Fatal pulmonary embolism following elective total knee replacement using aspirin in multi-modal prophylaxis — A 12 year study

The National Institute for Health and Clinical Excellence (NICE) has issued guidelines on which thromboprophylaxis regimens are suitable following lower limb arthroplasty. Aspirin is not a recommended agent despite being accepted in orthopaedic guidelines elsewhere. We assessed the incidence of fatal pulmonary embolism (PE) and all-cause mortality following elective primary total knee replacement (TKR) with a standardised multi-modal prophylaxis regime in a large teaching district general hospital.

We utilised a prospective audit database to identify those that had died within 42 and 90 days postoperatively. Data from April 2000 to 2012 were analysed for 42 and 90 day mortality rates. There were a total of 8277 elective primary TKR performed over the 12 year period. The multi-modal prophylaxis regimen used unless contraindicated for all patients included 75 mg aspirin once daily for four weeks. Case note review ascertained the causes of death. Where a patient had been referred to the coroner, they were contacted for post mortem results.

The mortality rates at 42 and 90 days were 0.36 and 0.46%. There was one fatal PE within 42 days of surgery (0.01%) who was taking enoxaparin because of aspirin intolerance. Two fatal PE’s occurred at 48 and 57 days post-operatively (0.02%). The leading cause of death was myocardial infarction (0.13%).

Fatal PE following elective TKR with a multi-modal prophylaxis regime is a very rare cause of mortality.