Risk Factors for Trimalleolar Ankle Fracture: A Single-Centre Retrospective Analysis

Background Obesity presents a growing public health crisis within the UK. Recent literature has identified a direct correlation between obesity and the incidence of ankle fractures in both men and women. In addition to this, the reported incidence of severe ankle fractures and those requiring operative fixation in the obese population is significantly higher than that in the non-obese population. This study aims to investigate associations between obesity and tri-malleolar ankle fracture, specifically, while reviewing any potential differences in gender. We will also examine the fracture rates in post-menopausal women to determine if menopause is an independent risk factor for trimalleolar ankle fracture. Method Search terms were used to identify all operatively managed ankle fractures listed on the virtual trauma board at a major trauma centre in Manchester, UK. The records of each of these patients were then reviewed on an individual basis to identify all trimalleolar ankle fractures (161 patients). Patient demographics and injury-specific data were collected and input into a data sheet using Microsoft Excel (Microsoft® Corp., Redmond, WA). Results Obesity and severe obesity were common and seen in 60 (37.3%) and 11 (6.8%) patients, respectively. Our cohort was found to have a significantly higher mean BMI (30.6 SEM = 0.59) than the national average (27.6) (p < 0.001). Women had a higher average BMI at 31.8, whereas the average BMI for men was 28.4. There were 49 (46.7%) postmenopausal women (aged ≥ 55 years old) in our sample size of 161 patients. This was significantly more than there were in the general population for the same sample size (p < 0.001). Conclusion Our paper demonstrates an association between obesity and trimalleolar ankle fracture. Furthermore, women were more prone to trimalleolar ankle fractures than men. However, we are unable to say if female gender is an independent risk factor since women in our study had a higher average BMI than the men. The findings around bone mineral density (BMD) are conflicting, and although there were many postmenopausal women in our cohort, recent studies suggest that menopause does not play a role in increasing the risk of ankle fracture. Further research should focus on the role of menopause as a risk factor in trimalleolar ankle fracture.