Accuracy of radiographic measurements of the cervical articular process joints of the horse.

摘要

Radiography is the standard imaging technique for diagnosing arthropathy of the caudal cervical articular process joints. Clinical studies used lateral and oblique radiographic views of the caudal cervical spine to determine the size of the articular process joints (APJ), which were then compared to reference values of clinically normal horses. The aim of this study is to evaluate the accuracy of such measurements. The cervical spine of 7 euthanized Warmblood horses, without major clinical alteration of the APJ were aligned and fixed in a neutral position. Lateral, oblique, and tangential radiographs of the lower neck were obtained using standardised technique. The x-ray beam was centered on the APJ of C5/6 and C6/7, respectively. The radiographic measurements were obtained by three different observers. All radiographic measurements were compared to the corresponding anatomical measurements obtained from the boiled out bones. The 95% Confidence Interval (CI) and the 95% Limit of Agreement (LOA) were calculated from the difference between the anatomical measurement and the radiographic measurement. The measurements of the maximum height and the length of the cervical body on the lateral radiographs were the most accurate measurements in this study. All other measurements of the three observers resulted in relatively high 95% CI and wide LOA. On the oblique views, the radiographic measurements show a low accuracy and it appears that radiography underestimates the true size of the APJ. The data of this cadaver study suggests that the range of differences between radiographic and anatomical measurements of cervical articular processes is higher than the differences between normal and diseased horses as proposed by other authors on lateral and oblique radiographs. Therefore, the radiographic measurements and their reference values for normal articular process joints of the lower neck in horses should be used with caution.