There have been a few research studies trying to answer just this question. Pedersen et al looked at hip replacements and found some association with post operative pneumonia and death. Browne et al showed blood transfusions with total hip replacement to have increased mortality, length of stay in the hospital and total hospital charges. A more recent and larger study by Hart et al found that there was no increase in serious complications in the first thirty days after having a blood transfusion during a total knee or total hip replacement.