EMERGENCY STABILIZATION TECHNIQUES FOR UNSTABLE PELVIC RING INJURIES – EFFECTS ON POSTERIOR STABILITY, COMPRESSION AND INTRAPELVIC VOLUME IN A CADAVER STUDY

Abstract

Background: Unstable pelvic ring fractures are frequently associated with severe hemodynamic instability and mortality. Hemorrhage control of these disrupted pelvic fractures requires an urgent reduction of the intrapelvic volume and immediate mechanical stabilization. The aim of this study was to investigate the control of the intrapelvic volume and pelvic stability by different modes of external stabilization in a cadaver model.

Methods: Various degrees of pelvic ring instability were induced in unembalmed human torsos. Haemorrhage induced volume displacement into the presacral and retroperitoneal space (RPP) was assessed by positioning two infusion lines right in front of the sacroiliac joint. The abdominal pressure measurement (IAP) was obtained by a percutaneous catheter in the abdominal cavity. Baseline pressure measurements of the intra pelvic volume were documented before and after dissection for uni-as bilateral instability. Reduction of pelvic instability was performed by non invasive T-POD^® Pelvic Stabilizer, a supraacetabular, iliac crest fixator, application of the pelvic C-Clamp without and with pelvic packing.

Results: Baseline measurements (RPP) of the intact pelvis showed an average increase of 8,03 cmH2O per 1000 cc of infused fluid. In case of uni- and bilateral instability the pressure decreased to a rate of 2,88 and 1,48 cmH2O per 1000 cc. Following the application of each device an increase of RPP of 3,5 cmH2O (pelvic binder), 3,2 cmH2O (anterior frames), 5,4 cmH2O (C-Clamp) and 8,4 cmH2O (C-Clamp + packing) per 1000 cc was obtained in case of unilateral instability. In bilateral disruptions a significantly lower increase of pressure up to 4,0 cmH2O was seen.

Conclusions: We investigated the efficacy of various external stabilization Methods: on potential hemorrhage on experimentally induced uni- and bilateral pelvic ring fractures. In case of intact pelvis the retroperitoneal space responds to fluid application with rapidly rising pressures. The application of external devices enable the reduction of the pelvic volume and thereby the retroper-itoneal pressure increase. The C-clamp combined with pelvic packing resulted to be superior.