Comparing Australian orthopaedic surgeons' reported use of thromboprophylaxis following arthroplasty in 2012 and 2017

Background: It is generally accepted that all arthroplasty patients should receive venous thromboembolism (VTE) and bleeding risk assessments, and that postoperative thromboprophylaxis be routinely prescribed where appropriate. Guideline recommendations regarding what to prescribe, however, have been inconsistent over the years, particularly regarding the appropriateness of aspirin. Our aim was to explore thromboprophylaxis patterns in use following hip and knee arthroplasty in Australia, and to examine associated variables.

Methods: Orthopaedic surgeons were invited via mail to participate in two national surveys, conducted in 2012 (N = 478) and 2017 (N = 820), respectively.

Results: The final response rates were 50.0 and 65.8% for 2012 and 2017, respectively. The thromboprophylaxis prescribing routines reported by respondents were divided into four categories: anticoagulant-only (the same anticoagulant-only routine for everyone), aspirin-only (aspirin for everyone), staged-supply (an anticoagulant during the initial postoperative period, followed by aspirin, for everyone) and risk-stratification routines (differing regimens depending on patients’ perceived risk of VTE). The most common approaches reported were anticoagulant-only routines; however, their popularity almost halved within the five-year period (from ~ 74% to ~ 41%). Conversely, staged-supply and risk-stratification protocol usage increased by more than two and nine times, respectively. In 2017, over one-half of surgeons reported prescribing aspirin in their practice. Reported concern for postoperative VTE and infections (OR 0.555 95% CI 0.396–0.779, p = 0.001 and OR 1.455 95% CI 1.010–2.097, p = 0.044 respectively), as well as Arthroplasty Society membership (OR 2.814 95% CI 1.367–5.790, p = 0.005) were predictors for use of aspirin (Cox and Snell R square = 0.072). The factor most commonly reported to shape surgeons’ protocols was research literature. Factors limiting prescribing of pharmacological prophylaxis included a perception that it increases bleeding and wound infection risk, is inconvenient, and lacks evidence applicable to real-world practice.

Conclusions: prevention post-arthroplasty is an evolving and multi-faceted entity, influenced by a range of factors and seemingly in need of robust evidence from large clinical trials to guide practice. The data highlighted potential short-falls in practice related to aspirin over-use, which could be further explored and addressed in future studies in order to optimise patient outcomes and reduce the significant morbidity and healthcare costs associated with VTE following these increasingly common surgical procedures.