Hettlich Bianca F, Fosgate Geoffrey T, Litsky Alan S
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio.
Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Pretoria, South Africa.
Vet Surg. 2017 Jan;46(1):95-102. doi: 10.1111/vsu.12581. Epub 2016 Nov 30.
To compare the biomechanical properties of 2 veterinary locking plates and monocortical screws/polymethylmethacrylate (PMMA) fixation in canine cadaveric cervical vertebral columns.
Biomechanical cadaveric study.
Nineteen cervical vertebral columns (C2-C7) from large breed, skeletally mature, canine cadavers were used. A cortical ring was placed as a disk spacer at C4-C5 in all specimens. Seven vertebral columns were plated at C4-C5 with two 4-hole, 3.5 mm string of pearls plates (SOP) and 6 vertebral columns were plated with two 6-hole, 2.4 mm titanium locking reconstruction plates (Ti recon plate). All screws were placed monocortically. Six vertebral columns had monocortical titanium screws and PMMA (Ti screws/PMMA) placed, tested as part of a prior study.
Stiffness testing in 3 directions was performed of the unaltered C4-C5 vertebral motion unit and repeated after placement of the disk spacer and implants. Data were compared using a linear mixed model that incorporated data from previously tested spines (Ti screw/PMMA).
The mean (95% CI) stiffness (N/m) in extension for SOP was 407 N/mm (330-503), for Ti recon plate was 284 N/mm (198-407) and for Ti screws/PMMA was 365 N/mm (314-428); in flexion for SOP was 250 N/mm (178-354), for Ti recon plate was 147 N/mm (106-204) and for Ti screws/PMMA was 311 (235-416); in lateral bending for SOP was 528 N/mm (441-633), for Ti recon plate was 633 N/mm (545-735) and for Ti screws/PMMA was 327 N/mm (257-412). There were no significant differences in stiffness between the 3 fixations for any outcome.
Monocortical fixation with two 3.5 mm SOP or two 2.4 mm Ti recon plates may be an alternate fixation to monocortical screws and PMMA.
比较两种兽医锁定钢板与单皮质螺钉/聚甲基丙烯酸甲酯（PMMA）固定犬尸体颈椎柱的生物力学特性。
生物力学尸体研究。
使用了19个来自大型品种、骨骼成熟的犬尸体的颈椎柱（C2 - C7）。在所有标本的C4 - C5处放置一个皮质环作为椎间盘间隔物。7个颈椎柱在C4 - C5处用两块4孔、3.5毫米串珠钢板（SOP）进行固定，6个颈椎柱用两块6孔、2.4毫米钛锁定重建钢板（钛重建钢板）进行固定。所有螺钉均单皮质置入。6个颈椎柱置入单皮质钛螺钉和PMMA（钛螺钉/PMMA），作为先前一项研究一部分进行测试。
对未改变的C4 - C5椎体运动单元进行三个方向的刚度测试，并在放置椎间盘间隔物和植入物后重复测试。使用纳入先前测试脊柱（钛螺钉/PMMA）数据的线性混合模型比较数据。
SOP在伸展时的平均（95%可信区间）刚度（N/m）为407 N/mm（330 - 503），钛重建钢板为284 N/mm（198 - 407），钛螺钉/PMMA为365 N/mm（314 - 428）；在屈曲时，SOP为250 N/mm（178 - 354），钛重建钢板为147 N/mm（106 - 204），钛螺钉/PMMA为311（235 - 416）；在侧弯时，SOP为528 N/mm（441 - 633），钛重建钢板为633 N/mm（545 - 735），钛螺钉/PMMA为327 N/mm（2,57 - 412）。对于任何结果，三种固定方式之间的刚度均无显著差异。
使用两块3.5毫米SOP或两块2.4毫米钛重建钢板进行单皮质固定可能是单皮质螺钉和PMMA固定的替代方法。
