Frozen shoulder is a very common cause of pain in the shoulder, but is poorly understood. In this post I will explain all about it and also hopefully dispel some of the myths!
What is frozen shoulder?
Frozen shoulder describes a specific condition which results in pain and loss of movement in the shoulder.
There are other problems which can cause stiffness in the shoulder such as arthritis or significant injury, but frozen shoulder is a specific disease. There is no such thing as a frozen knee or frozen hip and this condition occurs only in the shoulder.
Frozen shoulder has a number of characteristics. Firstly, the symptoms usually develop gradually and the patient will notice a progressive stiffening of the shoulder with worsening pain. It can take anything from a few days to many months to reach its most painful. The pain is most often felt in the upper outer arm (even though this area is itself not tender to touch or press).
I usually ask patients if the pain is worse when they reach out suddenly or jolt the shoulder, or if they try to reach behind their back. The answer to these questions is usually ‘yes’. Patients will often confirm that they have had occasional symptoms of numbness or tingling radiating into the arm. I will try to explain why these symptoms occur in due course.
Why does frozen shoulder happen?
The short answer to this is we don’t really know. We do know certain groups of people are more likely to get it than others.
Primary frozen shoulder (i.e. when it comes on out of the blue with no obvious cause) is most common in ladies in their forties and fifties and is also more common in diabetics and epileptics. That being said, it can affect pretty much any adult.
Frozen shoulder can also occur secondarily to other shoulder issues (e.g. tendon problems) or after even a minor injury or indeed surgery on the shoulder. In other words, anything which puts the shoulder ‘out of kilter’ in some way can cause the shoulder to be predisposed to its development.
There are also one or two medications which can increase the risk of getting frozen shoulder.
What causes the symptoms?
The shoulder joint is surrounded by a capsule. In frozen shoulder, this capsule becomes inflamed making it painful. The capsule then becomes thickened and tight, resulting in a stiff shoulder.
We understand the type of cells which migrate into the capsule to cause these changes. They are effectively a cross between scar forming cells and muscle cells. The cells lay down a type of scar tissue in the capsule and then contract in the way muscle cells do, resulting in thickening and tightening. This also explains why people have pain when they reach out suddenly or reach behind their backs, as in doing so they are stretching the tight inflamed capsule.
The nerve type symptoms are thought to be due to irritation of the nerves passing from the neck to the arm as a result of the abnormal mechanics and movement of the frozen shoulder.
How long does a frozen shoulder last?
Frozen shoulder has traditionally been described as having three distinct phases;
- freezing phase
- frozen phase
- thawing phase
These phases describe the progressive worsening, followed by a fairly static phase and finally the gradual resolution of symptoms. The length of these phases is variable as is the overall length of time which the condition may last.
We generally say the condition will last about one to two years, but unfortunately for many people the problems can persist for four or more years.
It used to be said that frozen shoulder always goes away of its own accord eventually, but there is increasing evidence that a significant number people will continue to have some symptoms long term.
There is also some evidence that without treatment, the final outcome may be less good than with treatment.
Do I need X-rays or scans if I have a frozen shoulder?
A shoulder surgeon should have no difficulty in diagnosing a frozen shoulder from the patient’s history and an examination.
Scans are usually not necessary before instigating treatment. Frozen shoulder is not seen on an X-ray but can usually be detected on an MRI scan as the thickening and tightening of the capsule is often evident.
What is the best treatment?
A few years ago, the existing studies were looked at all together, to try and see how effective each of the common treatments were at reducing the effects of frozen shoulder.
This so called ‘meta-analysis’ suggested that physiotherapy alone provided the least benefit. Steroid injection(s) were found to be more effective, but a steroid injection combined with physio was more effective still. Surgical options were found to be the most effective.
When treating a patient with frozen shoulder, I will always offer them a steroid injection along with physiotherapy, as it is best to try the simpler options before resorting to surgery. Depending upon the result, a further injection may be offered.
I have no doubt the earlier in the frozen shoulder process a steroid injection is administered; the more likely that it will be effective.
When I did some advanced training in shoulder arthroscopy in South Africa, I saw a very good demonstration of this very point. In a very busy practice, we saw numerous people with frozen shoulder. In South Africa, people would tend to consult a specialist almost as soon as they had a problem and initial consultation with physiotherapists or GP’s was much less common than in the UK. Thus we would see and inject people with frozen shoulder very early in the disease process.
Although we saw a very large number of such patients, not a single one ended up needing surgery. Thus, when I teach about frozen shoulder, I say ‘the most important thing is for the sufferer to have access to a steroid injection as soon as possible.’
If the level of symptoms remains unacceptable, the surgical options are discussed. Surgery involves an arthroscopic (keyhole) procedure to very carefully divide the tight parts of the capsule in a controlled fashion. Releases are performed until full range of movement is achieved.
It is important for the patient to engage in physiotherapy and perform exercises regularly. Inevitably many patients will stiffen up to a degree in the postoperative period, but virtually all gain worthwhile benefit from the surgery.
It is not uncommon, however, to regain complete range of movement and a pain free shoulder after the operation.
The old style of operative treatment involved putting a patient to sleep and forcing the shoulder to move. This so called ‘manipulation under anaesthesia’ has gone out of favour because of an unacceptably high incidence of inadvertently damaging important structures in the shoulder during the manipulation.
I have personally seen a couple of patients whose arms have been broken during manipulation in other hospitals, though fortunately this is pretty uncommon.
A treatment known as hydrodilatation has enjoyed variable popularity over the years, but recent studies suggest the result of this treatment does not compare favourably with the keyhole release procedure.
Many other treatments have been used in the past without evidence of their efficacy and I will not bother to mention them here.
Can frozen shoulder come back after treatment?
Frozen shoulder is not thought to recur in the same shoulder. Patients sometimes present with a frozen shoulder, having been told they have had frozen shoulder before. It is likely that this was misdiagnosed in the first place and they did not actually have the same problem in that shoulder previously.
Will I get it in the other shoulder?
This is a question patients often ask me. The answer is you are definitely at higher risk than the general population, but it is by no means inevitable. It is thought that about 30% of people with a frozen shoulder will develop the condition on the other side.