What is frozen shoulder?

Frozen shoulder is a painful and disabling condition in which the shoulder capsule becomes inflamed and stiff, resulting in the restricted range of motion of the shoulder. In some cases, the shoulder movements are so severely affected that the joint essentially becomes 'frozen'. Frozen shoulder is also known as adhesive capsulitis or shoulder contracture.

Frozen shoulder:

  • Typically takes 2-9 months to develop;
  • Is estimated to affect up to one in 50 people across the general population;
  • Typically affects one shoulder, but in a small number of people both shoulders may be affected, and;
  • Is commonly confused with a rotator cuff injury.  

 

Frozen shoulder limits your normal range of motion.In some cases, shoulder movements become so severely affected that the shoulder joint becomes 'frozen'.  

The shoulder joint capsule

The shoulder joint is surrounded by a fluid-filled capsule (which can be thought of as a sac) that holds the synovial fluid within the joint space. The capsule also holds together and supports the movement of the shoulder joint. If the capsule is too loose, the range of motion will be too great and the joint may dislocate. If the joint is too tight, the range of motion becomes too restricted to allow normal movement. 

Synovial

Pertaining to the fluid that lubricates joints (called synovia). A joint that produces synovia is referred to as a synovial joint.

Causes and risk factors

In frozen shoulder, the capsule thickens and swells because of the formation of adhesions that have formed inside the capsule.

The cause of frozen shoulder is not yet clear; however, it appears to be more likely to occur in people with recent immobilisation of their shoulder following an injury or surgery. People with diabetes are also particularly prone to developing frozen shoulder.

Other risk factors for frozen shoulder include:

Adhesions

Bands of scar tissue that join two surfaces of the body that are not usually connected.

Heart disease

A class of diseases that involves the dysfunction of the heart and/or the blood vessels.

Diabetes

A metabolic disorder that is caused by problems with insulin secretion and regulation and which is characterised by high blood sugar levels. Also known as diabetes mellitus.

Dupuytren's contracture

A shortening and thickening of the tissue of the palm of the hand that leads to the clawing of the fingers.

Signs and symptoms

The symptoms associated with frozen shoulder may begin gradually and worsen over time.

Some of the more general symptoms may include:

  • Marked pain, especially when jerking the shoulder or making sudden movements;
  • Reduced arm swinging with walking;
  • Difficulty reaching above shoulder height;
  • Inability to throw a ball;
  • Inability to reach for something;
  • Difficulty sleeping on the affected side;
  • Stooped, rounded shoulders;
  • Neck and back pain, and;
  • Stiffness and swelling around the shoulder joint.

More specifically, the symptoms associated with frozen shoulder are typically classified across four phases:

  • Initial phase - during this phase, pain is present, but the range of motion in the shoulder joint remains fairly unaffected:
  • Freezing - during this phase, the capsule within the joint becomes increasingly inflamed and thickened. As it thickens, it results in a progressively restricted range of motion. The freezing phase is commonly associated with intense pain around the shoulder area, which may come and go:
  • Frozen - during this phase there is no further reduction in the range of motion and the level of pain is greatly reduced, and;
  • Thawing - during this phase, there is a gradual improvement in the range of motion, but there may be some associated weakness with the use of the shoulder.

If no treatment is received, each of these phases can potentially last for around 6-8 months.

Methods for diagnosis

Diagnosis of frozen shoulder is based on a physical examination and your detailed medical history. During the physical examination, you may be asked to perform several actions involving the shoulder and arm, so that your range of motion can be assessed. You may be asked to reach across your chest to touch the opposite shoulder, reach behind your back to scratch yourself and raise your arms above head height. Your doctor may also move your arm around the shoulder joint to evaluate your range of motion, which may help them distinguish between frozen shoulder and a rotator cuff injury.

Frozen shoulder and arthritis are the only two conditions that can cause the loss of motion in every direction of the shoulder. Frozen shoulder is the more common of these two conditions

Imaging

Frozen shoulder can generally be diagnosed based on clinical examination alone, but imaging tests may be ordered to rule out other structural problems. An X-ray may be used to eliminate arthritis. An ultrasound or a magnetic resonance imaging (MRI) scan can be used to exclude rotator cuff injury.

Magnetic resonance imaging

A type of imaging that uses a magnetic field and low-energy radio waves, instead of X-rays, to obtain images of organs.

Ultrasound

A scan that uses high-frequency soundwaves to produce images of the body’s internal structures.

X-ray

A scan that uses ionising radiation beams to create an image of the body’s internal structures.

Types of treatment

Frozen shoulder treatment involves controlling the pain and improving the shoulder's range of motion.

Medications

Pain-relief medications such as paracetamol or ibuprofen may help treat the pain. Icepacks or heat packs can also provide some pain relief. These should not be placed directly on the skin, as they may cause skin damage. Wrap them in a towel first.

Physical therapy

Physical therapy is used to maintain the range of motion, stretch the shoulder joint and strengthen its tendons. It may take weeks for progress to become apparent.

Corticosteroid injection

Some people may find relief from their symptoms when corticosteroids are injected into their shoulder.

Shoulder manipulation

While under a general anaesthetic, the patient's shoulder joint is manually manipulated into different positions to help loosen overly tight tissues.

Surgery

If more conservative treatments have not proved effective, surgery may be recommended for some people with frozen shoulder. The surgical procedure is carried out under general anaesthetic and uses an arthroscope to remove the scar tissue from the shoulder joint, which allows an increased range of motion. Sterile water can also be injected into the shoulder joint capsule to help stretch the tissue and increase the range of motion. It may take months after the surgery for the full range of motion to return.

Arthroscope

An instrument used to view inside a joint and treat joint conditions.

Corticosteroids

A medication that resembles the cortisol hormone produced in the brain. It is used as an anti-inflammatory medication.

General anaesthetic

An anaesthetic given to a person to put them to sleep while having an operation or medical procedure. Afterwards, the person regains consciousness and usually has no memory of the procedure. A general anaesthetic is given in hospital by a specialist called an anaesthetist.

Tendons

Dense bands of connective tissue that attach muscles to bones.

Potential complications

  • Stiffness and pain continue despite therapy;
  • Possible fracture of arm if moved forcefully during manipulation, and;
  • Surgical complications - infection, bleeding, swelling, stiffness and recurrence of frozen shoulder.

Fracture

A complete or incomplete break in a bone.

Infection

Entry into the body of microorganisms that can reproduce and cause disease.

Prognosis

Most people recover from frozen shoulder within two years without treatment. Physical therapy and pain-relief medications can speed this up. Relapses in the same shoulder are uncommon.

Prevention

Early treatment can help stop the progression of the condition. People with diabetes can reduce their risk of developing frozen shoulder by properly managing their diabetes.

A gentle, progressive range of motion exercises can help stretch the shoulder and reduce the risk of developing frozen shoulder after surgery or injury. 

Diabetes

A metabolic disorder that is caused by problems with insulin secretion and regulation and which is characterised by high blood sugar levels. Also known as diabetes mellitus.