Retrospective audit of blood transfusion and comparison with haemoglobin concentration in patients undergoing elective primary and revision lower limb arthroplasty.

We retrospectively audited the incidence of blood transfusion and related this to preoperative haemoglobin levels in 181 patients undergoing lower limb arthroplasty over a six-month period. This included 102 primary total knee replacements, 52 primary total hip replacements, 11 revision total knee replacements and 16 revision total hip replacements. The overall incidence of transfusion was 16.0%. The incidence in primary arthroplasty was 11% (9.8% for total knee replacements and 13.5% for total hip replacements), and in revision surgery was 44.4% (27.3% for total knee replacements and 56.3% for total hip replacements). Combining data for primary total knee replacements and primary total hip replacements, a preoperative haemoglobin threshold of 120 g/l divided patients into high and low risk groups for transfusion. Below or equal to this threshold the incidence of transfusion was 47.7%; above this threshold the incidence was 7.2%. We suggest that patients having primary lower limb arthroplasty with a preoperative haemoglobin of 120 g/l or less should undergo investigation of their anaemia and optimisation of erythropoeisis.