Department of Orthopedics, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shanxi, China.
Eur Spine J. 2020 May;29(5):1159-1166. doi: 10.1007/s00586-020-06307-9. Epub 2020 Feb 1.
Pedicle screw and rod instrumentation based on titanium can produce satisfying strength and stiffness for spinal fusion. However, excessive stiffness produced by titanium rods may cause stress shielding. Thus, polyetheretherketone (PEEK) rods with a low modulus of elasticity were introduced as substitutes for titanium rods. The purpose of this paper is to compare the effectiveness of PEEK rods versus titanium alloy rods in anterior spinal fusion with a new sheep model.
Sheep models of anterior-posterior cervical fusion were innovatively adopted in our study. Twenty-four sheep were randomly divided into a control group and a treatment group that received anterior-posterior cervical fixation with titanium rods or PEEK rods, respectively. Then, surgical segments were harvested and assessed by X-ray, micro-CT and histological examination to evaluate the efficiency of bone fusion.
No complications related to fixation were found during the research process. The results of the X-ray showed a stronger spinal fusion in the PEEK rod groups than in the titanium rod group at 12 weeks postoperatively, and both groups underwent bone fusion at 24 weeks postoperatively. The results of micro-CT showed that fixation with PEEK rods achieved better bone ingrowth at an early postoperative stage (12 weeks) compared to fixation with titanium rods (bone volume fraction (BVF): 20.26 ± 4.36% vs 14.48 ± 3.49%, p < 0.05). The same trend was detected in the histological analysis, where the mineralized bone fraction in the experiment group (21.01 ± 3.48%) was significantly higher than that in the control group (16.73 ± 2.95%). In addition, better osseointegration was found in the experiment group at the early postoperative stage at 12 weeks (bone apposition (BA): 16.22 ± 3.24% vs 11.67 ± 3.63%, p < 0.05). However, there were no significant differences at 24 weeks postoperatively.
PEEK rods can be used safely in a sheep model of anterior-posterior cervical fixation. Compared to traditional titanium rods, earlier and more evident bone fusion was found in the PEEK rods group. These slides can be retrieved under Electronic Supplementary Material.
基于钛的椎弓根螺钉和棒器械可以为脊柱融合提供令人满意的强度和刚度。然而，钛棒产生的过高刚度可能会导致应力屏蔽。因此，低弹性模量的聚醚醚酮（PEEK）棒被引入作为钛棒的替代品。本文旨在通过一种新的绵羊模型比较 PEEK 棒与钛合金棒在前路脊柱融合中的效果。
我们创新性地采用了绵羊颈椎前后路融合模型。24 只绵羊被随机分为对照组和治疗组，分别接受钛棒或 PEEK 棒前路后路颈椎固定。然后，通过 X 射线、微 CT 和组织学检查对手术节段进行评估，以评价骨融合的效率。
在研究过程中未发现与固定相关的并发症。X 射线结果显示，术后 12 周时 PEEK 棒组的脊柱融合更强，两组均在术后 24 周时发生骨融合。微 CT 结果显示，在术后早期（12 周），与钛棒固定相比，PEEK 棒固定具有更好的骨长入（骨体积分数（BVF）：20.26±4.36%比 14.48±3.49%，p<0.05）。组织学分析也显示了同样的趋势，实验组的矿化骨分数（21.01±3.48%）明显高于对照组（16.73±2.95%）。此外，在术后 12 周的早期，实验组的骨整合更好（骨沉积（BA）：16.22±3.24%比 11.67±3.63%，p<0.05）。然而，在术后 24 周时没有显著差异。
PEEK 棒在前路颈椎固定的绵羊模型中可以安全使用。与传统钛棒相比，PEEK 棒组的骨融合更早、更明显。这些幻灯片可以在电子补充材料中检索到。
