Risk of Venous Thromboembolism after Total Knee Arthroplasty in Patients with Rheumatoid Arthritis

Objective.To compare the incidence of venous thromboembolism (VTE) following total knee arthroplasty (TKA) between patients with rheumatoid arthritis (RA) and those with osteoarthritis (OA).Methods.The subjects were composed of 1084 Japanese patients with OA and 204 with RA. Primary effectiveness outcomes were any deep vein thrombosis (DVT) as detected by bilateral ultrasonography up to postoperative Day 10 (POD10) and pulmonary embolism (PE) up to POD28. The main safety outcomes were bleeding and death from any cause up to POD28. Plasma D-dimer levels were measured before and at POD10 after TKA.Results.The study cohort was composed of 1288 patients from 34 hospitals. There was no death up to POD28. PE occurred in 2 patients with OA and in no patients with RA. The incidence of primary effectiveness outcome was 24.3% and 24.0% in patients with OA and RA, respectively. The incidence of major bleeding up to POD28 was 1.3% and 0.5% in patients with OA and RA, respectively. No differences in the incidence of VTE (symptomatic/asymptomatic DVT plus PE) or bleeding were noted between patients with RA and OA. D-dimer levels on POD10 were significantly higher in patients with OA compared with those with RA. Also, D-dimer levels on POD10 were significantly lower in patients receiving fondaparinux than in patients without pharmacological prophylaxis.Conclusion.Despite some differences in demographic data, patients with RA and OA have equivalent risks of VTE and bleeding following TKA.