The effect of the radial head and prosthetic radial head replacement on resisting valgus stress at the elbow.
The effect of the radial head and prosthetic radial head replacement on resisting valgus stress at the elbow.
复制标题
桡骨头和假体桡骨头置换对抵抗肘部外翻应力的影响。
作者：
Pribyl Cr;M. Kester;S. Cook;Edmunds Jo;M. E. Brunet
在解剖状态下、桡骨头切除术后以及插入硅橡胶和聚甲基丙烯酸甲酯（PMMA）桡骨头置换物后，对5个新鲜的未防腐肘关节进行了外翻应力抵抗力测试。桡骨头切除后，外翻应力的抵抗力平均降低28%。与相应屈曲角度的完好肘关节值相比，PMMA和Silastic植入物分别平均恢复了86%和78%的外翻刚度。旋前、旋后和前臂中性旋转测试表明外翻刚度无差异。对于每个肘关节，外翻应力阻力在完全伸展时最大，与相应的完全伸展值相比，在所有其他屈曲角度下下降约30%。这些数据支持桡骨头作为体外肘关节外翻应力稳定器的概念。此外，该数据证明了当前桡骨头置换系统在恢复该生物力学功能方面的无效性，并表明使用更硬的植入物材料可能有利于抵抗外翻应力。附加试验旨在确定更硬植入物在临床和生物学水平上的性能。
Five fresh nonembalmed elbows were tested for resistance to valgus stress in their anatomic state, after radial head resection, and after insertion of Silastic and polymethylmethacrylate (PMMA) radial head replacements. The resistance to valgus stress was found to be reduced an average of 28% after radial head resection. The PMMA and Silastic implants restored valgus stiffness an average of 86% and 78% respectively, as compared to intact elbow values for corresponding flexion angles. Testing in pronation, supination and neutral forearm rotation demonstrated no difference in valgus stiffness. For each elbow, resistance to valgus stress was greatest at full extension and dropped approximately 30% at all other flexion angles as compared to corresponding full extension value. These data support the concept of the radial head as a stabilizer to valgus stress in the in vitro elbow. Further, this data demonstrated the ineffectiveness of current radial head replacement systems in restoring this biomechanical function and suggest that the use of a stiffer implant material may be beneficial in resisting valgus stress. Additional testing is indicated to determine the performance of a stiffer implant at the clinical and biological levels.