Peculiarities of homeostatic system in highland conditions using llizarov distraction transosseous osteosynthesis method

Purpose. The purpose is to study the reaction of homeostasis system in stable and in distraction llizarov transosseous ostesysnthesis of the limbs bones at experimental animals (dogs) in highland conditions. Material and Methods. 63 adult mongrels aged from 1 to 3 years with 10-20 kg body weight and 15 cm minimal length of tibia were included in the experiment. Open osteosotmy of tibial mid-shaft followed by Kirschner wires insertion through tibial bone and llizarov frame assembly comprising 3 or 4 rings was performed under IV anaesthesia at 3200 m altitude above sea level. In experimental group including 33 mongrels the distraction was performed on the 5th day after osteotomy by 1 mm rate divided into 4 times within 10 days but in control group comprising 30 dogs the distraction was not provided. Every 10 days after distraction blood samples were taken in both groups to examine coagulation; the samples were taken from subcutaneous lateral tibial vein, ex tempora mixing with 3,8% solution of sodium citrate at 9:1 ratio. Then the plasma was separated and examined biochemically according to the accepted standards. Results. We obtained the data witnessing activation of coagulation component of homeostatic system in stable osteosynthesis of the limb bones using llizarov fixator with simultaneous inhibition of fibrinolytic component. In distraction osteosynthesis hyper-coagulation trend in homeostasis system with simultaneous suppression of fibrinolytic blood activity is vividly defined within the entire experiment period. Conclusion. Transosseous distraction osteosynthesis in highland condition causes considerable shifts in the system of homeostasis with definite domination of coagulation component which promotes formation of pre-thrombotic condition. Limb segment lengthening on the background of pre-thrombotic condition increases the risk of thromboembolic complications in highland conditions and requires appropriate measures of prophylaxis