Measuring Knee Laxity and Pivot Shift in ACL-Deficient Patients
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- This is an observational study: the protocol does not assign a study treatment.
- Who it may be relevant to
- Registry conditions: Anterior Cruciate Ligament (ACL) Tear. Basic parameters: 18 years — 65 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- United States
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Objective Quantification of Knee Laxity Using a Robotic Knee Testing System and Correlation With Clinical Pivot Shift Grade in ACL-Deficient Patients
Overview
The goal of this observational study is to learn whether the Robotic Knee Testing system can measure knee looseness in adults with an anterior cruciate ligament, or ACL, tear. The main question it aims to answer is whether measurements from the Robotic Knee Testing system are related to the doctor's pivot shift exam grade. Participants will complete one study visit before ACL reconstruction. During the visit, both knees will be tested in the Robotic Knee Testing system. Researchers may also review existing medical information and imaging.
Detailed description
This study includes two parts. In Phase 1, researchers will adjust the Robotic Knee Testing system settings to identify testing conditions that are safe, tolerable, and able to reproduce knee motion similar to the pivot shift exam.
During Phase 1, the device will test how knee motion changes when the leg is placed in different positions. Researchers will evaluate whether tibial internal rotation and knee flexion angle change varus-valgus knee motion. They will also evaluate whether varus-valgus knee position and knee flexion angle change internal-external tibial rotation. These tests are intended to help identify device settings that may reproduce the coupled motion seen during a clinical pivot shift exam.
The robotic torque-motion curves will also be reviewed for abrupt changes, discontinuities, or "jumps." These findings may represent the knee moving from a stable position into an unstable position.
In Phase 2, participants will be tested using the finalized device settings from Phase 1. The device will apply controlled anterior-posterior, internal-external rotation, and varus-valgus movements while measuring knee motion in six degrees of freedom. Researchers will compare the robotic measurements with the pivot shift grade documented by the treating orthopedic surgeon.
When available, existing MRI or X-ray images may also be reviewed to evaluate whether knee bone structure is related to robotic laxity measurements or pivot shift severity. No additional imaging will be performed for this study.
Primary outcome measures
- Clinician-graded pivot shift [Time frame: Before ACL reconstruction, during the preoperative clinical exam and/or examination under anesthesia.]
- Association Between RKT Knee Motion Measurements and Clinician-Graded Pivot Shift Grade [Time frame: RKT testing at the preoperative study visit and pivot shift grading before ACL reconstruction]
Secondary outcome measures (3)
- RKT Torque-Motion Hysteresis Curve Features [Time frame: During RKT testing at the preoperative study visit before ACL reconstruction]
- Effect of Knee Position on RKT Motion Measurements [Time frame: During RKT testing at the preoperative study visit before ACL reconstruction]
- Association Between Bone Morphology and Knee Instability Measurements [Time frame: Existing imaging reviewed after enrollment and before data analysis]
Eligibility criteria
Inclusion criteria
- Adults aged 18-65 years
- Confirmed ACL tear by MRI or arthroscopic diagnosis
- Able to provide informed consent
Exclusion criteria
- Prior major surgery on the affected knee
- Multi-ligament knee injury
- Active infection or inflammatory arthropathy
- Inability to tolerate passive motion testing
- Pregnant or planning to become pregnant during the study period
- Unable to provide informed consent
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Observational model
- Cohort
Study locations
United States · 1 center
- Trailer — Atlanta
Identifiers
NCT: NCT07688967 · 15940