1. What is frozen shoulder?
Frozen shoulder (also known as adhesive capsulitis) is a common shoulder condition characterised by pain and stiffness. It is often a self-limiting condition, but typically takes a couple of years to run its course and can cause significant pain and disability in the meantime.
What causes frozen shoulder?
Arthroscopy of a frozen shoulder showing severe capsulitis
The truth is no-one really knows the underlying cause. It may be triggered by trauma or surgery, and it may complicate other shoulder conditions such as a rotator cuff tear or calcific tendonitis. However it can also happen out of the blue.
What we do know is that the capsule, the lining of the joint, becomes inflamed and then increasingly thickened and fibrosed. The shoulder is usually a very mobile joint. To allow this movement, the capsule is normally quite loose and baggy. In a frozen shoulder, the fibrosed capsule tightens up which physically restricts movements in all directions. Any sudden movements against this tight and inflamed capsule can be very painful.
It is more common in diabetics. Unfortunately they also tend to have more severe and long-lasting symptoms.
What is the natural course of frozen shoulder?
Frozen shoulder is usually divided into three stages:
I – The painful phase
During the painful phase, the capsule becomes inflamed, but hasn’t really had time to tighten up. This means that the shoulder becomes increasingly painful and movements may be uncomfortable. However the shoulder should still be reasonably mobile. It can be difficult to make an accurate diagnosis at this stage because the stiffness which typifies the condition hasn’t yet set in. This typically lasts a few months.
II – The frozen phase
The capsule has now become thickened and fibrosed. This means that shoulder movements become increasingly limited. The capsule is also still very red and inflamed which means that any sudden movements cause pain. This is the most disabling and painful stage. This typically lasts 4 to 12 months.
III – The thawing phase
The redness and inflammation in the capsule has now subsided which means that the shoulder is much less painful. Stiffness remains, but gradually improves as the capsular fibrosis resolves. Movement slowly increases, though may not return entirely to normal. This typically lasts 4 to 8 months, but may continue for several years.
What are the symptoms of frozen shoulder?
The two main symptoms are pain and stiffness. The pain is typically worse with sudden movements and also at night. Once the frozen phase has set in, movements become increasingly limited. You may be unable to raise your arm above shoulder height or reach behind your back or out to the side.
How do you diagnose frozen shoulder?
The diagnosis is mainly clinical. This means that a specialist can usually make the diagnosis based on your symptoms and an examination of your shoulder. However it is important to get a shoulder x-ray in order to rule out arthritis, as the latter can also cause pain and stiffness.