The author reviewed 603 consecutive articles and scientific presentations pertaining to adult lower extremity orthopedic research from 2 major American orthopedic journals and 2 major American orthopedic meetings. The prevalence of commercial funding in these studies was 50%. Clinical studies of total hip arthroplasty implants by American investigators were commercially sponsored in 75% of studies. Commercially funded hip research reported positive outcomes in 93% of studies, whereas independently funded researchers reported good results in only 37%. Funded clinical studies of total knee arthroplasty implants yielded good results in 75%; this is in contrast to the findings of independently funded investigators, who reported positive conclusions in only 20% of studies. Investigators receiving royalties reported no negative outcomes related to the respective devices. The source of research funding was strongly correlated with reported outcomes.