Differences in Classification Between Mono- and Polytrauma and Low- and High-Energy Trauma Patients With an Ankle Fracture: A Retrospective Cohort Study

Although fracture type and treatment options for ankle fractures are well defined, the differences between mono- and polytrauma patients and low- and high-energy trauma have not been addressed. The aim of the present study was to compare the fracture type and trauma mechanism between mono- and polytrauma and low- and high-energy trauma patients with an ankle fracture. We performed a single-center retrospective cohort study. Fractures were classified according to the Lauge-Hansen classification and a descriptive classification. High-energy trauma (HET) was defined using triage criteria. All other patients were classified as having experienced low-energy trauma (LET). The patients were divided into 2 groups according to the injury severity score (ISS). Monotrauma patients were defined as patients with an ISS of 4 to 11 with an isolated ankle fracture or an ankle fracture with a minor contusion or laceration. Polytrauma patients were defined as patients with an ISS of ≥16 with ≥2 body regions involved. Patients with an ISS from 12 to 15 were excluded. A total of 96 patients were eligible for analysis. Of the 96 patients, 62 had experienced monotrauma and 34 had experienced polytrauma. A significant difference was found between the mono- and polytrauma patients in the Lauge-Hansen classification (p < .001). Monotrauma patients had a high incidence of an isolated supination external rotation injury. Supination adduction and pronation abduction injuries were more often observed in polytrauma patients. The same pattern was observed for ankle fractures after HET compared with LET (p < .001), because all pronation abduction and supination adduction injuries were observed after a HET mechanism. The results of the present study indicate that polytrauma patients sustain different types of ankle fractures than patients with an isolated ankle fracture. This difference likely results from the high-energy transfer associated with polytrauma, because pronation abduction and supination adduction injuries were only observed after HET.