Does Preoperative Weight Loss Affect Outcomes After Total Knee Arthroplasty?

Patients with obesity (body-mass index [BMI], ≥30 kg/m²) who undergo total knee arthroplasty (TKA) have higher risks for revision TKA and postoperative adverse outcomes. But does preoperative weight loss lessen these risks? Mayo Clinic investigators previously reported that weight loss wasn't associated with fewer postoperative adverse outcomes among patients with obesity who underwent total hip arthroplasty (THA; NEJM JW Gen Med Jun 1 2025 and J Bone Joint Surg Am 2025; 107:849). Now, the same investigators report the effects of preoperative weight loss on postoperative outcomes among ≈3700 patients with obesity (mean age, 68; mean BMI, 36 kg/m²) who underwent TKA.

From baseline weight measured 1 to 24 months before surgery, 41% of patients…