Deep vein thrombosis after total knee arthroplasty

Background and purpose: The incidence of deep vein thrombosis (DVT) after total knee arthroplasty (TKA) in the Asian population is probably higher than is commonly assumed by clinicians. The purpose of this study was to investigate the incidence of DVT after TKA in a southern Taiwanese population and to determine whether routine prophylaxis against DVT is indicated. Materials and methods: The incidence of DVT was investigated in 107 ascending venograms performed in 105 knees in 102 patients after TKA. Observations were made and interpreted by orthopedic radiologists blinded to the clinical condition of the patients. The correlation of DVT with the medical conditions, anesthesia type, and local physical findings were analyzed. Results: The overall incidence of DVT after TKA was 63.6% (68/107); 95.6% (63/68) of cases involved the distal veins in the calf and only 4.4% (3/68) involved the proximal vein at the popliteal level. There was no higher incidence of thrombosis in the femoral and iliac veins, and no pulmonary embolism. Approximately 70% of patients with DVT were symptomatic and required treatment. There was no statistically significant correlation of DVT with medical condition, including diabetes mellitus, hypertension, body weight, varicosity, history of thromboembolic disorder and congestive heart failure, or the type of anesthesia or bone cement used. There was a positive correlation of DVT with local physical findings including calf girth enlargement, leg edema, and skin discoloration, and a negative correlation with findings including Homans' sign, cord induration, venous engorgement, and knee effusion. Conclusion: The incidence of DVT after TKA in this southern Taiwanese cohort was similar to that in Western populations, and higher than is commonly assumed by clinicians at this facility. However, the rate of proximal thrombosis and pulmonary embolism was much lower than in previous studies from Western populations. The majority of cases of DVT involved the veins in the calf; approximately 70% of patients were symptomatic and required treatment.