Rigo Matteo, Cinti Filippo, Menchetti Marika, Ventura Laura, Pratesi Andrea
Clinica Veterinaria San Marco, Veggiano, Italy.
Department of Animal Medicine, Production and Health, Università di Padova, Padua, Italy.
Vet Comp Orthop Traumatol. 2025 Jul 22. doi: 10.1055/a-2653-2592.
To evaluate the feasibility and accuracy of vertebral pedicle screws in cats using a custom 3D-printed drill guide and 3D-printed vertebral columns.To simulate the surgical procedure, six vertebral columns from adult cats were 3D-printed. The columns were printed with a radiolucent material (PLA enriched with calcium carbonate-PLA+). One 3D-printed guide was created for each vertebra (from T10 to L7). Each preplanned hole was drilled and filled with a graphite cylinder for better visualization of the tunnel. All the phantoms were CT-scanned after the drilling operation. Each hole was graded using a modified classification scheme (grades 0 to 3) and compared to the planned tunnel angle. We enrolled one 5-year-old female patient with spinal trauma requiring vertebral stabilization presented at our hospital.A total of 126 holes were drilled. The overall mean screw deviation angle was 0.61 degrees (SD = 0.72). In safety evaluation, 117 (93%) screws were contained in the pedicle (grade 0), 7 screws (5.5%) were outside the pedicle by less than 0.5 mm (grade 1), and 2 (1.5%) screws were between 0.5 and 1 mm outside the pedicle. In the thoracic segment, all the holes (48/48) were classified as a grade 0, while in the lumbar segment, with a total of 78 holes drilled, there were 69 holes classified as grade 0 (88%), 7 holes classified as grade 1 (8.9%), and 2 holes classified as grade 2 (2.5%). The feline patient had suffered a T12 complete oblique vertebral body fracture. A total of six 1.7 mm screws, 20 mm long, (Fix-In, INTRAUMA) were placed: three in T12 and three in T13.Overall, there was a mean deviation of the hole angle from the planned angle of 0.61 degrees. The overall safety was 91.2% (screws graded as 0). A statistically significant association between screw grades and vertebral segment was found (-value 0.02) as all the thoracic vertebrae are grade 0, while grade 1 and grade 2 were found only in the lumbar segment. Using pedicle screws in cats' vertebrae may reduce surgical trauma, as it requires exposure of only the most dorsal portion of the vertebral lamina, avoiding the need to expose the costal attachments. Also, placing cement dorsally is easier and can incorporate screw heads bilaterally. We effectively and safely performed the surgical procedure in one clinical case. Based on our results, the use of pedicle screws, previously applied in canine patients, could also be extended to feline patients, provided that 3D-printed guides are used to ensure accurate placement.
使用定制的3D打印钻孔导向器和3D打印的脊柱来评估猫椎弓根螺钉置入的可行性和准确性。为模拟手术过程，对6只成年猫的脊柱进行了3D打印。脊柱采用一种可透射线的材料（富含碳酸钙的聚乳酸-PLA+）打印而成。为每个椎体（从T10至L7）制作了一个3D打印导向器。每个预先规划好的孔都进行了钻孔，并填充了石墨圆柱体以便更好地观察隧道。钻孔操作后对所有模型进行CT扫描。每个孔使用改良的分类方案（0至3级）进行分级，并与规划的隧道角度进行比较。我们收治了一名5岁雌性脊柱创伤患者，该患者在我院就诊，需要进行椎体稳定手术。总共钻了126个孔。螺钉总体平均偏差角度为0.61度（标准差=0.72）。在安全性评估中，117枚（93%）螺钉位于椎弓根内（0级），7枚螺钉（5.5%）位于椎弓根外但距离小于0.5毫米（1级），2枚（1.5%）螺钉位于椎弓根外0.5至1毫米之间。在胸段，所有的孔（48/48）均分类为0级，而在腰段，总共钻了78个孔，其中69个孔分类为0级（88%），7个孔分类为1级（8.9%），2个孔分类为2级（2.5%）。该猫患者发生了T12椎体完全斜形骨折。总共置入了6枚1.7毫米、长20毫米的螺钉（Fix-In，INTRAUMA）：3枚置入T12，3枚置入T13。总体而言，孔角度与规划角度的平均偏差为0.61度。总体安全性为91.2%（螺钉分级为0级）。发现螺钉分级与椎体节段之间存在统计学显著关联（P值0.02），因为所有胸椎均为0级，而1级和2级仅在腰段发现。在猫的椎体中使用椎弓根螺钉可能会减少手术创伤，因为它仅需暴露椎板最背侧部分，无需暴露肋骨附着处。此外，在背侧放置骨水泥更容易，并且可以双侧纳入螺钉头部。我们在1例临床病例中有效且安全地实施了手术。根据我们的结果，先前应用于犬类患者的椎弓根螺钉使用方法，在使用3D打印导向器确保准确置入的情况下，也可扩展应用于猫类患者。
