Effectiveness of additional transmalar Kirschner wire fixation for a zygoma fracture

BACKGROUND: The purpose of this study was to verify the effectiveness of transmalar Kirschner wire fixation as additional fixation for the treatment of zygoma fractures. METHODS: The authors compared two methods for zygoma fixation at the frontozygomatic suture from both theoretical and clinical viewpoints: miniplate fixation (plate fixation) and miniplate fixation with an additional transmalar Kirschner wire fixation (wire plus plate fixation). For the theoretical study, the authors produced zygoma fractures on 20 skull simulation models; these were generated on the basis of computed tomographic data of actual dry skulls. In their simulation surgery, they fixed the fractured zygoma with the above-mentioned two fixation methods, producing 20 plate fixation models and 20 wire plus plate fixation models. A 10-kgf load was then applied on the fractured zygoma in the anteroposterior and superoinferior directions. Finally, the stresses around the fixation screws and the deviation of the zygoma were calculated using finite element analysis. For the clinical study, the authors compared the postoperative zygoma alignment based on computed tomography of six patients treated with plate fixation and eight patients treated with wire plus plate fixation using a visual analogue scale. RESULTS: In the theoretical study, the wire plus plate fixation models demonstrated a significant decrease in both the stresses around the screws and the deviation of the fractured bone compared with the plate fixation models. In the clinical study, the visual analogue scale scores for the wire plus plate fixation group were significantly higher than those for the plate fixation group. CONCLUSION: Because the additional transmalar Kirschner wire fixation can effectively increase the stability of the fractured zygoma that has been fixed with one miniplate, it should be recommended as an effective technique for the treatment of complicated zygoma fractures.