Section of Diagnostic Imaging, Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
Acta Vet Scand. 2012 May 1;54(1):27. doi: 10.1186/1751-0147-54-27.
Lumbosacral transitional vertebra (LTV) is a common congenital and hereditary anomaly in many dog breeds. It predisposes to premature degeneration of the lumbosacral junction, and is a frequent cause of cauda equina syndrome, especially in German shepherd dogs. Ventrodorsal hip radiographs are most often used in diagnosis of LTV in screening programs. In this study, value of laterolateral lumbar spine radiographs as additions to ventrodorsal radiographs in diagnosis of LTV, and characteristics of LTV and the eighth lumbar vertebra (L8) in laterolateral radiographs were studied. Additionally, computed tomography (CT) features of different types of LTV were elucidated.
The ventrodorsal pelvic and laterolateral lumbar spine radiographs of 228 German shepherd dogs were evaluated for existence and type of LTV. Morphology of transverse processes was used in classification of LTV in ventrodorsal radiographs. The relative length of sixth (L6) and seventh (L7) vertebrae (L6/L7) was used in characterization of these vertebrae in laterolateral radiographs. CT studies were available for 16 dogs, and they were used for more detailed characterization of different types of LTV. Non-parametric χ2 statistics, generalized logit model for multinomial data, and one-way analysis of variance was used for statistical analyses.
In all, 92 (40%) dogs had a LTV, the most common type being separation of first spinous process from the median crest of the sacrum in 62 dogs (67% of LTV). Eight dogs had eight lumbar vertebrae. Those dogs with LTV had longer L7 in relation to L6 than dogs with normal lumbosacral junctions. When L6/L7 decreased by 0.1 units, the proportion of dogs belonging to the group with L8 was 14-fold higher than in the group with normal lumbosacral junctions. L8 resembled first sacral vertebra (S1) in length and position and was therefore classified as one type of LTV. With CT it was shown that categorizing LTV, based on shape and visibility of transverse processes seen in ventrodorsal radiographs, could be misleading.
We suggest that L8 be included as a part of the LTV complex, and the laterolateral radiographs of the lumbar spine be considered as an addition to ventrodorsal projections in the screening protocols for LTV.
腰骶过渡椎（LTV）是许多犬种中常见的先天性和遗传性异常。它易导致腰骶关节过早退化，是马尾综合征的常见原因，尤其是在德国牧羊犬中。在筛选计划中，腰骶部矢状面和背腹位髋关节射线照相术最常用于诊断 LTV。在这项研究中，研究了侧位腰椎射线照相术作为诊断 LTV 的附加手段的价值，以及 LTV 和第八腰椎（L8）在侧位射线照相术中的特征。此外，还阐明了不同类型 LTV 的 CT 特征。
评估了 228 只德国牧羊犬的腰骶部矢状位骨盆和侧位腰椎射线照相术，以确定 LTV 的存在和类型。在矢状面 X 光片中，使用横突形态对 LTV 进行分类。在侧位 X 光片中，使用第六（L6）和第七（L7）腰椎（L6/L7）的相对长度来描述这些腰椎的特征。对 16 只狗进行了 CT 研究，并将其用于更详细地描述不同类型的 LTV。使用非参数 χ2 检验、多变量数据的广义对数模型和单向方差分析进行统计分析。
共有 92 只（40%）狗存在 LTV，最常见的类型是 62 只狗（67%的 LTV）的第一棘突与骶骨中线嵴分离。8 只狗有 8 个腰椎。与正常腰骶关节相比，存在 LTV 的狗的 L7 相对于 L6 较长。当 L6/L7 减少 0.1 个单位时，属于 L8 组的狗的比例比属于正常腰骶关节组的狗高 14 倍。L8 在长度和位置上与第一骶椎（S1）相似，因此被归类为 LTV 的一种类型。通过 CT 显示，根据矢状面 X 光片中所见的横突形状和可见性对 LTV 进行分类可能会产生误导。
我们建议将 L8 作为 LTV 复合体的一部分，并建议在 LTV 的筛选方案中考虑添加腰椎的侧位 X 光片。
