Increased operating room time in patients with obesity during primary total knee arthroplasty: conflicts for scheduling.

Obesity is associated with increased complications related to total knee arthroplasty (TKA), but the relationship between body mass index (BMI) and operating room time during TKA is unknown. A total of 454 unilateral primary TKAs (2005-2009) were reviewed and categorized by BMI (normal weight, 18.5-25 kg/m(2); overweight, 25-30 kg/m(2); obese class I, 30-<35 kg/m(2); class II, 35-40 kg/m(2); class III, >40 kg/m(2)). Intraoperative time measurements (total room time, anesthesia induction time, tourniquet time, closing time, surgery time) were compared across the BMI groups. Comparing normal weight to obese class III, time differences were significant in total room time (24 minutes, P < .01), surgery time (16 minutes, P < .01), tourniquet time (7.5 minutes, P < .01), and closure time (8 minutes, P < .01). Armed with this information, BMI can be used to better allocate operating room time for TKA.