The application of Caprini Risk Assessment Model in evaluation of deep vein thrombosis for patients with end-stage osteoarthritis before arthroplasty

Background: Deep vein thrombosis (DVT) was a fatal complication of knee arthroplasty. We had neglected the risk factors of preoperative DVT although patients undergoing knee arthroplasty were at high risk for VTE. This study was to determine the risk factors for preoperative DVT and application of Caprini Risk Assessment Model (RAM) in patients with end-stage knee osteoarthritis (OA). Methods: : We retrospectively analyzed 1808 cases with end-stage knee OA undergoing primary knee arthroplasty from May 2015 to December 2020. Based on the results of ultrasonography in lower extremities, all patients were divided into non-DVT group and DVT group. Distribution of risk factors and risk levels were compared using χ 2 test between two groups. Binary logistic regression analysis was used to determine the risk factors and relationship of risk levels and preoperative DVT. Results: : The incidence of preoperative DVT was 5.53% (n=100). Distribution of the study population by risk level was low, 4.09%; moderate, 23.95%; high, 66.98%; and highest 4.98%. Female (P=0.002), age (P=0.012), swollen legs (P=0.035) and history of blood clots (P<0.001) was correlated with preoperative DVT. Difference among four risk levels was significant (P=0.007). Patients with highest risk level had statistically significant association with preoperative DVT (P=0.005, OR=2.93, 95%CI [1.375-6.246]). Conclusion: The incidence of preoperative DVT was 5.53% in end-stage knee OA patients. The gender (female) and age were independent risk factors for preoperative DVT. The risk group classification by Caprini RAM was significantly associated with preoperative DVT. The usage of Caprini RAM before knee arthroplasty may be beneficial for prophylaxis of DVT.