Study On The Accuracy And Application Value Of Measuring The Degree Of Shortening After Mid-shaft Clavicle Fracture By Bilateral Method

Objective To evaluate the accuracy and application value of measuring the degree of shortening after mid-shaft clavicle fracture by bilateral method.Methods We compared the bilateral method with the calibration method,which was chosen as the gold standard,to analyze the accuracy of the bilateral method.Posteroanterior(PA)radiograph,Anteroposterior(AP)20°cephalad radiograph and Posteroanterior(PA)20°caudad radiograph of the bilateral clavicle were filmed by x-ray to calculate the shortening by the bilateral method and the calibration method.The results were analyzed by Bland-Altman test to study their consistency.Results The limit of agreement(d±1.96s)calculated by the bilateral method and the calibration method were PA-10.98~10.00mm,AP20°-18.98~10.95mm,PA20°-18.93~13.88mm,respectively.The PA radiograph had the smallest error relatively.There were 5 cases which got a shortening of more than 15millimeter by the bilateral method,but only 1 by the calibration method.There were 10cases which got a shortening of more than 15 millimeter by the calibration method,but only 1 by the bilateral method.Conclusion Measuring the shortening of mid-shaft clavicle fracture by the bilateral method has a large error,and its accuracy is not enough.So it can't be used to determine the choice of operation.However,in the absence of a better choice,the clavicle shortening measured by the bilateral method in the PA radiograph is closer to the true value.