What Is Arthritis in the Shoulder?

What is arthritis in the shoulder, and what can be done about it? This condition affects millions of people, significantly impacting their daily lives and overall quality of life. In this post, we’ll explore the anatomy of the shoulder, the different forms of arthritis that can affect it, and the full spectrum of treatment options available today.

• Shoulder arthritis is an umbrella term that includes osteoarthritis (OA), rheumatoid arthritis (RA), post-traumatic arthritis, and rotator cuff tear arthropathy.
• Arthritis can affect the main ball-and-socket joint (glenohumeral) or the joint at the top of the shoulder (acromioclavicular or AC joint).
• Many patients begin treatment with non-surgical methods like physical therapy, NSAIDs, and injections. For severe arthritis when conservative methods fail to provide relief, surgery may be a recommended treatment option.

The shoulder is one of the most mobile joints in the human body. This range of motion, however, comes at a cost. The shoulder’s complexity can also make it vulnerable to injury and degenerative conditions like arthritis.

The shoulder is not just one joint; it is a complex of several articulations. The glenohumeral joint is the classic ball-and-socket joint. The head of the humerus, the upper arm bone, acts as the ball. The glenoid, a shallow socket on the shoulder blade, acts as the socket. A smooth, resilient tissue called articular cartilage covers the surfaces of both the ball and the socket. This cartilage allows the bones to glide effortlessly against each other and provides shock absorption.

The second key joint is the acromioclavicular (AC) joint. This joint sits at the very top of the shoulder. It connects the acromion, which is part of the shoulder blade, to the clavicle, or collarbone. 

Arthritis can develop in either or both of these joints. When arthritis strikes, this protective cartilage begins to break down. This breakdown can lead to bone rubbing against bone. This friction causes the pain, stiffness, and loss of motion that characterize shoulder arthritis.

Osteoarthritis is a common form of arthritis, often referred to as “wear-and-tear” arthritis. It typically affects individuals over the age of 50 and develops slowly over many years. In the shoulder, OA can affect both the glenohumeral and the AC joints.

• Glenohumeral Osteoarthritis: This condition involves the main ball-and-socket joint. The articular cartilage wears away gradually. This leads to pain deep within the shoulder, and patients often report difficulty lifting their arm or reaching behind their back. The pain may worsen with activity and improve with rest in the early stages.
• Acromioclavicular (AC) Joint Osteoarthritis: AC joint arthritis frequently causes pain localized to the top of the shoulder. Patients may feel tenderness when pressing on the joint. Pain may occur when reaching across the body or sleeping on the affected side.

Rheumatoid arthritis is a systemic, autoimmune disease. With RA, the body’s immune system mistakenly attacks the synovium, the lining of the joint capsule. This attack causes inflammation and swelling. Over time, the inflamed synovium can invade and destroy the cartilage and bone. RA can affect both shoulders simultaneously. It may also affect other joints, such as the hands and wrists. The pain and stiffness associated with RA are often worse after periods of rest.

This type of arthritis develops after a shoulder injury. A fracture of the humerus or glenoid can damage the articular cartilage. A severe shoulder dislocation may also lead to this condition. The joint surface can become irregular following the injury, which may accelerate the wear-and-tear process. Post-traumatic arthritis can develop many years after the initial injury.

This is a complex form of shoulder arthritis that occurs when a massive, long-standing rotator cuff tear develops. The rotator cuff muscles normally hold the ball of the joint centered in the socket. When these muscles fail, the humeral head moves upward. This abnormal position causes the head to rub against the acromion. Patients with this condition often experience pain and significant weakness.

While the exact progression of arthritis can vary, several factors may increase a person’s risk.

• Age: Cartilage naturally loses some of its elasticity and ability to repair itself over time.
• Genetics: A family history of arthritis suggests a potential genetic predisposition.
• Previous Injury: A prior fracture, dislocation, or ligament tear can predispose the joint to post-traumatic arthritis.
• Repetitive Stress: Certain occupations or sports involve frequent, heavy overhead use. These activities can accelerate the wear on the AC and glenohumeral joints.
• Infection: A joint infection, though rare, can rapidly destroy cartilage.
• Underlying Conditions: Various systemic diseases may also contribute to joint damage.

The symptoms of shoulder arthritis typically develop gradually. They may start as mild discomfort and progress to debilitating pain. Common symptoms include:

• Pain: Patients often describe a deep, aching pain in the joint. The pain may radiate down the arm. For AC joint arthritis, the pain is usually sharp and localized to the top of the shoulder.
• Stiffness: The shoulder’s range of motion may decrease over time. Simple tasks like reaching a high shelf or combing hair become challenging.
• Crepitus: A grinding, clicking, or catching sensation may occur with movement. This sound is caused by the rough, damaged cartilage surfaces rubbing together.
• Night Pain: Pain that wakes a person from sleep is a possible symptom. Finding a comfortable sleeping position can become difficult.
• Weakness: As the condition worsens, muscle weakness may develop. This is particularly true in cases of rotator cuff tear arthropathy.

When a patient presents with shoulder pain, the diagnostic process may include a clinical evaluation and imaging tests. The process begins with a detailed discussion of your medical history. Your doctor may ask about the onset of your pain, its location, and factors that make it better or worse. A physical examination follows, where your shoulder’s range of motion, strength, and stability may be assessed.

Imaging tests may be used to support the diagnosis:

• X-rays: Standard X-rays can show the joint space and the presence of bone spurs (osteophytes). They can also be used to assess the position of the humerus head.
• Magnetic Resonance Imaging (MRI): An MRI provides detailed images of soft tissues. This includes the rotator cuff tendons and the labrum. We may order an MRI if we suspect a concurrent rotator cuff tear.
• Computed Tomography (CT) Scan: A CT scan provides detail of the bone structure. Surgeons often use it for surgical planning.

For most patients, we begin treatment with conservative, non-surgical methods. The goal of these treatments is to manage pain, reduce inflammation, and maintain function. While non-surgical options cannot reverse the damage, they may improve quality of life in many cases.

Making simple changes to daily habits can provide substantial relief.

• Activity Modification: Patients are generally advised to avoid activities that aggravate their symptoms. This may mean temporarily reducing or eliminating heavy lifting and repetitive overhead movements.
• Rest and Ice/Heat: Applying ice packs for 15 to 20 minutes several times a day may help reduce acute inflammation and pain. Heat, such as a warm shower or heating pad, may help relax stiff muscles before activity.

Physical therapy is usually a key component of non-surgical management. A physical therapist designs a personalized program, focused on maintaining or improving the shoulder’s range of motion, along with strengthening. Consistency is key.

Various medications can help control the pain and inflammation associated with arthritis. Nonsteroidal anti-inflammatory drugs (NSAIDs) can help reduce both pain and inflammation. Acetaminophen primarily targets pain and may be an option for patients who cannot tolerate NSAIDs.

When non-surgical treatments no longer provide adequate relief, we may consider surgical intervention. Surgery aims to remove damaged tissue, repair structural problems, or replace the entire joint. The choice of procedure depends heavily on the type and severity of the arthritis.

Arthroscopy is a minimally invasive surgical technique. We use a small camera and instruments inserted through tiny incisions. This procedure may provide relief for early-stage arthritis.

• Debridement: The surgeon cleans out loose fragments of cartilage and inflamed tissue. This process can smooth the joint surfaces.
• AC Joint Resection (Distal Clavicle Excision): For isolated AC joint arthritis, the surgeon removes a small portion of the collarbone end. This creates a space between the bones.

Joint replacement surgery, or arthroplasty, is a treatment option for severe, end-stage arthritis. This procedure involves replacing the damaged joint surfaces with artificial components.

• Total Shoulder Arthroplasty: This procedure replaces both the ball (humeral head) and the socket (glenoid) with prosthetic parts. It generally requires a healthy, functioning rotator cuff.
• Reverse Total Shoulder Arthroplasty: This is often a recommended treatment for rotator cuff tear arthropathy. The “ball” and “socket” components are reversed. The ball is placed on the shoulder blade. The socket is placed on the upper arm bone. This design allows the deltoid muscle to power the arm, compensating for a non-functional rotator cuff.

Shoulder arthritis is a condition involving the breakdown of protective cartilage in the glenohumeral or AC joints. This process leads to pain, stiffness, and loss of motion. The most common form is osteoarthritis, or “wear-and-tear” arthritis. However, inflammatory conditions like rheumatoid arthritis and damage from past injuries, known as post-traumatic arthritis, can also contribute.

Diagnosis relies on a thorough clinical evaluation and imaging studies, primarily X-rays. Treatment follows a stepped approach. We usually begin with conservative management. This may include activity modification, physical therapy, and medications like NSAIDs. When these methods fail, surgical options may be recommended.

The most frequent cause is age-related wear and tear (osteoarthritis). Arthritis may also result from an autoimmune disease like rheumatoid arthritis, prior injuries (fractures or dislocations), or a long-standing rotator cuff tear.

Many patients initially experience a deep, aching pain in the shoulder and increasing stiffness. Over time, daily activities such as reaching overhead, lifting objects, or even sleeping comfortably may become difficult. Some people notice grinding or popping sensations during movement.

Surgery may be discussed when non-surgical treatments no longer provide adequate relief or stiffness and pain begin to interfere significantly with daily life. The type of surgery depends on the severity of the arthritis, the condition of the rotator cuff, and the patient’s functional goals.