摘要目的 建立肱骨髁上骨折体外模型,通过3DCT测量、实测、公式推导三种方法观察肱骨远端移位情况与提携角变化,并分析结果,验证3DCT测量的准确性,明确肱骨远端移位与提携角变化相关性.方法 经防腐处理的小儿离体上肢20具,制成肱骨髁上骨折模型,分别为水平横断和斜型横断(前低后高),调整模型至标准前后位在X线下分别测量内旋、内倾、内旋加内倾三种情况下提携角的变化,同样在3DCT技术下模拟上述模型内旋、内倾、内旋加内倾三种情况下提携角的变化,对比研究实测、3DCT模拟和测量、理论公式推导的结果,验证3DCT测量及公式推导的准确性,明确肱骨远端移位与肘关节提携角的相关性.结果 无论是体外实测、3DCT测量与公式推导,测量结果差异无统计学意义(P＞0.05).不论是水平横断还是斜型横断,内倾、内旋、内倾加内旋都与提携角的变化成负相关(P＜0.01),内移与提携角无相关性.结论 肱骨远端移位与提携角变化的3DCT测量方法是可靠的.建立肱骨远端移位与提携角变化的理论公式,有助于通过数学模型预测提携角的变化.内倾、内旋是引起提携角减小的主要因素.建立一种3DCT复位的模型,可以为肱骨髁上骨折的复位提供理论指导.

abstractsObjective To compare the accuracy of actual measurement,three-dimensional computed tomography reconstruction technology (3DCT) measurement,and formula calculation for the supracondylar fractures of the humerus (SFH) in children.Methods Twenty arms of embalmed children were taken for SFH,which were divided into the horizontal transverse case and oblique transverse case(lower in front and higher behind).Carrying angles of internal rotation,internal tilt,internal translation,internal rotation and tilt were measured under X-ray and three-dimensional CT.And the correlation of displacement of distal humerus and carrying angle was compared with the actual model,3DCT model and the formula.Results No significant difference was noted between the results measured by the actual model,3DCT model or the formula calculation (P＞0.05).Internal rotation,internal tilt,internal rotation and tilt are negatively correlated with the carrying angle in both horizontal and oblique transverse cases (P＜ 0.01).There was no correlation between internal translation and the carrying angle.Conclusions The 3DCT measurement of rotating displacement of distal humerus and carrying angle is accurate,and can guide supracondylar fracture reduction in children.The theoretical formula about the displacement of distal humerus and the carrying angle changes can predict the changes in carrying angle.Internal rotation and internal tilt are the main factors of carrying angle reduction.