Departments of Bioengineering and Orthopaedic Surgery, Engineering Center for Orthopaedic Research Excellence (E-CORE), Colleges of Engineering and Medicine, University of Toledo, 5046 NI, MS 303, Toledo, OH, 43606, USA.
Department of Orthopedic Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, USA.
Eur Spine J. 2021 Aug;30(8):2351-2359. doi: 10.1007/s00586-021-06863-8. Epub 2021 May 22.
This study's objective was to assess biomechanical parameters across fused and contralateral sacroiliac joints (SIJs) and implants during all spinal motions for both sexes. Various SIJ implant devices on the market are used in minimally invasive surgeries. These implants are placed across the joint using different surgical approaches. The biomechanical effects of fusion surgical techniques in males and females have not been studied.
The validated finite element models of a male, and a female spine-pelvis-femur were unilaterally instrumented across the SIJ using three screws for two SIJ implants, half threaded and fully threaded screws placed laterally and posteriorly to the joint, respectively.
Motion and peak stress data at the SIJs showed that the female model exhibited lower stresses and higher reduction in motion at the contralateral SIJ in all motions than the male model predictions with 84% and 71% reductions in motion and stresses across the SIJ.
Implants exhibited higher stresses in the female model compared to the male model. However, chances of SIJ implant failure in the female patients are still minimal, based on the calculated factor of safety which is still very high. Both lateral and posterior surgical approaches were effective in both sexes; however, the lateral approach may provide a better biomechanical response, especially for females. Moreover, implant design characteristics did not make a difference in the implants' biomechanical performance. SIJ stabilization was primarily provided by the implants which were the farthest from the sacrum rotation center.
本研究旨在评估男女两性所有脊柱运动时融合和对侧骶髂关节（SIJ）及植入物的生物力学参数。市场上有各种 SIJ 植入物设备用于微创手术。这些植入物通过不同的手术方法放置在关节上。融合手术技术对男性和女性的生物力学影响尚未得到研究。
使用三个螺钉对男性和女性脊柱-骨盆-股骨的经过验证的有限元模型进行单侧 SIJ 器械固定，两种 SIJ 植入物分别使用半螺纹和全螺纹螺钉横向和向后放置在关节处。
SIJ 的运动和峰值应力数据表明，与男性模型预测相比，女性模型在所有运动中对侧 SIJ 的应力较低，运动减少 84%，SIJ 运动减少 71%。
与男性模型相比，女性模型中的植入物显示出更高的应力。然而，根据计算的安全系数，女性患者的 SIJ 植入物失败的可能性仍然很小，该安全系数仍然非常高。两种侧向和后向手术方法在两性中均有效；然而，侧向方法可能提供更好的生物力学反应，尤其是对女性。此外，植入物设计特性对植入物的生物力学性能没有影响。SIJ 稳定主要由离骶骨旋转中心最远的植入物提供。
