Hemodynamics and Tissue Temperature in Bone Union Area of Long Bones Primary Fractures and Refractures: <i>in vivo</i> Experiment

Abstract

Background. Adequate blood flow in tissues during bone union is a factor that enables to achieve positive treatment results.
 Aim of study to study in vivo experiment the features of temperature response and blood flow in consolidation area of tibial primary fractures and refractures.
 Methods. A tibial fracture was simulated in rats and then immobilized with external fixator. In series 1 (n = 13) the fixation was kept until union. In series 2 (n = 18) a refracture was simulated 21 days after the surgery and refixed until union. The blood flow and tissue temperature were studied in the fracture area in normal conditions; 21 and 35 days after fracture or refracture; 28 days after the end of fixation.
 Results. The temperature and blood flow were of the same type, but of different intensity. Three types of reactions were identified: 1) reduced blood flow velocity and tissue temperature, signs of venous outflow difficulty; 2) increased blood flow, unchanged venous outflow, reduced tissue temperature; 3) slight blood flow decrease, increased venous outflow, slight tissue temperature increase. By the end of fixation (35 days) all parameters in series 1 returned to normal. 28 days after the end of fixation the tissue temperature and venous outflow returned to normal in series 2 animals with the first and the second types of hemodynamics, their blood flow velocity decreased. As for the third type, the tissue temperature returned to normal, the venous outflow and the blood flow velocity increased.
 Conclusion. In case of primary fractures, the blood flow and the tissue temperature normalized by the end of fixation. In case of refractures the changes persisted 1 month after the end of fixation.