Establishment and evaluation of a canine vertebral augmentation puncture model under fluoroscopic guidance
Objective To establish a fluoroscopic percutaneous vertebral augmentation model in dogs by measuring and analyzing canine spinal anatomy.We also assessed the effectiveness and safety of this modeling method by postoperative radiological analysis.Methods Morphological measurements were taken in six dogs,aged approximately 12~24 months,and the following parameters of the lumbar vertebrae were determined:height of the L1~L7 vertebrae,width of the vertebral base,distance from the upper edge of the intervertebral disc to the narrowest part of the vertebra,distance from the vertical line of the spinous process to the upper edge of the intervertebral disc,and vertical distance from the midpoint of the transverse process to the lower edge of the intervertebral disc.These measurements were obtained to clarify the anatomical characteristics of the canine vertebrae and determine the optimal location,direction,and depth for bone-cement injection.A percutaneous vertebral augmentation model was subsequently established in the L4,L5,and L6 vertebrae of six healthy Beagle dogs,weighing 20~25 kg.The dogs were euthanized 4 weeks post-surgery and examined radiologically.Primary observations included the surgical duration,postoperative distribution of the implanted bone cement,and integrity of the vertebral canal and anterior edge of the vertebrae.Results Anatomical observation of the canine vertebrae revealed that the vertebral height increased gradually from L1~L5 and then decreased from L5~L7.The width of the vertebral base increased consistently from L1~L7.The distance from the vertical line of the spinous process to the upper edge of the intervertebral disc showed an increasing trend from L1~L7(1.9~4.0 mm).The distance between the midpoint of the base of the transverse process and the lower edge of the intervertebral disc increased gradually from L1~L5(4.7~6.9 mm).There was no significant difference in the distance between the midpoint of the base of the transverse process and the lower edge of the intervertebral disc in the L4,L5,and L6 segments among the dogs(P=0.925).The midpoint of the root of the transverse process of the spine was taken as the puncture point,and the insertion direction and horizontal plane were at an angle of 20°~30°,with a head tilt of 5°~15° and a puncture depth of 1.2~1.5 cm.If the puncture was directed towards the caudal side of the vertebra,the angle of the needle tail was 30°~35°,with a penetration depth of 1.5~1.8 cm.This technique allowed the successful construction of a canine vertebral puncture surgical model.A total of 15 canine vertebral puncture surgical models were successfully created,with an average surgery time of 22.7±4.6 min(15~30 min)per vertebral segment.During surgery,one vertebral segment experienced spinal cord injury result ing in paralysis of the hind limbs and bowel and bladder incontinence.Two vertebral cortical bones fractured,but there were no deaths due to anesthesia or infection.Four weeks post-surgery,micro-computed tomography-based three-dimensional reconstructions consistently showed bone cement distributed within the trabecular bone of the canine vertebrae,with newly formed bone tissue enveloping the implanted material.There was no leakage,and no complications such as damage to the vertebral canal or the anterior wall of the vertebrae.Conclusions A safe and reliable canine vertebral augmentation puncture model can be successfully established based on the anatomy of the canine lumbar vertebrae(L4~L6)and using the midpoint of the base of the transverse process as a bony landmark.
vertebral augmentationvertebral body punctureanimal modeltransverse process of the spinepuncture approach