Introduction
As the name implies, Frozen Shoulder is where a shoulder stiffens up so much that it is very difficult to lift the arm up beyond shoulder height and cannot perform normal movements such as reaching behind the back or moving the arm across the front of the body. Technically frozen shoulder is defined as 'significant movement loss' which in practice is not being able to move the arm more than 100 degrees away from the body.
Originally called 'frozen shoulder' in the 1930s, the medical term for the condition is 'adhesive capsulitis' as it is due to inflammation of the glenohumeral joint capsule, which wraps around the shoulder joint. It can come on quite suddenly and out of nowhere and in this case is called 'idiopathic frozen shoulder'. It affects around a quarter of a million people in Australia.
Causes
The immediate cause of the condition is a substantial shrinking of the capsule itself which in turn causes pain and stiffness. Medical science has not determined the precise underlying cause of frozen shoulder – however, some people are at more risk of developing the condition than others including:
- Women – the condition is slightly more common in women than men.
- Age – more common in people over 40.
- People who have undergone any treatment (surgical or non-surgical) which has required immobilisation of the shoulder for an extended time (or where the person has been more protective of the affected arm or not adhered to a rehabilitation exercise program).
- People with diabetes, Parkinson's disease, cardiovascular disease, stroke, lung disease or thyroid conditions.
Symptoms
Symptoms include:
- Permanent dull pain (and subsequent sleep issues).
- Rapid arm movements cause sharp pain.
- Difficulty with day-to-day activities such as getting dressed, personal hygiene etc.
- Very restricted arm/shoulder movement.
Frozen shoulder generally progresses through three sequential stages:
- Freezing – there is initially some pain and the ability to move the joint progressively decreases. This stage can last 3-9 months. It is sometimes also referred to as the 'red' phase as this is how the capsule appears when examined during an arthroscopy (see arthroscopic releases for frozen shoulder) due to bleeding and inflammation.
- Frozen – during this period the primary symptom is stiffness, with less pain than in stage one. This second stage can last 9-15 months. It is sometimes also referred to as the 'pink' phase (for the same reasons as above).
- Thawing – this stage is a gradual return to normal movement, and is sometimes referred to as the 'white' phase. This final stage can be 15-24 months in duration.
Total length of recovery is generally two and half years from first onset.
Tests / Diagnosis
The first stage of diagnosis is a physical examination, including a review of strength and range of motion of the arm and shoulder, as well as a review of medical history.
This may be followed by imaging via x-ray, ultrasound or MRI or a combination of these. X-rays will not show any soft tissue, but will help exclude the condition being caused by something else. Ultrasound allows the rotator cuff tendons to be assessed during movement – if these are not damaged, a diagnosis of frozen shoulder is more likely. An MRI scan produces very detailed images of bones and soft tissue and may be used to validate the diagnosis.
Treatment
Most cases of frozen shoulder are treated without surgery – a combination of pain medication with gentle movement and stretches and gentle exercises to maintain strength. In some cases, surgery to the ligaments and the capsule itself may be necessary to increase movement of the shoulder.