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.