Association between pre-operative body mass index and post-operative decline in activities of daily living in patients with total knee arthroplasty.

PURPOSE: It is well established that total knee arthroplasty (TKA) yields favourable outcomes, including pain reduction, improved physical function, and improved activities of daily living (ADL). However, some patients may experience limited post-operative ADL, potentially influenced by obesity. This study aimed to examine the relationship between decline in ADL ability and pre-operative body mass index (BMI) during hospitalization. METHODS: This retrospective cohort study included 201 patients with TKA. The outcome measure was post-operative ADL ability, assessed using the Barthel Index (BI). RESULTS: The percentage of patients with reduced ADL was 26.9%. In the unadjusted model, a higher pre-operative BMI was significantly associated with greater odds of a decline in BI (OR 1.09, 95% CI 1.01-1.18, P = 0.020). This association remained significant after adjustment for age, sex, CCI, and KL classification (adjusted OR 1.12, 95% CI 1.03-1.22, P = 0.009). CONCLUSION: We found that post-operative ADL limitations were more pronounced in patients with a higher pre-operative BMI.