Abstract: Objective To detect the changes of serum arachidonic acid (AA) and epoxyeicosatrienoic acid (EETs) in rabbits with cerebral trauma and ulna fracture, and to explore the relationship between the changes and fracture healing. MethodsRabbits were randomly divided into four groups: a sham group (Group S, n=6), a fracture group (Group F, n=12), a cerebral trauma group (Group T, n=6), a cerebral trauma combined with fracture group (Group TF, n=12). Fracture and cerebral trauma models were established using improved Feeney free fall injury device. The levels of serum AA and EETs were detected by ELISA on Days 1, 3, 7, 14 and 21 after modeling. Meanwhile, behavioral changes like food intake and the load time of the diseased limb were recorded. Furthermore, on Days 14 and 35 after modeling, the rabbits were subjected to X ray examination at their right front limbs. Then, 6 rabbits in both Groups F and TF were randomly sacrificed and the fracture tissues were taken for H-E staining. ResultsThe levels of AA and EETs were increased in Groups T, F and TF after modeling (P＜0.05), which reached the peak on Day 3and then gradually reduce. The increase in Group TF was more remarkable in Groups F and T (P＜0.05). According to H-E staining, Group F showed a typical process of fracture healing, but the callus formation and reforming in Group TF were in advance, and fracture healing was accelerated. ConclusionsCerebral trauma combined with fracture can accelerate the process of fracture healing, which is probably related to the changes of serum AA and EETs.