Anterior Cruciate Ligament (ACL) Tear
Conditions
Keywords
anterior cruciate ligament, pivot shift, knee instability, robotic knee testing
Brief summary
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.
Interventions
None listed
Sponsors
Arthroresearch LLC
Study design
Observational model
COHORT
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Clinician-graded pivot shift | Before ACL reconstruction, during the preoperative clinical exam and/or examination under anesthesia. | Clinician-graded pivot shift from 0 to 3, obtained from the treating orthopedic surgeon's preoperative clinical exam and/or examination under anesthesia before ACL reconstruction. |
| Association Between RKT Knee Motion Measurements and Clinician-Graded Pivot Shift Grade | RKT testing at the preoperative study visit and pivot shift grading before ACL reconstruction | Relationship between Robotic Knee Testing measurements of tibiofemoral motion and clinician-graded pivot shift grade from 0 to 3. RKT measurements may include tibial translation and rotation during robotic testing. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| RKT Torque-Motion Hysteresis Curve Features | During RKT testing at the preoperative study visit before ACL reconstruction | Torque-displacement and torque-rotation curves from robotic testing will be evaluated for features such as slope changes, curve area, discontinuities, or "jumps" that may reflect knee instability. |
| Effect of Knee Position on RKT Motion Measurements | During RKT testing at the preoperative study visit before ACL reconstruction | RKT measurements will be compared across different testing conditions, including tibial internal rotation angle, varus-valgus knee position, knee flexion angle, and preset torque thresholds, to identify settings associated with pivot-shift-like motion. |
| Association Between Bone Morphology and Knee Instability Measurements | Existing imaging reviewed after enrollment and before data analysis | Existing MRI or X-ray images may be reviewed to assess bone morphology, including posterior tibial slope and femoral-tibial plateau geometry, and compare these measures with RKT measurements and pivot shift grade. |
Countries
United States
Contacts
CONTACTSamantha J Beckley, PhD
CONTACTShaun K Stinton, PhD
PRINCIPAL_INVESTIGATORShaun K Stinton, PhD
Arthroresearch LLC
Outcome results
None listed