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This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.

Following knee replacement surgery, a home-based exercise programme delivered by rehabilitation assistants was as effective as traditional physiotherapy given at a clinic. New research found that both approaches had a similar effect.

Increasing numbers of people are having knee replacements and needing rehabilitation. As many one in three say that surgery does not lead to a good outcome in terms of pain and what they are able to do afterwards.

Researchers designed a programme of rehabilitation exercises to be delivered at home by a rehabilitation assistant. This study found that the home-based approach was no more effective than physiotherapy in a clinic as usual. Home-based care using rehabilitation assistants was cheaper on some measures, however, and both patients and clinicians liked it.

The results show that home-based rehabilitation given by assistants supervised by physiotherapists is an effective alternative to traditional clinic-based physiotherapy. This could allow trusts to look again at the skill mix they need to deliver rehabilitation services in their area, and decide whether this model might work for them. 

Further information on knee replacement is available on the NHS website.

What’s the issue?

More than 100,000 people had a knee replacement in the UK in 2017, and numbers are rising. Surveys of patients have found that up to one in three (15 – 30%) experience little or no improvement after surgery. People undergoing knee replacement are increasingly likely to be older and to have more than one long-term health condition. 

At present, rehabilitation therapy varies widely around the country. Some people are seen for regular appointments in clinics, others are sent home with a list of exercises to do on their own. 

The study was set up to see whether a targeted rehabilitation programme could improve outcomes. Called Community-based Rehabilitation after Knee Arthroplasty (CORKA), the programme is delivered in people’s homes. Researchers compared CORKA to standard care (up to six sessions with a physiotherapist). They looked at patients' outcomes, costs and acceptability to both patients and clinicians.

What’s new?

Patients thought to be at risk of a poor outcome after knee replacement were selected from 14 NHS hospitals across the UK. The 621 people who agreed to take part were randomly assigned to have standard rehabilitation care or the CORKA intervention. 

The CORKA intervention included personalised rehabilitation exercises aimed at helping people carry out tasks. People in this group also received help with adaptations to their home to ensure it was safe for exercises and everyday living. Rehabilitation assistants visited them in their homes for a first assessment and up to six follow-up sessions.

The group receiving usual care had between one and six rehabilitation sessions with a physiotherapist. 

One year later, people in both groups said they were able to do more everyday tasks and activities, than at the start of the trial. There was no difference in average scores between the groups. 

There was similarly little difference in other outcomes such as knee pain and function; quality of life; how quickly people can stand from a chair; whether they can walk in a figure of eight; or stand on one leg. 

Overall, when all costs were considered, CORKA was cheaper to deliver than standard care. The study found that:

    • the CORKA programme was cheaper to provide than standard care (£65 per person)
    • people in the CORKA group had more primary care and hospital appointments after treatment, making their NHS costs slightly higher (£77 per person) 
    • when all costs to society were taken into account, including time off work for people attending appointments and unpaid care from friends and relatives, total costs were lower for CORKA than for standard care (£316 per person).

Interviews with 10 patients showed they appreciated the CORKA intervention. They were glad not to have to travel to appointments, and said they got more done in appointments at home than in hospital. They enjoyed the company of the visitor and felt it was helpful for the clinician to adapt their home environment.

The physiotherapists and rehabilitation assistants also said they gained from the experience, although some assistants reported feeling out of their comfort zone. 

Why is this important?

Current NICE guidelines for rehabilitation after knee replacement state that a member of the physiotherapy team should give advice on self-directed rehabilitation exercises before the patient leaves hospital. They recommend supported group or individual rehabilitation for certain groups of people, including people who find self-directed rehabilitation is not working. 

The CORKA programme is a feasible alternative to standard knee replacement rehabilitation, and is less expensive on some measures. It was popular with patients, who felt that their treatment was adapted to their individual needs. In addition, it removed the need for them to travel to hospital, which can be difficult for many reasons including caring responsibilities, or other long-term conditions. 

This model of delivering rehabilitation has implications for the workforce: fewer physiotherapists but more rehabilitation assistants would be needed to implement it more widely. It could be considered when NHS Trusts are reconfiguring services

What’s next?

The COVID-19 pandemic meant that hospitals involved in the trial had to halt in-person rehabilitation such as CORKA, although some may choose to reintroduce it as services open up again. 

The researchers will provide details of the CORKA intervention to any NHS Trust interested in taking it up. They say that good communication between the Trust carrying out the surgery and the Trust carrying out the rehabilitation helps identify the patients likely to benefit from the intervention.

You may be interested to read

This summary is based on: Barker KL, and others. Outpatient physiotherapy versus home-based rehabilitation for patients at risk of poor outcomes after knee arthroplasty: CORKA RCT. Health Technology Assessment 2020;24:65  

A paper on rehabilitation targeted at people at risk of poor outcomes: Hamilton DF, and others. Targeting rehabilitation to improve outcomes after total knee arthroplasty in patients at risk of poor outcomes: randomised controlled trial. BMJ 2020;371:m3576 

National Institute for Health and Care Excellence (NICE) guidance and evidence review for rehabilitation after joint replacement: Joint replacement (primary): hip, knee and shoulder. NICE guideline [NG157]. 2020 

A paper on variation in physiotherapy provision: Smith TO, and others. Demographic and geographical variability in physiotherapy provision following hip and knee replacement. An analysis from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man. Physiotherapy 2020;106:1-11 

Recent research from the same authors comparing home-based rehabilitation with traditional physiotherapy: Barker KL, and others. Home-based rehabilitation programme compared with traditional physiotherapy for patients at risk of poor outcome after knee arthroplasty: the CORKA randomised controlled trial. BMJ Open 2021;11:e052598


Funding: This research was funded by the NIHR Health Technology Assessment programme.

Conflicts of Interest: A number of researchers declared competing interests, including receiving grants and fees from the NIHR and the NICE. 

Disclaimer: Summaries on NIHR Evidence are not a substitute for professional medical advice. They provide information about research which is funded or supported by the NIHR. Please note that the views expressed 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.

NIHR Evidence is covered by the creative commons, CC-BY licence. Written content and infographics may be freely reproduced provided that suitable acknowledgement is made. Note, this license excludes comments and images made by third parties, audiovisual content, and linked content on other websites.

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