Shoulder pain is a common issue that can significantly limit movement and affect daily life. A frequent cause of this discomfort, particularly as people age, is the formation of a shoulder bone spur. These abnormal bony growths are structural changes that develop within the joint over time, often as a result of wear and tear. Around 70% of individuals over the age of 60 show evidence of bone spurs, though not all cause symptoms.
Defining the Shoulder Bone Spur
The medical term for a bone spur is an osteophyte, which is a bony projection that forms along the edges of bones where they meet to form a joint. These growths are essentially the body’s attempt to stabilize a joint that is experiencing stress or degeneration. Osteophytes do not cause pain on their own; instead, the pain results when the spur rubs against or presses on surrounding soft tissues like tendons, nerves, or ligaments.
In the shoulder, one frequent location for these bony outgrowths is beneath the acromion, the bony roof of the shoulder blade, where the spur can narrow the space above the rotator cuff tendons. Spurs can also develop along the margins of the glenohumeral joint, the main ball-and-socket connection, or on the rim of the glenoid cavity.
Common Causes and Risk Factors
Shoulder bone spurs generally develop as a reaction to chronic inflammation and joint instability. The most common underlying cause is degenerative joint disease, or osteoarthritis, where the protective cartilage cushioning the ends of the bones wears down over time. As the cartilage deteriorates, the bones may start to rub together, prompting the body to create extra bone in an effort to repair the damage and stabilize the joint.
Chronic friction and impingement are also major factors, especially in the subacromial space. A spur under the acromion can pinch the rotator cuff tendons, a condition often referred to as subacromial impingement syndrome. Repetitive overhead activity, common in certain sports or occupations, places high stress on the shoulder joint, accelerating the wear-and-tear process. Other risk factors include advanced age, previous shoulder injuries like rotator cuff tears or fractures, and inflammatory joint conditions such as rheumatoid arthritis.
Recognizable Symptoms and Diagnostic Methods
Patients often experience persistent pain when the bone spur begins to interfere with surrounding structures. This pain can be a dull ache or sharp discomfort, particularly with movement or when lifting the arm overhead, and may worsen at night or after physical activity. Stiffness and a restricted range of motion are also common, making daily tasks like reaching behind the back or rotating the arm difficult.
A physical examination by a healthcare provider is the first step in diagnosis, assessing the shoulder’s mobility, tenderness, and any signs of impingement. Imaging tests are then used to confirm the presence and location of the osteophyte, with X-rays being the primary tool for visualizing the bony growths and assessing joint space narrowing. For a more detailed look at soft tissues, such as the rotator cuff tendons, a Magnetic Resonance Imaging (MRI) scan may be ordered to determine if the spur is causing tendon damage or inflammation.
Treatment Approaches
Treatment for a shoulder bone spur begins with conservative strategies aimed at managing symptoms and improving function. Non-surgical options include rest, avoiding aggravating activities, and using over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce pain and inflammation. Physical therapy (PT) is also essential, focusing on strengthening the muscles around the shoulder to improve stability and restore range of motion.
If these initial measures do not provide sufficient relief, a doctor may recommend a corticosteroid injection directly into the joint space. This injection delivers anti-inflammatory medication that can reduce swelling and pain, offering temporary relief. When conservative treatments fail to alleviate severe, persistent symptoms, surgical intervention may be considered. This procedure is often performed arthroscopically to remove or shave down the bone spur, a process known as acromioplasty or subacromial decompression.