Glenohumeral arthritis is the wearing down of cartilage inside the main ball-and-socket joint of your shoulder. The glenohumeral joint is where your upper arm bone (humerus) meets your shoulder blade (scapula), and both surfaces are normally covered in smooth cartilage that allows the joint to glide with minimal friction. When that cartilage breaks down over a larger area, the joint becomes painful, stiff, and rough in its movement. It’s less common than arthritis in the hip or knee, but it can be just as disabling.
How the Shoulder Joint Wears Down
In a healthy shoulder, the cartilage coating on both the ball (humeral head) and the socket (glenoid) absorbs impact and keeps bone from grinding against bone. Small, isolated areas of cartilage damage are called focal defects. When the damage spreads across a wider surface, it becomes arthritis. Over time, the joint space between the two bones narrows, bony spurs (osteophytes) form along the edges, and the underlying bone thickens and hardens. In advanced stages, the cartilage wears away completely, leaving bone rubbing directly on bone.
Doctors grade the severity on X-rays by measuring how much joint space remains and how large the bone spurs have grown. In mild cases, spurs are small (under 3 mm) and the joint space is only slightly narrowed. Moderate arthritis shows spurs between 3 and 7 mm with visible joint irregularity. Severe arthritis means spurs larger than 7 mm, significant narrowing, and hardening of the bone surfaces, often with small cysts forming inside the bone.
What It Feels Like
Pain is the hallmark symptom, and it can show up in the front, side, or back of the shoulder. Early on, it tends to flare with overhead activity or after heavy use and settle down with rest. As arthritis progresses, pain becomes more constant and can disrupt sleep, especially if you roll onto the affected side.
Stiffness is the other defining feature. You’ll notice it as a gradual loss of range of motion, particularly in rotating your arm outward (like reaching behind your head) or lifting it overhead. This stiffness develops slowly enough that many people compensate without realizing how much movement they’ve lost until routine tasks, like reaching a high shelf or fastening a seatbelt, become difficult. The combination of pain and restricted motion is what typically separates glenohumeral arthritis from conditions like rotator cuff tears, which may hurt but often preserve more range of motion.
How It Differs From Frozen Shoulder
Frozen shoulder (adhesive capsulitis) can look similar because it also causes pain and stiffness. The key differences are the timeline and the underlying cause. Frozen shoulder tends to come on relatively quickly, often over weeks to months, and is linked to risk factors like diabetes and thyroid disease. Glenohumeral arthritis develops over years and shows clear structural changes on X-rays, including joint space narrowing, bone spurs, and cartilage loss. Frozen shoulder involves inflammation and tightening of the joint capsule, not cartilage destruction, and it often resolves on its own over one to three years.
Common Causes and Risk Factors
Osteoarthritis, the wear-and-tear type, is the most common form in the shoulder. It typically develops after age 40 and becomes increasingly prevalent with age. Globally, osteoarthritis affected roughly 595 million people in 2020, about 7.6% of the world’s population, with total cases more than doubling since 1990. While the shoulder is affected less often than the knee or hip, the same age-related cartilage breakdown drives the process.
Previous injury to the shoulder is one of the strongest contributors to developing arthritis earlier than you’d otherwise expect. Recurrent shoulder dislocations are a well-established path to glenohumeral arthritis. Each time the ball slips out of the socket, it can chip cartilage and damage the bone surfaces. Research tracking patients with shoulder instability over an average of 15 years has found elevated rates of arthritis in both those treated with surgery and those managed without it. Other injuries that raise your risk include fractures involving the joint surface, labral tears, and rotator cuff tears.
Less commonly, inflammatory conditions like rheumatoid arthritis can attack the shoulder lining and destroy cartilage from the inside out. Avascular necrosis, where blood supply to the humeral head is disrupted (sometimes from long-term steroid use or heavy alcohol consumption), can also lead to joint collapse and arthritis.
Non-Surgical Treatment Options
Most people start with conservative treatment, and it can manage symptoms effectively for years. Physical therapy focuses on strengthening the muscles around the shoulder, particularly the rotator cuff, to stabilize the joint and take pressure off damaged cartilage. Gentle range-of-motion exercises help maintain flexibility. Anti-inflammatory medications can reduce pain and swelling during flare-ups.
When oral medications and therapy aren’t enough, injections directly into the joint are a common next step. Steroid injections provide meaningful short-term relief. In clinical studies, steroid injections reduced shoulder pain and disability scores by about 44% at one month. Combining a steroid with a lubricating gel (hyaluronic acid) showed even stronger results, cutting pain and disability scores by roughly 58% at one month. However, the benefit from steroid-based injections tends to fade. By three to six months, studies show no significant difference in pain levels between injected and non-injected groups. Hyaluronic acid on its own has a slower onset, taking two to five weeks to kick in, but may provide relief lasting up to six months.
Activity modification also plays a role. Avoiding repetitive overhead motions, adjusting how you sleep, and using ice after activity can all help keep symptoms manageable without medication.
When Surgery Becomes the Best Option
Surgery enters the conversation when pain persists despite months of conservative treatment and begins to significantly limit daily life. The main surgical option for advanced glenohumeral arthritis is shoulder replacement (arthroplasty), and there are two primary types.
An anatomic total shoulder replacement is the standard approach when your rotator cuff tendons are still intact. It replaces the damaged ball with a metal implant and resurfaces the socket with a plastic component, mimicking the natural anatomy. Implant survival rates for anatomic replacements are approximately 95% at five years, 83% at ten years, and around 60% at twenty years, with an overall revision rate of about 17%.
A reverse total shoulder replacement flips the mechanics of the joint: the ball is placed on the socket side and the socket on the arm side. This design relies on the deltoid muscle rather than the rotator cuff to power the shoulder, making it the clear choice for patients who have significant rotator cuff damage alongside their arthritis. Reverse replacements have shown strong durability, with studies reporting 89% to 93% implant survival at ten years and revision rates around 10% at the decade mark. In patients under 65, survival rates are 91% to 98% at five years and 88% at ten years.
Younger patients and those with only mild to moderate damage may be candidates for less invasive procedures like arthroscopic debridement (cleaning out loose cartilage and bone fragments) or a partial resurfacing. These options can buy time but generally don’t provide the same long-term pain relief as a full replacement in advanced disease.
What Recovery Looks Like
After shoulder replacement, your arm will be in a sling for four to six weeks. Physical therapy starts within the first week or two, initially focusing on gentle, passive motion where the therapist moves your arm for you. Active movement and strengthening exercises are gradually introduced over the following months. Most people see significant pain relief within the first few weeks and continue gaining strength and motion for six months to a year.
The realistic expectation is meaningful pain relief and improved function, not a return to a perfectly normal shoulder. Overhead athletes and heavy laborers may need to modify their activities permanently. For most people, though, daily tasks, recreational activities, and sleep become dramatically easier after recovery is complete.