Abstract
Research Type:
Level 3 - Retrospective cohort study, Case-control study, Meta-analysis of Level 3 studies
Introduction/Purpose:
Ankle injuries involving the talus are complex and can lead to avascular necrosis (AVN) due to the talus's unique anatomical and vascular characteristics, which make it susceptible to circulatory disruptions after injuries. The role of Aspirin and other anticoagulants in preventing AVN is debated, with some studies suggesting potential benefits while others find no significant effect. This study aimed to investigate the effect of Aspirin as well as other anticoagulants and their correlation with talar AVN incidence.
Methods:
A retrospective review of medical records from 167 patients evaluated for talar AVN at three academic tertiary centers was conducted, comprising 70 patients with AVN and 97 controls without AVN. Data collected included anticoagulant use categorized into aspirin alone, other anticoagulants alone, combination therapy, or no anticoagulant treatment. We also included patients demographics including age, sex, body mass index (BMI) as well as injury related factors including Hawkins sign and Hawkins classification in our analysis. Associations between anticoagulant use and the presence of talar AVN, as well as the influence of BMI, age, sex, Hawkins sign and Hawkins classification, were analyzed with a significance level set at p < 0.05.
Results:
Age and sex distributions were similar between groups (p =0.11, p=0.69), but BMI was significantly higher in the AVN group (p < 0.001). A negative Hawkins Sign was strongly associated with AVN (OR=129.0, 95% CI: 39.31–423.38, p< 0.001). Higher Hawkins Classification also increased AVN risk (p < 0.001), in our cohort all of the Hawkins Type IV fracture dislocations developed AVN, whereas Type III fractures had an OR of 5.8, p< 0.001. Anticoagulation use differed significantly between groups (p=0.003). Patients receiving no anticoagulation (OR = 4.50, p=0.01) or anticoagulants without aspirin (OR = 3.32, p = 0.01) had higher AVN odds, while aspirin use—alone or in combination—was not associated with increased risk (Table 1).
Conclusion:
Aspirin use was associated with a lower incidence of talar AVN, while patients receiving no anticoagulation or anticoagulants without aspirin had significantly higher odds of AVN. This finding suggests a potential protective effect of aspirin, warranting further investigation into its role in AVN prevention. Additionally, a negative Hawkins Sign and higher Hawkins Classification, particularly Type III, were strong predictors of AVN, and increased BMI was also associated with a higher AVN risk.
