Genicular embolisation for knee osteoarthritis
| ISRCTN | ISRCTN50216144 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN50216144 |
| IRAS number | 324901 |
| Secondary identifying numbers | CPMS 68970, Grant Code: NIHR134096 |
- Submission date
- 17/06/2025
- Registration date
- 09/07/2025
- Last edited
- 14/07/2025
- Recruitment status
- Recruiting
- Overall study status
- Ongoing
- Condition category
- Musculoskeletal Diseases
Plain English summary of protocol
Background and study aims
This study is looking at whether a new treatment called genicular artery embolisation (GAE) could be a helpful option for people with ongoing pain from knee osteoarthritis. Knee osteoarthritis is a painful condition. In the early stages, patients often benefit from lifestyle changes and exercises. When the knee becomes very damaged, they may require a knee replacement surgery to alleviate the pain and improve symptoms. In between the early and advanced stages, pain can become a major problem. A new treatment has been developed which aims to relieve pain in the knee by blocking (embolisation) small extra blood vessels around the knee. Early studies seem to show some benefit, but a larger study is needed to see if the treatment is effective at reducing pain. If it works, it could help a lot of people with knee osteoarthritis who are in a “treatment gap” between simple care and complex surgery.
Who can participate?
Adult patients with diagnosed painful knee osteoarthritis who have presented to secondary (hospital) care and previously tried existing treatments
What does the study involve?
Participants will be randomly assigned to either receive the active treatment (GAE), which uses microbeads to block off extra blood vessels in the knee, or a very similar placebo where only salt water is injected. Participants will not be aware what treatment they are undergoing. Participants will also have one or two MRI scans and will be asked to complete questionnaires assessing pain and function up to 12 months later.
What are the possible benefits and risks of participating?
Participants' knee pain may or may not improve following the procedure. With all medical procedures, there is a small risk of problems, which will be assessed by treating clinicians and discussed with participants.
Where is the study run from?
University of Oxford (UK)
When is the study starting and how long is it expected to run for?
May 2024 to December 2027
Who is funding the study?
The National Institute of Health Research (NIHR), Efficacy and Mechanism Evaluation (EME) programme (UK)
Who is the main contact?
Dr Anjali Shah, geko@ndorms.ox.ac.uk
Contact information
Scientific
Surgical Intervention Trials Unit
Botnar Research Centre
Nuffield Department of Orthopaedics Rheumatology and Musculoskeletal Sciences (NDORMS)
University of Oxford
Windmill Road
Headington
Oxford
OX3 7LD
United Kingdom
| Phone | +44 (0)1865 613460 |
|---|---|
| anjali.shah@ndorms.ox.ac.uk |
Principal Investigator
Botnar Research Centre
Nuffield Department of Orthopaedics Rheumatology and Musculoskeletal Sciences (NDORMS)
University of Oxford
Windmill Road
Headington
Oxford
OX3 7LD
United Kingdom
| Phone | +44 (0)1865 223421 |
|---|---|
| andrew.price@ndorms.ox.ac.uk |
Principal Investigator
John Radcliffe Hospital
Headley Way
Headington
Oxford
OX3 9DU
United Kingdom
| Phone | +44 (0)1865 221497 |
|---|---|
| raman.uberoi@ouh.nhs.uk |
Study information
| Study design | Randomized; Interventional; Design type: Treatment, Imaging, Other |
|---|---|
| Primary study design | Interventional |
| Secondary study design | Randomised controlled trial |
| Study setting(s) | Hospital |
| Study type | Treatment |
| Participant information sheet | Not available in web format, please use the contact details to request a patient information sheet |
| Scientific title | Genicular artery embolisation for the symptomatic treatment of knee osteoarthritis refractory to conservative management (GEKO) |
| Study acronym | GEKO |
| Study objectives | To determine, in patients with painful knee osteoarthritis (OA), if genicular artery embolisation (GAE) is effective at reducing pain at 6 months post-randomisation, compared to a placebo intervention. |
| Ethics approval(s) | Approved 09/07/2025, Health and Social Care Research Ethics Committee A (HSC REC A; Office for Research Ethics Committees Northern Ireland (ORECNI), Business Services Organisation, Northern Ireland; +44 (0)28 95 361404; reca@hscni.net) ref: 25/NI/0081 |
| Health condition(s) or problem(s) studied | Knee osteoarthritis |
| Intervention | The study will be a multi-centre two-arm randomised controlled trial with 1:1 allocation, comparing the clinical efficacy of genicular artery embolisation with a placebo procedure. Participants and follow-up assessors will be blinded to the randomisation allocation. Participants will be recruited from knee orthopaedic clinics. They will have the opportunity at their appointment to ask any questions they have about the study. Screening forms will be completed at each site. These will detail any reasons for exclusion and non-participation. On the day of the procedure, but prior to the procedure, possible eligibility will be re-confirmed and participants will complete a baseline questionnaire. Completing the baseline questionnaire will confirm whether the participant has moderate/severe knee pain measured by the pain Visual Analogue Scale (VAS) score (35-74 moderate, 75-100 severe) and therefore eligible for the study. Those who do not meet the eligibility criterion of moderate/severe pain would not undergo the procedure as pain is the main indication for treatment, and they would not proceed with the study. During the procedure, a medical image (angiogram) will be taken to check if the patient does have knee hypervascularity, and therefore, to confirm they are eligible for the study and can be randomised to the study. If the participant does not have knee hypervascularity, then they will not be able to have the intervention and they will not be randomised to the study. For these ineligible patients, a complications check will be made at 6 weeks after the procedure. Participants with knee hypervascularity will be randomised during the procedure to receive one of two possible interventions. Randomisation will function via the REDCap database online system. Group 1 will receive genicular artery embolisation and group 2 will have a placebo procedure with no embolisation. Participants will be blinded to their allocation. The participants will need a day at the hospital for the procedure and usual pre- and post-procedure care. Most participants will be able to go home on the same day if all goes well. Study follow-up consists of participant questionnaires at 6 weeks, 3 months, 6 months and 12 months post randomisation, and a contrast MRI scan at 3 months for a subgroup of 90 participants, and a standard MRI scan at 6 months for all participants. The questionnaires include a validated visual analogue scale (VAS), Knee Injury Osteoarthritis Outcome Score (KOOS), painDETECT, and EQ-5D-5L validated questionnaires, and bespoke complications and health research use questionnaires. There will be a check for complications for all patients randomised in the study on the procedure day and up to 12 months post-procedure. During the study we will consent participants for long-term follow-up and access to their routine NHS records (HES data linkage). This will allow for assessment of any long-term effects. This further follow-up would be subject to the receipt of additional funding. There is an embedded 8-month pilot phase within the study to assess: recruitment rate; ability to maintain assessor and patient blinding; adherence to the randomised procedure and early retention rates. In addition, we have embedded secondary mechanistic outcomes, taking advantage of the controlled placebo trial methodology to investigate the link between synovitis, hypervascularity and knee pain in osteoarthritis using standard and contrast-enhanced MRI and angiograms. Radiologists within the central team will review the first three patients who have a procedure with each site radiologist to assess the number of patients found to not have knee hypervascularity, and to assess whether the procedure went smoothly, as reported by the radiologists performing the procedure. |
| Intervention type | Procedure/Surgery |
| Primary outcome measure | Pain measured using the visual analogue scale (VAS) at 6 months follow-up |
| Secondary outcome measures | Measured at baseline, 6 weeks, 3, 6 and 12 months: 1. Pain measured using VAS 2. Knee function measured using the Knee Injury and Osteoarthritis Outcome Score (KOOS) 3. Pain measured using painDETECT 4. Health-related quality of life measured using EQ-5D-5L 5. Health resource use measured using a bespoke questionnaire |
| Overall study start date | 01/05/2024 |
| Completion date | 31/12/2027 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Sex | Both |
| Target number of participants | Planned Sample Size: 216; UK Sample Size: 216 |
| Key inclusion criteria | 1. Diagnosis of painful knee OA 2. Radiographic evidence of OA (KL 2-4) 3. Previously treated with NICE non-operative intervention, as determined by the treating clinician 4. Moderate/severe pain (to be confirmed when completing the baseline questionnaire ahead of the procedure measured by the pain Visual Analogue Scale [VAS] score) (35-74 moderate, 75-100 severe) 5. Not listed for or being considered as a candidate for joint replacement surgery 6. Aged 18 years or above 7. Knee hypervascularity suitable for embolisation (to be confirmed with an angiogram during the study procedure) 8. Patient willing and able to give informed consent |
| Key exclusion criteria | 1. Patient previously participated in the GEKO trial (only one knee can be entered into the trial) 2. Received a steroid injection in the study knee in the past 6 weeks, or is scheduled to have a steroid injection prior to the study procedure 3. Infection or malignancy around the knee 4. Inflammatory arthropathy 5. History of acute injury to the knee (within 6 months) 6. Surgery to the involved knee in the past 6 months 7. Previous knee replacement (partial or total) in either limb 8. Severe allergic reaction to radiological contrast media, including iodine-based CT-contrast or Gadolinium-based MRI contrast 9. Objection (religious or personal) to the use of medical materials made from pigs 10. Allergy to gelatine from pigs (which is within the micro-beads used in the intervention) 11. Known significant renal impairment 12. Peripheral artery disease of the affected leg 13. Pregnant or lactating 14. Hepatic impairment 15. Clotting abnormality 16. Osteonecrosis |
| Date of first enrolment | 31/07/2025 |
| Date of final enrolment | 30/06/2026 |
Locations
Countries of recruitment
- England
- Scotland
- United Kingdom
- Wales
Study participating centres
Headley Way
Headington
Oxford
OX3 9DU
United Kingdom
Treliske
Truro
TR1 3LJ
United Kingdom
Lodge Road
Caerleon
Newport
NP18 3XQ
United Kingdom
Southmead Road
Westbury-on-trym
Bristol
BS10 5NB
United Kingdom
St Marys Hospital
South Wharf Road
London
W2 1BL
United Kingdom
Derriford Road
Derriford
Plymouth
PL6 8DH
United Kingdom
Prescot Street
Liverpool
L7 8XP
United Kingdom
Anlaby Road
Hull
HU3 2JZ
United Kingdom
London
SE1 7EH
United Kingdom
Clifford Bridge Road
Coventry
CV2 2DX
United Kingdom
Hills Road
Cambridge
CB2 0QQ
United Kingdom
80 Newark Street
London
E1 2ES
United Kingdom
Maes-y-coed Road
Cardiff
CF14 4HH
United Kingdom
Sponsor information
University/education
Research Governance, Ethics & Assurance
Joint Research Office
Boundary Brook House
Churchill Drive
Headington
Oxford
OX3 7GB
England
United Kingdom
| rgea.sponsor@admin.ox.ac.uk | |
| Website | https://www.ox.ac.uk |
"ROR" |
https://ror.org/052gg0110 |
Funders
Funder type
Government
Government organisation / National government
- Alternative name(s)
- National Institute for Health Research, NIHR Research, NIHRresearch, NIHR - National Institute for Health Research, NIHR (The National Institute for Health and Care Research), NIHR
- Location
- United Kingdom
Results and Publications
| Intention to publish date | 31/12/2028 |
|---|---|
| Individual participant data (IPD) Intention to share | No |
| IPD sharing plan summary | Data sharing statement to be made available at a later date |
| Publication and dissemination plan | Planned publication in a high-impact peer-reviewed journal |
| IPD sharing plan | The datasets generated during and/or analysed during the current study will be available upon request from the Chief Investigator. |
Editorial Notes
14/07/2025: Contact details updated.
17/06/2025: Study's existence confirmed by the NIHR.
