Singh Vaneet, Rawlinson Jeremy, Hallab Nadim
Medtronic Spine, 2600 Sofamor Danek Dr., Memphis, Tennessee, 38132.
Rush University, Chicago, Illinois.
J Orthop Res. 2018 Jul;36(7):1980-1990. doi: 10.1002/jor.23855. Epub 2018 Feb 13.
Options to treat early-onset scoliosis include guided-growth systems with sliding action between rods and pedicle screws. The wear was previously measured in an in vitro test, and in this in vivo rabbit model, we evaluated the local and systemic biological response to the stainless steel debris. Compared to the previous study, a relatively higher volume of representative wear particles with a median particle size of 0.84 μm were generated. Bolus dosages were injected into the epidural space at L4-L5 for a minimum of 36 rabbits across three treatment groups (negative control, 1.5 mg, and 4.0 mg) and two timepoints (12 and 24 weeks). Gross pathology evaluated distant organs and the injection site with a dorsal laminectomy to examine the epidural space and dosing site. Peri-implanted particle tissues were stained for immunohistochemical and quantitatively analyzed for IL-6 and TNF-α cytokines. Based on ISO 10993-6:2007 scoring, particles in the high-dose group were primarily non-irritant (12 weeks) with one slightly irritant. At 24 weeks, inflammatory cell infiltration was non-existent to minimal with all groups considered non-irritant at the injection site. Material characterization confirmed that particles detected in distant organs were stainless steel or contaminants. At 12 weeks, stainless steel groups demonstrated statistically increased amounts of cytokine levels compared to control but there was a statistical decrease for both at 24 weeks. These findings indicate that stainless steel wear debris, comparable to the expected usage from a simulated growth guidance system, had no discernible untoward biological effects locally and systemically in an animal model. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1980-1990, 2018.
治疗早发性脊柱侧弯的方法包括带有棒与椎弓根螺钉之间滑动作用的引导生长系统。此前已在体外试验中测量了磨损情况，而在这个体内兔模型中，我们评估了对不锈钢碎屑的局部和全身生物学反应。与之前的研究相比，产生了相对较高体积的代表性磨损颗粒，中位粒径为0.84μm。将大剂量药物注入L4-L5节段的硬膜外间隙，对三个治疗组（阴性对照组、1.5mg组和4.0mg组）的至少36只兔子在两个时间点（12周和24周）进行研究。大体病理学评估远处器官以及通过背部椎板切除术检查硬膜外间隙和给药部位的注射部位。对植入颗粒周围组织进行免疫组织化学染色，并对IL-6和TNF-α细胞因子进行定量分析。根据ISO 10993-6:2007评分，高剂量组的颗粒在12周时主要为无刺激性（有一个为轻度刺激性）。在24周时，所有组在注射部位均无炎症细胞浸润至轻微炎症，均被认为无刺激性。材料表征证实，在远处器官中检测到的颗粒为不锈钢或污染物。在12周时，与对照组相比，不锈钢组的细胞因子水平在统计学上有所升高，但在24周时两者均出现统计学下降。这些发现表明，与模拟生长引导系统的预期使用情况相当的不锈钢磨损碎屑，在动物模型中在局部和全身均未产生明显的不良生物学效应。© 2018年骨科研究协会。由Wiley Periodicals, Inc.出版。《矫形外科学研究》36:1980-1990, 2018。
