Department of Neurosurgery, Faculty of Medicine, University of Freiburg, Breisacher Str. 64, Freiburg 79106, Germany.
Stryker Leibinger GmbH & Co. KG, Bötzinger Straße 41, Freiburg 79111, Germany.
Biomater Adv. 2022 May;136:212754. doi: 10.1016/j.bioadv.2022.212754. Epub 2022 Mar 17.
Current alloplastic materials such as PMMA, titanium or PEEK don't show relevant bone ingrowth into the implant when used for cranioplasty, ceramic implants have the drawback being brittle. New materials and implant designs are urgently needed being biocompatible, stable enough for cranioplasty and stimulating bone formation. In an in vivo critical size sheep model circular cranial defects (>2.4 cm) were covered with three different types of a 3D-printed porous titanium scaffolds with multidirectional, stochastically distributed architecture (uncoated scaffold, hydroxyapatite-coated scaffold, uncoated scaffold filled with a calcium phosphate bone cement paste containing β-TCP granules). An empty titanium mesh served as control. Among the different investigated setups the hydroxyapatite-coated scaffolds showed a surprisingly favourable performance. Push-out tests revealed a 2.9 fold higher force needed in the hydroxyapatite-coated scaffolds compared to the mesh group. Mean CT density at five different points inside the scaffold was 2385HU in the hydroxyapatite-coated group compared to 1978HU in the uncoated scaffold at nine months. Average lateral bone ingrowth after four months in the hydroxyapatite-coated scaffold group was up to the implant center, 12.1 mm on average, compared to 2.8 mm in the control group covered with mesh only. These properties make the investigated scaffold with multidirectional, stochastically distributed structure superior to all products currently on the market. The study gives a good idea of what future materials for cranioplasty might look like.
目前用于颅骨修复的同种异体材料如 PMMA、钛或 PEEK 都不能使植入物与骨骼有相关的长入，陶瓷植入物的缺点是脆性。需要紧急寻找新的材料和植入物设计，这些材料和植入物设计需要具有生物相容性、足够稳定以用于颅骨修复并能刺激骨形成。在一个体内临界尺寸绵羊模型中，用三种不同类型的 3D 打印多孔钛支架覆盖圆形颅骨缺损（>2.4cm），这些支架具有多方向、随机分布的结构（未涂层支架、羟基磷灰石涂层支架、未涂层支架填充含有β-TCP 颗粒的磷酸钙骨水泥糊）。一个空钛网作为对照。在不同的研究方案中，羟基磷灰石涂层支架的表现出人意料地好。推出试验显示，羟基磷灰石涂层支架的所需力比网组高 2.9 倍。在羟基磷灰石涂层支架组中，在支架内的五个不同点的平均 CT 密度为 2385HU，而在未涂层支架中为 9 个月时的 1978HU。在羟基磷灰石涂层支架组中，四个月后侧向骨长入的平均值在支架中心达到 12.1mm，而仅用网覆盖的对照组为 2.8mm。这些特性使具有多方向、随机分布结构的研究支架优于目前市场上的所有产品。该研究很好地展示了未来颅骨修复材料的样子。
