Anterior cruciate ligament tear increases the risk of venous thromboembolism: a population‐based cohort study

PURPOSE: Previous studies highlighted an increased risk of venous thromboembolism (VTE) among patients with anterior cruciate ligament reconstruction (ACLR); however, the risk for those with ACL tear but without undergoing ACLR has not been reported yet. The aim of this study was to evaluate the risk of VTE among ACL tear individuals with or without ACLR derived from the general population. METHODS: A cohort study was conducted using data from the IQVIA Medical Research Database of the United Kingdom. Up to five non-ACL tear individuals (n = 22,235) were matched to each case of ACL tear (n = 4474) by age, sex, body mass index and entry-time. The relation of ACL tear to VTE [pulmonary embolism (PE) and deep vein thrombosis (DVT)] was examined using a multivariable Cox proportional hazard model. A sub-cohort analysis, in which the ACL tear individuals were stratified into those with ACLR and those without ACLR, was also conducted. RESULTS: VTE developed in 13 individuals with ACL tear and nine individuals without ACL tear (incidence rates: 3.1 vs. 0.4/1000 person-years), with multivariable-adjusted hazard ratio (HR) being 6.59 (95% CI 2.28-19.08) in 1-year follow-up. For ACL tear individuals with ACLR, the HR was 11.44 (95% CI 2.71-48.28), and for those without ACLR, the HR was 6.02 (95% CI 1.44-24.25), compared with individuals without ACL tear. CONCLUSION: This large-sample population-based cohort study provides the first evidence on an increased risk of VTE in ACL tear individuals regardless of subsequent ACLR, which supports the necessity for monitoring venous-thromboembolic complications in the target population, including those without ACLR. LEVEL OF EVIDENCE: III.