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

Plain English Summary

Not provided at time of registration

Trial website

Contact information



Primary contact

Dr Ian Russell


Contact details

Department of Health Sciences and Clinical Evaluation
University of York
Alcuin College
YO10 5DD
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number

G0001133 (P/Care init)

Study information

Scientific title


DAMASK (Direct Access to Magnetic resonance imaging: Assessment for Suspect Knees)

Study hypothesis

Each year 15% of all patients consult General Practitioners (GPs) for musculo-skeletal disorders. Examination of the knee is now one of the commonest musculo-skeletal applications of Magnetic Resonance Imaging (MRI). There is evidence that MRI allows accurate assessment of meniscal and ligamentous injuries of the knee. With explicit clinical indications in selected patients it can avoid an expensive invasive arthroscopy, reducing the waiting times for those who do need one. However, whether management using MRI affects patients’ quality of life has not been rigorously evaluated. Hence there is uncertainty about whether recommending open access MRI to avoid hospital referral is appropriate. This reflects wide variation both in GPs’ access to, and use of MRI, and in associated costs. Thus the question whether patients presenting to GPs with continuing knee problems should be referred for an MRI scan or directly to an orthopaedic surgeon is crucial to patient management and outcome, and thus to cost-effectiveness.

1. To evaluate:
a. whether the early use of MRI through open access affects subsequent diagnosis and management
b. whether it improves patient outcomes
c. whether it reduces net costs to the NHS, patients and society
2. To explore patient and practitioner preferences for open access to MRI and to investigate the generalisability of results obtained from the three experimental sites in York, Wrexham and Aberdeen

By including Cardiff, where direct access to MRI has been available for eight years, we shall study the effect of such access on the case mix of GP referrals for direct MRI and referrals to the orthopaedics department.

Ethics approval

The trial protocol was designed to comply with the Declaration of Helsinki as adopted by the World Medical Association. UK Northern and Yorkshire Multi-Centre Research Ethics Committee approved the protocol (reference number MREC/1/3/59).

Study design

Multicentre, randomised controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type

Quality of life

Patient information sheet


Knee problems


All general practice staff are invited to a training session about the appropriate use of MRI and interpretation of findings.

Within practices individual participants will be randomised between:
1. The local radiology department for an MRI scan - depending on the result of the scan the GP might then refer the participant to be seen by an orthopaedic surgeon; and
2. The local orthopaedic department for a consultation with the specialist - depending on the result of this visit, the surgeon might then send the participant for an MRI scan.

To ensure that the evaluation covers events up to and including arthroscopy we shall follow patients from random allocation for 24 months using questionnaires asking about their general health and experience of knee pain. Economic analyses will compare benefits to participants with costs to both the NHS and participants themselves.

Intervention type



Not Specified

Drug names

Primary outcome measures

The primary outcome measure is the change in the physical functioning sub-scale of the Short Form 36-item questionnaire (SF-36) at six months. A change of 6.75 points on the scale has been agreed as being clinically significant.

Secondary outcome measures

No secondary outcome measures

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. People aged between 18 and 55
2. Suspected internal derangement of the knee suggesting meniscal or ligamentous patello-femoral joint-pain
3. Continuing symptoms at least six weeks after the initial consultation during the study period despite conservative treatment (e.g., analgesics, physiotherapy or tubigrip)
4. GP is considering orthopaedic or MRI referral

Participant type


Age group



Not Specified

Target number of participants


Participant exclusion criteria

1. The GP judges that urgent orthopaedic referral is necessary at the initial consultation
2. Suspected osteoarthritis or other non-traumatic arthropathy
3. Isolated patello-femoral joint pain
4. Previous MRI scan within this episode of care
5. Previous surgical intervention (excluding diagnostic arthroscopy) on the same knee
6. Contraindications to the use of MRI, for example pacemaker, intra-cranial aneurysm clips, or orbital metallic foreign body
7. Patients who reside in Orkney or Shetland

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Department of Health Sciences and Clinical Evaluation
YO10 5DD
United Kingdom

Sponsor information


University of York (UK)

Sponsor details

YO10 5DD
United Kingdom

Sponsor type




Funder type

Research council

Funder name

Medical Research Council (MRC) (UK) (ref: G0001133)

Alternative name(s)


Funding Body Type

private sector organisation

Funding Body Subtype

other non-profit


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

Results - basic reporting

Publication summary

1. 2006 protocol in
2. 2007 results re influence of MRI on GP's decision in
3. 2008 results re effectiveness of GP's access to MRI in
4. 2008 results re cost-effectiveness of MRI in
5. 2010 participant feedback survey results in

Publication citations

  1. Protocol

    Brealey SD, Atwell C, Bryan S, Coulton S, Cox H, Cross B, Fylan F, Garratt A, Gilbert FJ, Gillan MG, Hendry M, Hood K, Houston H, King D, Morton V, Orchard J, Robling M, Russell IT, Torgerson D, Wadsworth V, Wilkinson C, The DAMASK trial protocol: a pragmatic randomised trial to evaluate whether GPs should have direct access to MRI for patients with suspected internal derangement of the knee., BMC Health Serv Res, 2006, 6, 133, doi: 10.1186/1472-6963-6-133.

  2. Participant feedback survey results

    Brealey S, Andronis L, Dennis L, Atwell C, Bryan S, Coulton S, Cox H, Cross B, Fylan F, Garratt A, Gilbert F, Gillan M, Hendry M, Hood K, Houston H, King D, Morton V, Robling M, Russell I, Wilkinson C, Participants' preference for type of leaflet used to feed back the results of a randomised trial: a survey., Trials, 2010, 11, 116, doi: 10.1186/1745-6215-11-116.

  3. Brealey SD, , Influence of magnetic resonance of the knee on GPs' decisions: a randomised trial., Br J Gen Pract, 2007, 57, 541, 622-629.

  4. Effectiveness of GP access to magnetic resonance imaging of the knee: a randomised trial., Br J Gen Pract, 2008, 58, 556, e1-8; discussion 774, doi: 10.3399/bjgp08X342651.

  5. Cost-effectiveness of magnetic resonance imaging of the knee for patients presenting in primary care., Br J Gen Pract, 2008, 58, 556, e10-6, doi: 10.3399/bjgp08X342660.

Additional files

Editorial Notes