Thromboembolic disease is associated with a high degree of morbidity and mortality. There is increasing pressure for elective orthopaedic patients, including those undergoing foot and ankle surgery, to be prescribed chemical thromboprophylaxis post-operatively in order to reduce the risk of a thromboembolic event. The risks of chemical thromboprophylaxis in terms of increased bleeding, wound problems and HIT are well documented. The aim of this study was to determine the incidence of clinically significant thromboembolic events in patients undergoing elective foot and ankle surgery with and without the use of aspirin.

We audited a consecutive series of 1625 patients undergoing elective foot and ankle surgery between 2003 and 2010. Between 2003 and 2006 inclusive, aspirin was used post operatively as chemical thromboprohylaxsis. Between 2007 and 2010, no chemical thromboprohylaxsis was used. The follow-up period for all patients was at least three months post-operatively. Most patients were reviewed at 3 months by the senior surgeon. Those who were reviewed less than 3 months (patients undergoing minor procedures) were contacted via telephone to confirm whether a thromboembolic event had been diagnosed.

There was no loss to follow up. Of the 1625 patients, 555 patients received aspirin and 1070 patients received no chemical thromboprohylaxsis. 5 of 1625 (0.31%) patients developed a clinically significant thromboembolic event. 3 patients developed a DVT at an average time of 5 weeks post operatively. 2 patients developed non-fatal PE at an average time of 7 weeks post operatively. 3 of the 5 thromboembolic events occurred in the aspirin group (all DVT's) whereas 2 of the 5 (all PE) developed in the non aspirin group.

The incidence of clinically significant thromboembolic events is low in elective orthopaedic foot and ankle surgery. We suggest that the benefit of chemical thromboprophylaxis does not outweigh its potential risks in foot and ankle surgery.

The incidence of deep-vein thrombosis (DVT) and pulmonary embolism (PE) is thought to be low following foot and ankle surgery, but the routine use of chemoprophylaxis remains controversial. This retrospective study assessed the incidence of symptomatic venous thromboembolic (VTE) complications following a consecutive series of 2654 patients undergoing elective foot and ankle surgery. A total of 1078 patients received 75 mg aspirin as routine thromboprophylaxis between 2003 and 2006 and 1576 patients received no form of chemical thromboprophylaxis between 2007 and 2010. The overall incidence of VTE was 0.42% (DVT, 0.27%; PE, 0.15%) with 27 patients lost to follow-up. If these were included to create a worst case scenario, the overall VTE rate was 1.43%. There was no apparent protective effect against VTE by using aspirin.

We conclude that the incidence of VTE following foot and ankle surgery is very low and routine use of chemoprophylaxis does not appear necessary for patients who are not in the high risk group for VTE.