Hoffmeier Konrad L, Hofmann Gunther O, Mückley Thomas
Universitätsklinikum Jena, Department of Trauma, Hand and Reconstructive Surgery, ErlangerAllee 101, D-07747 Jena, Germany.
Clin Biomech (Bristol). 2009 Oct;24(8):637-41. doi: 10.1016/j.clinbiomech.2009.06.004. Epub 2009 Jul 24.
Currently available polyaxial locking plates represent the consequent enhancement of fixed-angle, first-generation locking plates. In contrast to fixed-angle locking plates which are sufficiently investigated, the strength of the new polyaxial locking options has not yet been evaluated biomechanically. This study investigates the mechanical strength of single polyaxial interfaces of different volar radius plates.
Single screw-plate interfaces of the implants Palmar 2.7 (Königsee Implantate und Instrumente zur Osteosynthese GmbH, Allendorf, Germany), VariAx (Stryker Leibinger GmbH & Co. KG, Freiburg, Germany) und Viper (Integra LifeSciences Corporation, Plainsboro, NJ, USA) were tested by cantilever bending. The strength of 0 degrees, 10 degrees and 20 degrees screw locking angle was obtained during static and dynamic loading.
The Palmar 2.7 interfaces showed greater ultimate strength and fatigue strength than the interfaces of the other implants. The strength of the VariAx interfaces was about 60% of Palmar 2.7 in both, static and dynamic loading. No dynamic testing was applied to the Viper plate because of its low ultimate strength. By static loading, an increase in screw locking angle caused a reduction of strength for the Palmar 2.7 and Viper locking interfaces. No influence was observed for the VariAx locking interfaces. During dynamic loading; angulation had no influence on the locking strength of Palmar 2.7. However, reduction of locking strength with increasing screw angulation was observed for VariAx.
The strength of the polyaxial locking interfaces differs remarkably between the examined implants. Depending on the implant an increase of the screw locking angle causes a reduction of ultimate or fatigue strength, but not in all cases a significant impact was observed.
目前可用的多轴锁定钢板是对第一代角度固定锁定钢板的进一步改进。与已得到充分研究的角度固定锁定钢板不同，新型多轴锁定钢板的强度尚未进行生物力学评估。本研究调查了不同掌侧桡骨钢板单多轴界面的机械强度。
通过悬臂弯曲试验对Palmar 2.7（德国阿伦多夫市Königsee Implantate und Instrumente zur Osteosynthese GmbH公司）、VariAx（德国弗赖堡市Stryker Leibinger GmbH & Co. KG公司）和Viper（美国新泽西州普林斯顿市Integra LifeSciences Corporation公司）三种植入物的单螺钉 - 钢板界面进行测试。在静态和动态加载过程中获取0度、10度和20度螺钉锁定角度下的强度。
Palmar 2.7界面显示出比其他植入物的界面更高的极限强度和疲劳强度。在静态和动态加载中，VariAx界面的强度约为Palmar 2.7的60%。由于Viper钢板的极限强度较低，未对其进行动态测试。在静态加载下，Palmar 2.7和Viper锁定界面的螺钉锁定角度增加会导致强度降低。VariAx锁定界面未观察到影响。在动态加载过程中，角度对Palmar 2.7的锁定强度没有影响。然而，观察到VariAx随着螺钉角度增加锁定强度降低。
在所检查的植入物中，多轴锁定界面的强度有显著差异。根据植入物的不同，螺钉锁定角度的增加会导致极限强度或疲劳强度降低，但并非在所有情况下都观察到显著影响。
