Ligament; LaxityFLEXNCT05177549
Evaluation of Anterior Tibial Translation of the Knee in Healthy Women, at Two Times of the Menstrual Cycle, on Hormonal Contraceptives or Not (FLEX)
A study testing Bilateral knee examination with Lachmeter® in people with Ligament; Laxity, run by Centre Hospitalier Universitaire de Nice at 1 site in France.
Trial summary
Women's participation in sports at all levels has been increasing in recent decades. Many individual and team sports are at risk of anterior cruciate ligament (ACL) injury. This injury leads to a permanent or long-lasting interruption of sports practice and to significant medical and economic expenses. Read more about this study
- Who is it for?
- Ages 18 to 40 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Ligament; Laxity
- What is being tested?
- Bilateral knee examination with Lachmeter®
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 45 participants
- Where
- 1 siteFrance
- Study dates
- 8 Jun 2022to 4 Aug 2023
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 18 to 40 years
- Women only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Woman between 18 and 40 years old
- No history of surgery of the 2 lower limbs
- No change in contraceptive method in the last 6 months
- Signature of the informed consent
- Affiliation to the social security system
- To be at Day 14 of her menstrual cycle (+/-1 day) (the first day of the cycle (Day1) being considered as the first day of the menstrual period), except for those on micro-progestative contraception not regulated
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- By inclusion group:
- For women without hormonal contraception: No method of contraception Or a copper intrauterine device Regular cycles of 26 to 33 days
- For women on estrogen-progestin contraception: Correct use of the estrogen-progestin pill according to the MA Or wearing a vaginal ring according to the MA protocol Or wearing a contraceptive skin patch according to the MA protocol Regular cycles of 26 to 33 days
- For women on micro-progestin contraception : Continuous use of the micro-progestogen pill Or wearing a subcutaneous hormonal implant,
- Exception: women on micro-progestin contraception who are not regulated:
- They may have an irregular cycle or no cycle to be included
- They can be included on any day if they have no cycle
Who cannot join
- Pregnancy or breastfeeding in progress
- Hormonal intrauterine device or injectable contraception
- Menopause (defined as no menstruation for one year)
- Surgery: tubal ligation, oophorectomy, adnexectomy, hysterectomy
- History of microcrystalline or infectious pathology localized to the knee
- History of systemic or localized inflammatory joint disease of the knee
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- History of fracture, severe sprain or dislocation of the knee joint
- History of osteoarticular or congenital diseases that may lead to laxity (Marfan syndrome, trisomy 21, Ehlers-Danlos syndrome...)
- Sign of hyperlaxity evaluated by a Beighton score higher than 4 (see appendix)
- BMI > 25
- Daily alcohol consumption above the thresholds recommended by Public Health in France (more than 2 glasses per day)
- Woman unable to understand the protocol
- Intense or unusual physical exercise during the last 72 hours (e.g.: marathon, triathlon, competitive cycling race...)
- Woman under guardianship, curatorship or deprived of liberty
Trial locations and contacts
1 site in 1 country.
About this study
Women's participation in sports at all levels has been increasing in recent decades. Many individual and team sports are at risk of anterior cruciate ligament (ACL) injury. This injury leads to a permanent or long-lasting interruption of sports practice and to significant medical and economic expenses. Women are recognized as being more at risk of anterior cruciate ligament injury with a risk 6 times higher than men. Hyperlaxity is a risk factor for anterior cruciate ligament injury, but the pathophysiological bases are little studied. Hormonal impregnation and certain periods of the menstrual cycle (ovulatory phase) are risk factors for anterior cruciate ligament injury. It therefore seems interesting to investigators to study the influence of hormonal impregnation on ligament laxity. To date no study has investigated such a relationship.
- Conditions
- Ligament; Laxity
- Being tested
- Bilateral knee examination with Lachmeter®
- Keywords
- hormonal impregnation
- Medical subject headings
- Joint Instability
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Bilateral knee examination with Lachmeter®Other
Bilateral knee examination with Lachmeter®. Examination repeated 3 times on each knee
| Study group | Role | What they receive |
|---|---|---|
| on estrogen-progestin contraception | Experimental | Not described Receives: Other: Bilateral knee examination with Lachmeter® |
| under micro-progestational contraception | Experimental | Not described Receives: Other: Bilateral knee examination with Lachmeter® |
| without hormonal contraception | Experimental | Not described Receives: Other: Bilateral knee examination with Lachmeter® |
What is being measured
The primary outcome is the main question the study is designed to answer.
anterior tibial translation of the knee
The anterior tibial translation of the knee will be considered as representative of the anterior laxity of the knee of women under hormonal contraception via the Lachman test at 30° measured with a digital arthrometer type Lachmeter® (bilateral examination repeated 3 times on each knee).The degree of laxity will be evaluated thanks to the international classification IKDC:
- Grade A 0 to 2 mm = normal
- Grade B 3 to 5 mm = almost normal
- Grade C 6 to 10 mm = abnormal
- Grade D > 10 mm = severely abnormal
Measured: Day1 (inclusion visit)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Jan 2022
- Study start8 Jun 2022
- Primary completion4 Aug 2023
- Study completion4 Aug 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Ligament; LaxityStudies of the same condition, open and under way.
- More trials run by Centre Hospitalier Universitaire de NiceThe sponsor's other registered studies.
- 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
- Prevention
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 45 participants (actual)
Sponsor and investigators
- Lead sponsor
- Centre Hospitalier Universitaire de Nice
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Christian ROUX, Principal investigator, Centre Hospitalier Universitaire de Nice
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05177549
- Sponsor's protocol ID
- 19-AOI-01
- Acronym
- FLEX
- Status last verified
- May 2026
- First submitted
- 16 Nov 2021
- Last updated
- 26 May 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 26 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of Anterior Tibial Translation of the Knee in Healthy Women, at Two Times of the Menstrual Cycle, on Hormonal Contraceptives or Not (FLEX)
- ClinicalTrials.gov ID
- NCT05177549
- Acronym / sponsor ID
- FLEX / 19-AOI-01
- Conditions
- Ligament; Laxity
- Keywords
- hormonal impregnation
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 45 participants (actual)
- Lead sponsor
- Centre Hospitalier Universitaire de NiceUniversity, hospital or other
- Study start
- 8 Jun 2022 (actual)
- Primary completion
- 4 Aug 2023 (actual)
- Study completion
- 4 Aug 2023 (actual)
- First posted
- 4 Jan 2022 (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.
Women's participation in sports at all levels has been increasing in recent decades. Many individual and team sports are at risk of anterior cruciate ligament (ACL) injury. This injury leads to a permanent or long-lasting interruption of sports practice and to significant medical and economic expenses. Women are recognized as being more at risk of anterior cruciate ligament injury with a risk 6 times higher than men. Hyperlaxity is a risk factor for anterior cruciate ligament injury, but the pathophysiological bases are little studied. Hormonal impregnation and certain periods of the menstrual cycle (ovulatory phase) are risk factors for anterior cruciate ligament injury. It therefore seems interesting to investigators to study the influence of hormonal impregnation on ligament laxity. To date no study has investigated such a relationship.
Study design
- Primary purpose
- Prevention
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| on estrogen-progestin contraception | Experimental | Other: Bilateral knee examination with Lachmeter® |
| under micro-progestational contraception | Experimental | Other: Bilateral knee examination with Lachmeter® |
| without hormonal contraception | Experimental | Other: Bilateral knee examination with Lachmeter® |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (13 listed)
- Woman between 18 and 40 years old
- No history of surgery of the 2 lower limbs
- No change in contraceptive method in the last 6 months
- Signature of the informed consent
- Affiliation to the social security system
Key exclusion criteria (14 listed)
- Pregnancy or breastfeeding in progress
- Hormonal intrauterine device or injectable contraception
- Menopause (defined as no menstruation for one year)
- Surgery: tubal ligation, oophorectomy, adnexectomy, hysterectomy
- History of microcrystalline or infectious pathology localized to the knee
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 |
|---|---|---|
| Bilateral knee examination with Lachmeter®Bilateral knee examination with Lachmeter®. Examination repeated 3 times on each knee | Other | on estrogen-progestin contraception, under micro-progestational contraception, without hormonal contraception |
Primary outcome
anterior tibial translation of the knee
Time frame: Day1 (inclusion visit)
The anterior tibial translation of the knee will be considered as representative of the anterior laxity of the knee of women under hormonal contraception via the Lachman test at 30° measured with a digital arthrometer type Lachmeter® (bilateral examination repeated 3 times on each knee).The degree of laxity will be evaluated thanks to the international classification IKDC: * Grade A 0 to 2 mm = normal * Grade B 3 to 5 mm = almost normal * Grade C 6 to 10 mm = abnormal * Grade D > 10 mm = severely abnormal
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 26 May 2026.
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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.
Christian ROUX principal investigator
Centre Hospitalier Universitaire de Nice
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Bilateral knee examination with Lachmeter® in people with Ligament; Laxity, run by Centre Hospitalier Universitaire de Nice at 1 site 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 13 inclusion and 14 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: finished, as of the sponsor's last update on 26 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
anterior tibial translation of the knee (time frame: Day1 (inclusion visit)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 26 May 2026.