Normal index of dorsal atlantoaxial distance in dogs

ABSTRACT Thirty healthy dogs had their cervical spines radiographed, and the dorsal atlantoaxial distance and others vertebral anatomical parameters were measured. These data were assessed using the Pearson correlation coefficient. After detection of the best correlation parameter, we used the dimensional correlation coefficient of formula (CCD). In the second stage of the study, radiographs of the 33 dogs with atlantoaxial subluxation (SAA) were used. In each radiographic image, the CCD formula was applied. All normal and subluxation radiographic images were randomized, and submitted to subjective analysis. It was observed that the anatomical parameter with the highest correlation is the length of the spinous process of the axis, obtaining a mean value of 0.056 index and 0.019 standard deviation. Index mean value obtained in dogs with the disease of 0.287 and standard deviation of 0.123. The subjective analysis revealed 88.89% to 95.24% agreement, while the result obtained by the CCD formula was shown to be 100% effective in the diagnosis of SAA. We suggest the use of the CCD formula to obtain the index of normality of the atlantoaxial distance with a mean value of 0.056 and maximum of 0.098, and it is concluded that the index is highly effective in the diagnosis of subluxation between the atlas and the axis.

摘要：选取30只健康犬进行颈椎X线摄影，测量其背侧寰枢间距及其他椎骨解剖参数。采用皮尔逊相关系数（Pearson correlation coefficient）对上述数据进行分析评估。筛选出最优相关参数后，采用公式（CCD）的维度相关系数开展后续分析。本研究第二阶段纳入33例确诊寰枢椎半脱位（SAA）患犬的X线影像，对每一张X线影像应用CCD公式进行计算。将所有正常与半脱位状态的X线影像随机化处理后，开展主观阅片分析。研究发现相关性最高的解剖参数为枢椎棘突长度，其正常组的均值为0.056，标准差为0.019；患犬组的该参数均值为0.287，标准差为0.123。主观阅片分析的一致性达88.89%~95.24%，而CCD公式的诊断结果对SAA的诊断有效性达100%。本研究建议采用CCD公式计算寰枢间距正常化指数，该指数正常参考值均值为0.056，最大值为0.098；且该指数在寰枢椎半脱位的诊断中具有极高的有效性。