Commentary & Perspective
The Relative Risk of Infection from Transfusions After Arthroplasty
Commentary on articles by Richard Friedman, MD, FRCSC, et al.: ‘‘Allogeneic Blood Transfusions and Postoperative Infections After Total Hip or
Knee Arthroplasty’’ and Erik T. Newman, MD, et al.: ‘‘Impact of Perioperative Allogeneic and Autologous Blood Transfusion on Acute Wound
Infection Following Total Knee and Total Hip Arthroplasty’’
Adolph J. Yates Jr., MD
For more than a quarter century, orthopaedic surgeons and their patients have been plagued with heightened concerns over
complications from blood transfusions. The initial cause for increased caution, starting in the mid-1980s, was the increased
awareness of bloodborne transmission of retroviral disease in the form of human immunodeficiency virus (HIV) and the new,
near-concurrent ability to identify Hepatitis C separately from Hepatitis A and B1. The sense of burgeoning epidemics of both
diseases and the incomplete ability of screening to prevent their transmission led to a new willingness to avoid transfusions at
progressively lower hematocrits as well as an explosion of enthusiasm for preoperative autologous blood donations.
A second cause for concern, which grew more slowly over the next decade, was that of transfusion-related immunomodu-
lation. Direct clinical measurements of components of the immune system being suppressed by allogeneic blood exposure have
been demonstrated; these measurements have been coupled, mostly outside of the orthopaedic literature, with clinical reports of
increased rates of infection and more frequent recurrence of tumors2. The most immediate concern for orthopaedic surgeons was
the question of increased risk from transfusion for infections after insertion of prosthetic implants. Despite the frequent invocation
of such risk as a reason to delay transfusion, the arthroplasty-specific literature has beenvaried and relatively underpowered on this
question. As pointed out by Friedman et al. (one of the two articles discussed in this commentary), the articles that did address this
question clinically have been single-center studies compromised by small patient group sizes.
In this edition of The Journal, two articles with large patient groups are published that specifically address the question of
transfusion-related immunomodulation and the risk for infection after total joint arthroplasty. The issue of sufficient statistical
power was addressed in each article by taking advantage of two very different large collections of clinical outcomes. The study by
Prevent Deep Venous Thrombosis and Pulmonary Embolism) trials, which were focused on the evaluation of the efficacy of
rivaroxaban in the prevention of venous thromboembolic disease after lower-extremity total joint arthroplasty. The study by
Newman et al. retrospectively looks, from a single large center’s experience over a decade, at a large series of patients who had
undergone total joint arthroplasty.
At first glance, the conclusions might seem contradictory. Friedman et al. report a higher incidence of wound inflammation
or infection in the patients receiving allogeneic transfusions. Newman et al., after risk adjustment, report no greater risk for
postoperative infection with or without allogeneic transfusions.
However, because of the limitations of retrospective studies, the two studies do not differ as much in their outcomes as it
might seem at first glance. By definition of being retrospective, these studies did not give the researchers the opportunity to define
common important end points and data fields to be captured.
of wound infection or inflammation, not all of which might meet the definition of a true infection. These occurrences, along with
respiratory and urinary tract infections, were the negative outcomes reported as being influenced by allogeneic transfusions.
However, the same study showed no difference in the groups for bone and joint infections, which might be interpreted as being the
acute wound infections of greatest concern to the surgeon and patient. The exact definition of this outcome grouping is not given.
The Newman study uses as an end point the surrogate of reoperation for suspected infection, even if cultures were negative. This
end point excluded reoperations for presumed non-infectious reasons. The authors followed through on late outcomes of these
select cases to try to reasonably mitigate the limitations of their database. When adjusted forother risks, this study also did not find
any influence on acute wound infections from allogeneic transfusion exposure.
COPYRIGHT ? 2014 BY THE JOURNAL OF BONE AND JOINT SURGERY, INCORPORATED
J Bone Joint Surg Am. 2014;96:e33(1-3)