Optimization of Obesity for Total Knee Replacement With Glucagon-like Peptide-1 Receptor Agonist

Patients in intervention group will have GLP-1RA semaglutide for 48 weeks and then stops for one month before and after TKR following the latest anesthesia guideline for GLP-1RA. Followed by TKR They will continue semaglutide for 48 weeks during the post-operative follow-up period. This is decided based on balancing treatment effect of semaglutide, waiting time for TKR, and TKR follow-up requirement. In Hong Kong, waiting time for TKR would be \~4 years and so a period of 12 months treatment of semaglutide is reasonable. And in the STEP 6 trial, weight loss at week 52 (-12%) is similar to that in study end at week 68(-13·2%), and STEP5 trial showed maintaining semaglutide to week 104 could maintain weight loss of similar degree as in week 52. And the consensus of assessing TKR Patient-Reported Outcome Measures (PROMs) is one year follow up.

If patients are randomized to the control group, they will receive routine follow-up with general advice on diet and physical activity but will not receive semaglutide, and will not be offered a specific management program for their weight. This is in line with current practice.