Preclinical Surgical Research Laboratory, C. Wayne McIlwraith Translational Medicine Institute, Department of Clinical Sciences, Colorado State University, Fort Collins, Colorado.
Orthopaedic Bioengineering Research Laboratory, Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado.
J Orthop Res. 2021 Apr;39(4):780-787. doi: 10.1002/jor.24835. Epub 2020 Sep 4.
The knee is the most common site for translational cartilage research in sheep, though topographic features of articular cartilage across surfaces are unspecified. We aimed to characterize the mechanical, morphological, and biochemical properties of articular cartilage across ovine knee surfaces and document variations between and within surface locations. Regions of interest (ROIs) were delineated across surfaces of 10 healthy ovine knees. Articular cartilage at each ROI was measured for creep indentation, thickness, and glycosaminoglycan (GAG) and collagen content. Variables were compared between surface locations (trochlea, and lateral [LFC] and medial [MFC] femoral condyles) and between ROIs within each surface location. Correlations between variables were also assessed. Articular surface location had a significant effect on creep (P < .0001), thickness (P < .0001), and collagen (P = .0007), but not GAG (P = .28). Significant differences in percent creep between ROIs were found within the LFC (P < .0001), MFC (P < .0001), and trochlea (P = .0002). Cartilage thickness was different between ROIs within the LFC, MFC, and trochlea (all P < .0001). The LFC (P = .002) and trochlea (P = .01) each had significant differences in GAG between ROIs. Collagen content between ROIs was different within the LFC (P = .0003), MFC (P = .0005), and trochlea (P < .0001). Collagen content was correlated with thickness (r = -.55), percent creep (r = .47), and GAG (r = -.21). Percent creep was correlated with thickness (r = -.64) and GAG (r = -.19). Topographic variations in mechanical, morphological, and biochemical properties exist across knee cartilage surfaces in sheep. Recognition of this variability is important to optimize study protocols and improve accuracy of results.
膝关节是绵羊关节软骨转化研究中最常见的部位，尽管关节软骨的地形特征在各表面均未明确。我们旨在描述绵羊膝关节各表面关节软骨的力学、形态和生化特性，并记录各表面位置之间和内部的变化。在 10 个健康绵羊膝关节的各表面划定了感兴趣区域（ROI）。对每个 ROI 的关节软骨进行蠕变压痕、厚度和糖胺聚糖（GAG）和胶原含量测量。在表面位置（滑车，以及外侧 [LFC] 和内侧 [MFC] 股骨髁）之间以及每个表面位置内的 ROI 之间比较变量。还评估了变量之间的相关性。关节表面位置对蠕变（P < .0001）、厚度（P < .0001）和胶原（P = .0007）有显著影响，但对 GAG 没有影响（P = .28）。在 LFC（P < .0001）、MFC（P < .0001）和滑车（P = .0002）内的 ROI 之间发现了显著的百分比蠕变差异。LFC、MFC 和滑车内的 ROI 之间的软骨厚度也不同（均 P < .0001）。LFC（P = .002）和滑车（P = .01）之间的 ROI 之间 GAG 也有显著差异。LFC 内 ROI 之间的胶原含量不同（P = .0003）、MFC（P = .0005）和滑车（P < .0001）。胶原含量与厚度（r = -.55）、百分比蠕变（r = .47）和 GAG（r = -.21）相关。百分比蠕变与厚度（r = -.64）和 GAG（r = -.19）相关。绵羊膝关节软骨各表面存在力学、形态和生化特性的地形变化。认识到这种变异性对于优化研究方案和提高结果的准确性非常重要。
