Temple M M, Bae W C, Chen M Q, Lotz M, Amiel D, Coutts R D, Sah R L
Department of Bioengineering, University of California-San Diego, La Jolla, California 92093-0412, USA.
Osteoarthritis Cartilage. 2007 Sep;15(9):1042-52. doi: 10.1016/j.joca.2007.03.005. Epub 2007 Apr 30.
To determine the time sequence of biochemical and structural events associated with, and hypothesized to underlie, age-associated tensile weakening of macroscopically normal adult human articular cartilage of the knee.
Macroscopically normal human articular cartilage of the lateral and medial femoral condyles (LFC and MFC) from Young (21-39 yrs), Middle (40-59 yrs), and Old (>/=60 yrs) age donors were analyzed for tensile properties, surface wear, and cell and matrix composition.
Variations in tensile, compositional, and surface structural properties were indicative of early, intermediate, and late stages of age-associated cartilage deterioration, occurring at an earlier age in the MFC than the LFC. Differences between Young and Middle age groups (indicative of early-to-intermediate stage changes) included decreased mechanical function in the superficial zone, with a loss of (or low) tensile integrity, and surface wear, with faint striations and mild staining on the articular surface after application of India ink. Differences between Middle and Old age groups (indicative of intermediate-to-late stage changes) included maintenance of moderate level biomechanical function, a decrease in cellularity, and a decrease in matrix glycosaminoglycan content. Tissue fluorescence increased steadily with age.
Many of these age-associated differences are identical to those regarded as pathological features of cartilage degeneration in early osteoarthritis. These findings provide evidence for the roles of mechanical wear, cell death, and enzymatic degradation in mediating the progression through successive and distinguishable stages of early cartilage deterioration.
确定与宏观正常的成人膝关节软骨年龄相关拉伸弱化相关且被假设为其基础的生化和结构事件的时间顺序。
对来自年轻（21 - 39岁）、中年（40 - 59岁）和老年（≥60岁）供体的股骨内外侧髁（LFC和MFC）的宏观正常人体关节软骨进行拉伸性能、表面磨损以及细胞和基质组成分析。
拉伸、组成和表面结构特性的变化表明了与年龄相关的软骨退变的早期、中期和晚期阶段，MFC的退变发生年龄早于LFC。年轻和中年组之间的差异（表明早期到中期变化）包括表层机械功能降低，拉伸完整性丧失（或较低），以及表面磨损，印度墨水染色后关节表面有细微条纹和轻度染色。中年和老年组之间的差异（表明中期到晚期变化）包括维持中等水平的生物力学功能、细胞数量减少以及基质糖胺聚糖含量降低。组织荧光随年龄稳步增加。
许多这些与年龄相关的差异与早期骨关节炎中软骨退变的病理特征相同。这些发现为机械磨损、细胞死亡和酶促降解在介导早期软骨退变连续且可区分阶段进展中的作用提供了证据。
