Postoperative D-dimer levels predict venous thromboembolisms detected with contrast-enhanced computerized tomography in patients undergoing anterior cruciate ligament reconstruction

BACKGROUND: In the literature, factors associated with postoperative venous thromboembolisms (VTEs) after anterior cruciate ligament reconstruction (ACLR) are limited. This study aimed to investigate the incidence of venous thromboembolisms (VTEs) after anterior cruciate ligament reconstruction (ACLR) and to identify risk and predictive factors for VTEs. METHODS: This retrospective study included 136 patients who underwent arthroscopic ACLR with mechanical prophylaxis between April 2012 and July 2022. Contrast-enhanced computed tomography (CT) was applied to detect VTEs comprising deep venous thromboses and pulmonary embolisms 7 days after surgery. Data including age, sex, body mass index, concomitant treatments, graft types, smoking status, operative and tourniquet times, postoperative D-dimer levels, and other laboratory test results, were collected for analyses. The incidence of radiographically confirmed VTEs and the associated risk factors, such as age, sex, body mass index, concomitant treatments, graft types, smoking status, operative and tourniquet times, postoperative D-dimer levels, and other laboratory test results, were analyzed. RESULTS: The overall incidence of radiographic VTEs was 11.0% (15 cases) in 136 patients. There was one symptomatic patient who had Homan’s sign. Multivariable analysis indicated that postoperative D-dimer level was an independent factor related to a radiographic VTE after ACLR, although there was no association between radiographic VTEs and preoperative status or operation status. The optimal cutoff value for postoperative D-dimer level was 2.8 μg/ml according to the receiver operating characteristic curve analysis, with a sensitivity of 80.0% and specificity of 83.5%. CONCLUSION: The incidence of ACLR-associated radiographical VTEs (deep venous thrombosis and pulmonary embolism) under mechanical prophylaxis was 11.0% in this study. An elevated D-dimer level at 7 days after surgery is an independent predictor of VTE in patients undergoing ACLR. The postoperative D-dimer level is a more reliable marker for identifying VTE in patients who underwent ACLR.