Putzer David, Egger Valentina, Pallua Johannes, Thaler Martin, Schmölz Werner, Nogler Michael
Experimental Orthopaedics, Department of Orthopaedics and Traumatology, Medical University of Innsbruck, Innsbruck, 6020, Austria.
Department of Surgery, Spital Zollikerberg, Zurich, 8125, Switzerland.
BMC Musculoskelet Disord. 2024 Dec 21;25(1):1058. doi: 10.1186/s12891-024-08148-9.
Cementoplasty has been successfully used for treating fractures in various parts of the human body, although the use in weight-bearing long bones is a subject of controversial debate. Strategies to improve the mechanical properties of polymethylmethacrylate-based bone cement (BC) comprise changing the chemical composition or the application of metal reinforcement strategies. In clinical practice reinforced bone cement is used despite biomechanical basic research regarding this topic being scare.
The aim of the present study was to evaluate the biomechanical properties of two different reinforcement strategies against non-reinforced polymethylmethacrylate-based BC subjected to bending stress.
In this controlled comparative laboratory analysis, we evaluated two types of reinforcement strategies in comparison to a control group (C). BC was reinforced with a Kirschner wire (group CW) or with a prestressed twinned steel cable (group CC); control group C was native polymethylmethacrylate-based BC. All the samples were prepared using a custom-made mould and underwent 4-point bending stress until fracture using a testing machine. Flexural strength, maximum strain, and Young's modulus were assessed for the three groups and compared using the Kruskal‒Wallis test.
The mean flexural strength in MPa was 48 ± 12 in C, 64 ± 6 in CW, and 63 ± 14 in CC. A significantly greater flexural strength of + 33% was found in both reinforced groups than in the C group (C vs. CW p = 0.011, C vs. CC p = 0.023). Regarding the flexural strength, no statistically significant difference could be found between the two reinforcement strategies CW and CC (p = 0.957). The maximum strain was 3.0% in C and CW and 3.8% in CC and no difference between the three groups was observed (p = 0.087). The Young's modulus in GPa was 2.7 for C, 2.8 for CW, and 2.4 for CC. The comparison of Young's module using the Kruskal-Wallis test showed no statistically significant difference between CC, CW and C (p = 0.051).
We detected an improvement in flexural strength in the reinforced groups. Both reinforcement through K-wire and prestressed cables promoted increased flexural strength. Furthermore, less material failure was observed with possible realignment and subsequent residual stability despite bone cement fracture. From a biomechanical view, the concept of macro metal reinforcement of osteoplasty is viable.
骨水泥成形术已成功用于治疗人体各个部位的骨折，尽管在负重长骨中的应用存在争议。改善聚甲基丙烯酸甲酯基骨水泥（BC）力学性能的策略包括改变化学成分或应用金属增强策略。在临床实践中，尽管关于这一主题的生物力学基础研究较少，但仍使用增强骨水泥。
本研究旨在评估两种不同增强策略与未增强的聚甲基丙烯酸甲酯基骨水泥在弯曲应力作用下的生物力学性能。
在这项对照比较实验室分析中，我们评估了两种增强策略，并与对照组（C）进行比较。骨水泥用克氏针增强（CW组）或用预应力双股钢缆增强（CC组）；对照组C为天然聚甲基丙烯酸甲酯基骨水泥。所有样本均使用定制模具制备，并使用试验机进行四点弯曲应力直至断裂。评估三组的弯曲强度、最大应变和杨氏模量，并使用Kruskal-Wallis检验进行比较。
C组的平均弯曲强度（MPa）为48±12，CW组为64±6，CC组为63±14。两个增强组的弯曲强度均显著高于C组，增幅为+33%（C组与CW组比较，p = 0.011；C组与CC组比较，p = 0.023）。关于弯曲强度，两种增强策略CW和CC之间未发现统计学显著差异（p = 0.957）。C组和CW组的最大应变为3.0%，CC组为3.8%，三组之间未观察到差异（p = 0.087）。C组的杨氏模量（GPa）为2.7，CW组为2.8，CC组为2.4。使用Kruskal-Wallis检验比较杨氏模量，CC组、CW组和C组之间未发现统计学显著差异（p = 0.051）。
我们检测到增强组的弯曲强度有所提高。通过克氏针和预应力缆索增强均能提高弯曲强度。此外，尽管骨水泥发生骨折，但通过可能的重新排列和随后的残余稳定性观察到材料破坏较少。从生物力学角度来看，骨成形术的宏观金属增强概念是可行的。
