Quantitative assessment of pelvic reduction using a pretensioned external fixator in unstable pelvic injuries: a retrospective study

Introduction Conventional anterior external fixation provides effective stabilization in pelvic injuries but has limited ability to reduce and control posterior pelvic ring displacement, particularly in type C fractures. Although several anterior fixation systems capable of posterior compression have been described, many remain complex and impractical in emergency settings. Purpose To evaluate the effectiveness of a pretensioned pelvic external fixator (PPEF) as a reduction tool in unstable pelvic fractures across different clinical scenarios. Methods A retrospective study was conducted including 28 patients treated with PPEF between 2012 and 2024. In 24 cases, the device was used as emergency stabilization, and in 4 cases as an adjunct or intraoperative reduction tool. Pelvic reduction was assessed using pre- and postoperative CT scans. Anterior and posterior diastasis, as well as vertical displacement, were measured. Radiological outcomes were classified using Matta/Tornetta criteria. Subgroup analyses were performed according to fracture type (A/B vs C), presence of sacral or pubic fractures, and bilateral involvement. Results Posterior diastasis decreased from 2.54 ± 2.09 cm preoperatively to 0.30 ± 0.67 cm postoperatively. Anterior diastasis improved from 2.54 ± 3.00 cm to 0.35 ± 0.51 cm. Vertical displacement was reduced from 1.18 ± 0.95 cm to 0.36 ± 0.52 cm. Excellent or good radiological outcomes were achieved in 89.3% of cases. No significant differences were observed between fracture types or injury patterns. The complication rate was low, with pin site infection in 7.1% of cases (n = 2) and no observed re-displacement. Conclusion The pretensioned pelvic external fixator is a simple and effective technique for achieving immediate radiological reduction in unstable pelvic injuries. It provides reliable correction of displacement, including in type C fractures, and may serve as a valuable tool in both emergency management and as an adjunct to definitive fixation, particularly in resource-limited settings. Level of evidence IV Retrospective study.