ACL - Anterior Cruciate Ligament RuptureK-STARTS +NCT07249645
Description of Return to Sport in Amateur Athletes Who Underwent Several Functional Tests (K-STARTS, Vertical Jumps and Soleus Muscle Strength) After Initial ACL Reconstruction
A study testing Physical tests in people with ACL - Anterior Cruciate Ligament Rupture, run by GCS Ramsay Santé pour l'Enseignement et la Recherche.
Trial summary
ACL injuries are incapacitating for both professional and amateur athletes, with long-term repercussions on performance and return to sport (RTS). Surgical reconstruction of the ACL is the main treatment option. Despite this, recurrence rates are high. Read more about this study
- Who is it for?
- Ages 18 to 30 years
- Conditions the study is for
- ACL - Anterior Cruciate Ligament Rupture
- What is being tested?
- Physical tests
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 230 participants
- Where
- No sites listed yet
- Study dates
- 1 Oct 2026to 31 Jul 2029
- 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 18 to 30 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Patient, male or female, aged between ≥ 18 and ≤ 30 years old
- Amateur athlete with a Tegner score ≥ 5
- Patient with primary ACL reconstruction dating back 6 months
- Patients with ACL damage in one knee only
- Patients who have undergone an isokinetic strength test with results that do not contraindicate functional testing
- Patients affiliated with or covered by a social security scheme
- French-speaking patients who have signed an informed consent form
Who cannot join
- Patients treated for bilateral ACL reconstruction
- Patients who are professional athletes or compete at a national level
- Patients with severe associated disorders (neurological, connective tissue, congenital diseases)
- Patients with multiple ligament defects or associated osteotomy
- Patients already included in another study
- Protected patients: adults under guardianship, curatorship or other legal protection, deprived of their liberty by judicial or administrative decision
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Description of Return to Sport in Amateur Athletes Who Underwent Several Functional Tests (K-STARTS, Vertical Jumps and Soleus Muscle Strength) After Initial ACL Reconstruction.
ACL injuries are incapacitating for both professional and amateur athletes, with long-term repercussions on performance and return to sport (RTS).
Surgical reconstruction of the ACL is the main treatment option. Despite this, recurrence rates are high. Half of all recurrences occur within 8 months of reconstruction, and 70% within the first 6 months after RTS. Decision to RTS is therefore an important one, as returning too early can increase the risk of recurrence, while returning too late delays a return to pre-injury performance levels. As described by the Bern Consensus, RTS consists of three phases :
Read more
- Phase 1: Return to participation (RTp)
- Phase 2: Return to sport (RTS)
- Phase 3: Return to performance (RTP)
RTS decision must be based on multiple factors, including psychological, athletic and functional components, as well as specific nature of the patient's activities. However, few individual tests have been associated with a specific level of RTS. Furthermore, the majority of studies rely on subjective and non-objective assessments to determine whether the athlete has returned to their pre-injury level.
It would therefore be relevant to study the RTS time of patients who have performed a combination of several objective functional tests whose results could be complementary, in particular the K-STARTS, the CMJ, the DJ and the measurement of soleus muscle strength.
Read the detailed description
ACL injuries are incapacitating for both professional and amateur athletes, with long-term repercussions on performance and return to sport (RTS). Only 60% of amateurs return to their pre-injury level of performance.
Surgical reconstruction of the ACL is the main treatment option. Despite this, recurrence rates are high (ranging from 17% to 40% depending on the population). Half of all recurrences occur within 8 months of reconstruction, and 70% within the first 6 months after RTS. The decision to RTS is therefore an important one, as returning too early can increase the risk of recurrence, while returning too late delays a return to pre-injury performance levels. As described by the Bern Consensus, RTS consists of three phases :
- Phase 1: Return to participation (RTp)
- Phase 2: Return to sport (RTS)
- Phase 3: Return to performance (RTP)
RTS decision must be based on multiple factors, including psychological, athletic and functional components, as well as specific nature of the patient's activities. However, few individual tests have been associated with a specific level of RTS. Furthermore, the majority of studies rely on subjective and non-objective assessments to determine whether the athlete has returned to their pre-injury level. It would therefore be relevant to study the RTS time of patients who have performed a combination of several objective functional tests whose results could be complementary, in particular the K-STARTS, the CMJ, the DJ and the measurement of soleus muscle strength :
- The Knee Santy Athletic Return to Sport (K-STARTS) test, which includes psychological and functional assessments of the knee. The K-STARTS test consists mainly of horizontal jumps that assess the functional capabilities of the knee.
- The contribution of the knee joint during various horizontal and vertical jumping tasks was assessed : a greater contribution of the knee during propulsion in vertical vs. horizontal jumps (34.1% vs. 12.9%, respectively) was reported and, conversely, a greater contribution of the knee during landing in horizontal vs. vertical jumps (64.7% vs. 34.3%, respectively) was reported. Thus, the combination of vertical and horizontal jumps would allow for a functional assessment of the knee during the different phases of jumping. Counter-Movement Jump (CMJ) and drop jump (DJ) are the main types of vertical jumps recommended for functional assessment of the knee.
- Measurement of soleus muscle strength. Recent studies have shown a decrease in the contribution of the soleus muscle during propulsion and landing in horizontal and vertical jumps in subjects with ACL injury.
- Conditions
- ACL - Anterior Cruciate Ligament Rupture
- Being tested
- Physical tests
- Keywords
- Return To Sport ACL injury
- Medical subject headings
- Anterior Cruciate Ligament Injuries
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Physical testsOther
K-STARTS, CMJ, DJ, and soleus muscle strength measurement
| Study group | Role | What they receive |
|---|---|---|
| K-STARTS + | Experimental | K-STARTS + arm involves following tests : K-STARTS, CMJ, DJ and soleus muscle strength measurement Receives: Other: Physical tests |
What is being measured
The primary outcome is the main question the study is designed to answer.
Return to sport
This is time period (in months) between surgery and:
- The date of return to sport (phase 2) for patients who resumed sport
- The end of follow-up (timepoint date/date of death/date of loss of contact) for patients who did not resume sport
Measured: 18 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Nov 2025
- Study start1 Oct 2026 (estimated)
- Primary completion31 Jul 2029 (estimated)
- Study completion31 Jul 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ACL - Anterior Cruciate Ligament RuptureStudies of the same condition, open and under way.
- More trials run by GCS Ramsay Santé pour l'Enseignement et la RechercheThe 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
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 230 participants (estimated)
Sponsor and investigators
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07249645
- Sponsor's protocol ID
- 2025-A01104-45
- Acronym
- K-STARTS +
- Status last verified
- Aug 2026
- First submitted
- 18 Nov 2025
- Last updated
- 20 Aug 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 20 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Description of Return to Sport in Amateur Athletes Who Underwent Several Functional Tests (K-STARTS, Vertical Jumps and Soleus Muscle Strength) After Initial ACL Reconstruction.
- ClinicalTrials.gov ID
- NCT07249645
- Acronym / sponsor ID
- K-STARTS + / 2025-A01104-45
- Conditions
- ACL - Anterior Cruciate Ligament Rupture
- Keywords
- Return To Sport ACL injury
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 230 participants (estimated)
- Lead sponsor
- GCS Ramsay Santé pour l'Enseignement et la RechercheUniversity, hospital or other
- Study start
- 1 Oct 2026 (estimated)
- Primary completion
- 31 Jul 2029 (estimated)
- Study completion
- 31 Jul 2029 (estimated)
- First posted
- 25 Nov 2025 (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.
ACL injuries are incapacitating for both professional and amateur athletes, with long-term repercussions on performance and return to sport (RTS).
Surgical reconstruction of the ACL is the main treatment option. Despite this, recurrence rates are high. Half of all recurrences occur within 8 months of reconstruction, and 70% within the first 6 months after RTS. Decision to RTS is therefore an important one, as returning too early can increase the risk of recurrence, while returning too late delays a return to pre-injury performance levels. As described by the Bern Consensus, RTS consists of three phases :
- Phase 1: Return to participation (RTp)
- Phase 2: Return to sport (RTS)
- Phase 3: Return to performance (RTP)
RTS decision must be based on multiple factors, including psychological, athletic and functional components, as well as specific nature of the patient's activities. However, few individual tests have been associated with a specific level of RTS. Furthermore, the majority of studies rely on subjective and non-objective assessments to determine whether the athlete has returned to their pre-injury level.
It would therefore be relevant to study the RTS time of patients who have performed a combination of several objective functional tests whose results could be complementary, in particular the K-STARTS, the CMJ, the DJ and the measurement of soleus muscle strength.
Detailed description
ACL injuries are incapacitating for both professional and amateur athletes, with long-term repercussions on performance and return to sport (RTS). Only 60% of amateurs return to their pre-injury level of performance.
Surgical reconstruction of the ACL is the main treatment option. Despite this, recurrence rates are high (ranging from 17% to 40% depending on the population). Half of all recurrences occur within 8 months of reconstruction, and 70% within the first 6 months after RTS. The decision to RTS is therefore an important one, as returning too early can increase the risk of recurrence, while returning too late delays a return to pre-injury performance levels. As described by the Bern Consensus, RTS consists of three phases :
- Phase 1: Return to participation (RTp)
- Phase 2: Return to sport (RTS)
- Phase 3: Return to performance (RTP)
RTS decision must be based on multiple factors, including psychological, athletic and functional components, as well as specific nature of the patient's activities. However, few individual tests have been associated with a specific level of RTS. Furthermore, the majority of studies rely on subjective and non-objective assessments to determine whether the athlete has returned to their pre-injury level. It would therefore be relevant to study the RTS time of patients who have performed a combination of several objective functional tests whose results could be complementary, in particular the K-STARTS, the CMJ, the DJ and the measurement of soleus muscle strength :
- The Knee Santy Athletic Return to Sport (K-STARTS) test, which includes psychological and functional assessments of the knee. The K-STARTS test consists mainly of horizontal jumps that assess the functional capabilities of the knee.
- The contribution of the knee joint during various horizontal and vertical jumping tasks was assessed : a greater contribution of the knee during propulsion in vertical vs. horizontal jumps (34.1% vs. 12.9%, respectively) was reported and, conversely, a greater contribution of the knee during landing in horizontal vs. vertical jumps (64.7% vs. 34.3%, respectively) was reported. Thus, the combination of vertical and horizontal jumps would allow for a functional assessment of the knee during the different phases of jumping. Counter-Movement Jump (CMJ) and drop jump (DJ) are the main types of vertical jumps recommended for functional assessment of the knee.
- Measurement of soleus muscle strength. Recent studies have shown a decrease in the contribution of the soleus muscle during propulsion and landing in horizontal and vertical jumps in subjects with ACL injury.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| K-STARTS + | Experimental | Other: Physical testsK-STARTS + arm involves following tests : K-STARTS, CMJ, DJ and soleus muscle strength measurement |
Who may qualify
- Ages
- 18 to 30 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (7 listed)
- Patient, male or female, aged between ≥ 18 and ≤ 30 years old
- Amateur athlete with a Tegner score ≥ 5
- Patient with primary ACL reconstruction dating back 6 months
- Patients with ACL damage in one knee only
- Patients who have undergone an isokinetic strength test with results that do not contraindicate functional testing
Key exclusion criteria (6 listed)
- Patients treated for bilateral ACL reconstruction
- Patients who are professional athletes or compete at a national level
- Patients with severe associated disorders (neurological, connective tissue, congenital diseases)
- Patients with multiple ligament defects or associated osteotomy
- Patients already included in another study
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 |
|---|---|---|
| Physical testsK-STARTS, CMJ, DJ, and soleus muscle strength measurement | Other | K-STARTS + |
Primary outcome
Return to sport
Time frame: 18 months
This is time period (in months) between surgery and: * The date of return to sport (phase 2) for patients who resumed sport * The end of follow-up (timepoint date/date of death/date of loss of contact) for patients who did not resume sport
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 20 Aug 2026.
- Individual participant dataSharing planned: No
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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.
Questions about this trial
What is this clinical trial studying?
A study testing Physical tests in people with ACL - Anterior Cruciate Ligament Rupture, run by GCS Ramsay Santé pour l'Enseignement et la Recherche.
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 7 inclusion and 6 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: opening soon, as of the sponsor's last update on 20 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
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?
Contact Bertrand SONNERY-COTTET (+33437530022, sonnerycottet@aol.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Return to sport (time frame: 18 months). 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 20 Aug 2026.