Department of Orthopedic Oncology, Xi-jing Hospital, The Fourth Military Medical University, Xi'an 710032, China.
J Mater Sci Mater Med. 2011 Jun;22(6):1579-88. doi: 10.1007/s10856-011-4313-8. Epub 2011 Apr 13.
The objective of this study was to compare the benefits of titanium 2448 (Ti2448) half-pin and titanium-6 aluminium-4 vanadium (TAV) half-pin on reducing pin loosening during external fracture fixation. Although having similar strength, Ti2448 half-pin had even lower elastic modules (33 GPa) when compared with TAV half-pin (110 GPa), which was similar to that of cortical bone (20 GPa). In the external fixation of tibial model fractures and canine cadaveric tibia fractures, Ti2448 half-pin had greater recoverable deformation and less stress concentration at the pin-bone interface in compression, torsion, and four-points bending test. Then, tibial fractures were created in 24 dogs and stabilized with four half-pins of either Ti2448 or TAV in each animal. At 4 and 8 weeks postoperatively, fracture healing and pin loosening was assessed by radiographic grading scale. The scores of Ti2448 group were significantly higher than those of TAV group. Micro-CT analysis also indicated larger quantity and higher quality of newly formed bone at pin-bone interface in Ti2448 group. Histology observation showed the newly formed bone integrated well into the threads of Ti2448 half-pins. In contrast, there was a layer of necrotic tissue between the bone tissue and TAV half-pin at pin-bone interface in TAV group. The extraction torque values of Ti2448 half-pins near the fracture line were significantly higher than those TAV pins. In conclusion, the Ti2448 half-pin with low elastic modulus could enhance osseointegration and reduce pin loosening when compared with TAV half-pin. It is a promising biomaterial for constructing external fixation system in clinical application.
本研究旨在比较钛 2448（Ti2448）半钉和钛 6 铝 4 钒（TAV）半钉在减少外部骨折固定中钉松动的益处。尽管强度相似，但 Ti2448 半钉的弹性模量（33GPa）甚至比 TAV 半钉（110GPa）更低，与皮质骨（20GPa）相似。在胫骨模型骨折和犬尸体胫骨骨折的外部固定中，Ti2448 半钉在压缩、扭转和四点弯曲试验中具有更大的可恢复变形和钉骨界面处更小的应力集中。然后，在 24 只狗中创建胫骨骨折，并在每只动物中用四个 Ti2448 或 TAV 半钉稳定。术后 4 周和 8 周，通过放射学分级量表评估骨折愈合和钉松动情况。Ti2448 组的评分明显高于 TAV 组。微 CT 分析还表明，Ti2448 组钉骨界面处新形成的骨量更大、质量更高。组织学观察显示，新形成的骨与 Ti2448 半钉的螺纹结合良好。相比之下，TAV 组钉骨界面处的骨组织与 TAV 半钉之间存在一层坏死组织。骨折线附近 Ti2448 半钉的拔出扭矩值明显高于 TAV 钉。总之，与 TAV 半钉相比，低弹性模量的 Ti2448 半钉可增强骨整合并减少钉松动。它是一种很有前途的生物材料，可用于临床应用中的外部固定系统构建。
