An Experimental Study Of External Fixation Of Femoral Fractures Under Ultrasound Versus Fluoroscopy In Canine

Objective: We use the theory of damage control orthopaedics in this study, and the femoral fracture models were created by osteotomy. To explore the efficacy of ultrasound for guiding closed reduction and external fixation of extremity fracture in the canine.Method: Ten healthy adult beagle dogs without osteoporosis, tumor, lesion and deformities verified by radiographs were used in this experiment. Bilateral femoral fracture models were individually created by osteotomy at 6 cm above the distal end of the femur. Subsequently, fracture in each side was closely reduced and fixed with an ORTHOFIX frame, monitored with ultrasound(the ultrasound group) or fluoroscopy(fluoroscopy group) randomly. The length of operation, efficiency of fracture reduction fixation, induction position and alignment of fracture, and pin placement were compared between the two groups.Result: The operative time in an average lasted(34.3±1.8) min in the ultrasound group, while(43.8±2.3) min in the fluoroscopy group, there was statistically significant difference between two groups(p<0.05). In term of fracture reduction and fixation, the reposition percent of fractured ends was(89.3±3.6)%in the ultrasound group, by contrast,(91.6±3.7)% in the fluoroscopy group. In addition, the angulation of fracture was(4.4±1.5)° in the coronal plane and(5.9±1.7)° in the sagittal plane in the fluoroscopy group, in comparison,(3.5±1.1)° and(4.8±1.9)° respectively in the fluoroscopy group. According to the criteria of pin placement, excellent and good pin placement was 92.5% in the ultrasound group, by comparison, 100% in the fluoroscopy group. However,there was no statistical difference between the two groups in anyone of the aforementioned parameters in reference to reduction and fixation of fracture(p>0.05). The results show that the ultrasound group’s operative time is shorter,the fracture reduction is satisfied, the pin placement control is good, and no radiation damage.Conclusion: Under ultrasound monitoring, satisfactory reduction and fixation of femoral fracture with the external fixator could be achieved in this experiment model in the canine. It implies that portable ultrasonic system is effective and alternative to fluoroscopy, especially in rescuing the wounded with extremity fracture in the battlefield.