Hindfoot Ankle Reconstruction Nail Trial (HARNT). Population analysis of surgical treatment of complex ankle fractures in the United Kingdom

R. Ahluwalia, D. Coffey, I. Reichert, T. Stringfellow, C. Wek, S. Ping Tan,

Introduction: The management of open or unstable ankle and distal tibial fractures pose many challenges. In certain situations, hindfoot nailing (HFN) is indicated, however this depends on surgeon preference and regional variations exist. This study sought to establish the current management and outcomes of complex ankle fractures in the UK.

Methods: A National collaborative study in affiliation with BOTA was conducted and data retrospectively collected between January 1^st – June 30^th 2019. Adult patients with open and closed complex ankle fractures (AO43/44) were included. Complex fractures included the following patient characteristics: diabetes +/- neuropathy, rheumatoid arthritis, alcoholism, polytrauma and cognitive impairment. We obtained data on fixation choice and patient outcomes. Institutional approval was obtained by all centres, and statistical analysis was performed including propensity matching.

Results: Fifty-six centres provided data for 1360 patients. The average age of the cohort was 53.9 years +/-19 (SD) with a male/female ratio of 1:1.3. 920 patients were ASA 1/2, 440 were ASA 3/4; 316 had diabetes, and 275 were open fractures. Most fractures were AO44 (71.2%) and more commonly associated with diabetes (P<0.001), alcoholism (P<0.007), open (P<0.013), and advanced age (55.7 vs. 46.3).1227 patients underwent primary-fixation (111 HFN), with the remainder treated with external-fixation (84 definitive). Of the 111 HFN, 35% underwent primary fusion. Wound complication and thromboembolic rates were greater in the HFN group compared to ORIF groups (P<0.003), being more evident in the HFN group with primary fusion even after propensity matching. However, 1081 patients were non-weightbearing post-op contrary to the BOAST guidance.

Conclusion: This is the first National collaborative audit of complex ankle fractures. Hindfoot nails were used in 9% of patients and we observed more complications in this group when compared to other cohorts. Despite BOAST guidance, only 21% of patients undergoing operative management were instructed to fully weightbear post-operatively.