LETSTABILITY LTFNCT06885372
Long-term Follow up of the Stability 1 Trial
A study testing Lateral Extra-Articular Tenodesis (LET) and ACL Reconstruction in people with LET and ACL Reconstruction, run by Western University, Canada at 8 sites in 2 countries.
Trial summary
From 2014-2017, across 7 Canadian and 2 European sites, we randomized 618 patients at high-risk of re-injury, to anterior cruciate ligament reconstruction (ACLR) with or without a lateral extraarticular tenodesis (LET) and demonstrated that the addition of the LET reduced the risk of instability (RRR=0.38; 95%… Read more about this study
- Who is it for?
- Ages 14 to 25 years
- Conditions the study is for
- LET, ACL Reconstruction, Osteoarthritis (OA) of the Knee
- What is being tested?
- Lateral Extra-Articular Tenodesis (LET) and ACL Reconstruction
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 510 participants
- Where
- 8 sitesin 2 countries
- Study dates
- 1 Nov 2024to Mar 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 14 to 25 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- ACL deficient knee
- skeletally mature to 25 years of age
- 2 or more of:
- competitive pivoting sport
- grade 2 pivot shift or greater
- generalized ligament laxity - Beighton score of 4 or greater
Who cannot join
- previous ACL reconstruction on either knee
- multi-ligament injury (two or more ligaments requiring surgical attention)
- symptomatic articular cartilage defect requiring treatment other than debridement
- greater than 3 degrees of asymmetric varus
- unable to complete outcome questionnaires
Trial locations and contacts
8 sites in 2 countries. Contact the study team or a site near you to ask about taking part.
8 sites in 2 countries
Canada7 sites
Banff Sport Medicine Clinic
Banff, Alberta, T1L 1B3
University of Calgary
Calgary, Alberta, T2N 1N4
McMaster University
Hamilton, Ontario, L8N 3Z5
Queens University
Kingston, Ontario, K7L 2V7
Fowler Kennedy Sport Medicine Clinic
London, Ontario, N6A 3K7
Fraser Health Authority
New Westminster, British Columbia, V3L 5P5
Pan Am Clinic
Winnipeg, Manitoba, R3M 3E4
United Kingdom1 site
University Hospitals Coventry and Warwickshire NHS Trust
Coventry, CV2 2DX
About this study
From 2014-2017, across 7 Canadian and 2 European sites, we randomized 618 patients at high-risk of re-injury, to anterior cruciate ligament reconstruction (ACLR) with or without a lateral extraarticular tenodesis (LET) and demonstrated that the addition of the LET reduced the risk of instability (RRR=0.38; 95% Confidence Interval (CI), 0.21-0.52; P=0.0001) and graft re-rupture (RRR, 0.67; 95% CI, 0.36-0.83; P=0.001). As a result, practice has changed; there has been a large increase in the proportion of orthopaedic surgeons recommending the addition of an LET at the time of ACLR and an increase in the number of patients requesting an LET from their surgeon. There is some weak evidence suggesting that in the longer term, the LET may increase the risk of developing osteoarthritis (OA) in that knee. Knee OA affects over 4.4 million Canadians and the number of younger adults being diagnosed with knee OA is growing and is a primary reason for seeking healthcare in Canada. The impact of OA in Canada is enormous and projected to cost Canada $17.5 billion annually in lost productivity alone by 2031. This study will use imaging and patient-reported Knee Outcomes Osteoarthritis Score (KOOS) to evaluate the incidence of OA at 10-years post ACL reconstruction with and without LET. We will also collect information about overall knee health, patient-reported outcomes, costs associated with knee injury, rehabilitation and disability, clinical failure, functional ability, and sport participation. It is crucial that we understand the risks of developing knee OA associated with the addition of an LET to an ACLR so that surgeons and patients can make informed decisions, not just for their immediate post injury treatment of the failed ligament, but for the potential long-term consequences of that decision.
- Conditions
- LET, ACL Reconstruction, Osteoarthritis (OA) of the Knee
- Being tested
- Lateral Extra-Articular Tenodesis (LET), ACL Reconstruction
- Keywords
- ACL, ACL injuries, ACL reconstruction, LET, Osteoarthritis, Knee osteoarthritis, Orthopaedics, Anterolateral ligament, Lateral Extra-articular Tenodesis (LET)
- Medical subject headings
- Osteoarthritis, Anterior Cruciate Ligament Injuries, Osteoarthritis, Knee
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Lateral Extra-Articular Tenodesis (LET)Procedure or surgery
Lateral extra-articular tenodesis: A 1cm wide x 8cm long strip of iliotibial band is fashioned, leaving the Gerdys tubercle attachment intact. The graft is tunneled under the fibular collateral ligament (FCL) and attached to the femur with a Richards' staple (Smith \& Nephew), just distal to the intermuscular septum, proximal to the femoral insertion of the FCL. Fixation is performed with the knee at 70 degrees flexion, neutral rotation. Minimal tension is applied to the graft. The free end is then looped back onto itself and sutured using the No. 1 vicryl.
ACL ReconstructionProcedure or surgery
Anatomic ACL reconstruction using a four-strand autologous hamstring graft. If the diameter of the graft is found to be less than 7.5mm, semitendinosus will be tripled (5 strand graft) providing a greater graft diameter. Femoral tunnels will be drilled using an anteromedial portal technique, with femoral fixation provided by an Endobutton or equivalent. Tibial fixation will be provided by interference screw.
| Study group | Role | What they receive |
|---|---|---|
| ACL Reconstruction | Active comparator | Standard ACL reconstruction only. Receives: Procedure: ACL Reconstruction |
| ACL + LET | Experimental | Anatomic ACL reconstruction following the same procedure as the active comparator group with an added lateral extra-articular tenodesis (LET). Receives: Procedure: Lateral Extra-Articular Tenodesis (LET); Procedure: ACL Reconstruction |
What is being measured
The primary outcome is the main question the study is designed to answer.
Lateral compartment knee OA
As was conducted at baseline and two years postoperative in the Stability 1 study, patients will undergo a standing semi-flexed posterior to anterior (PA) radiograph of both knees.
Measured: 10 Years
Region-specific quality of life using the Knee Osteoarthritis and outcomes Score (KOOS)
The KOOS is a 42-item knee-specific questionnaire with five separately reported domains, including pain (9 items), other symptoms (7 items), function in daily living (17 items), function in sports/recreation (5 items) and knee-related quality of life (4 items). Domain scores represent the average of all items in the domain standardized to a score from 0 to 100 (worst to best). This instrument has face validity and has demonstrated construct validity, excellent test-retest reliability for each domain (range, 0.75 to 0.93) and has been shown to be responsive to change in patients undergoing ACLR.
Measured: 10 Years
Secondary outcomes (9)
Disease-specific quality of life using the ACL Quality of Life Questionnaire (ACL-QOL)
The ACL-QOL has five domains that query physical symptoms, occupational concerns, recreational activities, lifestyle, and social and emotional aspects. Each item has one 100 mm visual analogue scale response option, with labeled anchors at 0 mm (e.g., extremely difficult) and 100 mm (e.g., not difficult at all). Scores are calculated by converting the average of each of the five domain scores to a total average score out of 100% where 100% represents the best possible score.
Measured: 10 Years
The Marx Activity Rating Scale (MARS)
The MARS Activity Rating Scale is a four-item activity rating scale. The patient is asked to rate how often they were able to perform each activity (e.g. running, cutting, decelerating, and pivoting) in their most healthy and active state. The patient is provided with five categories of frequency of each functional activity, ranging from less than one time in a month to four or more times in a week. One point is allocated for each category of frequency and a maximum score of 16 points can be awarded. The MARS has demonstrated excellent test-retest reliability and construct validity in patients with disorders of the knee.
Measured: 10 Years
Subjective symptoms, function and activity (IKDC)
The International Knee Documentation Committee Subjective Knee Form (IKDC) is a knee-specific functional outcome that consists of 18-items about symptoms (7 items), sports activities (10 items) and function (1 item). Likert scales, a dichotomized item and 11 point rating scales make up the response options, and total score ranges from 0 (total limitation) and 100 (no limitations). The IKDC has shown test-retest reliability and good construct validity in patients with issues at the knee.
Measured: 10 Years
MRI
MRI will be performed only on patients recruited from the lead site at the Fowler Kennedy Sport Medicine Clinic (n=196). Similar to the imaging protocol used at the two-year visit, patients will undergo bilateral 3 Tesla MRI on a Siemens Magneton Trio magnet, and a 15-channel Siemens PRISMA knee coil at the 10-year visit. Longer T1rho and T2 relaxation times have shown to be associated with worsening cartilage quality. These changes can also be seen prior to the development of radiographic changes of OA, therefore, MRI can be used as a method for early detection of degenerative changes. The high incidence of arthritic changes observable at the 10 year time point using MRI (compared to plain radiographs), justifies the use of MRI in the subgroup of patients at the lead site.
Measured: 10 Years
Patient Reported Quality of Life (ACL QOL)
The ACL-QOL has five domains that query physical symptoms, occupational concerns, recreational activities, lifestyle, and social and emotional aspects.
Each item has one 100 mm visual analogue scale response option, with labeled anchors at 0 mm (e.g., extremely difficult) and 100 mm (e.g., not difficult at all). Scores are calculated by converting the average of each of the five domain scores to a total average score out of 100% where 100% represents the best possible score. The ACL-QOL has demonstrated validity in patients with ACL injury and responsiveness to change in patients following ACLR.
Measured: 10 Years
4-Item Pain Intensity Measure (P4)
Four-item questionnaire that asks patients to report the amount of pain they experience throughout the day (morning, afternoon, evening) and with activity. Each item response is a visual analog scale ranging from 0 (no pain) to 10 (as bad as it can be). The total score is a sum of the four responses to a maximum score of 40. The P4 has demonstrated good test-retest reliability and the ability to detect changes in pain intensity in patients with muscle and joint injuries. Because men and women may experience and report pain differently, we have included the Gender Role Expectation of Pain questionnaire to examine its association with pain and quality of life reporting in this study.
Measured: 10 Years
Clinical Failure
As previously described, clinical failure is defined as a composite of symptomatic instability requiring revision ACL surgery, or symptomatic instability with positive pivot shift, or asymmetrical pivot shift greater than the contralateral side.
Measured: 10 Years
Objective Functional Measures
Range of motion (ROM) measurement will include passive knee extension and active-assisted knee flexion. For passive knee extension, the patient is seated with legs extended on a table, heel propped so that the calf and upper thigh clear the treatment table. We will instruct the patient to relax both quadriceps and hamstrings to assure passive measurement. For active assisted knee flexion, the patient is seated with both legs extended on a table. We will instruct them to perform active-assisted knee flexion by placing one hand under their thigh to initiate flexion and then clasp both hands just below the tibial tuberosity. We will measure flexion and extension in degrees using a goniometer. For both measurements, we will centre the fulcrum of the goniometer over the lateral epicondyle of the femur. We will then align the stationary arm of the goniometer with the greater trochanter of the femur and the moving arm with the lateral malleolus at the ankle.
Measured: 10 Years
Adverse Events
We will record adverse events including painful hardware, graft rupture, and reasons for re-operation (e.g., painful knee joint, meniscal injuries, ACLR revision, contralateral ACLR, etc.). Given the significance of these types of events, we expect excellent recall.
Measured: 10 Years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Mar 2025
- Study start1 Nov 2024
- Primary completionMar 2027 (estimated)
- Study completionMar 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for LETStudies of the same condition, open and under way.
- More trials run by Western University, CanadaThe 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
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 510 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Western University, Canada
- Sponsor type
- University, hospital or other
- Collaborators
- Canadian Institutes of Health Research (CIHR)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06885372
- Sponsor's protocol ID
- 104524
- Acronym
- STABILITY LTF
- Status last verified
- May 2026
- First submitted
- 13 Mar 2025
- Last updated
- 14 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 14 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Long-term Follow up of the Stability 1 Trial
- ClinicalTrials.gov ID
- NCT06885372
- Acronym / sponsor ID
- STABILITY LTF / 104524
- Conditions
- LET, ACL Reconstruction, Osteoarthritis (OA) of the Knee
- Keywords
- ACL, ACL injuries, ACL reconstruction, LET, Osteoarthritis, Knee osteoarthritis, Orthopaedics, Anterolateral ligament
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 510 participants (estimated)
- Lead sponsor
- Western University, CanadaUniversity, hospital or other
- Collaborators
- Canadian Institutes of Health Research (CIHR)
- Study start
- 1 Nov 2024 (actual)
- Primary completion
- Mar 2027 (estimated)
- Study completion
- Mar 2027 (estimated)
- First posted
- 20 Mar 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.
From 2014-2017, across 7 Canadian and 2 European sites, we randomized 618 patients at high-risk of re-injury, to anterior cruciate ligament reconstruction (ACLR) with or without a lateral extraarticular tenodesis (LET) and demonstrated that the addition of the LET reduced the risk of instability (RRR=0.38; 95% Confidence Interval (CI), 0.21-0.52; P=0.0001) and graft re-rupture (RRR, 0.67; 95% CI, 0.36-0.83; P=0.001). As a result, practice has changed; there has been a large increase in the proportion of orthopaedic surgeons recommending the addition of an LET at the time of ACLR and an increase in the number of patients requesting an LET from their surgeon. There is some weak evidence suggesting that in the longer term, the LET may increase the risk of developing osteoarthritis (OA) in that knee. Knee OA affects over 4.4 million Canadians and the number of younger adults being diagnosed with knee OA is growing and is a primary reason for seeking healthcare in Canada. The impact of OA in Canada is enormous and projected to cost Canada $17.5 billion annually in lost productivity alone by 2031. This study will use imaging and patient-reported Knee Outcomes Osteoarthritis Score (KOOS) to evaluate the incidence of OA at 10-years post ACL reconstruction with and without LET. We will also collect information about overall knee health, patient-reported outcomes, costs associated with knee injury, rehabilitation and disability, clinical failure, functional ability, and sport participation. It is crucial that we understand the risks of developing knee OA associated with the addition of an LET to an ACLR so that surgeons and patients can make informed decisions, not just for their immediate post injury treatment of the failed ligament, but for the potential long-term consequences of that decision.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| ACL Reconstruction | Active comparator | Procedure: ACL ReconstructionStandard ACL reconstruction only. |
| ACL + LET | Experimental | Procedure: Lateral Extra-Articular Tenodesis (LET), Procedure: ACL ReconstructionAnatomic ACL reconstruction following the same procedure as the active comparator group with an added lateral extra-articular tenodesis (LET). |
Who may qualify
- Ages
- 14 to 25 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (6 listed)
- ACL deficient knee
- skeletally mature to 25 years of age
- 2 or more of:
Key exclusion criteria (5 listed)
- previous ACL reconstruction on either knee
- multi-ligament injury (two or more ligaments requiring surgical attention)
- symptomatic articular cartilage defect requiring treatment other than debridement
- greater than 3 degrees of asymmetric varus
- unable to complete outcome questionnaires
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 |
|---|---|---|
| Lateral Extra-Articular Tenodesis (LET)Lateral extra-articular tenodesis: A 1cm wide x 8cm long strip of iliotibial band is fashioned, leaving the Gerdys tubercle attachment intact. The graft is tunneled under the fibular collateral ligament (FCL) and attached to the femur with a Richards' staple (Smith \& Nephew), just distal to the intermuscular septum, proximal to the femoral insertion of the FCL. Fixation is performed with the knee at 70 degrees flexion, neutral rotation. Minimal tension is applied to the graft. The free end is then looped back onto itself and sutured using the No. 1 vicryl. | Procedure or surgery | ACL + LET |
| ACL ReconstructionAnatomic ACL reconstruction using a four-strand autologous hamstring graft. If the diameter of the graft is found to be less than 7.5mm, semitendinosus will be tripled (5 strand graft) providing a greater graft diameter. Femoral tunnels will be drilled using an anteromedial portal technique, with femoral fixation provided by an Endobutton or equivalent. Tibial fixation will be provided by interference screw. | Procedure or surgery | ACL + LET, ACL Reconstruction |
Primary outcome
Lateral compartment knee OA
Time frame: 10 Years
As was conducted at baseline and two years postoperative in the Stability 1 study, patients will undergo a standing semi-flexed posterior to anterior (PA) radiograph of both knees.
Region-specific quality of life using the Knee Osteoarthritis and outcomes Score (KOOS)
Time frame: 10 Years
The KOOS is a 42-item knee-specific questionnaire with five separately reported domains, including pain (9 items), other symptoms (7 items), function in daily living (17 items), function in sports/recreation (5 items) and knee-related quality of life (4 items). Domain scores represent the average of all items in the domain standardized to a score from 0 to 100 (worst to best). This instrument has face validity and has demonstrated construct validity, excellent test-retest reliability for each domain (range, 0.75 to 0.93) and has been shown to be responsive to change in patients undergoing ACLR.
9 secondary outcomes
Disease-specific quality of life using the ACL Quality of Life Questionnaire (ACL-QOL)
Time frame: 10 Years
The Marx Activity Rating Scale (MARS)
Time frame: 10 Years
Subjective symptoms, function and activity (IKDC)
Time frame: 10 Years
MRI
Time frame: 10 Years
Patient Reported Quality of Life (ACL QOL)
Time frame: 10 Years
4-Item Pain Intensity Measure (P4)
Time frame: 10 Years
Clinical Failure
Time frame: 10 Years
Objective Functional Measures
Time frame: 10 Years
Adverse Events
Time frame: 10 Years
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 14 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.
The record lists no contact. Use the official record to reach the sponsor.
8 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Lateral Extra-Articular Tenodesis (LET) and ACL Reconstruction in people with LET and ACL Reconstruction, run by Western University, Canada at 8 sites in 2 countries.
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 6 inclusion and 5 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: enrolling by invitation, as of the sponsor's last update on 14 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 8 sites in Canada, United Kingdom. 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?
Lateral compartment knee OA (time frame: 10 Years). 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?
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 14 May 2026.