The Association of Total Knee Arthroplasty with Weight Loss in the Look AHEAD (Action for Health in Diabetes) Clinical Trial.

BACKGROUND: Patients who have obesity seldom lose weight after total knee arthroplasty (TKA). The Look AHEAD trial randomized patients with type 2 diabetes who had overweight or obesity to a 10-year intensive lifestyle intervention (ILI) or diabetes support and education (DSE).

METHODS: Of the total 5,145 participants enrolled who had a median 14-year follow-up, a subset of 4,624 met inclusion criteria. The ILI aimed at achieving and maintaining a 7% weight loss and included weekly counseling the first 6 months, with decreasing frequency thereafter. This secondary analysis was undertaken to determine what effects a TKA had on patients participating in a known successful weight loss program and specifically if there was a negative impact on weight loss or their Physical Component Score (PCS).

RESULTS: The analysis suggests that the ILI remained effective for maintaining or losing weight after TKA. Participants in ILI had significantly greater percent weight loss than those in DSE both before and after TKA (ILI-DSE before TKA: -3.6% (-5.0, -2.3); after TKA: -3.7% (-4.1, -3.3); both P<.0001). When comparing percent weight loss before to after TKA, there was no significant difference within either the DSE or ILI group (LSMEAN±SE ILI: -0.36%±0.3, P=0.21; DSE: -0.41%±0.29, P=0.16). PCS scores improved after TKA (P<.001), but no difference was found between TKA ILI and DSE groups before or after surgery.

CONCLUSION: Participants who had a TKA did not have an altered ability to adhere to intervention goals to maintain weight loss or obtain further weight loss. The data suggest patients who have obesity can lose weight after TKA on a weight loss program.