Cahill David W, Martin George J, Hajjar Michael V, Sonstein William, Graham Lloyd B, Engelman Robert W
Department of Neurosurgery, College of Medicine, University of South Florida, Tampa, Florida 33606, USA.
J Neurosurg. 2003 Mar;98(2 Suppl):195-201. doi: 10.3171/spi.2003.98.2.0195.
The authors conducted a pilot study to determine whether a bioresorbable intervertebral fusion device composed of 85/15 polylactide-polyglycolide (PLA-PGA) copolymer packed with bone autograft is a suitable alternative to promote arthrodesis after anterior cervical discectomy (ACD) in a caprine model.
The caprine cervical spine model has been used to evaluate interbody healing and fusion after application of bone grafts and instrumentation. Whether a bioresorbable device is suitable for facilitating intervertebral bone union has not been determined. Twelve goats underwent two-level ACD and fusion; eight received bioresorbable cages packed with autologous bone, and four received autologous bone alone. Goats were maintained without an orthosis and after 12 weeks underwent physical, radiographic, and histological evaluation. Cages had structurally degraded, and two had become extruded. Stable intervertebral union developed in three (19%) of 16 cage-implanted interspaces, and one (14%) of seven bone autograft-implanted interspaces; each was judged manually to be rigid (Grade 2), radiographically to be bridged by new osseous densities (Grade 2), and histologically to have marked new bone formation (Grade 3). A primarily fibrous union, however, stabilized the cage-implanted interspaces, and eight (50%) had developed a 4 to 6-mm foreign body granuloma. These interposed soft tissues were not present in the stable autologous bone-implanted interspace, which had successfully become fused.
Interbody cages composed of 85/15 PLA-PGA copolymer contributed to a stable fibrous union, degraded. and produced granuloma after 12 weeks. Additional evaluations are necessary to determine whether other copolymer mixtures, or other bioresorbable materials, can contribute to an arthodesis without deleterious consequences.
作者进行了一项初步研究，以确定由85/15聚乳酸-聚乙醇酸（PLA-PGA）共聚物填充自体骨组成的生物可吸收椎间融合器是否是促进山羊模型颈椎前路椎间盘切除术后（ACD）椎间融合的合适替代物。
山羊颈椎模型已用于评估应用骨移植和器械后的椎间愈合和融合情况。生物可吸收装置是否适合促进椎间骨融合尚未确定。12只山羊接受了两级ACD和融合手术；8只接受了填充自体骨的生物可吸收椎间融合器，4只仅接受了自体骨。山羊未佩戴矫形器，12周后进行体格、影像学和组织学评估。椎间融合器结构已降解，2个已脱出。16个植入椎间融合器的间隙中有3个（19%）形成了稳定的椎间融合，7个植入自体骨的间隙中有1个（14%）形成了稳定的椎间融合；每个间隙经手动判断为坚硬（2级），影像学显示有新骨密度桥接（2级），组织学显示有明显的新骨形成（3级）。然而，主要为纤维性融合稳定了植入椎间融合器的间隙，8个（50%）间隙出现了4至6毫米的异物肉芽肿。在成功融合的稳定的自体骨植入间隙中不存在这些插入的软组织。
由85/15 PLA-PGA共聚物组成的椎间融合器有助于形成稳定的纤维性融合，12周后降解并产生肉芽肿。需要进行更多评估，以确定其他共聚物混合物或其他生物可吸收材料是否能促进椎间融合而不产生有害后果。
