Effect of BMI on complications rate, reoperation and functional outcome after Total Knee Arthroplasty, A Systematic Review of Literature
Abstract Purpose The body mass index (BMI) is widely recognized as a prognostic factor in multiple operations; however, the relationship between the BMI and outcomes following total knee arthroplasty (TKA) is extensively debated. We aimed to evaluate the effect of the BMI at different cutoff values on the outcomes following primary TKA. Methods Electronic databases (PubMed/Medline, Embase and Web of Science) were systematically searched for studies investigating the association between the BMI and outcomes following primary TKA. Two investigators independently reviewed studies for eligibility. A meta-analysis was performed using Review Manager 5.2 software from the Cochrane Collaboration. Results Thirteen articles were identified. The postoperative Knee Society Score appeared to trend lower in obese (BMI ≥ 30 kg/ m2) patients than in non-obese (BMI < 30 kg/m2) patients. The meta-analysis showed that revision with follow-up ≥2 years, any infection, superficial infection and deep vein thrombosis occurred statistically more frequently in obese patients. Conclusion Patients with a BMI ≥ 30 kg/m2 are at a higher risk of lower functional scores and developing complications following primary TKA. It appears reasonable to encourage obese patients to lose weight before selective TKA.