Does body mass index affect the early outcome of primary total hip arthroplasty?

There is little evidence describing the influence of body mass index on the outcome of total hip arthroplasty (THA). Eight hundred patients undergoing primary cemented THA were followed for a minimum of 18 months. The Harris Hip Score (HHS) and Short Form 36 were recorded preoperatively and at 6 and 18 months postoperatively. In addition, other significant events were noted, namely death, dislocation, reoperation, superficial and deep infection, and blood loss. Multiple regression analysis was performed to identify whether body mass index (BMI) was an independently significant predictor of the outcome of THA. No relationship was seen between the BMI of an individual and the development of any of the complications noted. The HHS was seen to increase dramatically postoperatively in all patients. Body mass index did predict for a lower HHS at 6 and 18 months. This effect was small when compared with the overall improvements in these scores. There was no influence on the Short Form 36 component scores. On the basis of this study, we can find no justification for withholding THA solely on the grounds of BMI.