Weight loss and physical activity after total knee replacement: Study protocol for the Healthy Living randomized controlled trial

Background: Most people who receive a total knee replacement (TKR) are physically inactive and meet criteria for overweight/obesity, putting them at increased risk of poor functional outcomes and chronic diseases. This paper describes the protocol and procedures for the Healthy Living Study, a 12-month randomized controlled trial comparing outcomes between a patient-centered weight loss program and chronic disease self-management program in adults with TKR. Methods: ) who received a TKR ≤6 months previously. Participants will be randomized to either a) PACE, a 12-month telephone-based program focused on reducing calories and increasing physical activity to facilitate a 7 % weight loss or b) a Chronic Disease Self-Management (CDSM) control group which provides education on how to manage chronic diseases while avoiding content related to physical activity or diet. Assessments conducted at baseline, 6, 12 (post-intervention) and 18 months (following a 6-month no intervention period) will assess change in weight (primary outcome), physical activity, pain, and physical function. Secondary aims will examine the cost-effectiveness of PACE, as well as potential behavioral and psychosocial mediators of weight loss and TKR-related outcomes. Conclusion: This protocol paper describes the design, rationale, and behavioral interventions for the Healthy Living randomized controlled trial which will target an important clinical population and determine whether a patient-centered weight loss program after TKR is an effective solution to improve outcomes.