The incidence of venous thromboembolism following total knee arthroplasty: a prospective study by using computed tomographic pulmonary angiography in combination with bilateral lower limb venography.

Venous thromboembolism (VTE), presenting as deep vein thrombosis (DVT) and pulmonary embolism, is one of the major complications following total knee arthroplasty (TKA). We conducted this prospective observational study to identify the prevalence of VTE among patients undergoing TKA by using computed tomographic pulmonary angiography in combination with bilateral lower limb venography. We enrolled consecutive patients admitted to our institution for primary unilateral TKA from September 2013 to July 2014. All participants underwent a standard surgical procedure of TKA. Computed tomographic pulmonary angiography and bilateral lower limb venography were performed within a week after the operation. We compared age, sex, BMI, comorbidities, data of laboratory tests, operation time and thromboprophylaxis between VTE group and non-VTE group to identify the risk factors. A total of 109 patients were enrolled in this study. The incidence of symptomatic DVT, asymptomatic DVT, symptomatic pulmonary embolism and asymptomatic pulmonary embolism following TKA was 4.6, 18.3, 1.8 and 1.8%, respectively. Elevated level of D-dimer was significantly associated with postoperative VTE. The incidence of VTE following TKA was high despite thromboprophylaxis, and asymptomatic DVTs accounted for a large proportion of thrombotic events.