British national guidelines recommend agents which antagonise factor Xa or warfarin as prophylaxis of venous thromboembolism (VTE) in lower limb arthroplasty. However, they discourage the use of aspirin prophylaxis.

We conducted a prospective, multi-centre audit between two national centres, Ninewells Hospital in Dundee and the Royal Infirmary in Edinburgh to compare bleeding and VTE risk. Only Edinburgh routinely uses aspirin as VTE prophylaxis. The study comprises a number of cycles from 2013 to 2015. Consecutive groups of patients were identified prospectively using elective theatre data and information extracted from their case-notes on type of VTE prophylaxis, VTE occurrence, wound complications and length of hospital stay for a period of nine weeks post-operatively.

262 Edinburgh patients and 92 Dundee patients were included. Most Edinburgh patients were prescribed aspirin in hospital and on discharge (188/262, 71.8%), in line with local protocol. In Dundee, dalteparin was most commonly prescribed in hospital (68/92, 73.9%) and rivaroxaban on discharge (57/92, 62.0%).

The Edinburgh group had a 1.5% incidence of pulmonary embolus (PE) and a 1% rate of deep venous thrombosis (DVT), 2% had problems with wound haematoma and one patient (0.4%) required a transfusion; no wound washouts were required. In Dundee there was 0% PE, 2% DVT, 5% had problems with haematoma, 3% required transfusion and 2% required washout. There was no difference in length of hospital stay, with a mode of 4 days for both centres.

Non-fatal PE was prevented in Dundee patients but possibly at the cost of greater incidence of wound complications.