Arthritis in the shoulder is a breakdown of the smooth cartilage that cushions the bones inside the joint, causing pain, stiffness, and gradual loss of motion. The shoulder has two joints where arthritis can develop: the main ball-and-socket joint (where the upper arm bone meets the shoulder blade) and the smaller joint at the top of the shoulder where the collarbone connects. Most shoulder arthritis affects the ball-and-socket joint, and it can result from normal wear and tear, autoimmune disease, injury, or other conditions that damage the joint surfaces over time.
How the Joint Breaks Down
In a healthy shoulder, a layer of cartilage covers both the ball of the upper arm bone and the shallow socket it sits in. This cartilage lets the bones glide against each other with almost no friction. When arthritis develops, that cartilage thins, roughens, and eventually wears away entirely, leaving bone grinding against bone.
The pattern of wear depends on the type of arthritis. In the most common form, degenerative arthritis, the socket tends to wear down more on the back side, while the ball develops a patch of bare bone in the center surrounded by a rim of remaining cartilage and bony spurs. In inflammatory types like rheumatoid arthritis, the cartilage is destroyed more evenly across both surfaces. These different patterns matter because they influence which treatments work best and how the joint will behave over time.
Types of Shoulder Arthritis
Osteoarthritis
This is the wear-and-tear form, most common in people over 50. Years of use gradually thin the cartilage, and the body responds by forming bone spurs around the joint edges. It tends to worsen slowly, over years or even decades.
Rheumatoid and Inflammatory Arthritis
These are autoimmune conditions where the body’s immune system attacks healthy joint tissue. Because the destruction is driven by inflammation rather than mechanical wear, cartilage loss tends to be more uniform across the entire joint surface. Rheumatoid arthritis often affects both shoulders and other joints simultaneously.
Post-Traumatic Arthritis
Any significant shoulder injury, including dislocations, fractures, or severe impacts, can damage the cartilage surface and set the stage for arthritis years later. The joint may feel fine after the initial injury heals, then gradually develop stiffness and pain as the damaged cartilage deteriorates.
Rotator Cuff Tear Arthropathy
This type develops when a large, long-standing rotator cuff tear destabilizes the joint. Without the rotator cuff holding the ball centered in the socket, the ball migrates upward and grinds against the bony arch above it. Over time, this causes cartilage erosion, bone loss, and eventually collapse of the ball itself. It’s a distinct condition that requires a different surgical approach than standard arthritis.
Avascular Necrosis
Sometimes the blood supply to the ball of the shoulder gets cut off, causing bone tissue to die. The bone weakens, collapses, and the joint surface crumbles. The most common risk factors are long-term steroid use, heavy alcohol consumption, sickle cell disease, and severe fractures. Four-part fracture-dislocations of the shoulder approach a nearly 100% rate of avascular necrosis, while less severe fracture patterns carry lower but still significant risk.
What Shoulder Arthritis Feels Like
The hallmark symptom is a deep ache in the shoulder that worsens with activity and improves with rest, at least initially. As the condition progresses, pain can become constant and often intensifies at night, making it hard to sleep on the affected side.
Stiffness is the other defining feature. You may notice you can’t reach behind your back, overhead, or across your body the way you used to. Simple tasks like fastening a bra, reaching a high shelf, or putting on a coat become difficult. Many people also feel or hear grinding, clicking, or crunching inside the joint when they move their arm. Over time, the shoulder may lose range of motion significantly enough that daily activities become genuinely limited.
The location of the pain can help distinguish which shoulder joint is affected. Arthritis in the main ball-and-socket joint typically causes deep pain in the back or side of the shoulder. Arthritis in the smaller collarbone joint causes pain more at the top of the shoulder, often noticeable when reaching across the body.
How It’s Diagnosed
Standard X-rays combined with a physical exam are usually enough to diagnose shoulder arthritis and gauge its severity. X-rays reveal the telltale signs: narrowing of the joint space where cartilage has worn away, bone spurs forming around the joint edges, and changes in bone density. Specific X-ray views can highlight different parts of the shoulder. A view angled slightly upward, for example, better reveals bone spurs at the collarbone joint.
MRI is sometimes used when the diagnosis is uncertain, when avascular necrosis is suspected (since early stages look normal on X-ray), or when the doctor needs to evaluate the rotator cuff. In avascular necrosis, MRI can detect bone changes at stage one, well before any abnormality appears on a standard X-ray.
Non-Surgical Treatment
Most people start with conservative approaches, and many manage their symptoms effectively for years without surgery. The core strategies include activity modification (avoiding positions and movements that trigger pain), physical therapy to maintain range of motion and strengthen the muscles supporting the joint, and anti-inflammatory medications to reduce pain and swelling.
Corticosteroid injections are a common next step when oral medications aren’t enough. Research on image-guided injections for shoulder arthritis shows meaningful improvement in both pain and function for up to about four months. Pain relief, interestingly, can persist at a reduced level for up to 12 months, even after the functional benefits fade. In one study, about 59% of patients went a full year without needing a repeat injection or surgery. The severity of arthritis on X-ray didn’t predict how well the injection worked, but people with worse function at baseline tended to notice the biggest improvements.
Ice, heat, and gentle stretching also help manage flare-ups. The goal of all non-surgical treatment is the same: keep you comfortable and functional for as long as possible.
When Surgery Becomes an Option
Surgery is typically considered when pain and loss of function persist despite months of conservative treatment. The main surgical option for advanced shoulder arthritis is joint replacement, where the damaged surfaces are replaced with metal and plastic components.
Two types of replacement exist. A standard (anatomic) replacement mimics the shoulder’s natural anatomy, with a metal ball and a plastic socket. A reverse replacement flips that arrangement, placing the ball on the socket side and the socket on the arm side. The reverse design is specifically used when the rotator cuff is too damaged to support a standard replacement, as in rotator cuff tear arthropathy. Studies report that reverse shoulder replacements have a survival rate of roughly 85% to 90% at 10 years.
Recovery follows a predictable pattern. Most people can handle light daily activities like getting dressed and simple household tasks within two to three weeks. More demanding activities, including lifting heavy objects, sports, and intense workouts, are typically off limits for several months. Physical therapy after surgery is essential and continues for weeks to months, gradually restoring strength and range of motion.
Acromioclavicular Joint Arthritis
The smaller joint at the top of the shoulder, where the collarbone meets the shoulder blade, is a separate and common site of arthritis. It often develops from repetitive overhead use or after a previous shoulder separation. Pain concentrates at the top of the shoulder and flares when you reach across your body or press overhead. Treatment follows the same progression as other forms of shoulder arthritis: activity modification, anti-inflammatory medications, injections, and, if those fail, a minor surgical procedure to remove a small amount of bone from the end of the collarbone so the two surfaces no longer grind together.