The symptoms of acromioclavicular arthritis (AC joint arthritis) tend to progress gradually; sometimes symptoms may seemingly get better only to return again later.

For symptoms and treatments for another common type of shoulder arthritis, see What Is Shoulder Osteoarthritis (Glenohumeral Arthritis)?

Many people initially attribute shoulder soreness or stiffness to lack of exercise or getting older. Early recognition of symptoms and appropriate activity modification and treatment can sometimes slow or eliminate progression of AC joint osteoarthritis symptoms. By doing so, patients can guard against other shoulder joint problems that can result from AC joint arthritis, such as tendinitis and shoulder impingement syndrome.


Joint tenderness and pain. Tenderness and pain due to acromioclavicular osteoarthritis is normally isolated, occurring at the front and top of the shoulder where the scapula and clavicle meet. (Tenderness and pain at the back of the shoulder may be a sign of glenohumeral arthritis. More diffuse pain can be a sign of another problem, such as shoulder bursitis or tendinitis.)

See symptoms and treatment information for the joint pain and tenderness caused by Shoulder Bursitis

Pain with certain motions. People with acromioclavicular arthritis have difficulty with cross-body arm movement—holding the arm out straight and then moving it in a horizontal plane across the body, toward the other shoulder. Reaching up and across the body to put on a car seat belt can pose a challenge. A person may also have pain when performing a bench press or push up, reaching behind the back, or reaching overhead.

Inactivity makes it worse. The joint area can become stiff after long periods of inactivity (e.g., sleeping) and get better after short bouts of activity.


Swelling. When arthritis causes friction between bones, the surrounding soft tissue can become irritated and swell. Swelling at the top and front of the shoulder is sometimes seen in patients with AC joint arthritis.

In most but not all cases, the symptoms of AC joint osteoarthritis come and go, becoming worse and more frequent over months or years. Acromioclavicular osteoarthritis pain may flare up after high-intensity activities, such as tennis or weightlifting.