Frozen shoulder, or adhesive capsulitis to give it its proper medical name, is a common shoulder problem that occurs in about 3-5% of the population. It is characterised by severe pain and stiffening of the shoulder joint. This stiffness can cause significant disability, particularly in people of working age. It is important to realise that there are other medical conditions that can masquerade as frozen shoulder or mimic its symptoms. The other main cause of shoulder stiffness and pain together is glenohumeral (shoulder arthritis). Differentiating between the causes of shoulder stiffness can be difficult and it is generally accepted that an X-ray is required to make a definitive diagnosis. Frozen shoulder is often banded about as a general 'umbrella' diagnosis for shoulder pain; it's a diagnosis that lots of people get when they don't actually have it, and vice-versa. As with lots of shoulder problems, we still don't fully understand frozen shoulder and as such there are several theories about what causes it and how it progresses. What we do know is that it typically affects people between the age of 40 and 60, though people outside this age range can still develop frozen shoulder. There are other well documented risk factors that include female gender, diabetes, thyroid disease and having had recent surgery or trauma. What is frozen shoulder?
The shoulder joint is lined by a structure that we call the joint capsule; this can be thought of as a bag surrounding the joint (see image above; this is a right shoulder viewed from the front). The capsule is baggy and has folds in certain areas, this allows the capsule to unfurl as the arm is moved in to different positions. With frozen shoulder, parts of the capsule become thickened, scarred and inflamed. This not only causes pain, but as the capsule can no longer unfurl due to being scarred, the shoulder becomes very stiff.
Historically, people have described frozen shoulder as having three distinct phases; freezing (pain), frozen (pain and stiffness) and thawing (resolving stiffness). Classically there is no trigger and you can't identify a reason for the pain. People often describe having had niggling pain for some time which suddenly becomes severe for no reason. Sudden jarring movements can be intensley painful. The shoulder then becomes stiff and people find that they are unable to reach their hand behind their back, reach in to cupboards or wash their hair.
Frozen shoulder is described as being self limiting, i.e. It's natural history will always lead to resolution and it will get better. Generally people quote a time frame of 18 months to two years for symptoms to resolve. However, literature suggests that people still experience a degree of pain and stiffness at seven years after onset. As such there are several treatment options available to try and speed up resolution.
Misdiagnosis is common with frozen shoulder and getting an early, accurate diagnosis is key to appropriate treatment. In the early painful stage a steroid injection into the shoulder joint can be effective in reducing symptoms and preventing progression. There is little evidence to suggest that there is any role for physiotherapy in this stage of true frozen shoulder. If anything lots of aggressive physiotherapy at this stage is likely to make things worse. The caveat here is that the important part is getting an accurate diagnosis so that appropriate treatment can be actioned.
Physiotherapy has much more of a role to improve range of motion and alleviate symptoms of stiffness when pain has subsided. Sometimes with the best will in the world the stiffness remains unchanged. If this is the case then intervention such as hydrodilatation injection may be considered. This is an injection under X-ray or ultrasound guidance where a volume of fluid is forced in to the joint to stretch the capsule. Literature suggests that around 70% of people are very happy with this both in terms of reduced pain and increased movement. Key hole surgery to release the scar tissue is considered the gold standard treatment i.e. It has the best outcomes. It is important to remember that any intervention is to speed up recovery not to cure the problem.
How can you help yourself?
Appropriate stretches and exercises are key to recovery, and accurate diagnosis will guide this. Take regular and effective analgesia to allow you to use the arm as normally as possible.