HARnT-2 hindfoot nail or pro-tibial screw fixation for early mobilisation: multi-centre comparative study of utilisation & outcomes in complex ankle fractures

J. Bethel, A.-A. Najefi, M. Davies, E. Gosney, K. Patel, R. Ahluwalia

Introduction: Hindfoot intramedullary nail fixation (HFN) or fibula pro-tibial screw fixation (PTS) are surgical options for ankle fractures in patients with multiple co-morbidities; we compared their outcomes.

Methods: A retrospective review of 135 patients who underwent HFN fixation (87 patients) or PTS fixation (48 patients) for ankle fractures (AO/OTA A/B/C) from 5 major trauma centres. Patient demographic data, co-morbidities, Charlson Co-morbidity Index Score (CCIS), weight-bearing, and post-operative complications were recorded. Radiographs were assessed for non-union and anatomical reduction.

Results: HFN estimated 10-year survival was 27±31% and was 48±37% for PTS (p<0.001). Average time to full weightbearing (FWB) in the HFN group was 1.7±3.3 weeks compared to 7.8±3.8 weeks in the PTS group (p<0.001). Despite this, HFN fixation carried a greater VTE risk (p=0.02). HFN accompanied by joint preparation had greater risk of infection (p=0.01), metalwork failure (p=0.02) and wound breakdown (p=0.01). The overall complication rate in diabetic patients was 56%, but 76% in HFN patients. In the HFN group 17 (20%) patients died at 1 year. Patients with open fractures(p=0.01), dementia (p<0.05), and a higher CCIS (p=0.04) were more likely to die after HFN surgery. Age and co-morbidity matched data showed a higher rate of complications and mortality in those above 75 years fixed with a HFN, irrespective of CCIS. In those between 60-75 years, there was a greater risk of superficial infection and mortality after HFN, irrespective of CCIS. These complications were not seen after PTS.

Conclusion: HFN carries a greater risk of superficial infections, VTE and mortality compared to PTS, independent of age and CCIS. Diabetes leads to a greater comparative risk of deep infections, wound breakdown and non-union in HFN. Alternative methods of fixation (e.g. PTS) should be considered before HFN. HFN may be suitable in selective indications where other methods are not appropriate.