Abstract:

BACKGROUND: It is dispute which placement methods are adaptable when repairing clavicle middle segment comminuted fractures using open reduction and internal fixation, therefore, the biomechanical difference between anterior and upper reconstruction plate internal fixation should be verified, which can provide guidance for clinical treatment.
OBJECTIVE: To compare the biomechanical characteristics of upper and anterior reconstruction plate internal fixation for middle clavicular fractures.
METHODS: Totally 12 adult clavicles (24 clavicles) were prepared for middle fractures models, fixed using 6 holes reconstruction plate, and randomly divided into 3 groups: in the upper plate group (n=9) and the anterior plate group (n=9), the reconstruction plates were fixed at the upper or anterior of the clavicle fracture specimen, there were 3 screws at the each end of fracture lines. In the normal specimen group (n=6), there was no treatment. The biomechanical characteristics of each specimen were tested and compared. 
RESULTS AND CONCLUSION: Three-point bending test, torsional strength and stiffness measurement demonstrated that there were no significant difference between the upper plate, anterior plate and normal specimen groups (P < 0.05); the tension test showed that the tensile strength and stiffness of the anterior plate group were larger than that of the upper plate group (P < 0.05), with stronger pull-out resistance (P < 0.05). Simultaneously, the anti-putout power of the anterior plate group was less than the upper plate group (P < 0.05). It revealed that the anterior reconstruction plate internal fixation is an ideal method for treating middle clavicular fracture.