Department of Orthopaedic Surgery, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY 10461, USA.
Department of Orthopaedic Surgery, Rutgers New Jersey Medical School, 33 Overlook Rd, Suite 305, Summit, NJ 07901, USA.
Spine J. 2019 Apr;19(4):755-761. doi: 10.1016/j.spinee.2018.09.008. Epub 2018 Sep 18.
To characterize the gross, histologic, and systemic changes caused by implantation of metal fragments commonly used in commercial bullets into the intervertebral disc.
Long-term complications of retained bullet fragments in the spine have been documented in the literature; however, the impact of different metal projectiles on the intervertebral disc has not been described. This study was performed to assess the local effects of the metallic bullet fragments on the intervertebral disc and their systemic effects regarding metal ion concentrations in serum and solid organs.
Animal Model Study.
Funding for this project was provided by the Cervical Spine Research Society in the amount of $10,000. Copper, lead, and aluminum alloys from commercially available bullets were surgically implanted into sequential intervertebral discs in the lumbar spine of six canines. Kirschner wire implantation and a sham operation were performed as controls. Radiographs were performed to confirm the location of the bullets. Animals were sacrificed at 4, 6, and 9 months postimplantation. Whole blood, plasma, cerebrospinal fluid, kidney tissue, and liver tissue samples were analyzed for copper and lead concentrations. Histologic and gross samples were examined at the time of sacrifice.
Significant tissue reactions were noted in the discs exposed to copper and lead. Copper resulted in significantly more severe disc degeneration than either the lead or aluminum alloy. In the short interval follow-up of this study, no statistically significant trend was observed in whole blood, plasma, cerebrospinal fluid, and tissue levels.
This study demonstrates that the canine intervertebral disc is differentially susceptible to metallic fragments depending on the composition. Trends were noted for increasing levels of lead and copper in liver tissue samples although statistical significance could not be reached due to short time interval and small sample size. The metallic composition of retained fragments can be a determining factor in deciding on surgical intervention.
描述商业子弹中常用金属碎片植入椎间盘引起的大体、组织学和全身变化。
文献中已经记录了脊柱内残留子弹碎片的长期并发症；然而，不同金属弹丸对椎间盘的影响尚未描述。本研究旨在评估金属子弹碎片对椎间盘的局部影响及其对血清和实体器官中金属离子浓度的全身影响。
动物模型研究。
该项目的资金由颈椎研究学会提供，金额为 10,000 美元。来自市售子弹的铜、铅和铝合金被手术植入六只犬的腰椎的连续椎间盘。进行克氏针植入和假手术作为对照。进行 X 光检查以确认子弹的位置。动物在植入后 4、6 和 9 个月时被处死。对全血、血浆、脑脊液、肾组织和肝组织样本进行铜和铅浓度分析。在处死时检查组织学和大体样本。
暴露于铜和铅的椎间盘出现明显的组织反应。铜导致的椎间盘退变明显比铅或铝合金更严重。在这项研究的短期随访中，全血、血浆、脑脊液和组织水平均未观察到统计学上显著的趋势。
本研究表明，犬椎间盘对金属碎片的易感性取决于金属碎片的组成。尽管由于时间间隔短和样本量小，无法达到统计学意义，但在肝组织样本中观察到铅和铜水平升高的趋势。残留碎片的金属成分可能是决定是否进行手术干预的一个决定因素。
