Adhesive capsulitis - Frozen shoulder
Illustration of a healthy shoulder capsule

Definition

Adhesive capsulitis is commonly termed frozen shoulder. It is a condition causing strong pain and rigidity of the shoulder joint. Adhesive capsulitis can manifest as an acute pathology and/or progress to a chronic stage.

A pathologic shoulder capsule characteristic of frozen shoulder

Pathology

Adhesive capsulitis is caused by chronic inflammation and thickening of the shoulder capsule with the formation of adhesions that render the shoulder rigid and painful. With the reduction of the capsule volume the movement of the shoulder is heavily reduced. When arising from a traumatic impact, adhesive capsulitis can be associated with bone fractures, lesion to the capsule, tendon injury and scar formation. The condition can also develop due to excessive scar formation post-surgery to the shoulder. The exact pathophysiology remains unclear.

The stages of a frozen shoulder rely on duration and intensity of pain

Classification

A frozen shoulder normally progresses slowly. Three stages of the diseases have been identified, each one of the duration of several months:

Freezing or Painful Stage This is the most painful phase that consequently restricts the movement of the shoulder. It can last between 6 and 12 weeks.

Frozen Stage Although the pain is reduced in this phase, it is associated with worsening of shoulder stiffness. The duration varies between 4 and 6 months.

Thawing Stage During this stage, the mobility of the shoulder gradually improves. It takes up to over a year to restore shoulder mobility. 10-15% of the patients suffer from persisting stiffness and the shoulder never returns to normal function.

Left: Distal radius intraarticular, displaced fracture; Middle: Older distal radius fracture with callus formation; Right: Distal radius and ulna fracture, extraarticular and displaced

No 2.

Intra-articular fracture extends to the wrist joint (or articulation)

Extra-articular fracture is located outside of the wrist joint

Open fracture when bone fragments perforate the skin

Comminuted fracture when the bone breaks into multiple fragments

Non-displaced when the anatomical alignment of the bone is maintained or displaced when the bone fragments move apart.

Melone’s classification describes the characteristics of intra-articular fractures of the radius:

i    Stable fracture

ii    Unstable "die-punch"

iii   "Spike" fracture

iv Split fracture

v   Explosion injuries

Acetabular fracture of the pelvis

Acetabular fractures

These fractures are divided into:

Anterior pillar (not weight bearing part of joint)

Posterior pillar (often associated with dislocation of the hip including the weight bearing part of joint)

Transverse

Comminuted involving both column type 

Sacral / coccygeal fractures

The sacrum is a triangular-shaped bone formed by 5 fused vertebrae, which provide a posterior wall to the pelvic ring. At each side of the sacrum, the ala structures articulate with the ilium bones forming the sacro-iliac joints. Sacral fractures are usually parallel to the spine and can involve the ala. Less frequently sacral fractures may display an “H” shape, including a transversal fracture uniting both sides of the sacrum. Three zones are described where sacral fractures can occur that are along vertical lines relative to the alignment of the foramina. Sacral fractures may result in sacral instability and require treatment via sacroplasty (injection of bone glue into the fracture). Surgery is necessary in case of associated neurological symptoms.

Fractures of the coccyx involve the tailbone, the terminal portion of the spine situated below the sacrum formed by 3 to 5 fused vertebrae. Coccyx fractures occur when falling on a seated position. They are more common in elderly women and seldom require surgical treatment.

Prolonged shoulder immobilisation may result in a frozen shoulder

Causes

The causes leading to a frozen shoulder have not been fully elucidated. This pathology may be unrelated to specific diseases or injuries but is frequently observed after trauma and post-surgery to the shoulder or arm. A frozen shoulder is mostly the consequence of prolonged immobilisation due to the use of a sling or following a continued period of ongoing shoulder pain. It can also be caused by an incorrect posture during work or sport activities.

Diabetes may be a risk factor for a frozen shoulder

Risk factors

Frozen shoulder does not correlate with specific professions or sports but is mostly linked to ageing in individuals between 40 and 60 years. In women it is twice as frequent than in men. It has been associated with chronic diseases including diabetes type 2 (up to 40% incidence), cardiovascular diseases, hyper/hypothyroidism as well as stroke and Parkinson’s disease.

Pain is typical in daily living activities

Symptoms

Pain is the main symptom of a frozen shoulder being usually an aching pain of the shoulder area occasionally extending to the upper arm. Pain is significantly stronger at the initial stage of the condition. Other symptoms include:

Pain when lying on the shoulder

Difficulty in performing normal daily activities (brushing hair, putting on shirts or bras).

MRI scan showing pathology of a shoulder capsule

Diagnosis

The clinical examination for the diagnosis of a frozen shoulder begins with medical history and physical investigation using a variety of tests to assess changes in the range of shoulder movement. X-rays are taken to exclude the presence of other diseases (arthritis). Ultrasound and MRI are performed to visualise the pathological changes of the soft tissue structures of the shoulder joint. Subacromial bursitis is a possible associated pathology to a frozen shoulder.

Treatment

Local application of ice pack on the shoulder

Nonoperative treatment

Conservative treatment of a frozen shoulder includes measures to reduce pain and inflammation with application of ice and heat packs and administration of oral anti-inflammatory medications (NSAIDs) or local steroid injection with guidance via ultrasound. Physiotherapy begins as early as possible to restore mobility of the frozen shoulder. It includes stretching and exercise with passive and active movements. 

Example of arthroscopic surgery

Surgical treatment

If symptoms are not improving with conservative treatment and rehabilitation, in rare cases surgery is recommended. This includes a simple but robust manipulation of the shoulder under anaesthesia, whereby force is used to release the stiffness and restore flexibility of the joint. This does not require a surgical access to the shoulder. Alternative, shoulder arthroscopy, a minimally invasive procedure compared to open surgery, aims to dislodge the scarred tissue and remove the adhesions that impair the movement. Often both methods are combined to obtain optimal results.

Acupuncture for treatment of a frozen shoulder

Rehabilitation

Following surgery, physiotherapy is required to maintain the range of movement that was obtained with the intervention. The rehabilitation regime includes a variety of approaches:

Massage

Electrotherapy

Dry needling

Hydrotherapy

Acupuncture

Hydrodilatation

Gentle exercise to restore joint flexibility and muscle strength to the shoulder

Correction on modifying posture and sport activities

The time of recovery can last from several weeks to months. During this period physiotherapy is essential. Most patients have a satisfactory level of recovery, however for some, pain and residual shoulder stiffness may remain.

Antiinflammatory therapy can prevent a frozen shoulder

Prevention

Frozen shoulder usually does not reoccur but a few cases of recidivism have been reported. It is paramount that any form of shoulder or arm immobilisation is avoided or reduced to a minimum to prevent the onset of a frozen shoulder. This applies particularly after trauma and following surgery to the upper extremities. To facilitate maintenance of shoulder movements anti-inflammatory therapy is advised. Occasionally, at initial symptoms shoulder mobility is restored with early manipulation under anaesthesia.