ACUTE FAILURE CHARACTERISTICS OF 6 METHODS FOR INTERNAL-FIXATION OF CANINE FEMORAL OBLIQUE FRACTURES

A lung oblique osteotomy model of canine femoral fractures was created to compare six methods of internal fixation. The following methods we re tested: three cerclage wires, three lag screws, eight-hole dynamic compression plate attached with six cerclage wires, eight-hole dynamic compression plate attached with six cortical screws, eight-hole dynam ic compression plate attached with six cortical screws superimposed ov er three cerclage wires, and an eight-hole dynamic compression plate a ttached with six cortical screws superimposed over three lag screws. T he repaired femurs were mounted in a mechanical testing machine in an orientation designed to mimic physiological loading. Axial compression was applied which resulted in the test specimens experiencing simulta neous compressive and bending forces. The effects of the method of ost eotomy repair. bone temperature, and bone diameter were analyzed. The maximum load and the stiffness of the composite fixation and bones wer e determined. There were not any statistically significant differences in stiffness among the groups. All fixation methods, in which plates were attached with screws, resulted in significantly greater maximum l oad values than treatment techniques where plates were not used. None of the fixation methods attained a mean maximum load greater than 58% of the mean maximum load of the control femurs.