Bone Morphology as a Determinative Risk Factor for Type of Ankle Fracture

Abstract

Background: The aim of this study was to investigate the relationship between the radiographic bone morphology of the ankle and the observed fracture type. Methods: We retrospectively reviewed the patients who had visited our emergency department with ankle injuries between June 2012 and July 2018. All patients were treated with open reduction and internal fixation. Patients were categorized in two groups based on the fracture patterns (groups 1 and 2). Group 1 consisted of isolated lateral malleolar fractures, while group 2 comprised bimalleolar fractures. Group 1 was further divided into two groups; namely group A and B based on their classification into Weber type B and C fractures, respectively. Four radiographic parameters were measured postoperatively by standing whole-leg anteroposterior view of the ankle; talocrural angle (TCA), medial malleolar relative length (MMRL), lateral malleolar relative length (LMRL), and the distance between the talar dome and distal fibula. Results: One hundred and seventeen patients were included in group 1-A, 89 patients in group 1-B, and 168 patients in group 2. The values of TCA and MMRL were significantly higher in group 2 than in group 1. Lateral malleolar length/medial malleolar length ratio was also significantly different between the two groups. However, there were no significant differences between the groups in terms of LMRL and the distance between the tip of the distal fibula and talar process. LMLR and MMRL values between groups A and B were not significantly different (p=0.402 and p=0.592, respectively). However, there was a significant difference between the two groups in terms of TCA and the distance between the tip of the distal fibula and talar process. Conclusions: The talocrural angle, medial malleolar relative length, and lateral malleolar length/medial malleolar length were significantly higher in patients with bimalleolar fracture than in patients with isolated lateral malleolar fractures.

Can Anatomical Differences Contribute to the Etiology of Danis-Weber Type B Lateral Malleolus Fractures?

“…However, few studies have explored whether differences in anatomical morphology can predispose patients to fractures. It is generally accepted that having a "constrained" anatomy in the ankle may be a risk factor for fracture and that a less constrained anatomy may be a risk factor for ligament injury [5][6][7].…”