Osseointegrated implants transfer loads from native bone to a synthetic joint and can also function transdermally to provide a stable connection between the skeleton and the prostheses, eliminating many problems associated with socket prostheses. Additive manufacturing provides a cost-effective means to create patient-specific implants and allows for customized textures for integration with bone and other tissues. Our objective was to compare the osseointegration strength of two primary additive manufacturing methods of producing textured implants: electron beam melting (EBM) (mean Ra = 23 μm) and direct metal laser sintering (DMLS) (mean Ra = 10 μm). Due to spatial resolution, DMLS can produce surfaces with a roughness comparable to EBM. Two cohorts of Sprague-Dawley rats received bilateral, titanium implants in their distal femurs and were followed for 4 weeks. The first-cohort animals received EBM implants transcortically in one femur and a DMLS implant in the contralateral femur. The second cohort received DMLS implants (either fine textured or coarse textured to mimic EBM) in the intramedullary canal of each femur. Osseointegration was evaluated through mechanical testing and micro-computed tomography (bone volume fraction [BV/TV] and bone-implant contact [BIC]). The fixation strength of coarse textured implants provided superior interlocking relative to fine textured implants without affecting BV/TV or BIC in both cohorts. Coarse EBM implants in a transcortical model demonstrated an 85% increase in removal torque relative to the fine DMLS textured implants. The thrust load in the intramedullary model saw a 35% increase from fine to coarse DMLS implants.

中文翻译：

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通过电子束熔化和直接金属激光烧结制造的粗组织和细纹理植入物的骨整合。

骨整合植入物将负载从天然骨转移到合成关节，并且还可以透皮起作用，以在骨骼和假体之间提供稳定的连接，从而消除了与牙槽假体相关的许多问题。增材制造提供了一种具有成本效益的方式来创建患者特定的植入物，并允许定制的纹理与骨骼和其他组织整合。我们的目的是比较两种主要的制造纹理植入物的增材制造方法的骨整合强度：电子束熔化（EBM）（平均Ra = 23μm）和直接金属激光烧结（DMLS）（平均Ra = 10μm）。由于空间分辨率，DMLS可以产生具有与EBM相当的粗糙度的表面。两组Sprague-Dawley大鼠接受了双侧实验，在股骨远端股骨上植入钛，并随访4周。首批动物在一个股骨中经皮皮质地接受了EBM植入，在对侧股骨中接受了DMLS植入。第二个队列在每个股骨的髓内管中接受了DMLS植入物（精细纹理或粗糙纹理以模仿EBM）。通过机械测试和微型计算机断层扫描（骨体积分数[BV / TV]和骨-植入物接触[BIC]）评估骨整合。相对于精细纹理植入物，粗纹理植入物的固定强度提供了优异的互锁性，而不会影响两个队列中的BV / TV或BIC。经皮层模型中的粗EBM植入物显示出去除扭矩相对于DMLS纹理细化的植入物增加了85％。