NCT06193343 · University of Georgia
Steps Towards Osteoarthritis Prevention
(STOP)
What this study is about
Optimal knee joint loading, which refers to the forces acting on the knee caused by daily activities such as daily steps, plays an essential role in maintaining knee articular cartilage health and reducing the risk of osteoarthritis (OA).
View original scientific description
Optimal knee joint loading, which refers to the forces acting on the knee caused by daily activities such as daily steps, plays an essential role in maintaining knee articular cartilage health and reducing the risk of osteoarthritis (OA). After anterior cruciate ligament reconstruction (ACLR), individuals take fewer daily steps as compared to uninjured controls resulting in insufficient knee joint loading to joint tissues, but it is unclear how changes in daily steps impact knee joint cartilage health in OA development. Therefore, the overall single arm, longitudinal pre-test post-test study objective is to determine the mechanistic links between knee joint loading as measured by daily steps and comprehensive magnetic resonance imaging (MRI) measures of knee joint cartilage health post-ACLR. The central hypothesis is that individuals post-ACLR who take low daily steps will demonstrate deconditioned, less resilient cartilage characterized by poor tibiofemoral cartilage composition and greater cartilage strain.
Interventions
BEHAVIORAL
Adaptive Daily Step Promotion
Participants will wear a Fitbit monitor on their non-dominant wrist during a 10 to 14 day "run-in" screening to capture daily steps reported by the Fitbit but no daily step goals will be sent to the participant. The Fitbit monitor will be worn during all waking hours except water activities, and compliance will be considered as a day with ≥1,000 steps. Next, participants will undergo a 16-week intervention wearing the Fitbit monitor on their wrist and receive a text message each morning with a personalized, adaptive daily step count goal and a link used to confirm receipt of the goal. The preceding 10 days of step data will be rank ordered and the 60th percentile step count will be set as the goal for the next day. Goals will not exceed 10,000 daily steps.
Primary outcome measures
T2 relaxation times in the medial femoral condyle
Time frame: pre-intervention (baseline)
MRI marker of T2 relaxation times of medial femoral articular cartilage (i.e collagen organization) at pre-intervention (baseline)
T2 relaxation times in the lateral femoral condyle
Time frame: pre-intervention (baseline)
MRI marker of T2 relaxation times of lateral femoral articular cartilage (i.e collagen organization) at pre-intervention (baseline)
T2 relaxation times in the medial tibial condyle
Time frame: pre-intervention (baseline)
MRI marker of T2 relaxation times of medial tibial articular cartilage (i.e collagen organization) at pre-intervention (baseline)
T2 relaxation times in the lateral tibial condyle
Time frame: pre-intervention (baseline)
MRI marker of T2 relaxation times of lateral tibial articular cartilage (i.e collagen organization) at pre-intervention (baseline)
Change in T2 relaxation times in the medial femoral condyle
Time frame: pre-intervention (baseline), post-intervention (~18 weeks)
Change in MRI marker of T2 relaxation times of medial femoral articular cartilage (i.e collagen organization) from pre-intervention to post-intervention
Change in T2 relaxation times in the lateral femoral condyle
Time frame: post-intervention (~18 weeks)
Change in MRI marker of T2 relaxation times of lateral femoral articular cartilage (i.e collagen organization) from pre-intervention to post-intervention
Change in T2 relaxation times in the medial tibial condyle
Time frame: pre-intervention (baseline), post-intervention (~18 weeks)
Change in MRI marker of T2 relaxation times of medial tibial articular cartilage (i.e collagen organization) from pre-intervention to post-intervention
Change T2 relaxation times in the lateral tibial condyle
Time frame: pre-intervention (baseline), post-intervention (~18 weeks)
Change in MRI marker of T2 relaxation times of lateral tibial articular cartilage (i.e collagen organization) from pre-intervention to post-intervention
Average cartilage strain in the medial femoral condyle
Time frame: pre-intervention (baseline)
MRI marker of cartilage strain (i.e., acute change in cartilage thickness/resting cartilage thickness) of medial femoral articular cartilage at pre-intervention (baseline)
Average cartilage strain in the lateral femoral condyle
Time frame: pre-intervention (baseline)
MRI marker of cartilage strain (i.e., acute change in cartilage thickness/resting cartilage thickness) of lateral femoral articular cartilage at pre-intervention (baseline)
Average cartilage strain in the medial tibial condyle
Time frame: pre-intervention (baseline)
MRI marker of cartilage strain (i.e., acute change in cartilage thickness/resting cartilage thickness) of medial tibial articular cartilage at pre-intervention (baseline)
Average cartilage strain in the lateral tibial condyle
Time frame: pre-intervention (baseline)
MRI marker of cartilage strain (i.e., acute change in cartilage thickness/resting cartilage thickness) of lateral tibial articular cartilage at pre-intervention (baseline)
Change in average cartilage strain in the medial femoral condyle
Time frame: pre-intervention (baseline), post-intervention (~18 weeks)
Change in MRI marker of cartilage strain (i.e., acute change in cartilage thickness/resting cartilage thickness) of medial femoral articular cartilage from pre-intervention to post-intervention
Change in average cartilage strain in the lateral femoral condyle
Time frame: pre-intervention (baseline), post-intervention (~18 weeks)
Change in MRI marker of cartilage strain (i.e., acute change in cartilage thickness/resting cartilage thickness) of lateral femoral articular cartilage from pre-intervention to post-intervention
Change in average cartilage strain in the medial tibial condyle
Time frame: pre-intervention (baseline), post-intervention (~18 weeks)
Change in MRI marker of cartilage strain (i.e., acute change in cartilage thickness/resting cartilage thickness) of medial tibial articular cartilage from pre-intervention to post-intervention
Change in average cartilage strain in the lateral tibial condyle
Time frame: pre-intervention (baseline), post-intervention (~18 weeks)
Change in MRI marker of cartilage strain (i.e., acute change in cartilage thickness/resting cartilage thickness) of lateral tibial articular cartilage from pre-intervention to post-intervention
Daily steps
Time frame: Pre-intervention (baseline)
Average steps per day over 7 day physical activity monitor wear at pre-intervention (baseline)
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Provision of signed and dated informed consent form
- For children, signed and dated informed assent by child and parental permission form by parent/guardian to participate in the study
- Underwent an anterior cruciate ligament reconstruction (ACLR) between 6-60 months prior to enrollment
- Stated willingness to comply with all study procedures and lifestyle considerations and availability for the duration of the study
- Completed all other formal physical therapy and therapeutic exercise regimens, and will not be engaging in any other formal therapy for their ACLR during the study
- Physician clearance for unrestricted activity
- Owning a smartphone
- Demonstrate \< 8,000 steps per day during the screening phase of aim 2 as assessed using the Actigraph Link monitor
Exclusion criteria
- Underwent an ACLR revision surgery due to a previous anterior cruciate ligament (ACL) graft injury
- A multiple ligament surgery was indicated with their ACL injury
- A lower extremity fracture was suffered during the ACL injury
- The participant has previously been diagnosed with any diseases that affect joints is present in either knee including knee osteoarthritis inflammatory arthritis
- Pregnant or plans to become pregnant over next 4 months
- Body mass index (BMI) ≥ 36 kg/m2
- Unable to speak English
- Cochlear implant
- Metal in body (metal fragments, shrapnel, permanent make-up, body piercings that cannot be removed)
- Claustrophobia
- History of seizures
Where
- Athens, Georgia
Collaborators
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Apr 29, 2026 · Source of record for eligibility and locations