Comparison of a Patient-Centered Weight Loss Program starting before versus after knee replacement: A pilot study.

BACKGROUND: Most patients risk gaining weight in the years after knee replacement, adding further concern to a population that is mostly overweight/obese prior to surgery.

OBJECTIVE: Via a randomised pilot study, we assessed changes in weight during a Patient Centered Weight Loss Program (PACE) initiated either before or after knee replacement, while simultaneously examining the feasibility of recruiting and retaining participants over 26 weeks.

METHODS: Recruitment outreach was made to 133 patients scheduled for knee replacement. Sixteen participants were randomised to a 14-session weight loss program that started either ≤6 weeks before surgery (PACE) or at 12 weeks post-op (Delayed PACE). Repeated measures ANOVAs were used to examine preliminary changes in weight, function, patient-reported outcomes, and physical activity across time (baseline/pre-op, 12 and 26 weeks after surgery) and group.

RESULTS: Retention was 75% and 69% at 12 and 26 weeks after surgery, respectively. Weight significantly decreased across the 26 weeks (P<0.001). A group by time interaction (P=0.03) demonstrated Delayed PACE [-7.6±5.9kg (-7.9±5.9%)] lost significantly more weight than PACE [-2.5±2.7kg (-2.6±2.6%)] participants at 26 weeks. Significant improvements across time were seen for all function and patient reported outcomes, however activity did not change.

CONCLUSION: Conducting a behavioural intervention was challenging but feasible in a knee replacement population, with preliminary evidence suggesting that initiating a program 12 weeks after surgery produces greater weight losses at 26 weeks compared to a program starting before knee replacement.