Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland.
Osteoarthritis Cartilage. 2010 Mar;18(3):406-15. doi: 10.1016/j.joca.2009.11.007. Epub 2009 Nov 18.
The structure and composition of articular cartilage change during development and growth, as well as in response to varying loading conditions. These changes modulate the functional properties of cartilage. We studied maturation-related changes in the collagen network organization of cartilage as a function of tissue depth.
Articular cartilage from the tibial medial plateaus and femoral medial condyles of female New Zealand white rabbits was collected from six age-groups: 4 weeks (n=30), 6 weeks (n=30), 3 months (n=24), 6 months (n=24), 9 months (n=27) and 18 months (n=19). Collagen fibril orientation, parallelism (anisotropy) and optical retardation were analyzed with polarized light microscopy. Differences in the development of depth-wise collagen organization in consecutive age-groups and the two joint locations were compared statistically.
The collagen fibril network of articular cartilage undergoes significant changes during maturation. The most prominent changes in collagen architecture, as assessed by orientation, parallelism and retardation were noticed between the ages of 4 and 6 weeks in tibial cartilage and between 6 weeks and 3 months in femoral cartilage, i.e., orientation became more perpendicular-to-surface, and parallelism and retardation increased with changes being most prominent in the deep zone. At the age of 6 weeks, tibial cartilage had a more perpendicular-to-surface orientation in the middle and deep zones than femoral cartilage (P<0.001) and higher parallelism throughout the tissue depth (P<0.001), while femoral cartilage exhibited more parallel-to-surface orientation (P<0.01) above the deep zone after maturation. Optical retardation of collagen was higher in tibial than in femoral cartilage at the ages of 4 and 6 weeks (P<0.001), while at older ages, retardation below the superficial zone in the femoral cartilage became higher than in the tibial cartilage.
During maturation, there is a significant modulation of collagen organization in articular cartilage which occurs earlier in tibial than in femoral cartilage, and is most pronounced in the deep zone.
关节软骨的结构和组成在发育和生长过程中以及在响应不同的加载条件下会发生变化。这些变化调节软骨的功能特性。我们研究了软骨胶原网络组织的成熟相关变化，作为组织深度的函数。
从新西兰白兔的胫骨内侧平台和股骨内侧髁采集六个年龄组的关节软骨：4 周（n=30）、6 周（n=30）、3 个月（n=24）、6 个月（n=24）、9 个月（n=27）和 18 个月（n=19）。用偏光显微镜分析胶原纤维取向、平行度（各向异性）和光延迟。统计比较连续年龄组和两个关节位置之间深度方向胶原组织发育的差异。
关节软骨的胶原纤维网络在成熟过程中发生显著变化。在胫骨软骨中，从 4 至 6 周龄和在股骨软骨中从 6 周龄至 3 月龄之间，评估胶原结构的最明显变化是取向、平行度和延迟，即取向变得更垂直于表面，而平行度和延迟增加，最明显的变化发生在深层。在 6 周龄时，胫骨软骨的中深层区比股骨软骨更垂直于表面（P<0.001），整个组织深度的平行度更高（P<0.001），而成熟后股骨软骨的深层以上区更平行于表面（P<0.01）。4 至 6 周龄时，胫骨软骨的胶原光延迟比股骨软骨高（P<0.001），而在较老的年龄，股骨软骨浅层以下的延迟比胫骨软骨高。
在成熟过程中，关节软骨的胶原组织发生了显著的调节，这种调节在胫骨软骨中比在股骨软骨中更早发生，在深层最为明显。
