Implementing a Novel Orthopedic Polytraumatic Injury Model in Laboratory Mice

Background/Objective: Traumatic injury is consistently the leading cause of death up to middle age and largest factor in reducing United States economic productivity. Currently, there are few murine models that emulate orthopedic polytraumatic injury. Existing typically require sophisticated vascular access resulting higher costs. We have identified need for a simple easily reproducible model. Therefore, we developed new polytrauma mouse model which included femoral fracture, quadriceps muscle crush, andhemorrhagic shock.
 Methods: Sixty 12-week-old, C57BL/6 female mice were used this study. Briefly, mid-shaft femur fracture was surgically induced on right leg each stabilized by an intramedullary wire. Next, ipsilateral underwent interval crushing Then, create hemorrhagic shock, had approximately 400μL removed through retroorbital sinus. Lasty, resuscitated with intraperitoneal 1.6 ml saline 90 minutes later. Other served as uninjured controls. Splenocytes harvested control group at 0-, 1-, 4-, 24-hours post-trauma (n=12/group). Flow cytometric analyses animal survival examined.
 Results: Of 48 undergoing model, all survived their respective time point. There significant increase (p<0.05) neutrophils from 4-hour cohort compared control. also increases 24-hour natural killer (NK) cells (p<0.05), 0-hour (p<0.0001),1-hour (p<0.0001), groups (p<0.05).
 Conclusion: The shows effectiveness non-fatal, poly-traumatic injuries. Additionally, increased levels neutrophils, NK cells, along steady B consistent known immunologic traumatic response, further validating model’s ability survivable conditions.