Fischer Heilwig, Steffen Claudius, Schmidt-Bleek Katharina, Duda Georg N, Heiland Max, Rendenbach Carsten, Raguse Jan-Dirk
Department of Oral and Maxillofacial Surgery, Charité-Universitätsmedizin, Augustenburger Platz 1, 13353 Berlin, Germany.
Julius Wolff Institute and Berlin Institute of Health Center for Regenerative Therapies, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
Materials (Basel). 2022 Jan 27;15(3):982. doi: 10.3390/ma15030982.
Cranioplasty is a frequently performed procedure after craniectomy and includes several techniques with different materials. Due to high overall complication rates, alloplastic implants are removed in many cases. Lack of implant material osseointegration is often assumed as a reason for failure, but no study has proven this in cranioplasty. This study histologically evaluates the osteointegration of a computer-aided design and computer-aided manufacturing (CAD/CAM) titanium scaffold with an open mesh structure used for cranioplasty. A CAD/CAM titanium scaffold was removed due to late soft tissue complications 7.6 years after cranioplasty. The histological analyses involved the preparation of non-decalcified slices from the scaffold's inner and outer sides as well as a light-microscopic evaluation, including the quantification of the bone that had formed over the years. Within the scaffold pores, vital connective tissue with both blood vessels and nerves was found. Exclusive bone formation only occurred at the edges of the implant, covering 0.21% of the skin-facing outer surface area. The inner scaffold surface, facing towards the brain, did not show any mineralization at all. Although conventional alloplastic materials for cranioplasty reduce surgery time and provide good esthetic results while mechanically protecting the underlying structures, a lack of adequate stimuli could explain the limited bone formation found. CAD/CAM porous titanium scaffolds alone insufficiently osseointegrate in such large bone defects of the skull. Future research should investigate alternative routes that enable long-term osteointegration in order to reduce complication rates after cranioplasty. Opportunities could be found in mechano-biologically optimized scaffolds, material modifications, surface coatings, or other routes to sustain bone formation.
颅骨成形术是颅骨切除术后经常实施的一种手术，包括使用不同材料的多种技术。由于总体并发症发生率较高，许多情况下会移除异体植入物。植入材料缺乏骨整合常被认为是失败的原因，但在颅骨成形术中尚无研究证实这一点。本研究对一种用于颅骨成形术的具有开放网格结构的计算机辅助设计和计算机辅助制造（CAD/CAM）钛支架的骨整合进行了组织学评估。一个CAD/CAM钛支架在颅骨成形术后7.6年因晚期软组织并发症而被取出。组织学分析包括从支架内外侧制备未脱钙切片以及进行光学显微镜评估，包括对多年来形成的骨进行定量分析。在支架孔隙内，发现了含有血管和神经的活性结缔组织。仅在植入物边缘出现了排他性的骨形成，覆盖了面向皮肤的外表面面积的0.21%。面向大脑的支架内表面根本没有显示出任何矿化现象。尽管用于颅骨成形术的传统异体材料减少了手术时间，并在机械保护下层结构的同时提供了良好的美学效果，但缺乏足够的刺激可能解释了所发现的有限骨形成。单独的CAD/CAM多孔钛支架在颅骨如此大的骨缺损中骨整合不足。未来的研究应探索能够实现长期骨整合的替代途径，以降低颅骨成形术后的并发症发生率。在机械生物学优化的支架、材料改性、表面涂层或其他维持骨形成的途径中可能会找到机会。
