Higher body mass index leads to longer operative time in total knee arthroplasty.

Obesity has been shown to be a risk factor for degenerative knee arthritis and its incidence is increasing in epidemic proportions. Obesity has also been shown to be a risk factor for surgical complications associated with total knee replacement (TKR) surgery. There have been no prior investigations examining the relationship between body mass index (BMI) and surgical time during TKR. Two hundred and seventy three patients were evaluated and stratified by BMI. There was a direct linear relationship between BMI and operative time. In addition, the higher the BMI group, the younger the age at surgery, and obese class III patients experienced a higher rate of early post-operative complication. Therefore, patients should be counseled that obesity prior to TKR surgery might lead to a longer operative time and any sequelae associated with further exposure of the operative wound, especially with regard to higher rates of prosthetic joint infection (PJI).