External fixation of unstable pelvic fractures: a systematic review and meta-analysis

Background Unstable pelvic fractures are typically caused by high-impact trauma. Early stabilization is required to prevent further neurological or visceral injury, haemorrhage, reduce pain, infection and long-term deformity and disability. The aim was to review the optimal external fixation techniques and management for unstable pelvic fractures. Methods A total of 28 studies were identified from the initial database search. Seventeen studies met our inclusion criteria - eight prospective cohorts, four retrospective cohorts and five in vitro studies. This equated to 539 patients and 38 cadaveric (in vitro) models. Results Type B and double vertical fractures have less re-displacement (43.7% and 68.2% <5 mm, respectively) than Type C fractures (55.7% >15 mm) regardless of pin placement. Greater than 50% experience a complication with the most common being pin site infection (36%) and a trend towards increased infection with increasing pins was seen. Most can be managed with antibiotics alone (93%). A minimum time of 6-8 weeks in frame was required for definitive management of all fractures. Conclusion This review supports the use of supra-acetabular pins over iliac crest pins to decrease re-displacement, the least number of pins for the shortest amount of time and the largest size pin where possible. Type B fractures will generally have a better outcome than Type C fractures. Definitive management in a frame should be at least 8 weeks. Further studies directly comparing iliac crest and supra-acetabular pin placement are recommended.