The effect of body mass index on outcome in total hip arthroplasty: early analysis from the New Zealand Joint Registry.

This study assessed the early outcomes of total hip arthroplasty compared with body mass index (BMI). 5357 hip arthroplasties were evaluated. Oxford Scores, revision for any reason and other factors including American Society of Anaesthesiology scores, length of surgery and cementation of components were analyzed. Both a high and a low BMI predicted for worse Oxford Hip Scores. Obese and morbidly obese patients had significantly lower six month Oxford Scores than healthy patients, the lowest survival, were younger than all other groups and had greater proportions with fully un-cemented prostheses. At this early stage, the results show that outcome and early revision are statistically and clinically poorer for obese patients.