Optimum timing of conversion from DCO to definitive fixation in closed fractures of the lower limb: When and how?

Introduction: In damage control orthopaedics (DCO), fractures are initially stabilised with external fixation followed by delayed conversion to definitive internal fixation. The aim of this study is to determine whether the timing of the conversion influences the development of deep infection and fracture healing in a cohort of patients treated by DCO after a closed fracture of the lower limb. Furthermore, we wanted to evaluate whether the one-stage conversion procedure is always safe. Materials and methods: A retrospective cohort study was conducted at a single level 1 trauma centre. Ninety-four cases of closed fractures of lower limb treated by DCO subsequently converted to internal fixation from 2012 to 2019 were included. Development of deep infection, superficial infection, non-union and time to union were recorded. Patients were then divided into three groups according to the timing of conversion: Group A (<7 days), Group B (7-13 days), Group C (> 14 days). Comparison between groups was performed to assess intergroup variabilty. Results: The mean number of days between DCO and conversion was 6.7±4.52 (range 1-22). We observed one case of deep infection (1.1%), one case of non-union (1.1%), four cases of superficial infection (4.3%) and mean time to union was ±1.38 months. Comparison between groups demonstrated no significant correlation between timing of conversion and development of superficial or deep infection and non-union, while it highlighted that complexity of the fracture and longer surgical time of conversion procedure were significantly higher in Group C. Conclusions: One-stage conversion to definitive internal fixation within 22 days from DCO is a safe and feasible procedure, which does not influence the incidence of infection or non-union.