Frozen Shoulder (Adhesive Capsulitis)

Adhesive capsulitis is known as frozen shoulder because it is a condition that limits the range of motion of the joint.

Symptoms and causes

Frozen shoulder, medically known as adhesive capsulitis, is the inflammation and thickening of the connective tissue of the joint, which causes spontaneous fibrosis (formation of scar tissue). It is a painful condition that significantly limits the ability to move.

The main characteristic of adhesive capsulitis is joint stiffness, which prevents full shoulder movement, although it also causes intense pain.

The prognosis of frozen shoulder is generally good. Although recovery is slow, most patients regain full mobility without sequelae.

Symptoms

Adhesive capsulitis develops in three stages in which symptoms gradually evolve:

Inflammatory phase: this is the initial period, lasting between 2 and 9 months. Shoulder stiffness is perceived along with diffuse (difficult to localize) but intense pain, which worsens at night.
Stiffness phase: this is the intermediate phase, typically lasting between 4 and 12 months. There is a significant restriction in the joint’s range of motion and a decrease in pain. It is therefore characterized more by stiffness than by pain.
Resolution phase: also known as the thawing phase, it develops gradually and may last between 1 and 3 years. During this period, range of motion is progressively restored and pain disappears.

Causes

Frozen shoulder is classified into two types depending on the underlying cause:

Primary adhesive capsulitis: an idiopathic condition, meaning of unknown cause. It appears spontaneously and symptoms progressively worsen. It is often associated with hormonal, immunological, or biomechanical imbalances.
Secondary adhesive capsulitis: arises as a consequence of an underlying cause:

Intrinsic frozen shoulder: due to diseases affecting the internal structures of the shoulder:

Rotator cuff injury (the group of muscles and tendons that enable shoulder movement).
Biceps tendinopathy: inflammation of the tendon supporting the biceps muscle.
Subacromial syndrome or impingement: rotator cuff tendons are compressed by bone.
Prolonged immobilization after surgery or fracture.

Extrinsic frozen shoulder: results from conditions outside the shoulder:

Cervical radiculopathy: compression of a nerve root in the neck.
Fracture of the humerus or clavicle.
Acromioclavicular arthritis: the cartilage connecting the clavicle to the acromion (part of the scapula) wears down due to repetitive movements.
Scapulothoracic abnormalities: altered movement or positioning of the scapula.
Stroke: interruption of blood flow to the brain.
Tumor in the chest wall.
Breast cancer.

Systemic frozen shoulder: caused by diseases affecting the entire body:

Diabetes.
Heart disease.
Thyroid disorders: hyperthyroidism, hypothyroidism.
Anemia.

Risk Factors

Factors that increase the risk of developing frozen shoulder syndrome include:

Sex: more common in women.
Age: typically occurs between 40 and 60 years.
Diabetes.
Thyroid disorders.
Parkinson’s disease.
Shoulder trauma.
Previous shoulder surgery.
Prolonged shoulder immobilization.

Complications

If adhesive capsulitis is not properly treated or the shoulder does not respond as expected to therapy, it may lead to the following complications:

Postural alterations affecting the spine.
Loss of muscle mass.
Stiffness.
Inability to perform daily activities.
Insomnia.
Anxiety.

Prevention

Frozen shoulder cannot always be prevented, as its progression depends on the underlying cause. One way to reduce the likelihood of developing it is to maintain joint mobility after surgery or injury. To do so, it is recommended to:

Early mobilization: begin light movements as soon as permitted by the specialist.
Perform range-of-motion exercises daily, even if discomfort is present:

Pendulum exercises: swinging the arm back and forth and in circles.
External rotations.
Gently lifting the injured arm with assistance from the healthy arm.

Gradually strengthen the muscles.
Maintain proper posture during daily activities.
Avoid sleeping on the affected shoulder.

What specialist treats frozen shoulder?

Adhesive capsulitis is a condition managed within the specialty of Traumatology and Orthopedic surgery.

Diagnosis

The diagnosis of frozen shoulder is usually clinical and performed during a specialist consultation:

Medical history: includes patient history, lifestyle, general health status, and reported symptoms.
Physical examination: in addition to observing the shoulder at rest, the specialist asks the patient to move it to assess pain intensity and range of motion. Passive range of motion is also evaluated by the clinician manipulating the arm. Finally, the area is palpated to identify points of pain, inflammation, or deformities.

To rule out other conditions with similar symptoms, imaging tests may be requested:

X-ray: uses X-rays to detect fractures, dislocations, infections, calcium deposits, arthritis, osteoarthritis, or bone tumors.
CT scan (computed tomography): provides three-dimensional images of the shoulder using X-rays from different angles. It is used to identify complex fractures, injuries, dislocations, or tumors.
Magnetic resonance imaging (MRI): uses non-ionizing radiofrequency waves and an electromagnetic field to obtain detailed images of bones and soft tissues of the shoulder. It is effective for diagnosing tendinitis, bursitis, rotator cuff tears, dislocations, infections, fractures, arthritis, or tumors.

Treatment

The most common treatments for frozen shoulder, which are often combined, include:

Exercises to strengthen and maintain the joint’s range of motion. These are typically the same as those recommended for prevention.
Medication: analgesics and anti-inflammatory drugs help relieve pain and reduce swelling.
Physiotherapy: rehabilitation exercises help restore shoulder mobility.
Injections: in persistent cases that do not improve with exercise, substances are injected directly into the shoulder to promote recovery:

Steroids: improve movement and reduce pain.
Sterile solution to stretch the tissue and facilitate movement.

Arthroscopy: when none of the above treatments are effective, a minimally invasive surgical procedure is performed. Through several small incisions (0.5 to 1 cm), the necessary instruments are introduced, including a camera to guide the specialist, to remove scar tissue.