The impact of external fixation on mortality in patients with an unstable pelvic ring fracture: a propensity-matched cohort study

Aim There is not adequate evidence to establish whether external fixation (EF) of pelvic fractures leads to a reduced mortality. We used the Japan Trauma Data Bank database to identify isolated unstable pelvic ring fractures to exclude the possibility of blood loss from other injuries, and analyzed the effectiveness of EF on mortality in this group of patients. Patients and Methods This was a registry-based comparison of 1163 patients who had been treated for an isolated unstable pelvic ring fracture with (386 patients) or without (777 patients) EF. An isolated pelvic ring fracture was defined by an Abbreviated Injury Score (AIS) for other injuries of < 3. An unstable pelvic ring fracture was defined as having an AIS ≥ 4. The primary outcome of this study was mortality. A subgroup analysis was carried out for patients who required blood transfusion within 24 hours of arrival in the Emergency Department and those who had massive blood loss (AIS code: 852610.5). Propensity-score matching was used to identify a cohort like the EF and non-EF groups. Results With the use of propensity-score matching using the completed data, 346 patients were matched. When the propensity-score matching was adjusted, EF was associated with a significantly lower risk of death (p = 0.047). In the subgroup analysis of patients who needed blood transfusion within 24 hours and those who had massive blood loss, EF was associated with a significantly lower risk of death in patients who needed blood transfusion within 24 hours (p = 0.014) and in those with massive blood loss (p = 0.016). Conclusion The use of EF to treat unstable pelvic ring fractures was associated with a significantly lower risk of death, especially in patients with severe fractures. Cite this article: Bone Joint J 2018;100-B:233–41.