprains — helping patients recover quickly and safely. Whether you need conservative treatment or advanced care, we’ll create a personalized recovery plan to get you back to full strength.

Regain Shoulder Strength with Motion Orthopaedics

Don’t let an AC joint sprain keep you from the activities you love. If you’re dealing with shoulder pain or instability, Motion Orthopaedics is here to help.

Click here to request an appointment today and take the first step toward a pain-free, fully functional shoulder.