Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.
Department of Clinical Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
Ann Biomed Eng. 2022 Dec;50(12):1787-1797. doi: 10.1007/s10439-022-02991-4. Epub 2022 Jun 26.
In this study, we mapped and quantified changes of proteoglycan (PG) content and biomechanical properties in articular cartilage in which either blunt or sharp grooves had been made, both close to the groove and more remote of it, and at the opposing joint surface (kissing site) in equine carpal joints. In nine adult Shetland ponies, standardized blunt and sharp grooves were surgically made in the radiocarpal and middle carpal joints of a randomly chosen front limb. The contralateral control limb was sham-operated. At 39 weeks after surgery, ponies were euthanized. In 10 regions of interest (ROIs) (six remote from the grooves and four directly around the grooves), PG content as a function of tissue-depth and distance-to-groove was estimated using digital densitometry. Biomechanical properties of the cartilage were evaluated in the six ROIs remote from the grooves. Compared to control joints, whole tissue depth PG loss was found in sites adjacent to sharp and, to a larger extent, blunt grooves. Also, superficial PG loss of the surgically untouched kissing cartilage layers was observed. Significant PG loss was observed up to 300 µm (sharp) and at 500 µm (blunt) from the groove into the surrounding tissue. Equilibrium modulus was lower in grooved cartilage than in controls. Grooves, in particular blunt grooves, gave rise to severe PG loss close to the grooved sites and to mild degeneration more remote from the grooves in both sharply and bluntly grooved cartilage and at the kissing sites, resulting in loss of mechanical strength over the 9-month period.
在这项研究中，我们绘制并量化了马腕关节中靠近和远离软骨沟槽处以及对合关节面（吻接面）处的关节软骨中蛋白聚糖（PG）含量和生物力学特性的变化。在 9 匹成年设得兰矮马中，手术在随机选择的前肢的桡腕关节和中间腕关节中制造了标准的钝性和锐性沟槽。对侧对照肢体进行了假手术。手术后 39 周，马被安乐死。在 10 个感兴趣区域（ROI）（6 个远离沟槽，4 个直接围绕沟槽）中，使用数字密度计量法估计了 PG 含量作为组织深度和距沟槽距离的函数。在远离沟槽的 6 个 ROI 中评估了软骨的生物力学特性。与对照关节相比，在靠近锐性和更大程度上靠近钝性沟槽的部位发现了整个组织深度的 PG 损失。此外，还观察到手术未触及的吻接软骨层的浅层 PG 损失。从沟槽到周围组织中，在距沟槽 300 µm（锐性）和 500 µm（钝性）处观察到明显的 PG 损失。在沟槽软骨中，平衡模量低于对照组。沟槽，特别是钝性沟槽，在靠近沟槽的部位引起了严重的 PG 损失，在远离沟槽的部位引起了轻微的退行性变，在锐性和钝性沟槽以及吻接部位都引起了机械强度的丧失，这一过程持续了 9 个月。
