Physical Activity and Weight Loss to Improve Function and Pain after Total Knee Replacement - Total knee replacement (TKR) utilization continues to increase, placing substantial burden on the
economy. As patients live longer with TKR, it is essential to identify strategies that will maximize long-term
functional outcomes and promote health-related quality of life and independence as adults age after surgery.
The majority of TKR patients meet criteria for overweight/obesity and remain physically inactive after surgery,
both of which heighten the risk of poor functional outcomes and disability. Further, most patients will actually
gain weight within two years after surgery. Patients after TKR are also at an increased risk of death from
cardiovascular and mental diseases. Promoting weight management may be an effective strategy to improve
long-term functional and physical activity outcomes after TKR, reduce the risk of disability and death from
cardiovascular and mental diseases, and improve the value of the costly surgery.
We propose to examine the effectiveness of a Patient-Centered (PACE) weight loss program in adults
after TKR in a fully-powered, two-arm randomized controlled trial. Patients (n=250) will be randomized to
receive either (1) PACE weight loss program or (2) Chronic Disease Self-Management (CDSM) control group.
PACE participants will start the patient-centered program 12 weeks after TKR and continue for 12 months.
PACE is tailored to the patients’ needs and unique barriers to diet and physical activity. PACE focuses on
reducing caloric intake and increasing physical activity (aerobic and resistance) to facilitate a weight loss of at
least 7% of initial body weight. Coaching calls with a trained behavioral interventionist will occur weekly during
months 1-4, biweekly during months 5-6, and monthly during months 7-12. No coaching will occur during the
maintenance phase (months 13-18). CDSM will receive a self-directed version of the program and monthly
calls on topics not related to study outcomes. Data collection will occur at baseline (12 weeks after surgery), 6
months (end of intensive intervention), 12 months (end of treatment), and 18 months (maintenance).
Assessments will include measures of weight, secondary outcomes (e.g., physical activity, pain, function), and
potential mediators from our conceptual model (e.g., adherence, self-efficacy, autonomy, competence). Data
related to the cost of implementing the PACE weight loss intervention relative to Control will also be collected
to examine the cost-effectiveness of reducing weight on patient outcomes. The primary outcome is weight
change at 6 months.
The expected outcome from this study is to determine the effectiveness and long-term maintenance of
a refined patient-centered weight loss program tailored specifically for adults after TKR. If PACE is effective at
improving short- and long-term outcomes, and is found to be cost-effective, orthopedic centers and/or
insurance companies could consider offering this program to TKR patients, offering significant benefits to the
rising number of adults underdoing TKR.
