Frozen shoulder can make simple tasks – such as lifting your arm, sleeping on your side, getting out of bed, putting on a bra, driving or playing with your kids – painful and challenging.

This condition usually starts with pain suddenly developing in the shoulder and stiffness. Over time, the pain and stiffness get worse. It can drag on for months or even years.

So, what causes frozen shoulder? And can it be treated?

What is frozen shoulder?

This shoulder condition, also known as “adhesive capsulitis”, affects around 8% of men and 10% of women aged 25–64. But it’s more common over 40, especially for people in their 60s.

We don’t fully understand what causes frozen shoulder.

The tissues around the joint become tight, swollen and stiff. But we don’t know exactly why these changes occur and lead to pain and limited movement.

There are usually three stages:

• freezing – pain gradually gets worse and the shoulder becomes stiff, limiting the range of movement
• frozen – stiffness and pain usually peak, but may begin to ease
• thawing – pain and stiffness slowly improve, and movement begins to return.

While health professionals commonly accept it, this staged description suggests frozen shoulder will follow a predictable pattern and always get better on its own. But research suggests this is not always the case.

For example, the “freezing” stage is usually expected to last at least ten weeks. But some people will start to notice improved movement sooner.

Recovery stages will vary from person to person and can take months to years. Some people may not fully recover, even with treatment.

One 2020 study followed up with 215 patients with frozen shoulder. While over 70% of participants said they were happy with improvements in their symptoms, around 40% still had some movement restriction two years after their symptoms began.

Another study from 2008 found over a third of people they surveyed (41%) had ongoing symptoms two to seven years later, including pain and difficulty sleeping.

Who is most at risk?

Certain groups are more likely to develop frozen shoulder:

• women, especially during menopause
• people with diabetes
• older adults
• those with high cholesterol or thyroid problems.

There is some evidence genetics also plays a role, as a family history increases your risk.

But we need more high-quality research to understand what’s behind these risk factors.

For example, people with diabetes are around five times more likely to develop frozen shoulder than those without diabetes – and also have worse pain. This may be linked to diabetes-related changes in the body, such as reduced blood flow to tissues and chemical changes from high blood sugar. But the exact mechanisms are unclear, and research is yet to determine whether controlling blood sugar better could help prevent or slow frozen shoulder.

Similarly, women are 40% more likely to develop frozen shoulder than men, with one theory suggesting hormone fluctuations during menopause are responsible. But there is no clear evidence yet to support this.

How is frozen shoulder treated?

There is mixed evidence about which treatments are effective, including whether over-the-counter pain medication such as Voltaren helps.

Oral steroids

A review of the evidence suggests oral steroids, such as prednisolone, can provide some short-term pain relief and improve shoulder movement, compared to doing nothing or a placebo. But these benefits don’t seem to last beyond six weeks, and the evidence comes from a few small studies. These require a prescription.

Injections

High-quality evidence shows corticosteroid injections can provide short-term relief, compared to doing nothing.

There is also some limited evidence that corticosteroid injections and platelet rich plasma injections can provide better short-term pain relief, compared with over-the-counter pain relief and physiotherapy. However, the studies are small or poorly designed and the effects are small, so the evidence needs to be interpreted with caution.

Physiotherapy

Moderate-quality evidence suggests physiotherapy can help improve shoulder movement. Benefits of physio are greater when combined with a steroid injection, and followed up by doing the exercises at home. More research is needed to understand how well these treatments work in the long term.

What about surgery?

There are two main procedures for frozen shoulder, both done while the patient is unconscious under anaesthetic.

1. Manipulation under anaesthetic

This is a less invasive procedure where the surgeon stretches the shoulder, without cutting into the joint, to help loosen tight tissue that may be causing stiffness.

2. Arthroscopic capsular release

In this type of keyhole surgery, the surgeon cuts tight tissues inside the shoulder joint to try to free up shoulder movement.

Improvements from these procedures are typically small, and evidence suggests the results are not better than non-surgical treatments. For example, one study showed that after one year, patients who’d had surgery had similar improvements to those who’d had physiotherapy and a steroid injection, but no surgery.

These procedures also have several downsides. It’s more expensive than other treatments, carries additional risks, and typically requires weeks (and up to three months) of rehabilitation.

The bottom line

Being physically active and doing exercises can help if you’re experiencing pain and limited movement. But you don’t have to work this out alone. It’s a good idea to get advice on managing pain and how to stay active.

If you suspect you have frozen shoulder, it’s important to see a doctor or physiotherapist so they can rule out other conditions, such as fracture and arthritis.

A health professional can also discuss management – the potential benefits, harms, costs, and how easy it is to access each treatment option.

Fernando Sousa, Research Fellow in Physiotherapy, Monash University; Joshua Zadro, NHMRC Emerging Leader Research Fellow, Sydney Musculoskeletal Health, University of Sydney, and Peter Malliaras, Professor in Physiotherapy, Monash University

This article is republished from The Conversation under a Creative Commons license. Read the original article.