Frozen shoulder refers to a shoulder that has become “frozen stiff” due to inflammation inside the shoulder joint resulting in capsular contracture.
The inflamed capsule of the shoulder joint becomes thickened and contracted. This reduces the actual space inside the shoulder joint.
This condition is typically described as having three stages:
- Stage one: The “freezing” or painful stage, which may last from six weeks to nine months, and in which the patient has a slow onset of pain. As the pain worsens, the shoulder loses motion.
- Stage two: The “frozen” or adhesive stage is marked by a slow improvement in pain but the stiffness remains. This stage generally lasts from four to nine months.
- Stage three: The “thawing” or recovery, when shoulder motion slowly returns toward normal. This generally lasts from 5 to 26 months.
Adhesive Capsulitis and Pericapsulitis are common terms used to refer to the condition of frozen shoulder.
Adhesive capsulitis denotes the inflammation of the shoulder capsule leading to the tightening and sticking together of the shoulder capsule.
This results in a smaller shoulder volume hence leading to stiffness and pain.
The following picture shows the inside of a frozen shoulder. The shoulder joint capsule appears red and inflamed.
Pericapsulitis refers to the inflammation that occurs around the shoulder. Commonly, the pain is all around the shoulder during frozen shoulder.
This is due to inflammation of the tissues, muscles and tendons around the shoulder joint which contributes to the pathology.
There is a space above the shoulder joint and below the acromion bone (which is an extension of the shoulder blade/scapula). This space is called the “subacromial space” and it contains a fluid-filled sac called a bursa. This fluid filled sac acts as a lubricant during movement of the shoulder joint under the acromion bone. Extensive scar tissues can form in this space in patients with frozen shoulder and this contributes to the stiffness of the affected shoulder.
This picture shows the scar tissues in the subacromial space before and after surgical removal.
The cause of frozen shoulder is often unknown.
There are two different types of frozen shoulder:
- Primary frozen shoulder – whereby there is no real known cause and the condition just happens. It is associated with diabetic patients.
- Secondary frozen shoulder – whereby there is a cause for the onset of the frozen shoulder.
For example, a tear of the rotator cuff tendon in the shoulder joint causes pain which makes the sufferer moves the painful shoulder less and this gradually develops into a full-blown frozen shoulder.
It can also occasionally result from trauma to the shoulder.
Frozen shoulder most commonly affects patients between the ages of 40 to 60 years old, and it is two times more common in women than in men.
Patients with diabetes are at particular risk for developing a frozen shoulder. Their risk of developing frozen shoulder is five times as common compared to non-diabetics. Other endocrine abnormalities, such as thyroid problems, can also lead to this condition.
Patients who sustain a shoulder injury, or undergo surgery on the shoulder can develop a frozen shoulder joint. When injury or surgery is followed by prolonged joint immobilisation, the risk of developing a frozen shoulder is the highest.
Several systemic conditions such as heart disease and Parkinson’s disease have also been associated with an increased risk for developing a frozen shoulder.
Signs & Symptoms
Main symptoms of a frozen shoulder are:
- Shoulder pain; usually a dull, aching pain
- Limited movement of the shoulder
- Difficulty with activities such as brushing hair, putting on shirts or bras
- Pain when trying to sleep on the affected shoulder
Frozen shoulder without any known cause starts with pain. This pain prevents the patient from moving his arm. This lack of movement can lead to stiffness and even less motion. Over time, the patient is not able to do movements such as reaching overhead or behind.
Treatments generally involve the following:
- Stretching exercises to improve range of motions as well as prevent atrophy of surrounding shoulder muscles.
- Use of oral anti-inflammatory medications.
- Physiotherapy modalities – trigger point massage, ultrasound and heat therapy.
- Injection of corticosteroids into the shoulder – this allows the inflammation to reduce and hence decrease the pain to allow physiotherapy to proceed.
- Hydrodilatation – injection of saline into the contracted shoulder joint to break the adhesions and increase shoulder volume.
- Manipulation under anaesthesia – this allows the surgeon to break the adhesions in the frozen shoulder with the patient under anaesthesia.
Surgery is recommended if non-surgical treatment is not effective. This procedure (shoulder arthroscopy) is done under anesthesia. During surgery the scar tissue is released (cut) by bringing the shoulder through a full range of motion. Arthroscopic surgery can also be used to cut the tight ligaments and remove the scar tissue from the shoulder. After surgery, you may receive pain blocks (shots) so you can do physical therapy.