Knee Arthroplasty Activity Trial
Public ClinicalTrials.gov record NCT04107649. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
Total knee replacement (TKR) is a common and costly procedure widely used to relieve pain and improve function in patients with symptomatic advanced knee osteoarthritis (OA). As of 2013, the annual incidence of TKR was over 680,000 surgeries and annual costs exceeded $11 billion. Growing evidence suggests that while pain and functional status improve following TKR, physical activity (PA) typically does not surpass pre-TKR levels. Engagement in PA can meaningfully improve quality of life (QoL), pain, and function. Given the large investment in TKR, the effectiveness and cost-effectiveness of TKR could be substantially increased if TKR recipients became more physically active. The Knee Arthroplasty Activity Trial (KArAT) is a randomized controlled trial and participants will be randomly assigned to one of three arms. Participants across all arms will receive usual post-operative care for TKR surgery. Participants in the first arm will complete basic study activities, such as responding to surveys and attending two in-person clinic visits. Participants in the second arm will do the same and also receive a wrist-based physical activity tracker intervention. Participants in the third arm will receive a telephonic active coaching (motivational interviewing) and financial incentives (for reaching physical activity goals) (TAC(MI)+FI) based intervention, as well as a wrist-based physical activity tracker intervention. The second and third arms will be eligible to receive lottery-based financial rewards for wearing a wrist-worn activity tracker for twenty-four months during the study.
Study identification
- NCT ID
- NCT04107649
- Recruitment status
- Active, not recruiting
- Study type
- Interventional
- Phase
- Not applicable
- Enrollment
- 600 participants
Conditions and interventions
Conditions
Interventions
- Telephonic Active Coaching (Motivational Interviewing) + Financial Incentives Behavioral
- Wrist based activity tracker wear Behavioral
- Basic Study Activities Other
Behavioral · Other
Eligibility (public fields only)
- Age range
- 40 Years to 85 Years
- Sex
- All
- Healthy volunteers
- Healthy volunteers not accepted
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Apr 26, 2023
- Primary completion
- Jun 14, 2028
- Completion
- Jun 14, 2028
- Last update posted
- Nov 23, 2025
2023 – 2028
United States locations
- U.S. sites
- 5
- U.S. states
- 5
- U.S. cities
- 5
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| Northwestern Memorial Hospital | Chicago | Illinois | 60611 | — |
| University of Kansas Medical Center | Kansas City | Kansas | 66160 | — |
| Brigham and Women's Hospital | Boston | Massachusetts | 02115 | — |
| University of Nebraska Medical Center | Omaha | Nebraska | 68198 | — |
| University at Buffalo | Buffalo | New York | 14215 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT04107649, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Nov 23, 2025 · Synced Sep 5, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT04107649 live on ClinicalTrials.gov.