Acromioclavicular Joint Arthritis or Sprain: Causes, Symptoms, and Treatment

Reviewed By – Dr. Sameer Gohir
PhD, MSc, PG Cert MSK ultrasound, PG Cert. Non-Medical Prescribing, MCSP, MAPPN

What Is Acromioclavicular Joint Sprain (Shoulder Separation)?

The acromioclavicular (AC) joint is located at the top of the shoulder, where the collarbone (clavicle) meets a part of the shoulder blade called the acromion.

This joint is supported by ligaments, including the acromioclavicular and coracoclavicular ligaments. Injuries or degenerative conditions affecting the AC joint can cause significant shoulder pain and limited movement.

Shoulder pain from AC joint arthritis or sprain? Joint Injection Clinic near Kent and Essex offers care to help ease pain and restore your movement.

Schedule your consultation now!
AC Joint Arthritis or Sprain

What is Acromioclavicular Joint Sprain (Shoulder Separation)?

A shoulder separation is not a true injury to the main shoulder joint but rather a sprain of the ligaments that support the AC joint. It occurs when these ligaments are stretched or torn, often due to a fall directly on the shoulder or a forceful impact.

Causes of AC Joint Sprain:

  • Falls: Falling directly onto the shoulder is a common cause.
  • Direct Impact: A blow to the shoulder, often seen in contact sports, can also sprain the AC joint.

Symptoms of AC Joint Sprain:

  • Pain at the top of the shoulder, especially with movement.
  • Tenderness over the AC joint.
  • Swelling in the shoulder area.
  • Limited range of motion in the arm.
  • In more severe sprains, a visible bump may appear on top of the shoulder where the collarbone is displaced.

Treatment of AC Joint Sprain:

Treatment for an AC joint sprain depends on the severity of the ligament damage.

  • Mild Sprains: Rest, ice, pain relievers (such as over-the-counter NSAIDs), and use of a sling for a short period are often sufficient. Physical therapy may be recommended to restore range of motion and strength.
  • Severe Sprains: More severe sprains, where ligaments are significantly torn and the joint is unstable, may require surgical intervention to reconstruct the damaged ligaments and stabilize the joint.

What is Acromioclavicular Joint Arthritis?

AC joint arthritis, or osteoarthritis, is a degenerative condition that develops when the cartilage within the AC joint wears down over time. This wear and tear can lead to pain, stiffness, and reduced function.

Causes of AC Joint Arthritis:

  • Wear and Tear: The primary cause is the natural breakdown of cartilage due to daily use and stress on the joint.
  • Repetitive Overhead Activities: People who engage in activities involving frequent overhead lifting or movements, such as weightlifters, construction workers, and certain athletes, are more susceptible.
  • Previous Injury: A prior AC joint sprain or other injury can accelerate the development of arthritis in the joint.

Symptoms of AC Joint Arthritis:

  • Pain and tenderness at the top of the shoulder, particularly over the AC joint.
  • Pain that worsens with activities that involve bringing the arm across the chest or lifting overhead.
  • Pain that may be present even at rest, especially when sleeping on the affected side.
  • Decreased shoulder motion.
  • Swelling around the joint.
  • A clicking or snapping sensation with shoulder movement.
  • In some cases, a bump may form at the AC joint due to bone spurs.

Treatment of AC Joint Arthritis:

Treatment for AC joint arthritis focuses on managing pain and maintaining function.

  • Conservative Treatment: Rest, ice, and over-the-counter pain relievers are often the first line of treatment. Physiotherapy can help improve shoulder mechanics and reduce stress on the joint. Corticosteroid injections into the AC joint can provide temporary pain relief by reducing inflammation.
  • Surgical Treatment: If conservative measures are not effective, surgery may be considered. A common surgical procedure involves removing a small portion of the end of the collarbone (distal clavicle excision) to create more space in the joint and prevent bone-on-bone rubbing.

When to Seek Medical Attention

If you experience persistent shoulder pain, especially at the top of the shoulder, limited range of motion, or a visible deformity, it is important to consult a healthcare professional. A proper diagnosis is essential to determine the underlying cause of your pain and develop an appropriate treatment plan.

Get Help for AC Joint Arthritis or Sprain at Joint Injection Clinic

AC (acromioclavicular) joint arthritis or sprain can cause pain and swelling at the top of the shoulder, making lifting your arm, reaching overhead, or sleeping on your side uncomfortable. If shoulder pain or stiffness is affecting your work, exercise, or daily tasks, professional treatment can help you recover safely.

At Joint Injection Clinic, our experienced team offers evidence-based care to reduce pain, improve shoulder movement, and support your recovery.

We welcome patients at all three of our clinics:

Dartford Clinic – ideal for those in Kent and South East London

Address: Unit 30, 1st Floor, The Base Dartford Business Park, Victoria Road, Dartford, DA1 5FS.

Romford Clinic – easily accessible from Essex and Greater London

Address: Room no 8, Alliance Office Space 2-4 Eastern Road, Romford, Essex, RM1 3PJ.

Canterbury Clinic – serving East Kent and surrounding areas

Address: 12-17 Upper Bridge Street, Canterbury, CT1 2NF, United Kingdom.


Using ultrasound-guided assessments for accurate diagnosis, precision-guided injections when needed, and tailored rehabilitation plans, we help manage pain and improve shoulder mobility so you can return to your daily activities confidently.

Schedule your consultation now!