To analyze the incidence of deep venous thrombosis after total knee arthroplasty in patients with rheumatoid arthritis and to analyze the risk factors.

One hundred and sixteen cases of rheumatoid arthritis patients undergoing total knee arthroplasty in the Department of Sports Medicine and Adult Reconstructive Surgery, Nanjing Drum Tower Hospital from March 2010 to December 2018 were retrospectively analyzed, including 12 males and 104 females. Inclusion criteria were definite diagnosis, standard total knee arthroplasty, and available for preoperative and postoperative examination of thrombosis. Those without definite diagnosis, treated with unicompartmental knee arthroplasty, with preoperative thrombosis or unable to accept relating examinations were excluded. Age, gender, body mass index, hypertension, diabetes, triglycerides, postoperative bed rest time and pain visual analogue scale score were recorded. The patients were divided into thrombosis group and non-thrombosis group according to the incidence of deep vein thrombosis, and the difference of figures were compared. Chi-square test was used to examine categorical variables, and paired t test was adopted for metering data. Logistic regression analysis was used to verify the correlation of various risk factors and thrombosis.

Seventeen cases developed deep vein thrombosis, and the incidence rate was 14.7% (17/116). All the thrombosis was stable and no pulmonary embolism occurred. Thrombosis group had higher average age than the non-thrombosis group[(62.8±8.8) vs (56.4±11.1)years, t =2.272, P=0.025], and the proportion of people over 65 years old in thrombosis group was 47.1%, higher than 21.2% of the non-thrombosis group (χ²=3.88, P=0.049). Multivariate regression analysis revealed that age ≥65 years was an independent risk factor of postoperative deep vein thrombosis (OR=1.265, P =0.032).

The incidence of deep vein thrombosis after total knee arthroplasty in patients with rheumatoid arthritis is not low. Age ≥ 65 years is an independent risk factor for deep vein thrombosis after total joint replacement in patients with rheumatoid arthritis and it is suggested to conduct more aggressive thromboprophylaxis to those patients.