Shoulder Inflammation and Frozen Shoulder: Symptoms, Treatment, and Pain Relief for Shoulder Inflammation

When it comes to inflammation of the main shoulder joint, three clinical presentations are considered:

• rheumatoid arthritis of the shoulder
• bacterial shoulder inflammation
• inflammatory frozen shoulder (adhesive capsulitis)

They differ in terms of their causes, symptoms, and treatment.

We will examine these three conditions below.

50 to 80 percent of patients with rheumatoid arthritis develop shoulder involvement over the course of the disease. The following are affected:

• the main shoulder joint (glenohumeral joint),
• the space beneath the acromion (subacromial space), and
• the acromioclavicular joint.

The progression of rheumatoid arthritis in the shoulder does not differ fundamentally from that in other joints. However, the shoulder is particularly dependent on the integrity of the surrounding soft tissue structures. Therefore, inflammatory changes in the rotator cuff are of particular importance.

Muscles and soft tissues surrounding the shoulder joint © bilderzwerg | AdobeStock

Symptoms of rheumatoid arthritis of the shoulder

The typical clinical symptoms of rheumatoid arthritis also affect the shoulder. These include, for example

• morning stiffness,
• painful limitation of movement, and
• nighttime pain at rest.

Significant swelling of the shoulder joint may occur.

However, shoulder arthritis often remains largely asymptomatic for a long time, especially with a long-standing course of the disease and effective basic therapy. Compared to other joints, the symptoms are often less prominent.

Problems can arise due to increasing functional deficits of the rotator cuff. This is caused by inflammation

• of the synovial membrane (synovitis) and
• bursitis

. All signs of a rotator cuff tear, including weakness, are then present.

In other cases, symptoms of shoulder joint osteoarthritis (omarthrosis) develop, characterized by painful movement. Involvement of the acromioclavicular joint leads to a well-defined swelling and tenderness on pressure.

Comparison of a healthy shoulder joint with a joint affected by osteoarthritis © bilderzwerg | AdobeStock

Diagnosis of rheumatoid arthritis of the shoulder

In most cases, a diagnosis of rheumatoid arthritis has already been established by the time shoulder symptoms appear. Ultrasound is well-suited for assessing synovial changes and the condition of the rotator cuff. On X-rays, extensive wear and tear at the cartilage-bone junction of the humeral head is typical.

Look for

• defects in the glenoid fossa, which can be very extensive, and
• elevation of the humeral head in cases of a torn rotator cuff.

Magnetic resonance imaging (MRI) provides important information about the condition

• of the rotator cuff,
• the bone structure, and
• the cartilage lining of the joints

It also provides information on the extent of synovitis. It is therefore often indispensable for further diagnosis and planning surgical procedures.

Treatment and Prognosis for Rheumatoid Arthritis of the Shoulder

Systemic drug therapy for the underlying disease is the first line of treatment. Physical therapy is used to strengthen the muscles and prevent restricted movement at an early stage. Local cortisone injections are effective. The glenohumeral joint is also a candidate for radiosynoviorthesis.

In the early stages of the disease, surgical

• synovial membrane removal (synovialectomy) and
• bursectomy

be performed. Both arthroscopic and open surgical procedures are used.

Severe cases require total shoulder replacement. The available implants are the same as those used for shoulder osteoarthritis.

The term “bacterial omarthritis” refers to infections of the main shoulder joint and the accessory shoulder joints.

These are usually preceded by needle aspirations and drug injections. In addition to the main shoulder joint, the subacromial space is therefore the most likely source of bacterial colonization. Open injuries or surgeries are less common causes of infection, as is the spread of bacteria via the bloodstream.

Bacterial shoulder inflammation spreads rapidly from the subacromial space into the main joint—and vice versa—through a gap in the rotator cuff.

The rotator cuff, which has relatively poor blood supply, is then surrounded by pus and is at high risk.

If left untreated, the progression of bacterial shoulder inflammation can lead to complete destruction of the joint.

Symptoms of bacterial shoulder arthritis

Patients typically report an acute onset and complain of pain at rest as well as during movement. The shoulder joint may

• swollen,
• warm,
• red, and
• extremely tender to pressure

. However, especially in the shoulder joint, the absence of typical clinical signs of infection can be misleading! It is important to differentiate this condition from calcific tendinitis (tendinosis calcarea), which can cause similarly painful symptoms.

Pain in the shoulder also occurs in bacterial omarthritis © Bits and Splits | AdobeStock

Diagnosis of bacterial shoulder inflammation

The diagnostic procedures are the same as those required for joint infections in other locations:

• Blood tests for signs of inflammation,
• Joint aspiration with analysis of the synovial fluid for inflammatory cells and bacteria,
• X-ray,
• ultrasound, and
• MRI.

Treatment and Prognosis for Bacterial Shoulder Infection

The therapeutic principles also correspond to those for the general treatment of joint infections.

If the clinical picture is unclear, non-targeted antibiotic therapy is inappropriate. The primary focus is on surgical treatment of shoulder inflammation, which can be performed arthroscopically in the early stages. In more advanced stages, open surgical treatment of the joint is necessary.

The goal is to debride the joint and remove necrotic and highly inflamed tissue. A second or third surgical procedure may be necessary. Concurrently, targeted antibiotic therapy based on the bacterial spectrum is initiated.

If shoulder inflammation is detected early and treated properly, the prognosis for recovery is good. The infection can then heal completely, and the shoulder joint remains fully functional.

If treatment is delayed or inadequate, the shoulder joint may suffer severe, permanent damage.

Adhesive capsulitis refers to the distinct clinical condition of frozen shoulder. In this condition, glenohumeral mobility (the main shoulder joint) is restricted.

Other forms of shoulder stiffness develop when the joint is kept in a protective position for an extended period following trauma, infection, or surgery (secondary frozen shoulder). In adhesive capsulitis, however, there are no clinical, radiological, or anamnestic indications for the onset of the condition.

The cause of this condition is unclear; a dysfunction of connective tissue cells is a proposed explanation. The classification of adhesive capsulitis as an inflammatory disease is questionable. Inflammation of the joint capsule is not typical; if present, it is detectable at the histological level only in the early stages.

Later, the microscopic picture is characterized by a marked proliferation of connective tissue cells and structural changes in the connective tissue fibers. This results not only in thickening of the joint capsule but also in a significant narrowing of the joint space. Ultimately, this leads to a severe restriction of movement.

Symptoms of Frozen Shoulder

Adhesive capsulitis primarily affects women between the ages of 40 and 60. In one-third of cases, both shoulders are affected.

The natural course of adhesive capsulitis can be divided into three stages:

• In the initial “freezing phase” (the joint freezes), there is a rapid and painful stiffening of the shoulder joint.
• During the “frozen phase” (joint is frozen), the pain gradually subsides and the stiffness reaches its peak.
• In the subsequent “melting phase” (joint thaws), the pain subsides completely. The range of motion returns to normal.

The disease process extends over many months, with the phases being roughly equal in length. The resulting restriction of movement can be considerable and significantly impair the use of the arm.

External rotation and abduction of the shoulder joint are primarily affected.

Diagnosis of Frozen Shoulder

Laboratory tests and X-rays show no abnormalities except for a slight decrease in bone density due to inactivity toward the end of the disease.

The definitive diagnosis is made by arthrography showing

• only a narrow rim of contrast agent around the humeral head and
• an absence of bulging of the joint capsule, particularly downward.

Treatment and Prognosis for Inflammatory Frozen Shoulder

The condition typically resolves within 24 months. This outcome is virtually independent of any treatment administered in the interim. In isolated cases, however, persistent (partial) stiffness may occur, as seen in secondary frozen shoulder.

In principle, therefore, it is possible to wait for the condition to resolve spontaneously. Treatment is purely symptomatic, aimed at relieving pain. Physical therapy can help maintain current range of motion and muscle strength.

In Stage I, treatment focuses on nonsteroidal anti-inflammatory drugs (NSAIDs). Physiotherapy-based mobilization treatment should not be started until the acute symptoms have subsided.

Other therapeutic approaches aim to accelerate the spontaneous course of the disease. For a long time, shoulder brisement (mobilization under brief anesthesia) was the standard procedure. Today, other methods are available:

• arthroscopy with stretching of the joint capsule or even surgical release of the capsule, and
• arthrography with the additional high-pressure injection of a local anesthetic and cortisone.

This may result in temporary improvement. In some cases, it helps the patient cope more easily with the course of the disease.

What are the typical symptoms of shoulder inflammation?

The main symptom is stabbing or pulling pain in the shoulder, which is noticeable during activity but often also at rest (night pain). Patients frequently report difficulty raising their arm or reaching behind their back. This may be accompanied by swelling and warmth in the affected shoulder. If the inflammation becomes chronic, as in the case of frozen shoulder, the shoulder joint becomes increasingly stiff, resulting in severe limitations of movement in daily life.

What causes frozen shoulder?

Frozen shoulder, medically known as adhesive capsulitis, is an inflammation of the joint capsule. The tissue of the capsule thickens and adheres, causing the joint to literally “freeze.” The causes are often unclear (idiopathic), but it frequently occurs after accidents, surgeries, or in connection with metabolic disorders such as diabetes. The course of the condition is protracted and alternates between painful inflammatory phases and phases of stiffness, before it often resolves on its own.

How is shoulder inflammation treated?

Treatment usually begins with conservative measures. Pain relievers (such as ibuprofen) and cold therapy are used to alleviate pain and reduce inflammation. Physical therapy plays a central role, with targeted exercises designed to strengthen the muscles and maintain mobility. In cases of persistent inflammation, cortisone injections into the bursa or the joint space can help. Shock wave therapy has also proven effective, particularly for calcified tendon insertions.

When is shoulder surgery necessary?

Surgery is usually only considered if all conservative measures have failed over a period of months or if there is structural damage that will not heal on its own. Examples include a complete rotator cuff tear, severe osteoarthritis of the shoulder joint, or a bacterial infection requiring joint irrigation. The procedure is often performed using a minimally invasive technique (arthroscopic surgery).

What is the difference between bursitis and tendinitis in the shoulder?

Bursitis is an inflammation of the bursa. The bursa acts as a cushion beneath the acromion and often becomes inflamed due to impingement. Tendinitis, on the other hand, is inflammation of a tendon in the shoulder; it most commonly affects the tendon insertions of the rotator cuff. Both conditions cause similar symptoms and often occur together, as the swollen structures further narrow the space within the joint.

How long does inflammation in the shoulder last?

The course of the condition depends heavily on the cause. Acute inflammation caused by overuse can subside within a few weeks with consistent rest and medication. However, a frozen shoulder or chronic inflammation can persist for months or even up to two years. Patience and ongoing physical therapy are essential for pain relief in these cases.

How can I prevent shoulder inflammation?

Since many cases of shoulder inflammation result from muscular imbalances or poor posture, moderate exercise targeting the rotator cuff and the muscles around the shoulder blade is recommended. You should avoid one-sided overhead movements and maintain good posture to prevent narrowing the space under the acromion. Anyone prone to shoulder pain should reduce the strain on the shoulder at the first signs of discomfort.

How is shoulder inflammation diagnosed?

The orthopedic surgeon begins with a physical examination, assessing range of motion and specific pain points. Ultrasound and MRI (magnetic resonance imaging) are the methods of choice for visualizing inflammatory changes, tendon tears, or bursitis. An X-ray also helps identify bone changes such as osteoarthritis or calcium deposits.