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
Total knee replacement (TKR) involves replacing a damaged, worn or diseased knee with an artificial joint. It's a routine operation for knee pain most commonly caused by arthritis. In 2007-8 the NHS undertook over 70,000 TKRs in England and Wales, and the number of TKRs is expected to rise as the population gets older. We know that patients experience significant pain after a TKR operation and this can increase the time taken to get back to walking and normal activities. Pain levels may be changed if the painkillers are taken by the patient when they want to take them (patient-directed self-management of pain) rather than when the nurse gives them as part of a drugs round in hospital (treatment as usual). This study will compare these two methods.

Who can participate?
Adult patients (aged over 18) undergoing a primary (first) TKR operation.

What does the study involve?
Participants will be randomly divided into the two groups: patient-directed self-management of pain or treatment as usual. This study will investigate whether patient-directed self-management of pain improves levels of pain at three days after the operation or at discharge (whichever is the sooner) compared to treatment as usual. It will also compare the two groups up to 6 weeks after the operation for satisfaction with control of pain, return to walking and normal activities, any problems, and costs. We will also interview 10 patients and 10 ward staff to explore their experiences of the two methods.

What are the possible benefits and risks of participating?
It is hoped that the results of this study will help the NHS to improve pain control for patients after TKR. Information from this study may well be relevant to pain control after operations in general.

Where is the study run from?
Norfolk and Norwich University Hospital NHS Trust (UK).

When is study starting and how long is it expected to run for?
June 2011 to June 2013.

Who is funding the study?
National Institute of Health Research (NIHR) (UK).

Who is the main contact?
Prof Simon Donell

Trial website

Contact information



Primary contact

Prof Simon Donell


Contact details

Consultant Orthopaedic Surgeon & Honorary Professor
University of East Anglia
Norfolk and Norwich University Hospital NHS Trust
Colney Lane
United Kingdom
+44 (0)1603 287531

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

A randomised controlled trial of patient-directed self-management of pain (PaDSMaP) compared to treatment as usual following total knee replacement.



Study hypothesis

To investigate if PaDSMaP reduces pain at 3 days post-operatively or discharge (whichever is sooner) after primary total knee replacement compared to treatment as usual

Ethics approval

Cambridgeshire 1 Research Ethics Committee, 30/12/2010, ref: 10/H0304/52

Study design

Open-label randomised controlled trial

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


Musculoskeletal disease: Total knee replacement


Patients self-medicate their oral analgesics post total knee replacement when sufficently recovered from the anaesthetic. Treatment as usual comparator cohort have analgesics dispensed as per usual by nurses on drug rounds

Follow up length: Six weeks; Study entry: Single randomisation only

Intervention type



Drug names

Primary outcome measure

Pain levels for patients at three days post-operatively or at discharge (whichever is the sooner) as measure on a non-graded 10cm visual analogue scale (VAS)

Secondary outcome measures

1. Pain during inpatient stay and after six weeks post-operatively (non graded 10cm VAS)
2. Satisfaction with pain levels patient questionnaire
3. Satisfaction with Information About Medicines Scale (SIMS)
4. EuroQOL EQ-5D questionnaire (EQ-5D)
5. Oxford Knee Score (OKS)
6. Time to mobilisation after operation (e.g. day on which patient was able to stand up and transfer from bed to chair)
7. Medication usage (Inpatient Prescription Chart and CRF)
8. Adverse events (CRF)
9. A health resources questionnaire
10. Qualitative evaluation of patient's and health professionals' experiences

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. All adult patients (e.g. aged over 18) undergoing a primary total knee replacement operation
2. Must meet the Norfolk and Norwich University Hospital NHS Foundation Trust self-management of pain criteria
3. Are expected to require standard step 1-3 oral analgesics post-operatively (WHO 2009)
4. Post-operatively, patients must be awake and breathing independently, able to answer questions and follow commands to continue in the protocol
5. Are English speaking and literate (we expect patient participants to be able to read the information sheet and fill in a number of self-assessments)
6. Patients may have received regional blocks or epidural analgesia, and will start PaDSMaP or TAU as soon as they begin oral analgesia

Participant type


Age group




Target number of participants

Planned Sample Size: 144; UK Sample Size: 144

Participant exclusion criteria

1. Expected to require intensive care
2. Known or suspected to be opioid tolerant or dependent
3. Regular users of any modified release opiate preparation for > two weeks prior to total knee replacement
4. Recent history of drug or alcohol abuse
5. Patients who lack competence to consent by reason or dementia or any other reason
6. Any patient who does not self-administer at home

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Norfolk and Norwich University Hospital NHS Trust
United Kingdom

Sponsor information


Norfolk and Norwich University Hospital NHS Trust (UK)

Sponsor details

c/o Ms Kathryn Andrews
Colney Lane
United Kingdom
+44 (0)1603 286286

Sponsor type

Hospital/treatment centre



Funder type


Funder name

National Institute of Health Research (NIHR) Research for Patient Benefit (RfPB) (UK) ref: PB-PG-1208-18121

Alternative name(s)

Funding Body Type

Funding Body Subtype


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

2012 protocol in:
2018 results in:

Publication citations

  1. Protocol

    Donell S, Deane K, Swift L, Barton G, Balls P, Darrah C, Gray R, Patient directed self management of pain (PaDSMaP) compared to treatment as usual following total knee replacement: study protocol for a randomized controlled trial., Trials, 2012, 13, 204, doi: 10.1186/1745-6215-13-204.

Additional files

Editorial Notes

11/05/2018: Publication reference added.