We need to look for transfusion alternatives because transfusion or blood products is not without risk. Allogenic blood carries a small risk of disease transmission, but also causes immunomodulation, which increases infectious complications and hospital stay after total joint replacement surgery. Auto donation is extremely expensive and overutilised because so much is discarded. One important fact about auto donation is that it does not stimulate erythropoesis unless the patient’s haemoglobin drops below 10 g or 2 units are donated within the same week. Another important fact is that the patients who need to donate auto blood, at least in unilateral joint replacements, cannot donate enough to decrease their allogenic risk. These are the patients with pre-op haemoglobin between 10 and 13. Patients with haemoglobin above 13 can donate, but generally don’t need to because their allogenic risk is low. We recently reviewed two series of patients at our institution with almost 300 patients in each group and showed that we could decrease the allogenic risk of the patients to below 10% without auto donation by increasing pre-op haemoglobin to above 13. This is most easily accomplished with the use of recombinant human erythropoietin and iron supplementation. In our series, knee replacements have an average haemoglobin drop of 3.85 g with a standard deviation of 1.4 g and hip replacements have an average haemoglobin drop of 4.07 g with a standard deviation of 1.7 g. Thus, we are now able to look at our patients and determine the lowest level of haemoglobin that we feel comfortable with for that patient, determine their pre-op haemoglobin, and then plan the best haemoglobin management option, whether it be auto donation, intraoperative blood salvage, or erythropoietin.

The incidence of pain postoperative total knee replacement runs somewhere between 2 and 4% and is related initially to infections, patellar subluxation or dislocation, fractures, collapse, extensor mechanism rupture, referred pain, and reflex sympathetic dystrophy. Causes for pain after six months is usually associated with infection, loosening, instability, fractures, and referred pain. Trying to understand what causes the problem helps us to be able to evaluate the patient with postoperative pain and offer a resolution.