Initial definitive treatment of open femoral shaft fractures with retrograde nailing - is it safe? A retrospective analysis comparing antegrade to retrograde nailing

•Using RFN as initial definitive treatment in severe open femur fractures, we had no cases of septic arthritis.•There are high rates of secondary surgical procedures related to the initial injury of open femoral shaft fractures.•Rates of infection, functional outcomes, nonunions and reoperations, did not differ significantly between AFN and RFN in treatment of severe open femoral fractures. Treatment of severe open femoral fractures with retrograde intramedullary nailing, raises concerns of septic arthritis of the knee due to its intra-articular entrance point. There is little evidence concerning the safety of retrograde femoral nailing (RFN) usage in these cases, and what evidence there is does not necessarily include severe open fractures. Furthermore, the outcome of ballistic injuries treated in this manner and a comparison with antegrade femoral nailing (AFN), is yet to be established. The aim of this study was to examine the outcome of primary retrograde femoral nailing in high-grade open fractures and compare our results with similar fractures treated with AFN. A retrospective analysis of treated high-grade open femoral fractures, was performed at an academic level one trauma centre between 2006 and 2016. Included were all open femur shaft fractures treated with either RFN or AFN as primary fixation. We analysed both patient groups and compared outcomes including the infection rate, non-union rate and secondary interventions. Presence of knee pain and long-term function, was evaluated using the Short-Form 12 (SF-12) questionnaire. Forty-nine patients with open femoral shaft fractures whose primary treatment was intramedullary nailing (IMN), were included in the cohort. Thirty patients were treated with RFN and 19 with AFN. No septic arthritis of the knee was detected in either group. One patient in the RFN group and two in the AFN had a deep surgical wound infection. Excluding reoperations for locking screw removal due to local irritation, the reoperation rate was 22% with two patients treated for non-union in the RFN group and two in the AFN. When comparing outcome measures, including SF-12 scores and the reported knee pain rates of AFN and RFN groups, no significant differences were observed. Our study showed that retrograde femoral nailing as initial definitive treatment in high-grade open femoral shaft fractures, resulted neither in septic arthritis of the knee nor in an unacceptable infection rate. General outcomes regarding complications and re