Uppsala University, Department of Orthopedics, Uppsala, Sweden.
J Biomech. 2012 Apr 30;45(7):1156-60. doi: 10.1016/j.jbiomech.2012.02.004. Epub 2012 Mar 2.
In lower cancellous apparent bone density, it can be difficult to achieve adequate screw fixation and hence stable fracture fixation. Different strategies have been proposed, one of them is through augmentation using calcium phosphate cement in the region at or close to the screw thread itself. To support the hypothesis of an improved screw fixation technique by augmentation of the bone surrounding the implanted screw, in vivo biomechanical and densitometric studies are performed on rabbit specimen where normal and simulated weak bone quality are considered. In particular, the evolution of screw stability till 12 weeks following the implantation is quantified. A statistical significance in the pull out force for augmented versus non-augmented screws was found for the shorter time periods tested of ≤ 5 days whilst the pull out force was found to increase with time for both augmented and non-augmented screws during the 12 week course of the study. The results of the study demonstrate that the use of an injectable calcium phosphate cement which sets in vivo can significantly improve screw pull out strength at and after implantation for normal and simulated weak bone quality.
在较低的松质骨骨密度中，很难实现足够的螺钉固定，从而无法稳定骨折固定。已经提出了不同的策略，其中之一是通过在螺钉螺纹本身或附近的区域使用磷酸钙骨水泥进行增强。为了支持通过增强植入螺钉周围的骨来改善螺钉固定技术的假设，对兔标本进行了体内生物力学和密度计研究，其中考虑了正常和模拟的骨质疏松骨质量。特别是，定量研究了植入后 12 周内螺钉稳定性的演变。在测试时间≤5 天的较短时间内，发现增强型螺钉与非增强型螺钉的拔出力具有统计学意义，而在研究的 12 周过程中，增强型和非增强型螺钉的拔出力均随时间增加。研究结果表明，使用可在体内注射的可注射磷酸钙骨水泥可以显著提高正常和模拟骨质疏松骨质量的螺钉拔出强度。
