Identification of stable supination external rotation ankle fractures - A consensus opinion

G. Salt, V. Thorisdottir, S. Deakin, P. Vaughan

Background: The British Orthopaedic Association Standards for Trauma (BOAST) guidelines highlight the importance of identifying stability in the treatment of ankle fractures within 2 weeks of injury. In practice, it is the supination external rotation (SER) injuries when stability remains unclear and further assessment is required. We sought to form a sub-speciality, consensus opinion from British Orthopaedic Foot and Ankle Society (BOFAS) members, on how to determine stability in SER injuries.

Methods: We performed an electronic survey of all 456 BOFAS full members in autumn 2017. The survey contained two scenarios on how to determine stability in a young healthy patient with an isolated Weber B fracture and no talar shift: - 1. With medial tenderness 2. Without medial tenderness

Results: The response rate was 61%. In the presence of medial tenderness 71% of members would test for stability/talar shift by using weight-bearing (WB) radiographs. When medial tenderness was absent, 67% would still test stability in the same manner. The exception to this was when patients had no medial tenderness and had walked on their fracture prior to presentation. In this case 65% used the presentation radiograph, to look for talar shift and determine stability. The method and timing of WB radiographs varied, however the majority performed standing radiographs, barefooted at approximately 1 week following injury.

Conclusion: This survey provides a consensus on determining the stability of SER ankle fractures. Patients with un-displaced SER injuries who have not walked prior to presentation should undergo standing radiographs regardless of the presence or absence of medial tenderness, at approximately 1 week from injury. Medial tenderness does not determine stability.
Implications: To ensure early WB, individual units should ensure they have a pathway highlighting which ankle fractures should get WB radiographs including when and how they should be performed.