The incidence of symptomatic venous thromboembolism following orthopaedic surgery at Bay of Plenty District Health Board.

AIM: To investigate the incidence of symptomatic venous thromboembolism (VTE) after orthopaedic surgery.

METHOD: We performed a retrospective cohort study investigating the incidence of symptomatic VTE within 90 days of orthopaedic surgery in the Bay of Plenty District Health Board (DHB). Risk factors and antithrombotic regimens were also reviewed.

RESULTS: After 1,133 unilateral total hip joint replacements (THJRs), there were six VTEs (incidence 0.5%, 95% CI 0.2-1.1%), four deep vein thromboses (DVT) (0.4%, 0.1-0.9%) and three pulmonary emboli (PE) (0.3%, 0.1-0.8%). Following 898 unilateral total knee joint replacements (TKJRs), 18 patients developed VTEs (2.0%, 1.2-2.9%), five developed DVTs (0.6%, 0.2-1.3%) and 16 developed PEs (1.8%, 1.1-2.9%). There were five VTEs after 224 THJR revisions (2.2%, 1.0-5.1%), five VTEs after 110 TKJR revisions (4.5%, 2.0-10.2%) and 16 VTEs after 846 hip fracture surgeries (1.9%, 1.2-3.0%). VTE risk factors were ICU admission post operatively and having known coronary or cerebrovascular disease. Within 1 week of surgery, 38.5% (30/78) of VTEs were diagnosed and within 2 weeks 66.7% (52/78) were diagnosed. Aspirin was being taken by 44% (34/78) of VTE patients and 26% (19/78) were on more potent antithrombotics.

CONCLUSION: VTE is a rare complication of orthopaedic surgery. The highest risk period is the initial 2 weeks after a procedure. VTE can develop despite pharmacological thromboprophylaxis.