DESIGNED DEGRADABLE INTERBODY CAGES

描述(申请人提供)：目前矫正脊柱畸形和治疗伴有或不伴有神经根病的间盘源性轴性背痛的金标准手术是节段性脊柱融合术。目前，美国每年进行的脊柱融合术超过25万例。然而，目前的融合方法存在明显的缺陷，包括下沉、应力屏蔽以及不能直接输送骨形态发生蛋白(BMP)用于骨再生。我们建议开发可降解的聚合物融合器，其设计具有足够的机械完整性，以承受手术植入和脊柱负荷，同时为骨融合提供BMP的定向输送。具体地说，我们将通过计算优化承载和定向渗透性要求的设备设计，使用固体自由形状制造(SFF)技术由可降解聚合物制造融合器，并在尤卡坦小型猪脊柱融合术模型中进行体内测试，从而创建和测试可降解脊柱融合器原型，以满足这些承载和生物因子输送要求。我们假设，优化可降解脊柱椎间融合器以满足初始和中期负重以及定向生物因子输送的要求，将提供比现有可降解融合器更好的关节融合性，这些可降解融合器是由以前用于钛融合器的设计制造的。这一全球设计假设将通过以下三个具体目标进行检验：具体目标1：脊柱融合器的计算优化。具体目标2：器件制造和体外评价。具体目标3：在活体尤卡坦小型猪模型中测试融合性能。最终结果将验证所设计的可降解融合装置是否提供了比传统设计更好的融合结果，更广泛地说，优化方法是否可以用于提高其他骨骼重建装置的性能。

DESCRIPTION (provided by applicant): The current gold standard surgical intervention for spinal deformity correction and for discogenic axial back pain with or without concomitant radiculopathy is a segmental spinal fusion. Currently, over 250,000 spine fusions are performed yearly in the US. However, current fusion approaches suffer from significant drawbacks including subsidence, stress shielding, and the inability to direct delivery of bone morphogenic protein (BMP) for bone regeneration. We propose to develop degradable polymeric fusion cages that are designed to have sufficient mechanical integrity for withstanding surgical implantation and spinal loads, while at the same time providing directed delivery of BMP for bone fusion. Specifically, we will create and test prototype interbody degradable spinal fusion cages to meet these load bearing and biofactor delivery requirements by computationally optimizing device design for both load carrying and directed permeability requirements, fabricating the cages from degradable polymer using Solid Free-Form Fabrication (SFF) techniques, and testing these in vivo in a Yucatan minipig spine fusion model. We hypothesize that optimizing degradable spine interbody fusion cages to meet both the initial and the intermediate- term load carry as well as directed biofactor delivery requirements will provide superior arthrodesis compared to current degradable cages fabricated from designs previously used for titanium cages. This global design hypothesis will be tested through the following 3 specific aims: Specific Aim 1: Computational Optimization of Spinal Fusion Cages. Specific Aim 2: Device Fabrication and In Vitro Evaluation. Specific Aim 3: Test Fusion Performance in an In Vivo Yucatan minipig Model. The end result will verify if the designed degradable fusion device provides superior fusion results compared to conventional designs, and more broadly, whether the optimization approach could be utilized to improve performance of other skeletal reconstruction devices.