中文摘要：

目的 通过动物实验，评价X线和多层螺旋CT观察镁合金螺钉应用于膝关节术后影像学改变的可行性。方法 选择成年雌性比格犬16只，制造膝关节股骨内髁骨折，以镁合金螺钉进行固定，术后1、4、8及12周对其行X线和CT扫描，评价钉体降解和骨愈合的情况。结果 X线和CT均可以观察钉体降解和骨愈合情况，两者具有较好的评价一致性（Kappa值为0.60）。结论 X线和CT检查均能观察体内镁合金螺钉的降解和骨折愈合。

英文摘要：

Objective To observe the imaging changes after implantation of magnesium alloy in knee joints with X-ray and CT. Methods Sixteen female beagle were selected for the study. After the establishment of the internal femoral condylar fracture model at the legs, two cancellous bone lag screws of magnesium alloy were applied for fixation. X-ray scans and 3D CT reconstruction were performed in animals 1 week, 4 weeks, 8 weeks, and 12 weeks postoperatively for the observation of the effect of the degradation behavior of the screw and the bone healing, then the results were analyzed. Results Both X-ray scans and 3D CT could be used to observe the effect of the degradation behavior of the screw and the bone healing, and there was moderate agreement between the imaging examination methods（Kappa=0.60）. Conclusion Both X-ray scans and 3D CT can be used to observe the degradation behavior of the screw and the bone healing.