Adhesive Capsulitis (Frozen Shoulder)

Adhesive capsulitis, commonly known as “frozen shoulder”, is defined as the clinical syndrome characterized by painful restriction of both active and passive shoulder movement. It is a condition where the shoulder joint becomes stiff, painful, and difficult to move. It occurs due to inflammation and thickening of the joint capsule—the connective tissue that surrounds the shoulder joint. This thickened capsule tightens around the joint, restricting movement and causing pain.

Frozen shoulder is classified into two main types: Idiopathic (primary) and secondary. Primary frozen shoulder has no known cause, while secondary frozen shoulder is caused by a specific underlying condition or injury.

The main cause of adhesive capsulitis (frozen shoulder) is an inflammation in the joint, leading to the formation of scar tissue (fibrosis), development of adhesions (abnormal band of tissue) and shrinkage (thickening and contraction) of the joint capsule. The result is reduced space and movement within the joint, causing pain and limited mobility.

Causes are divided based on the type:

Idiopathic (Primary) Adhesive Capsulitis: The exact cause is unknown and it occurs spontaneously without an identifiable injury or event.

Secondary Adhesive Capsulitis: It develops following a specific event or condition affecting the shoulder. The most known causes are: trauma or surgery (rotator cuff repair, fractures, etc,), inflammatory conditions (e.g., calcific tendonitis, subacromial impingement, bursitis or rotator cuff tendinopathy) and shoulder immobilization after surgery, stroke or fracture.

Adhesive capsulitis is more likely to develop in individuals with certain systemic medical conditions, including:

• Diabetes mellitus: (Up to20–30% of diabetics may develop frozen shoulder)
• Thyroid disorders: (Both hypothyroidism and hyperthyroidism)
• Cardiovascular disease: (May affect microcirculation and healing in tissues)
• Parkinson’s disease: (Reduced mobility and altered neuromuscular function may contribute)

What other factors can increase the risk of developing “frozen shoulder?”

Age: Frozen shoulder occurs in about 2-3% of the general population and most commonly affects people between the ages of 30-60.

Gender: Women are more frequently affected than men.

Hormonal factors: Menopausal women or individuals with thyroid conditions or undergoing hormone therapy are at higher risk.

Other illnesses: Conditions like stroke may cause adhesive capsulitis due to immobility of the shoulder.

Frozen shoulder is a multifactorial condition, meaning several overlapping causes contribute to its development. While age, gender, and hormonal factors are important, chronic illnesses—particularly diabetes and thyroid disorders—and immobility are the most influential risk factors.

Adhesive capsulitis, whether primary (idiopathic) or secondary, typically progresses through a three-stage process, leading to a significant reduction or complete loss of shoulder joint movement due to adhesions and contraction of the joint capsule.

Disease Progression:

Stage 1: Freezing (Inflammatory Phase): Inflammation begins in the anterior part of the shoulder capsule, which holds the synovial fluid that helps joint movement. Pain gradually increases with shoulder movement and the patient often starts avoiding movement to reduce discomfort.

Stage 2: Frozen (Stiffening Phase): In the second phase, the joint capsule continues to shrink, leading to a significant decrease in shoulder mobility. This phase is often characterized by less pain than the initial “Freezing” phase, but the stiffness remains, making it difficult to perform daily activities.

Stage 3: Thawing (Recovery Phase): In the final stage of the condition, the shoulder is mechanically immobilized and completely stiff. At this stage, pain has typically fully subsided. Gradually, the shoulder begins to regain its normal range of motion, which can last from a few months to 2 years.

The diagnosis of the condition is clinical and it is based on the patient history and physical examination. During the physical examination, an almost complete loss of external rotation of the shoulder is observed, as well as a reduction in both internal rotation and abduction, compared to the healthy shoulder.

After discussing your symptoms and medical history, the doctor will examine your shoulder.

• Your doctor will move the shoulder carefully in all directions to see if movement is limited and if pain occurs with the motion. The range of motion when someone else moves your shoulder is called passive range of motion(PROM).
• Your doctor will compare this to the range of motion you display when you move your shoulder on your own (active range of motion or (AROM)).

People with frozen shoulder have limited range of both active and passive motion.

Frozen shoulder is often diagnosed based on the symptoms and a physical exam alone. While imaging tests like X-rays are not typically needed to confirm the diagnosis or predict its course, they can be used to rule out other conditions that may cause similar symptoms. These conditions include rotator cuff tears, arthritis, calcific tendonitis, and impingement syndrome.

In the first two stages, the treatment is conservative and aims to manage pain and restore motion:

• Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) (e.g., aspirin, ibuprofen): To reduce inflammation around the shoulder joint capsule and alleviate pain, especially during the early “freezing” stage.
• Physical therapy: Helps improve or maintain range of motion and prevent joint stiffness
• Injections (Corticosteroid Injections or Platelet Rich Plasma (PRP) Injections): They are administered in the glenohumeral joint or subacromial space to reduce inflammation and relieve pain. The PRP injections are made from the patient’s own blood and contain growth factors that promote healing. They improve pain and shoulder’s function.

These treatments aim to minimize symptoms and prevent long-term stiffness, possibly avoiding the need for surgical intervention.

Surgery for frozen shoulder is not recommended during the first two stages (freezing and frozen), which are characterized by pain and stiffness. These initial stages often improve with time and conservative treatment like physical therapy, anti-inflammatory medications, or steroid injections. Early surgical intervention can be risky and might worsen symptoms.

In the “thawing” phase (third stage) of adhesive capsulitis, shoulder pain typically subsides, and some range of motion returns. However, if the range of motion doesn’t improve sufficiently over time despite conservative treatments like physical therapy and medication, surgical intervention may be considered to restore shoulder mobility. This surgical approach, often arthroscopic capsular release, aims to release adhesions and improve joint mobility.

The procedure is performed arthroscopically. Arthroscopy is an effective and minimally invasive surgical technique for treating frozen shoulder. During the procedure, the surgeon inserts a small camera (arthroscope) and arthroscopic instruments through 2–3 very small incisions (4 mm) in the patient’s shoulder to release the frozen joint capsule.

The goal of this surgical procedure is to release adhesions (the scar tissue that has “frozen” the joint capsule), to cut thickened parts of the shoulder capsule and ligaments restricting movement and finally to restore the normal mobility of the shoulder joint.

Shoulder arthroscopy is a minimally invasive, outpatient procedure with short duration and faster recovery compared to open surgery with lower risk of complications like infections or prolonged stiffness.

Following shoulder arthroscopy, the patient begins an intensive and personalized physical therapy program from the very first postoperative day to prevent stiffness and encourage mobility. Early movement is essential to prevent the shoulder from becoming stiff again. The patient is encouraged to move the arm within a comfortable range to promote healing and flexibility and to restore joint mobility as quickly as possible.

Recovery includes a program of stretching, strengthening and flexibility exercises aimed at improving the shoulder’s mobility and functionality. The patient is regularly monitored by a specialized orthopedic surgeon to assess recovery progress and adjust the rehabilitation program accordingly. The orthopedic surgeon and physical therapist work together to ensure recovery is progressing optimally and to address any complications.

Each case is unique and requires a personalized approach from both the orthopedic surgeon and the patient’s physiotherapist.

The diagnosis of the condition is extremely complex, as there are many shoulder disorders that present with similar symptoms.

For this reason, it is important to consult an experienced and specialized orthopedic surgeon, who will provide a personalized diagnosis and determine the appropriate treatment plan based on the stage of the condition and the symptoms you are experiencing.

Dr. Panagiotis Pantos is a specialized Orthopedic Surgeon and the Director of the Orthopedic Clinic, Upper Limb Surgery Department, at the Athens Medical Group (AMG) (in Marousi) as well as the Scientific Director and Head of the Upper Limb and Sports Injuries Departments at “Osteon” Orthopedic & Spine Clinic. He treats the full range of shoulder joint conditions—either conservatively or surgically—using the most modern techniques and innovations in the field.

His many years of experience and specialization ensure reliable and safe results. Each patient is treated individually, supported by advanced facilities and state-of-the-art equipment provided by the Athens Medical Group (AMG).

How long does frozen shoulder syndrome usually last?

It typically lasts between 1 to 3 years, but this can vary based on individual cases. This syndrome has 3 stages and each stage has different duration and symptoms.

How can adhesive capsulitis of the shoulder be prevented?
Preventing frozen shoulder syndrome can be difficult, as its exact causes are not fully known.

However, the key is to maintain good mobility and strength in the shoulder, especially after an injury or surgery. Early physiotherapy and routine stretching exercises can help with prevention.

Can adhesive capsulitis affect both shoulders?

Frozen shoulder syndrome usually affects only one shoulder. However, in rare cases, it can affect both shoulders, though not at the same time.

What are the differences between adhesive capsulitis (frozen shoulder) and other shoulder conditions?

Adhesive capsulitis is distinguished from other shoulder conditions by the gradual and progressive loss of shoulder movement and persistent, constant pain. Unlike other conditions such as tendonitis or rotator cuff tears (tendon tears), which cause pain mainly during specific movements, frozen shoulder syndrome causes continuous restriction and stiffness. 

How common is frozen shoulder?

Frozen shoulder affects roughly 2-5% of the general population, but this can be higher in certain groups. Most commonly seen in people aged 30 to 60 years and It tends to affect women more than men. People with certain medical conditions are more prone to developing frozen shoulder. These include: diabetes mellitus (one of the strongest risk factors), thyroid disorders, cardiovascular disease, and prolonged immobilization of the shoulder (due to injury or surgery). The condition usually develops gradually and can last from several months to a few years, often progressing through stages of increasing pain, stiffness, and then gradual improvement. 

Can chronic stress or anxiety lead to a frozen shoulder?

Currently, there’s no scientific evidence that stress or anxiety directly cause frozen shoulder (adhesive capsulitis). However, stress and anxiety can amplify the perception of pain and discomfort in many musculoskeletal conditions, including frozen shoulder. Stress can increase muscle tension, reduce pain tolerance, and worsen inflammation, making symptoms feel more intense. Stress might also contribute to a vicious cycle where pain causes anxiety, which then increases muscle tightness and pain sensitivity, potentially worsening the overall experience of frozen shoulder. 

Can adhesive capsulitis affect the patient’s quality of life?

Frozen shoulder causes stiffness and significant reduction in shoulder range of motion. This limits the ability to perform everyday tasks like reaching overhead, dressing, cooking, driving or grooming. The persistent pain can affect sleep, mood, and motivation, leading to frustration and sometimes depression. As self-care becomes challenging, individuals may rely more on others for help with daily activities, which can impact independence and self-esteem. Physical limitations may interfere with work responsibilities and recreational activities, reducing overall life satisfaction.

Can immobility or overuse cause frozen shoulder syndrome?

One of the main causes of frozen shoulder is prolonged immobility. After an injury, surgery, or illness that limits shoulder movement (like a broken arm, stroke, or rotator cuff repair), the shoulder capsule can thicken and tighten, leading to frozen shoulder. Repetitive or excessive shoulder movements typically cause other shoulder problems like tendonitis or bursitis but aren’t directly linked to frozen shoulder. Maintaining gentle movement and physical therapy after injury or surgery is a key factor to prevent frozen shoulder by keeping the joint mobile and reducing scar tissue formation.