Vio War Adeline S, Kumar Neeraj, Chanda Souptick
Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781 039, Assam, India.
Med Biol Eng Comput. 2023 Jun;61(6):1473-1488. doi: 10.1007/s11517-023-02801-6. Epub 2023 Feb 10.
The success of cementless hip stems depends on the primary stability of the implant quantified by the amount of micromotion at the bone-stem interface. Most finite element (FE)-based preclinical studies on post-surgery stem stability rely on static analysis. Hence, the effect of dynamic gait loading on bone-stem relative micromotion remains virtually unexplored. Furthermore, there is a paucity of research on the primary stability of grooved stems as opposed to plain stem design. The primary aim of this FE study was to understand whether transient dynamic gait had any incremental effect on the net micromotion results and to further draw insights into the effects of grooved texture vis-à-vis a plain model on micromotion and proximal load transfer in host bone. Two musculoskeletal loading regimes corresponding to normal walking (NW) and stair climbing (SC) were considered. Although marginally improved load transfer was predicted proximally for the grooved construct under static loading, the micromotion values (max: NW ~ 7 μm; SC ~ 10 μm) were found to be considerably less in comparison to plain stem (max: NW ~ 50 μm; SC ~ 20 μm). For both physiological load cases, a significant surge in micromotion values was predicted in dynamic analyses as opposed to static analyses for the grooved stem (~ 390% greater). For the plain model, the increase in these values from static to dynamic loading is relatively moderate yet clinically significant (~ 230% greater). This suggests that the qualitative similarities notwithstanding, there were significant dissimilarities in the quantitative trends of micromotion for different cases under both analyses.
非骨水泥型髋关节柄的成功取决于植入物的初始稳定性，该稳定性通过骨 - 柄界面处的微动程度来量化。大多数基于有限元（FE）的术后柄稳定性临床前研究依赖于静态分析。因此，动态步态负荷对骨 - 柄相对微动的影响实际上仍未得到探索。此外，与普通柄设计相比，关于带槽柄初始稳定性的研究较少。本有限元研究的主要目的是了解瞬态动态步态是否对净微动结果有任何增量影响，并进一步深入了解带槽纹理相对于普通模型对宿主骨微动和近端负荷转移的影响。考虑了两种对应于正常行走（NW）和爬楼梯（SC）的肌肉骨骼负荷情况。尽管在静态负荷下预测带槽结构近端的负荷转移略有改善，但与普通柄相比，微动值（最大值：NW约7μm；SC约10μm）要小得多（最大值：NW约50μm；SC约20μm）。对于两种生理负荷情况，动态分析预测带槽柄的微动值与静态分析相比有显著激增（约大390%）。对于普通模型，这些值从静态负荷到动态负荷的增加相对适中，但在临床上具有显著意义（约大230%）。这表明，尽管定性相似，但在两种分析下不同情况的微动定量趋势存在显著差异。
