Morgan J P
Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis 95616, USA.
J Small Anim Pract. 1999 Apr;40(4):167-72. doi: 10.1111/j.1748-5827.1999.tb03784.x.
Transitional lumbosacral vertebral anomalies have for some time been suggested as a possible cause of cauda equina syndrome (especially in the German shepherd dog [GSD]), a condition recently thought to be inherited. The frequency of this condition within a large clinical population and the radiographic features used in its detection are reported. In a group of 143 patients, the sexes were similarly represented and the GSD was greatly overrepresented. The anomaly is characterised by separation of the first sacral segment that was identified on the lateral view by the presence of a radiolucent disc space between what are normally the first and second sacral segments. On the ventrodorsal view, the anomaly was characterised by separation of the spinous processes between what are normally the first and second sacral segments. In the presence of the transitional segment, the nature of the sacroiliac joint at the level of the anomalous segment varies from a strong ilial attachment, with the presence of a wing-like lateral process, to a weakened ilial attachment because of the presence of a lateral process, shaped as that seen on a lumbar segment. These patterns were present unilaterally or bilaterally and result in symmetrical or asymmetrical patterns. The effect of the weakening of the sacroiliac attachment was thought to result in premature disc degeneration, which, together with spinal canal stenosis, resulted in potential compression of the overlying spinal nerves and creation of a cauda equina syndrome. The condition is thought to have clinical significance and should be selected against in breeding, especially in the GSD.
一段时间以来，过渡性腰骶椎异常被认为可能是马尾综合征的一个病因（尤其是在德国牧羊犬[GSD]中），这种情况最近被认为是遗传性的。本文报告了该病症在一个大型临床群体中的发病频率以及用于检测的放射学特征。在一组143例患者中，性别分布相似，但GSD的比例过高。该异常的特征是第一骶椎节段分离，在侧位片上表现为通常的第一和第二骶椎节段之间存在一个放射性透亮的椎间盘间隙。在腹背位片上，该异常的特征是通常的第一和第二骶椎节段之间的棘突分离。在存在过渡节段的情况下，异常节段水平的骶髂关节性质各不相同，从具有强大的髂骨附着且有翼状外侧突，到因存在类似腰椎节段所见形状的外侧突而导致髂骨附着减弱。这些模式可单侧或双侧出现，并导致对称或不对称模式。骶髂关节附着减弱的影响被认为会导致椎间盘过早退变，这与椎管狭窄一起，导致覆盖其上的脊神经受压，并引发马尾综合征。这种情况被认为具有临床意义，在育种时应予以淘汰，尤其是在GSD中。
