Patients with more complex ankle fractures are associated with poorer patient-reported outcome: an observational study of 11,733 patients from the Swedish Fracture Register.

Background and purpose: Patient-reported outcome measures (PROMs) following ankle fractures, including all fracture types, have not been reported. It is therefore unclear whether fracture morphology correlates with outcome. We aimed to analyze PROMs in patients with an ankle fracture in relation to the Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) fracture classification using population-based register data from the Swedish Fracture Register (SFR).

Methods: All patients aged ≥ 18 years with an ankle fracture (AO/OTA 44A1-C3) registered in the SFR between 2012 and 2019 were retrieved from the register. Patients with completed PROM questionnaires (Short Musculoskeletal Function Assessment and EuroQol-Visual Analogue Scale) on both day 0 (pre-trauma) and 1-year post-trauma were included. The difference in PROMs between day 0 and 1 year was calculated for each patient (delta value) and mean delta values were calculated at group level, based on the AO/OTA fracture classification.

Results: 11,733 patients with 11,751 fractures with complete PROMs were included. According to the AO/OTA classification, 21% were A fractures, 67% were B fractures and 12% were C fractures. All groups of patients, regardless of fracture class (A1-C3), displayed an impairment in PROMs after 1 year compared with day 0. Type C fractures displayed a larger impairment in PROMs at group level than type B, which in turn had a greater impairment than type A. The same pattern was seen in groups 3, 2, and 1 for A and B fractures.

Conclusion: We found that the AO/OTA classification is prognostic, where more complex fractures were associated with poorer PROMs.