This is a plain English summary of an original research article
A so-called frozen shoulder is painful and stiff for months and sometimes years. People with the condition may be unable to move their arm or shoulder and the pain may disturb their sleep.
The three treatments most often offered by the NHS are physiotherapy, manipulation of the shoulder under general anaesthesia, and a form of keyhole (minimally-invasive) surgery called arthroscopic capsular release.
The largest comparison of these treatments to date found that, after a year, all three approaches were effective, but they had different benefits and drawbacks. Physiotherapy could be delivered more rapidly but was more likely to require follow-up treatment. Surgery carried higher risks and costs. Manipulation under anaesthesia was the most cost-effective treatment, but waiting times were longer than for physiotherapy.
The findings should help patients and clinicians decide on the most appropriate treatment. The study could reduce the use of surgery for people with a frozen shoulder, and make considerable cost savings for the NHS.
What’s the issue?
Frozen shoulder occurs when the soft tissue around the shoulder joint becomes inflamed and scarred. The cause is often unknown, but when the tissue shrinks to become tight around the joint, it can make movement so painful and stiff that people may struggle with basic daily activities and have disturbed sleep. Around one in 10 people in their 50s have frozen shoulder, and most are treated in the community. Those who do not improve are referred to hospital.
There is little good quality evidence on which of the three treatments commonly used in NHS hospitals (physiotherapy, keyhole surgery and manipulation under anaesthesia) leads to better outcomes. However, hospitals commonly offer keyhole surgery and manipulation because they are widely believed to lead to faster recovery. Both of these procedures involve anaesthesia, and therefore carry increased risks and costs. Many hospitals supplement them with steroid injections, but its use is variable.
The new study aimed to compare the effectiveness and cost-effectiveness of the three techniques and provide evidence to guide future practice.
The UK-wide trial looked at the treatment of 503 adult patients with frozen shoulder at 35 NHS hospitals. Each was randomised to receive either:
- structured physiotherapy (up to 12 weekly sessions including a home exercise programme and written advice on pain management) plus a steroid injection
- manipulation under anaesthetic with steroid injection followed by physiotherapy, or
- keyhole surgery followed by physiotherapy.
People in all three groups had improved shoulder function after one year and many had nearly full function. No treatment was clearly superior to the others in improving function or reducing pain, but each had different benefits and drawbacks.
- was the cheapest option
- had the shortest waiting times (an average of 14 days), which was valued by patients
- had no serious adverse events such as chest infection
- had the highest rates of people needing further treatment (15%).
Manipulation under anaesthetic:
- had a longer waiting time than for physiotherapy (57 days on average)
- improved quality of life
- had two serious adverse events reported
- had lower rates of people needing further treatment (7%).
- was the most expensive option, costing £1733 more per person than physiotherapy
- with the longest waiting time (72 days on average)
- had slightly better outcomes in shoulder function and pain than the other options, but this improvement was unlikely to be meaningful
- had the greatest risk of serious adverse events (8 reported)
- had the lowest rates of people needing further treatment (4%) of the three treatments.
Overall, the study found that manipulation under anaesthetic provided the best value for money of the three options.
Why is this important?
The study shows that a programme of structured physiotherapy – which can be provided at low cost to the NHS – is as effective as the other options, and many people value the shorter waiting times. However, the structured programme of up to 12 sessions, combined with steroid injection, is not currently offered by the NHS. There is considerable variation in the physiotherapy offered, and steroid injection is not usually given. The physiotherapy pathway used in the study would therefore need extra funds to deliver.
This information will help clinicians and patients decide together on the most appropriate treatment. For example, they show that for patients who wish (or need) to avoid a general anaesthetic, physiotherapy and a steroid injection is an effective alternative. The authors argue the results should lead to more selective use of keyhole surgery, thus reducing the cost and risks for patients.
The results should change practice, the study authors say, particularly to favour manipulation under anaesthetic over keyhole surgery.
The study did not examine a fourth treatment option called hydrodilatation, in which the steroid is injected with a large volume of saltwater (saline) to distend the shoulder, followed by physiotherapy. The technique was rarely used when this study was planned but has grown in popularity since then. The authors say its effectiveness should be formally tested in a trial.
You may be interested to read
The full paper: Brealey S, and others. Surgical treatments compared with early structured physiotherapy in secondary care for adults with primary frozen shoulder: the UK FROST three-arm RCT. Health Technology Assessment 2020;24
Further details are included in: Rangan A, and others. Management of adults with primary frozen shoulder in secondary care (UK FROST): a multicentre, pragmatic, three-arm, superiority randomised clinical trial. The Lancet 2020; 396: 977-89.
Summary of treatment options: Rangan A, and others. What is the most effective treatment for Frozen Shoulder? BMJ 2016; 354: i4162
Further research studying the experiences of trial participants and healthcare professionals: Srikesavan C, and others. Experiences and perceptions of trial participants and healthcare professionals in the UK Frozen Shoulder Trial (UK FROST): a nested qualitative study. BMJ Open 2021;11:e040829
Funding: This project was funded by the NIHR Health Technology Assessment programme.
Conflicts of Interest: One researcher has received funds from a medical device company.
Disclaimer: NIHR Alerts are not a substitute for professional medical advice. They provide information about research which is funded or supported by the NIHR. Please note that views expressed in NIHR Alerts are those of the author(s) and reviewer(s) and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care.