Knee OsteoarthritisENERGIENCT07370480
Knee Osteoarthritis and Thermal Spa Treatment
A study testing Thermal spa sessions and Thermal water in people with Knee Osteoarthritis, run by CEN Biotech at 2 sites in France.
Trial summary
The goal of this interventional study is to evaluate the effectiveness at 6 months of the Enghien-les-Bains thermal spa treatment on functional disability and pain, assessed by the Minimal Clinically Important Improvement (MCII), in patients with knee osteoarthritis. Read more about this study
- Who is it for?
- Ages 50 to 80 years
- Conditions the study is for
- Knee Osteoarthritis
- What is being tested?
- Thermal spa sessions and Thermal water
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 76 participants
- Where
- 2 sitesFrance
- Study dates
- 27 Jan 2026to 31 Dec 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 50 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Knee osteoarthritis with Kellgren and Lawrence stage 2 to 4 evidenced by a knee X-ray examination in the past 3 years.
- 100-normalized score of the WOMAC physical function subscale greater than or equal to 30.
- Signed inform consent.
- With health insurance affiliation.
Who cannot join
- Presented with balneotherapy contraindication or to certain adjuvant treatment techniques (balneation, hydrotherapy jets, massage): chronic infectious pathology, active cancer, decompensated cardiac, hepatic or renal insufficiency, "open" leg ulcer, immune deficiency, phlebitis, erysipelas or history of erysipelas, active thrombosis, behavioral disorders, etc.
- Presented with chronic pain for reasons other than osteoarthritis: chronic inflammatory rheumatism (rheumatoid arthritis, ankylosing spondylitis, lupus, psoriatic arthritis) or fibromyalgia.
- Patient scheduled for knee osteoarthrosis-related surgery within the next 7 months.
- Having had spa treatment in the past 6 months whatever the indication or intra-articular corticosteroid injection within the previous 90 days or hyaluronic acid infiltration or other viscosupplementation or platelet-rich plasma (PRP) injection within the previous 6 months.
- Having planned a spa treatment in another indication between inclusion and final visit.
- Residing more than 30 kilometers from Enghien-les-Bains at the time of spa treatment.
Show all 10Show fewer
- Women of childbearing potential who are not using effective contraception (estrogen/progestin or progestin-only oral, vaginal, transdermal, injectable or subcutaneous) or who plan to discontinue contraception within the next 7 months.
- Likely to be unable to comply with protocol or to attend visits, particularly in view of the duration of the research, or unable to read or understand French.
- Regulatory reason (guardianship or already enrolled in a clinical trial).
- Already included in a clinical trial or in the exclusion period of a clinical trial.
Trial locations and contacts
2 sites in 1 country.
France2 sites
Thermes d'Enghien-les-Bains
Enghien-les-Bains, 95880
Thermes d'Enghien-les-Bains
Enghien-les-Bains, Île-de-France Region, 95880
About this study
Official title: Evaluation of the Effectiveness of the Enghien-les-Bains Thermal Spa Treatment in the Rheumatology Indication in Patients With Knee Osteoarthritis. Indirect Comparison Study.
The goal of this interventional study is to evaluate the effectiveness at 6 months of the Enghien-les-Bains thermal spa treatment on functional disability and pain, assessed by the Minimal Clinically Important Improvement (MCII), in patients with knee osteoarthritis.
The study is conducted in patients aged 50 to 80 years with knee osteoarthritis (Kellgren-Lawrence grade 2 to 4) and a baseline functional impairment defined by a normalized WOMAC function score ≥ 30.
Read more
The main questions it aims to answer are:
- Does the Enghien-les-Bains thermal spa treatment result in a clinically meaningful improvement in pain and functional disability at 6 months in patients with knee osteoarthritis?
- Is the effectiveness of the Enghien-les-Bains thermal spa treatment superior to standard care, as assessed through an indirect comparison with an external control group from the ANGELLO randomized controlled trial (NCT0581943)? Patients receiving the Enghien-les-Bains thermal spa treatment are compared to the external control group of the ANGELLO randomized controlled trial (Saint-Jean-d'Angély), composed of non-spa-treated patients receiving standard care, to assess differences in pain and functional disability outcomes at 6 months.
Patients of the study:
- Undergo a standardized thermal spa treatment at Enghien-les-Bains.
- Continue usual medical care for knee osteoarthritis.
- Complete questionnaires and clinical assessments at baseline and at 6 months.
Read the detailed description
This study includes three medical visits with the investigator: one within 28 days before the thermal spa treatment, one at the end of the treatment, and one 6 months after the start of the treatment. At inclusion, informed consent is obtained, eligibility criteria are verified, and baseline data are collected, including self-administered questionnaires assessing pain, function, and quality of life before the start of the treatment.
During the 20-day thermal spa treatment, care provided and any adverse events are recorded. Clinical assessments and questionnaires are repeated at the end of the treatment. Additional patient-reported outcomes and treatment changes are collected at 3 months, and a final clinical evaluation and questionnaires are completed at 6 months.
An ancillary qualitative study evaluates the conditions under which the thermal spa treatment program is effective from the participants' perspective, including their engagement, lived experience, perceived benefits, facilitators and barriers, and any adaptations made. Data are collected through individual semi-structured face-to-face interviews at the end of the treatment, which are audio-recorded, fully transcribed, and qualitatively analyzed.
- Conditions
- Knee Osteoarthritis
- Being tested
- Thermal spa sessions, Thermal water, Standard of Care for Knee Osteoarthritis
- Keywords
- spa therapy, thermal treatment, balneotherapy, Rheumatology
- Medical subject headings
- Osteoarthritis, Knee
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Thermal spa sessionsOther
At least 4 spa sessions per day, 6 days a week during 3 consecutive weeks that may include daily: one whirlpool bath, one poultice application, one overall jet shower and one underwater massage with thermal water.
With the exception of the application of mud poultices and whirlpool bath, which cannot be substituted, other treatments may be replaced by: immersion bath with shower, penetrating shower, and local jet shower.
10-minute air diffusion baths are taken in individual tubs at 37°C. Mud is applied for 10 minutes as a poultice to both knees (minimum 2 per knee, 45°C), if necessary, to other painful osteoarthritis areas. A 3-minute overall jet shower is administered by a thermal spa staff member, using thermal water at 37°C. A 10-minute underwater massage is administered by a physiotherapist, under a thermal water spray bar at 37°C.
Thermal waterOther
Also called Natural Mineral Water of Enghiens-les-Bains
The water has a neutral pH (7), is cold (14 °C), and presents a moderate level of mineralization (571 mg/L) with a balanced ionic profile. It contains calcium (128 mg/L), bicarbonates (440 mg/L), sulfates (93 mg/L), magnesium (27.9 mg/L), and sodium (12.4 mg/L).
Standard of Care for Knee OsteoarthritisOther
Participants continue standard medical care for knee osteoarthritis as prescribed by their primary care physician, including analgesics and physiotherapy, according to routine clinical practice.
| Study group | Role | What they receive |
|---|---|---|
| Thermal spa treatment | Experimental | 18-day spa program with Waters of Enghien-les-Bains in addition to standard of care for knee osteoarthritis Receives: Other: Thermal spa sessions; Other: Thermal water; Other: Standard of Care for Knee Osteoarthritis |
What is being measured
The primary outcome is the main question the study is designed to answer.
Minimal Clinically Important Improvement (MCII) at 6 months
MCII is defined as a pain reduction of 19.9 mm or more on a 0-100 visual analogic scale (VAS), where 0 means no pain and 100 worse pain.
The percentage of patients achieving MCII is calculated and compared with that of the control group in the reference RCT (external comparison).
Measured: 6 months
Minimal Clinically Important Improvement (MCII) at 6 months
MCII is defined as a reduction of 9.1 points or more in the function subscale of the Physical function subscale of the Western Ontario and McMaster Universities Arthritis Index (WOMAC) in absence of knee surgery. WOMAC is a self-administered questionnaire that consists in 17 items: (17 items): using stairs, rising from sitting, standing, bending, walking, getting in / out of a car, shopping, putting on / taking off socks, rising from bed, lying in bed, getting in / out of bath, sitting, getting on / off toilet, heavy domestic duties, light domestic duties. The 100-normalized subscale score ranges from 0 (none) to 100 (worse functional limitations).
The percentage of patients achieving MCII is calculated and compared with that of the control group in the reference RCT (external comparison).
Measured: 6 months
Secondary outcomes (23)
Change from baseline of pain-related knee osteoarthritis at 20 days
Pain intensity is measured using a 0 (no pain)-100 (Worse pain) Visual Analogic Scale (VAS). Mean variation is compared with that of the control group in the reference RCT (external comparison).
Measured: Day 1 and 20 days
Change from baseline of pain-related knee osteoarthritis at 3 months
Pain intensity is measured using a 0 (no pain)-100 (Worse pain) Visual Analogic Scale (VAS). Mean variation is compared with that of the control group in the reference RCT (external comparison).
Measured: Day 1 and 3 months
Change from baseline of pain-related knee osteoarthritis at 6 months
Pain intensity is measured using a 0 (no pain)-100 (Worse pain) Visual Analogic Scale (VAS). Mean variation is compared with that of the control group in the reference RCT (external comparison).
Measured: Day 1 and 6 months
Change from baseline of the pain subscale of the WOMAC at 20 days
Pain subscale of the WOMAC is a self-administered questionnaire that consists in 5 items: during walking, using stairs, in bed, sitting or lying, and standing upright. The 100-normalized subscale score ranges from 0 (none) to 100 (worse pain limitations). Mean variation is compared with that of the control group in the reference RCT (external comparison).
Measured: Day 1 and 20 days
Change from baseline of the pain subscale of the WOMAC at 3 months
Pain subscale of the WOMAC is a self-administered questionnaire that consists in 5 items: during walking, using stairs, in bed, sitting or lying, and standing upright. The 100-normalized subscale score ranges from 0 (none) to 100 (worse pain limitations). Mean variation is compared with that of the control group in the reference RCT (external comparison).
Measured: Day 1 and 3 months
Change from baseline of the pain subscale of the WOMAC at 6 months
Pain subscale of the WOMAC is a self-administered questionnaire that consists in 5 items: during walking, using stairs, in bed, sitting or lying, and standing upright. The 100-normalized subscale score ranges from 0 (none) to 100 (worse pain limitations). Mean variation is compared with that of the control group in the reference RCT (external comparison).
Measured: Day 1 and 6 months
Changes from baseline of stiffness subscale of the WOMAC at 20 days
Stiffness subscale of the WOMAC is a self-administered questionnaire that consists in 2 items: during walking, using stairs, in bed, sitting or lying, and standing upright. The 100-normalized subscale score ranges from 0 (none) to 100 (worse stiffness limitations). Mean variation is compared with that of the control group in the reference RCT (external comparison).
Measured: Day 1 and 20 days
Changes from baseline of stiffness subscale of the WOMAC at 3 months
Stiffness subscale of the WOMAC is a self-administered questionnaire that consists in 2 items: during walking, using stairs, in bed, sitting or lying, and standing upright. The 100-normalized subscale score ranges from 0 (none) to 100 (worse stiffness limitations). Mean variation is compared with that of the control group in the reference RCT (external comparison).
Measured: Day 1 and 3 months
Changes from baseline of stiffness subscale of the WOMAC at 6 months
Stiffness subscale of the WOMAC is a self-administered questionnaire that consists in 2 items: during walking, using stairs, in bed, sitting or lying, and standing upright. The 100-normalized subscale score ranges from 0 (none) to 100 (worse stiffness limitations). Mean variation is compared with that of the control group in the reference RCT (external comparison).
Measured: Day 1 and 6 months
Change from baseline of physical function subscale of the WOMAC at 20 days
Physical function subscale of the Western Ontario and McMaster Universities Arthritis Index (WOMAC) is a self-administered questionnaire that consists in 17 items: (17 items): using stairs, rising from sitting, standing, bending, walking, getting in / out of a car, shopping, putting on / taking off socks, rising from bed, lying in bed, getting in / out of bath, sitting, getting on / off toilet, heavy domestic duties, light domestic duties. The 100-normalized subscale score ranges from 0 (none) to 100 (worse functional limitations). Mean variation is compared with that of the control group in the reference RCT (external comparison).
Measured: Day 1 and 20 days
Change from baseline of physical function subscale of the WOMAC at 3 months
Physical function subscale of the Western Ontario and McMaster Universities Arthritis Index (WOMAC) is a self-administered questionnaire that consists in 17 items: (17 items): using stairs, rising from sitting, standing, bending, walking, getting in / out of a car, shopping, putting on / taking off socks, rising from bed, lying in bed, getting in / out of bath, sitting, getting on / off toilet, heavy domestic duties, light domestic duties. The 100-normalized subscale score ranges from 0 (none) to 100 (worse functional limitations). Mean variation is compared with that of the control group in the reference RCT (external comparison).
Measured: Day 1 and 3 months
Change from baseline of physical function subscale of the WOMAC at 36 months
Physical function subscale of the Western Ontario and McMaster Universities Arthritis Index (WOMAC) is a self-administered questionnaire that consists in 17 items: (17 items): using stairs, rising from sitting, standing, bending, walking, getting in / out of a car, shopping, putting on / taking off socks, rising from bed, lying in bed, getting in / out of bath, sitting, getting on / off toilet, heavy domestic duties, light domestic duties. The 100-normalized subscale score ranges from 0 (none) to 100 (worse functional limitations). Mean variation is compared with that of the control group in the reference RCT (external comparison).
Measured: Day 1 and 6 months
Change from baseline of physical function subscale of the WOMAC at 6 months
Physical function subscale of the Western Ontario and McMaster Universities Arthritis Index (WOMAC) is a self-administered questionnaire that consists in 17 items: (17 items): using stairs, rising from sitting, standing, bending, walking, getting in / out of a car, shopping, putting on / taking off socks, rising from bed, lying in bed, getting in / out of bath, sitting, getting on / off toilet, heavy domestic duties, light domestic duties. The 100-normalized subscale score ranges from 0 (none) to 100 (worse functional limitations). Mean variation is compared with that of the control group in the reference RCT (external comparison).
Measured: Day 1 and 6 months
Change from baseline of total score of the WOMAC at 20 days
The scores for each of the 3 subscales (function, pain, stiffness) are summed up to calculate the total WOMAC score. The 100-normalized score ranges from 0 (none) to 100 (worse limitations).
Measured: Day 1 and 20 days
Change from baseline of total score of the WOMAC at 6 months
The scores for each of the 3 subscales (function, pain, stiffness) are summed up to calculate the total WOMAC score. The 100-normalized score ranges from 0 (none) to 100 (worse limitations).
Measured: Day 1 and 6 months
Changes from baseline of quality of life at 20 days
Quality of life is measured using EUROQOL (EQ-5D-3L) questionnaire. The EQ-5D-3L descriptive system comprises the following five dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has 3 levels: no problems, some problems, and extreme problems. The patient is asked to indicate his/her health state by ticking the box next to the most appropriate statement in each of the five dimensions. This decision results into a 1-digit number that expresses the level selected for that dimension. The digits for the five dimensions can be combined into a 5-digit number that describes patient health state. Mean variation is compared with that of the control group in the reference RCT (external comparison).
Measured: Day 1 and 20 days
Changes from baseline of quality of life at 3 months
Quality of life is measured using EUROQOL (EQ-5D-3L) questionnaire. The EQ-5D-3L descriptive system comprises the following five dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has 3 levels: no problems, some problems, and extreme problems. The patient is asked to indicate his/her health state by ticking the box next to the most appropriate statement in each of the five dimensions. This decision results into a 1-digit number that expresses the level selected for that dimension. The digits for the five dimensions can be combined into a 5-digit number that describes patient health state. Mean variation is compared with that of the control group in the reference RCT (external comparison).
Measured: Day 1 and 3 months
Changes from baseline of quality of life at 6 months
Quality of life is measured using EUROQOL (EQ-5D-3L) questionnaire. The EQ-5D-3L descriptive system comprises the following five dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has 3 levels: no problems, some problems, and extreme problems. The patient is asked to indicate his/her health state by ticking the box next to the most appropriate statement in each of the five dimensions. This decision results into a 1-digit number that expresses the level selected for that dimension. The digits for the five dimensions can be combined into a 5-digit number that describes patient health state. Mean variation is compared with that of the control group in the reference RCT (external comparison).
Measured: Day 1 and 6 months
Acceptable Symptom State (ASS) at 20 days
ASS is defined as VAS pain value of 32 mm or less or a WOMAC function subscale, normalized to a 0-100 score of 31 points or less. The percentage of patients achieving ASS is calculated and compared with that of the control group in the reference RCT (external comparison).
Measured: Day 20
Acceptable Symptom State (ASS) at 3 months
ASS is defined as VAS pain value of 32 mm or less or a WOMAC function subscale, normalized to a 0-100 score of 31 points or less. The percentage of patients achieving ASS is calculated and compared with that of the control group in the reference RCT (external comparison).
Measured: 3 months
Acceptable Symptom State (ASS) at 6 months
ASS is defined as VAS pain value of 32 mm or less or a WOMAC function subscale, normalized to a 0-100 score of 31 points or less. The percentage of patients achieving ASS is calculated and compared with that of the control group in the reference RCT (external comparison).
Measured: 6 months
Management of knee osteoarthritis over the study
Number and frequency of treatments for knee osteoarthritis (analgesics, chondro-protectors or antarthritics, intra-articular injections of corticoids and hyaluronic acid, physical or surgical treatments). Numbers and frequencies of treatments are compared with those of the control group in the reference RCT (external comparison).
Measured: 6 months
Safety of the18-day spa treatment (therapeutic indication: Rheumatology) at Enghien-les-Bains
Adverse effects related to the spa treatment are described using MedDRA, whether they occurred during or after the 18-day spa treatment.
Measured: 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Jan 2026
- Study start27 Jan 2026
- Primary completion10 Feb 2027 (estimated)
- Study completion31 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Knee OsteoarthritisStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- Prospective, single-arm, superiority study with external comparison (control group of a reference RCT)
- Masking
- None (open label)
- Enrolment
- 76 participants (estimated)
Sponsor and investigators
- Lead sponsor
- CEN Biotech
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Town Hall of Enghien-les-Bains
- Responsible party
- Sponsor
- Investigators
- Magali Ballard, MD, Principal investigator
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07370480
- Sponsor's protocol ID
- C1757
- Other IDs
- 2025-A00448-41
- Acronym
- ENERGIE
- Status last verified
- Sep 2026
- First submitted
- 13 Jan 2026
- Last updated
- 16 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: The informed consent obtained from participants does not include provisions for sharing individual participant data with external researchers.
Publications
Forestier R, Debiais F, Michel N, Schueller R, Juhel C. The effectiveness of a 3-week spa therapy on the 6-month mobility and functional ability of patients with knee osteoarthritis: the ANGELLO randomized controlled trial. Int J Biometeorol. 2025 Jul;69(7):1715-1724. doi: 10.1007/s00484-025-02927-2. Epub 2025 May 13.
PubMed 40358707
Study at a glance
From the registry record, last updated by the sponsor on 16 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of the Effectiveness of the Enghien-les-Bains Thermal Spa Treatment in the Rheumatology Indication in Patients With Knee Osteoarthritis. Indirect Comparison Study.
- ClinicalTrials.gov ID
- NCT07370480
- Acronym / sponsor ID
- ENERGIE / C1757
- Conditions
- Knee Osteoarthritis
- Keywords
- spa therapy, thermal treatment, balneotherapy, Rheumatology
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 76 participants (estimated)
- Lead sponsor
- CEN BiotechIndustry (pharma, biotech, devices)
- Collaborators
- Town Hall of Enghien-les-Bains
- Study start
- 27 Jan 2026 (actual)
- Primary completion
- 10 Feb 2027 (estimated)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 27 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this interventional study is to evaluate the effectiveness at 6 months of the Enghien-les-Bains thermal spa treatment on functional disability and pain, assessed by the Minimal Clinically Important Improvement (MCII), in patients with knee osteoarthritis.
The study is conducted in patients aged 50 to 80 years with knee osteoarthritis (Kellgren-Lawrence grade 2 to 4) and a baseline functional impairment defined by a normalized WOMAC function score ≥ 30.
The main questions it aims to answer are:
- Does the Enghien-les-Bains thermal spa treatment result in a clinically meaningful improvement in pain and functional disability at 6 months in patients with knee osteoarthritis?
- Is the effectiveness of the Enghien-les-Bains thermal spa treatment superior to standard care, as assessed through an indirect comparison with an external control group from the ANGELLO randomized controlled trial (NCT0581943)? Patients receiving the Enghien-les-Bains thermal spa treatment are compared to the external control group of the ANGELLO randomized controlled trial (Saint-Jean-d'Angély), composed of non-spa-treated patients receiving standard care, to assess differences in pain and functional disability outcomes at 6 months.
Patients of the study:
- Undergo a standardized thermal spa treatment at Enghien-les-Bains.
- Continue usual medical care for knee osteoarthritis.
- Complete questionnaires and clinical assessments at baseline and at 6 months.
Detailed description
This study includes three medical visits with the investigator: one within 28 days before the thermal spa treatment, one at the end of the treatment, and one 6 months after the start of the treatment. At inclusion, informed consent is obtained, eligibility criteria are verified, and baseline data are collected, including self-administered questionnaires assessing pain, function, and quality of life before the start of the treatment.
During the 20-day thermal spa treatment, care provided and any adverse events are recorded. Clinical assessments and questionnaires are repeated at the end of the treatment. Additional patient-reported outcomes and treatment changes are collected at 3 months, and a final clinical evaluation and questionnaires are completed at 6 months.
An ancillary qualitative study evaluates the conditions under which the thermal spa treatment program is effective from the participants' perspective, including their engagement, lived experience, perceived benefits, facilitators and barriers, and any adaptations made. Data are collected through individual semi-structured face-to-face interviews at the end of the treatment, which are audio-recorded, fully transcribed, and qualitatively analyzed.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Prospective, single-arm, superiority study with external comparison (control group of a reference RCT)
| Arm | Type | Receives |
|---|---|---|
| Thermal spa treatment | Experimental | Other: Thermal spa sessions, Other: Thermal water, Other: Standard of Care for Knee Osteoarthritis18-day spa program with Waters of Enghien-les-Bains in addition to standard of care for knee osteoarthritis |
Who may qualify
- Ages
- 50 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Knee osteoarthritis with Kellgren and Lawrence stage 2 to 4 evidenced by a knee X-ray examination in the past 3 years.
- 100-normalized score of the WOMAC physical function subscale greater than or equal to 30.
- Signed inform consent.
- With health insurance affiliation.
Key exclusion criteria (10 listed)
- Presented with balneotherapy contraindication or to certain adjuvant treatment techniques (balneation, hydrotherapy jets, massage): chronic infectious pathology, active cancer, decompensated cardiac, hepatic or renal insufficiency, "open" leg ulcer, immune deficiency, phlebitis, erysipelas or history of erysipelas, active thrombosis, behavioral disorders, etc.
- Presented with chronic pain for reasons other than osteoarthritis: chronic inflammatory rheumatism (rheumatoid arthritis, ankylosing spondylitis, lupus, psoriatic arthritis) or fibromyalgia.
- Patient scheduled for knee osteoarthrosis-related surgery within the next 7 months.
- Having had spa treatment in the past 6 months whatever the indication or intra-articular corticosteroid injection within the previous 90 days or hyaluronic acid infiltration or other viscosupplementation or platelet-rich plasma (PRP) injection within the previous 6 months.
- Having planned a spa treatment in another indication between inclusion and final visit.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Thermal spa sessionsAt least 4 spa sessions per day, 6 days a week during 3 consecutive weeks that may include daily: one whirlpool bath, one poultice application, one overall jet shower and one underwater massage with thermal water. With the exception of the application of mud poultices and whirlpool bath, which cannot be substituted, other treatments may be replaced by: immersion bath with shower, penetrating shower, and local jet shower. 10-minute air diffusion baths are taken in individual tubs at 37°C. Mud is applied for 10 minutes as a poultice to both knees (minimum 2 per knee, 45°C), if necessary, to other painful osteoarthritis areas. A 3-minute overall jet shower is administered by a thermal spa staff member, using thermal water at 37°C. A 10-minute underwater massage is administered by a physiotherapist, under a thermal water spray bar at 37°C. | Other | Thermal spa treatment |
| Thermal waterAlso: Natural Mineral Water of Enghiens-les-BainsThe water has a neutral pH (7), is cold (14 °C), and presents a moderate level of mineralization (571 mg/L) with a balanced ionic profile. It contains calcium (128 mg/L), bicarbonates (440 mg/L), sulfates (93 mg/L), magnesium (27.9 mg/L), and sodium (12.4 mg/L). | Other | Thermal spa treatment |
| Standard of Care for Knee OsteoarthritisParticipants continue standard medical care for knee osteoarthritis as prescribed by their primary care physician, including analgesics and physiotherapy, according to routine clinical practice. | Other | Thermal spa treatment |
Primary outcome
Minimal Clinically Important Improvement (MCII) at 6 months
Time frame: 6 months
MCII is defined as a pain reduction of 19.9 mm or more on a 0-100 visual analogic scale (VAS), where 0 means no pain and 100 worse pain. The percentage of patients achieving MCII is calculated and compared with that of the control group in the reference RCT (external comparison).
Minimal Clinically Important Improvement (MCII) at 6 months
Time frame: 6 months
MCII is defined as a reduction of 9.1 points or more in the function subscale of the Physical function subscale of the Western Ontario and McMaster Universities Arthritis Index (WOMAC) in absence of knee surgery. WOMAC is a self-administered questionnaire that consists in 17 items: (17 items): using stairs, rising from sitting, standing, bending, walking, getting in / out of a car, shopping, putting on / taking off socks, rising from bed, lying in bed, getting in / out of bath, sitting, getting on / off toilet, heavy domestic duties, light domestic duties. The 100-normalized subscale score ranges from 0 (none) to 100 (worse functional limitations). The percentage of patients achieving MCII is calculated and compared with that of the control group in the reference RCT (external comparison).
23 secondary outcomes
Change from baseline of pain-related knee osteoarthritis at 20 days
Time frame: Day 1 and 20 days
Change from baseline of pain-related knee osteoarthritis at 3 months
Time frame: Day 1 and 3 months
Change from baseline of pain-related knee osteoarthritis at 6 months
Time frame: Day 1 and 6 months
Change from baseline of the pain subscale of the WOMAC at 20 days
Time frame: Day 1 and 20 days
Change from baseline of the pain subscale of the WOMAC at 3 months
Time frame: Day 1 and 3 months
Change from baseline of the pain subscale of the WOMAC at 6 months
Time frame: Day 1 and 6 months
Changes from baseline of stiffness subscale of the WOMAC at 20 days
Time frame: Day 1 and 20 days
Changes from baseline of stiffness subscale of the WOMAC at 3 months
Time frame: Day 1 and 3 months
Changes from baseline of stiffness subscale of the WOMAC at 6 months
Time frame: Day 1 and 6 months
Change from baseline of physical function subscale of the WOMAC at 20 days
Time frame: Day 1 and 20 days
Change from baseline of physical function subscale of the WOMAC at 3 months
Time frame: Day 1 and 3 months
Change from baseline of physical function subscale of the WOMAC at 36 months
Time frame: Day 1 and 6 months
Change from baseline of physical function subscale of the WOMAC at 6 months
Time frame: Day 1 and 6 months
Change from baseline of total score of the WOMAC at 20 days
Time frame: Day 1 and 20 days
Change from baseline of total score of the WOMAC at 6 months
Time frame: Day 1 and 6 months
Changes from baseline of quality of life at 20 days
Time frame: Day 1 and 20 days
Changes from baseline of quality of life at 3 months
Time frame: Day 1 and 3 months
Changes from baseline of quality of life at 6 months
Time frame: Day 1 and 6 months
Acceptable Symptom State (ASS) at 20 days
Time frame: Day 20
Acceptable Symptom State (ASS) at 3 months
Time frame: 3 months
Acceptable Symptom State (ASS) at 6 months
Time frame: 6 months
Management of knee osteoarthritis over the study
Time frame: 6 months
Safety of the18-day spa treatment (therapeutic indication: Rheumatology) at Enghien-les-Bains
Time frame: 6 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 16 Sep 2026.
- Background: PubMed 40358707Forestier R, Debiais F, Michel N, Schueller R, Juhel C. The effectiveness of a 3-week spa therapy on the 6-month mobility and functional ability of patients with knee osteoarthritis: the ANGELLO randomized controlled trial. Int J Biometeorol. 2025 Jul;69(7):1715-1724. doi: 10.1007/s00484-025-02927-2. Epub 2025 May 13.
- Individual participant dataSharing planned: No. The informed consent obtained from participants does not include provisions for sharing individual participant data with external researchers.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Magali Ballard, MD principal investigator
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Thermal spa sessions and Thermal water in people with Knee Osteoarthritis, run by CEN Biotech at 2 sites in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 16 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Minimal Clinically Important Improvement (MCII) at 6 months (time frame: 6 months). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07370480, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 16 Sep 2026.