Frazer Lance L, Santschi Elizabeth M, Fischer Kenneth J
Bioengineering Graduate Program, University of Kansas, Lawrence, KS, USA.
College of Veterinary Medicine, Department of Clinical Sciences, Kansas State University, Manhattan, KS, USA.
Med Eng Phys. 2017 Oct;48:158-167. doi: 10.1016/j.medengphy.2017.06.019. Epub 2017 Jul 6.
Subchondral lucency (SCL), also referred to as subchondral bone cysts, can cause clinical problems in horses and humans. In humans, SCLs occur in youths and adolescents [1] due to mechanical factors (often related to athletics) and in skeletally mature individuals secondary to osteoarthritis (OA). In horses, SCL most commonly occurs in the medial femoral condyle (MFC) of growing horses (without OA), and causes lameness. The cause of equine SCL is debated, but bone trauma due to overload is the likely mechanism. Investigating the biomechanics of the healthy and cystic MFC is important to understand cyst growth and to provide a foundation for new treatment strategies. We hypothesize that SCL alters the mechanical environment of surrounding bone, which in the presence of continued loading, may lead to enlargement of the SCL. In this study, we developed and validated a finite element model of an equine stifle joint and investigated the stresses associated with varying sizes of SCL. We found substantial differences in tensile and shear stress at various stages of SCL development that suggest further bone damage leading to SCL enlargement. These data provide a first step in understanding of the altered mechanics of subchondral bone surrounding a SCL. Additional studies may provide the basis for improved treatment strategies for SCL in young horses, and may improve the understanding of SCL in humans.
软骨下透亮区（SCL），也被称为软骨下骨囊肿，可在马和人类身上引发临床问题。在人类中，SCL在青少年中因机械因素（通常与运动有关）而出现，在骨骼成熟个体中则继发于骨关节炎（OA）。在马身上，SCL最常见于生长中的马（无OA）的内侧股骨髁（MFC），并导致跛行。马SCL的病因存在争议，但过载导致的骨创伤可能是其机制。研究健康和囊性MFC的生物力学对于理解囊肿生长以及为新的治疗策略提供基础很重要。我们假设SCL会改变周围骨骼的力学环境，在持续负荷的情况下，这可能导致SCL扩大。在本研究中，我们开发并验证了马膝关节的有限元模型，并研究了与不同大小SCL相关的应力。我们发现在SCL发展的各个阶段，拉伸和剪切应力存在显著差异，这表明会进一步导致骨骼损伤，进而导致SCL扩大。这些数据为理解SCL周围软骨下骨力学改变迈出了第一步。更多研究可能为幼马SCL的改进治疗策略提供基础，并可能增进对人类SCL的理解。
