O'Donnell R J, Deutsch T F, Flotte R J, Lorente C A, Tomford W W, Mankin H J, Schomacker K T
Department of Orthopaedics, University of Washington School of Medicine, Seattle 98195, USA.
J Orthop Res. 1996 Jan;14(1):108-13. doi: 10.1002/jor.1100140118.
Massive cortical autografts and allografts have been found to incorporate into host bone very slowly and thus are subject to complications such as fatigue fracture and infection. In order to understand and improve the process of osteogenesis in these types of bone grafts, a new experimental model was developed using bone discs from rat calvaria prepared by demineralization and drilling of 0.5 mm diameter holes with a pulsed, 2.94 microns wavelength Erbium:Yttrium-Aluminum-Garnet laser. Four types of bone discs were analyzed: untreated (Type I), demineralized (Type II), laser-ablated (Type III), and laser-ablated then demineralized (Type IV). The discs were transplanted into a subcutaneous site in adult Sprague-Dawley rats and followed for as long as 6 weeks. Histologic analysis of the discs at weekly intervals with use of hematoxylin and eosin staining confirmed the presence of new bone growth in Type-II and Type-IV discs. The amount of new bone growth in each disc was estimated by determining the mineral x-ray attenuation coefficient, which is proportional to mineral density, from digitized radiographs of the discs. The results showed that the processes of demineralization (P < 0.001) and laser ablation with demineralization (p < 0.05) were both significant in enhancing new bone growth in this model. This study demonstrated that osteoinduction can be fostered in cortical bone through the processes of demineralization and laser ablation. To the extent that laser ablation may allow maintenance of structural integrity while altering the surface geometry in such a way as to promote ingrowth of new bone, this experimental model represents an advance in understanding how osteogenesis in cortical bone grafts might be improved.
大量的皮质骨自体移植和异体移植已被发现，其与宿主骨的融合非常缓慢，因此容易出现诸如疲劳骨折和感染等并发症。为了了解并改善这类骨移植中的骨生成过程，开发了一种新的实验模型，该模型使用通过脱矿质处理及用波长为2.94微米的脉冲铒:钇铝石榴石激光钻出直径0.5毫米的孔而制备的大鼠颅骨骨盘。分析了四种类型的骨盘：未处理的（I型）、脱矿质的（II型）、激光消融的（III型）以及先激光消融然后脱矿质的（IV型）。将这些骨盘移植到成年斯普拉格-道利大鼠的皮下部位，并持续观察长达6周。每周使用苏木精和伊红染色对骨盘进行组织学分析，证实II型和IV型骨盘中存在新骨生长。通过从骨盘的数字化射线照片中确定与矿物质密度成正比的矿物质X射线衰减系数，来估计每个骨盘中新骨生长的量。结果表明，脱矿质过程（P < 0.001）和脱矿质后激光消融过程（p < 0.05）在促进该模型中的新骨生长方面均具有显著意义。本研究表明，通过脱矿质和激光消融过程可以促进皮质骨中的骨诱导。就激光消融可能在改变表面几何形状以促进新骨向内生长的同时允许维持结构完整性而言，该实验模型代表了在理解如何改善皮质骨移植中的骨生成方面的一项进展。
