BACKGROUND The effects of the posterior slope of the tibial prosthesis on unicompartmental knee arthroplasty have not been fully evaluated and controversies still exist. OBJECTIVE This study evaluates the effects of the posterior slope of the tibia on contact stresses in polyethylene inserts and articular cartilage using finite element analysis. METHODS We generated a computational model followed by the development of a posterior tibial slope (PTS) from -1° to 15° cases with increments of 2° PTS models. Using a validated finite element (FE) model, we investigated the influence of the changes in PTS on the contact stress in the medial polyethylene insert and lateral cartilage. The FE model's loading condition is level walking, a normal daily activity. RESULTS The contact stress increased on the lateral articular cartilage as the PTS increased. The contact stress on the polyethylene insert differed from the contact stress on the lateral articular cartilage, and it generally increased as the PTS decreased. However, in the initial stance phase when an axial force was exerted, it increased as the PTS increased. CONCLUSIONS Our results show that an offset of ±2° from the initial anatomical tibial slope does not biomechanically affect the outcome.

中文翻译：

---

胫骨后倾斜对单室膝关节置换术的生物力学影响有限元分析。

背景技术胫骨假体后倾斜对单室膝关节置换术的影响尚未得到充分评估，并且仍然存在争议。目的本研究使用有限元分析评估胫骨后坡对聚乙烯插入物和关节软骨接触应力的影响。方法我们生成了一个计算模型，随后将胫骨后倾斜（PTS）从-1°扩展到15°，并以2°PTS模型递增。使用经过验证的有限元（FE）模型，我们研究了PTS的变化对内侧聚乙烯插入物和外侧软骨中接触应力的影响。有限元模型的负载条件是水平行走，这是正常的日常活动。结果随着PTS的增加，外侧关节软骨的接触应力增加。聚乙烯插入物上的接触应力不同于外侧关节软骨上的接触应力，并且通常随着PTS的降低而增加。但是，在初始姿态阶段，当施加轴向力时，它会随着PTS的增加而增加。结论我们的结果表明，与初始解剖胫骨倾斜度相差±2°不会对预后产生生物力学影响。