Condition category
Musculoskeletal Diseases
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Background and study aims
This study is looking at how well patients with osteoarthritis (a condition that affects the joints) recover after knee replacement surgery [also known as Total Knee Arthoplasty (TKA)]. Currently around 20% of patients are not satisfied after TKA so we are looking to find out if we can identify who will not recover well at an earlier stage, so that we might be able to help them sooner. We will try to determine if doing intense physiotherapy with patients who are not doing well at the first review (6 weeks after their operation) can improve how well they have recovered at one year. We will also use questionnaires and saliva samples to see if certain traits (such as age, sex, attitudes towards surgery, genetic factors etc) can predict who will not recover well after surgery. We hope the information collected during the study will improve our knowledge of why some people do not recover as well as others after TKA and will enable us to help better recovery of patients in the future.

Who can participate?
If you are over 16 years old, undergoing TKA because of osteoarthritis in Aberdeen or Edinburgh and are able to complete the questionnaires, you will be invited to join the TRIO-POPULAR study. At any of the study centres, if you are over 18 and undergoing TKA because of osteoarthritis you will be asked to complete an “Oxford Knee Score” questionnaire 6 weeks after your operation. If the score shows you are not recovering as well as we would hope, you will be invited to join the TRIO-physio study.

What does the study involve?
For TRIO-POPULAR you will be asked to complete a questionnaire before your operation and at 6 weeks, 3, 6 and 12 months after your operation date. You will be asked once during the study if you would like to provide saliva samples for a few tests. If you have a “poor” Oxford Knee Score 6 weeks after your operation you will be asked to join the TRIO-physio study. We will put you into one of two groups at random to either (1) complete exercises from a worksheet at home or (2) go to physiotherapy sessions at hospital and complete exercises at home. Everyone will see a physiotherapist for an assessment and be taught exercises. If you are in the group that has to come to the hospital for physiotherapy sessions you will come once a week for 6 weeks and will also be asked to do exercises twice a week at home on your own. If you are in the group that completes exercises from the worksheet at home you will do these 3 times a week for 6 weeks. No matter what group you are in, you will then come for a review at the hospital 14 weeks after your operation. You will be asked to complete questionnaires about your knee and do a “Get-up-and-Go” test with the Physiotherapist, which is a simple exercise where you are timed getting up from a chair and walking a short distance to check how well your knee is recovering. We will then post you questionnaires at 6 months and one year after your operation date to see how well you are recovering.

What are the possible benefits and risks of participating?
There are no additional risks in taking part in this study beyond those of having physiotherapy in general. You may experience some discomfort and/or swelling in the knee following exercise, but the therapist will guide you in performing the exercises and setting a correct intensity of exercise to help avoid this. We hope that the physiotherapy will help you recover better, but you may not directly benefit from taking part in this study. However, the knowledge gained from this study will benefit other people in the future by helping us to decide the best way to treat people who are recovering from TKA surgery.

Where is the study run from?
The study is being run by the Edinburgh Clinical Trials Unit in collaboration with the Universities of Edinburgh and Aberdeen. Aberdeen and Edinburgh are the main sites, with Oxford and Derby recruiting patients for the TRIO-physio study only.

When is the study starting and how long is it expected to run for?
The study will start in mid-July 2013 and is expected to run until July 2017. The recruitment period will last 18 months.

Who is funding the study?
Arthritis Research UK.

Who is the main contact?
Prof Hamish Simpson, (Professor of Orthopaedics and Trauma) University of Edinburgh

Trial website

Contact information



Primary contact

Prof Hamish Simpson


Contact details

Department of Trauma and Orthopaedics
Edinburgh Royal Infirmary
Chancellor's Building
49 Little France Crescent
EH16 4SB
United Kingdom

Additional identifiers

EudraCT number number


Protocol/serial number


Study information

Scientific title

Targeted Rehabilitation to Improve Outcome after total knee replacement: a multi-centre trial with an interventional and an observational arm



Study hypothesis

Interventional arm (TRIO-physio) – To determine if intense physiotherapy for patients performing poorly at their first post-operative review at 6 weeks can improve their outcome at one year.
Observational arm (TRIO-POPULAR)- To investigate predictors of unfavourable outcome following total knee arthroplasty (TKA) in order to further examine the combined effects of individual, clinical, psychosocial and biological markers in predicting poor outcome.

Ethics approval

1. The TRIO-physio study was approved by the South East Scotland Research Ethics Committee 01 on 17/04/2013, ref: 13\SS\0051
2. The TRIO-POPULAR study was approved by the Health and Social Care Research Ethics Committee 3 (HSC REC 3), 19/07/2013, ref: 13/NI/0101

Study design

Multi-centre trial with an interventional and observational arm. The interventional arm is a randomised controlled trial, the observational arm is an observational cohort study.

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Osteoarthritis of the knee


1. TRIO-POPULAR: Questionnaire at pre-operation, baseline, 6 weeks and 3, 6 &12 months post-operation. One-off saliva samples for cortisol and genetic analysis.
2. TRIO-Physio: Intervention is either completion of exercises from a worksheet at home or physiotherapy sessions at hospital and completion of exercises at home by participant. The group going to hospital for physiotherapy sessions will do so once a week for 6 weeks and will also be asked to do exercises twice a week at home. The group that completes
exercises from the worksheet at home will do these 3 times a week for 6 weeks. A timed “Get-up-and-Go” test will be completed with the physiotherapist by all participants before and after the intervention. An Oxford Knee Score, EQ-5D, health economic questionnaires will be completed at baseline, 14 weeks, 6 months and 1 year. In addition satisfaction
questionnaires will be collected at 6 months and 1 year.

Intervention type



Not Applicable

Drug names

Primary outcome measure

Oxford Knee Score at 52 weeks

Secondary outcome measures

TRIO-Physio study only:
1. Assess patient satisfaction with knee arthroplasty, pain relief and functional ability.
2. Patient functional improvements following physiotherapy (Timed-get-up-and-go test)
3. To evaluate the cost effectiveness of enhanced targeted physiotherapy.

TRIO-POPULAR study only:
Questionnaires to collect EQ5D, demographics, Hospital Anxiety and Depression Scale (HADS), social support, attitudes and concerns about illness, patient expectations about outcome, Pain Catastrophising Scale, Short-form Tampa Scale of Kinesophobia, Sleep Problem Scale, Prior health seeking behaviour, Pain Manikins, Co-morbidities, General Health (PROMIS), HPA, DNA collection, Brief Pain Inventory.

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Undergoing primary total knee arthroplasty for osteoarthritis.
2. Patients are able to consent and willing to comply with the study protocol
3. TRIO-physio only: Defined poor outcome (Oxford Knee Score less than or equal to 26) at first post-op review (6
4. TRIO-POPULAR only: Patients are eligible for inclusion if they are adults aged 16 years and over and understand oral and written English

Participant type


Age group




Target number of participants

TRIO-Physio: 440. TRIO-POPULAR: 750

Participant exclusion criteria

1. Patients undergoing revision knee arthroplasty or fully constrained knee arthroplasty
2. Knee replacement for a diagnosis other than osteoarthritis
3. TRIO-Physio only: Patients unable to attend the study physiotherapy intervention centres.
4. TRIO-Physio only: Patients subjected to procedures done purely for pain relief (such as for patients with no walking capacity)

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Department of Trauma and Orthopaedics
EH16 4SB
United Kingdom

Sponsor information


University of Edinburgh/NHS Lothian (UK)

Sponsor details

The Queen’s Medical Research Institute
47 Little France Crescent
EH16 4TJ
United Kingdom

Sponsor type




Funder type


Funder name

Arthritis Research UK (Reference No. 20100)

Alternative name(s)

Funding Body Type

private sector organisation

Funding Body Subtype

Other non-profit organizations


United Kingdom

Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

2014 protocol in
2018 results in
2020 results in (added 22/10/2020)

Publication citations

  1. Protocol

    Simpson AH, Hamilton DF, Beard DJ, Barker KL, Wilton T, Hutchison JD, Tuck C, Stoddard A, Macfarlane GJ, Murray GD, Targeted rehabilitation to improve outcome after total knee replacement (TRIO): study protocol for a randomised controlled trial., Trials, 2014, 15, 44, doi: 10.1186/1745-6215-15-44.

Additional files

Editorial Notes

22/10/2020:Publication reference added. 18/10/2018: Publication reference added.