Abstract
There is widespread appreciation amongst orthopaedic surgeons of the importance of thromboprophylaxis. However much of the evidence is based on surrogate outcomes of clinical end-points. This population-based study aims to identify the incidence and trends in venous thromboembolic disease (VTE) following total hip (THR) and knee arthroplasty (TKR) with death or readmission for VTE up to two years following surgery for all patients in Scotland as the primary outcome.
We used the Scottish Morbidity Record (SMR01) system to identify all patients undergoing hip or knee arthroplasty over the ten-year period from 1992 to 2001. Patients undergoing cataract surgery over the same period were identified as a control group. Record linkage for all patients to subsequent SMR01 and Registrar General records provided details of further admissions due to DVT or non-fatal PE and deaths within Scotland up to two years after the operation. The cause of death was determined from the Registrar General Records.
The incidence of VTE (including fatal pulmonary embolism (PE)) three months following primary THR was 2.27% and primary TKR was 1.79%. The incidence of fatal PE within three months of THR was 0.22% and TKR was 0.15%. The majority of events occurred in the interval from hospital discharge to six weeks after surgery. There was no apparent trend over the period. An apparent reduction in the overall mortality within 365 days of surgery appears to be due to a reduction in the incidence of acute myocardial infarct.
The data support the current advice that prophylaxis should be continued for at least six weeks following surgery. Despite increased uptake of prophylaxis regimens and earlier mobilisation, there has been no apparent change in the incidence of symptomatic VTE over the ten-years from 1992 to 2001.
