[Kinetic studies of the lumbar vertebrae and the lumbosacral transition in the German shepherd dog. 2. Our personal investigations].

The range and type of ventrodorsal motion between two adjacent vertebra (L3-S1) was analyzed on isolated vertebral columns of 13 German Shepherd Dogs. All except one were neurologically normal dogs. The movement from maximal flexion to maximal extension was divided into 5 degree steps. For each step, the center of motion was determined on laterolateral radiographs. It could be shown that mobility between two adjacent vertebra within the lumbar spine increases towards the lumbosacral region with the highest mobility in this joint. In the cranial portion of the lumbar spine, rotation and ventrodorsal (parallel) displacement between two adjacent vertebra was seen. Rotation dominated in the lumbosacral joint in 11 dogs, whereas parallel displacement was mainly seen in 2 dogs. Further studies on pathologic and surgically modified vertebral columns are necessary to clarify the significance of these findings in the pathogenesis of lumbosacral instability and cauda equina compression in the German Shepherd Dog.