ObjectiveTo evaluate the effects of dynamization of external fixation on open tibia and fibula fracture union.MethodsThe clinical data of 26 cases of open tibia and fibula fractures treated by external fixation were retrospectively analysed. According to different postoperative treatment methods, the patients were divided into elastic dynamic group (group A, n=13) and constant elastic fixation group (group B, n=13). There was no significant difference in gender, age, and fracture type between 2 groups (P>0.05). The removal time of external fixator in group B was evaluated by fracture healing time, X-ray film, and doctor’s experience. In group A, the growth of callus was examined based on X-ray film at 12 weeks after operation; the axial mechanical load ratio was tested, and dynamic loading was carried out when the axial mechanical load ratio was 5%-10%. The using time of external fixator, fracture healing time, and incidence of complications were compared between 2 groups.ResultsAll patients were followed up 4-13 months, with an average of 5.7 months. During the treatment, there was no complication such as loosening or breaking of the external fixator, fracture displacement, or re-fracture in 2 groups. The using time of external fixator in group A was (24.77±1.42) weeks and the fracture healing time was (23.04±1.30) weeks, which were all significantly reduced when compared with those in group B [(34.38±1.71) weeks and (32.46±1.66) weeks] (t=16.10, P=0.00; t=15.58, P=0.00). In group A, there were 2 cases of needle tract infection and 1 case of muscle weakness, the incidence of complication was 23.1%; in group B, there were 3 cases of needle tract infection, 1 case of muscle weakness, and 1 case of delayed union of fracture, the incidence of complication was 38.5%; there was no significant difference in the incidence of complication between 2 groups (P=1.000).ConclusionDynamization of external fixation can promote union of open tibia and fibula fractures with a high security.