Preoperative anemia may increase risk of DVT formation before TJA

China: Researchers from China found that preoperative anemia screening is necessary to identify preoperative deep vein thrombosis and perioperative blood transfusion in patients undergoing total joint arthroplasty.

The trial results were published in the Journal of Orthopedic Surgery and Research. 

Total joint arthroplasty (TJA) includes total hip and total knee arthroplasty (THA and TKA) and is one of the frequently performed procedures for osteoarthritis of the hip and knee. It is mostly associated with the complication of venous thromboembolism. Most of the patients who are undergoing TJA are anemic. Previous data have suggested that anemia is one of the risk factors in TJA but there were not many studies that identified any correlation between preoperative anemia and preoperative deep vein thrombosis development. Hence Xiaojuan Xiong et al conducted a trial to explore the correlation of the severity of preoperative anemia with deep vein thrombosis (DVT) in patients undergoing total joint arthroplasty (TJA). 

Between January 1, 2017, and December 31, 2021, nearly 2461 TJA patients were enrolled. They were classified into anemia and non-anemia groups based on preoperative Hb results and also DVT and non-DVT groups based on preoperative deep vein color ultrasound screening. Propensity score matching (PSM) analysis was used to establish a logistic regression model. Preoperative anemia of TJA patients was used as a dependent variable and DVT-related variables as covariates. The anemia and non-anemia groups were matched based on the ratio of 1:1 (835 pairs) using 0.01 as the caliper value. Binary logistic regression analysis was used to determine the correlation between anemia and the severity of anemia before TJA and DVT. 

Findings from the study: 

• In the total number of participants, preoperative anemia was observed in 872 cases (35.43%) and DVT in 170 cases (6.91%).
• The DVT risk of patients with preoperative, moderate, and severe anemia increased by 1.82, 2.77, and 8.26 times, respectively as per the binary logistic regression analysis after PSM. 
• The risks of blood transfusion in the perioperative period in patients with anemia, mild anemia, moderate anemia, and severe anemia increased by 3.52 times, 2.13, 7.22, and 61.37 times, respectively. 

Thus, Preoperative anemia increased the risk of DVT formation before TJA reiterating the necessity of screening for DVT before TJA. Also, they added that preoperative anemia is an independent risk factor for preoperative DVT and blood transfusion in the perioperative period for TJA patients. 

Further reading: Xiong, X., Xu, S., Li, T. et al. Correlation of the severity of anemia in patients undergoing total joint arthroplasty with preoperative deep vein thrombosis: a retrospective cohort study. J Orthop Surg Res 17, 554 (2022). https://doi.org/10.1186/s13018-022-03457-y