AI-Based Video Assessment of Anterior Knee Laxity (AI-LAX)

September 17, 2026 updated by: Jacopo Conteduca, ASL Lecce

Artificial Intelligence-Based Video Assessment of Anterior Knee Laxity Compared With Rolimeter in Patients With Anterior Cruciate Ligament Injury: A Prospective Validation Study

This prospective observational validation study aims to evaluate the accuracy and reliability of artificial intelligence-based video analysis for quantifying anterior knee laxity. Participants with unilateral anterior cruciate ligament (ACL) injury and ACL-intact controls will undergo bilateral knee examination using a Rolimeter by two independent orthopedic surgeons. Three consecutive measurements will be obtained for each knee and examiner. Each examination maneuver will be video recorded using a standardized acquisition protocol including a metric reference of known dimensions.

The videos will subsequently be analyzed independently by a multimodal artificial intelligence system blinded to clinical diagnosis, MRI findings, injured side, examiner measurements, and contralateral knee measurements. AI-derived anterior tibial translation and side-to-side difference will be compared with Rolimeter measurements. The primary objective is to assess agreement between AI-derived and Rolimeter-derived side-to-side difference. Secondary objectives include inter-examiner reliability, AI repeatability and the diagnostic accuracy of AI-derived measurements for identifying ACL injury.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Detailed Description

Each examiner will perform three consecutive Rolimeter measurements on both knees. Individual maneuvers will be video recorded so that the Rolimeter and AI measurements refer to the same mechanical examination. Videos will be pseudonymized and analyzed independently. The AI system will have no access to participant group allocation, MRI findings, injured side, Rolimeter measurements, or results from other videos belonging to the same participant.

A standardized metric reference positioned in the plane of the examined knee will be visible in each recording to permit estimation of displacement in millimeters. AI measurements will not be used for clinical decision-making.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
70

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Italy
      • Lecce, Italy, 73100
        • Ospedale Vito Fazzi
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

16 years to 55 years (Child, Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Adults undergoing prospective bilateral assessment of anterior knee laxity at a single orthopedic center. The study population will include two cohorts: participants with a unilateral, complete anterior cruciate ligament (ACL) injury confirmed by magnetic resonance imaging and ACL-intact control participants without clinical evidence or history of ACL injury.

All participants will undergo the same standardized bilateral knee examination using an arthrometer performed independently by two orthopedic examiners. Each examination maneuver will be video recorded for subsequent blinded AI-based assessment of anterior tibial translation.

Description

Inclusion Criteria:

  • General inclusion criteria
  • Age ≥16 years.
  • Ability to understand the study procedures and provide written informed consent.
  • Ability to undergo bilateral clinical assessment of anterior knee laxity.

ACL-Deficient Group

  • Unilateral complete anterior cruciate ligament (ACL) injury confirmed by magnetic resonance imaging (MRI).
  • Clinical evidence of anterior knee instability compatible with ACL deficiency.
  • Contralateral knee without known ACL injury or previous ACL reconstruction.
  • ACL-Intact Control Group
  • No history of ACL injury or ACL reconstruction in either knee.
  • No clinical evidence of anterior knee instability.
  • Negative clinical assessment for ACL deficiency in both knees.

Exclusion Criteria

  • Previous ACL reconstruction or other major ligament reconstruction of either knee.
  • Bilateral ACL injury.
  • Revision ACL injury or previous ACL surgery.
  • Concomitant complete injury of another major knee ligament requiring surgical treatment.
  • Previous major knee surgery that could affect anterior tibial translation.
  • Moderate-to-severe knee osteoarthritis or radiographic osteoarthritis greater than Kellgren-Lawrence grade 1.
  • Acute fracture involving the examined lower limb.
  • Neurological, neuromuscular, or other conditions that could interfere with standardized knee examination.
  • Inability to tolerate or complete the standardized arthrometer examination.
  • Inability or unwillingness to provide informed consent or consent for study video recording.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: COHORT
  • Time Perspectives: PROSPECTIVE

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
ACL-deficient participants

Adults with a unilateral, complete anterior cruciate ligament (ACL) injury confirmed by magnetic resonance imaging (MRI). Participants will undergo bilateral anterior knee laxity assessment using a Rolimeter by two independent orthopedic examiners. Three consecutive measurements will be obtained for each knee and examiner, and each examination maneuver will be video recorded for subsequent blinded AI-based analysis. The contralateral knee will serve as the within-subject reference for calculation of the side-to-side difference.
ACL-Intact Control Group

Adults without a history or clinical evidence of ACL injury or knee instability. Participants will undergo the same standardized bilateral anterior knee laxity assessment performed by two independent orthopedic examiners using a Rolimeter, with three consecutive measurements for each knee and examiner. Each examination maneuver will be video recorded and subsequently analyzed by the AI system using the same protocol applied to the ACL-deficient cohort.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Agreement Between AI-Derived and Arthrometer-Derived Side-to-Side Difference in Anterior Tibial Translation
Time Frame: Day 1 (index study examination)

Agreement between the side-to-side difference (SSD, mm) in anterior tibial translation estimated by artificial intelligence from standardized knee examination videos and the corresponding SSD obtained with an arthrometer. Agreement will be assessed using intraclass correlation coefficient (ICC, absolute agreement) and Bland-Altman analysis, including mean bias and 95% limits of agreement.
Day 1 (index study examination)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Measurement Error of AI-Derived Anterior Tibial Translation Compared With Arthrometer Measurements
Time Frame: Day 1 (index study examination)

The difference between AI-derived and arthrometer-derived measurements of anterior tibial translation will be quantified in millimeters using mean absolute error (MAE), root mean square error (RMSE), mean bias, and 95% limits of agreement.
Day 1 (index study examination)
Inter-Examiner Reliability of Arthrometer Measurements
Time Frame: Day 1 (index study examination)

Reliability of anterior tibial translation and side-to-side difference measurements obtained independently by two orthopedic examiners using an arthrometer. Inter-examiner reliability will be assessed using intraclass correlation coefficients with 95% confidence intervals and Bland-Altman analysis.
Day 1 (index study examination)
Agreement Between AI Measurements Derived From Examinations Performed by Different Examiners
Time Frame: Day 1 (index study examination)

Agreement between AI-derived anterior tibial translation and side-to-side difference obtained from videos of knee examinations performed independently by the two examiners. This outcome will assess the robustness of AI-derived measurements with respect to examiner-related variability.
Day 1 (index study examination)
Diagnostic Accuracy of AI-Derived Side-to-Side Difference for ACL Injury
Time Frame: Day 1 (index study examination)

The ability of AI-derived side-to-side difference to discriminate participants with complete anterior cruciate ligament injury from ACL-intact controls will be assessed using receiver operating characteristic (ROC) curve analysis. Area under the curve (AUC), sensitivity, specificity, positive predictive value, and negative predictive value will be calculated.
Day 1 (index study examination)
diagnostic Accuracy of Arthrometer-Derived Side-to-Side Difference for ACL Injury
Time Frame: Day 1 (index study examination)

The diagnostic performance of arthrometer-derived side-to-side difference for identifying complete anterior cruciate ligament injury will be evaluated using ROC curve analysis, including AUC, sensitivity, specificity, positive predictive value, and negative predictive value.
Day 1 (index study examination)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
ASL Lecce

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 15, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 12, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 17, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 22, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 22, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 17, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • ASLLECCE-AILAX-2026-01

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

De-identified data may be made available from the corresponding author upon reasonable request, subject to institutional and ethical approval.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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