Institute of Medical and Biological Engineering, School of Mechanical Engineering, University of Leeds, Leeds, United Kingdom.
Wrightington Wigan and Leigh NHS Trust, Wigan, United Kingdom.
PLoS One. 2022 Aug 18;17(8):e0272264. doi: 10.1371/journal.pone.0272264. eCollection 2022.
Different hip pathologies can cause geometric variation of the acetabulum and femoral head. These variations have been considered as an underlying mechanism that affects the tribology of the natural hip joint and changes the stress distribution on the articular surface, potentially leading to joint degradation. To improve understanding of the damage mechanisms and abnormal mechanics of the hip joint, a reliable in-vitro methodology that represents the in vivo mechanical environment is needed where the position of the joint, the congruency of the bones and the loading and motion conditions are clinically relevant and can be modified in a controlled environment. An in vitro simulation methodology was developed and used to assess the effect of loading on a natural hip joint. Porcine hips were dissected and mounted in a single station hip simulator and tested under different loading scenarios. The loading and motion cycle consisted of a simplified gait cycle and three peak axial loading conditions were assessed (Normal, Overload and Overload Plus). Joints were lubricated with Ringer's solution and tests were conducted for 4 hours. Photographs were taken and compared to characterise cartilage surface and labral tissue pre, during and post simulation. The results showed no evidence of damage to samples tested under normal loading conditions, whereas the samples tested under overload and overload plus conditions exhibited different severities of tears and detachment of the labrum at the antero-superior region. The location and severity of damage was consistent for samples tested under the same conditions; supporting the use of this methodology to investigate further effects of altered loading and motion on natural tissue.
不同的髋关节疾病会导致髋臼和股骨头的几何形状发生变化。这些变化被认为是影响自然髋关节摩擦学的潜在机制，并改变关节表面的应力分布，从而导致关节退化。为了更好地理解髋关节的损伤机制和异常力学，需要一种可靠的体外方法来模拟体内的机械环境，其中关节的位置、骨骼的吻合度以及加载和运动条件都具有临床相关性，并可以在受控环境中进行修改。本文开发并使用了一种体外模拟方法来评估加载对自然髋关节的影响。将猪髋关节解剖并安装在单工位髋关节模拟器中，并在不同的加载情况下进行测试。加载和运动周期包括简化的步态周期，评估了三种峰值轴向加载条件（正常、过载和过载加）。关节用林格氏溶液润滑，测试持续 4 小时。拍摄照片并进行比较，以在模拟前、模拟中和模拟后对软骨表面和盂唇组织进行特征描述。结果表明，在正常加载条件下测试的样本没有损伤的证据，而在过载和过载加条件下测试的样本在前上区域显示出不同程度的盂唇撕裂和分离。在相同条件下测试的样本的损伤位置和严重程度一致；支持使用这种方法进一步研究改变加载和运动对自然组织的影响。
