Changes of degenerated articular cartilage of osteoarthritis of the knee after high tibial osteotomy, with special reference to regeneration

对127例膝关节骨性关节炎患者行胫骨高位截骨术。观察HTO后关节软骨再生情况并进行分类，比较两次手术平均间隔25个月取出钢板时与初次HTO时关节软骨再生情况。28个膝关节的活检标本取自股骨内侧髁，在初次胫骨高位截骨时，股骨内侧髁关节面的负重部分明显退化。在取出接骨板时，股骨内侧髁关节软骨的再生分为0期（无再生变化），第1阶段（粉红色和淡黄色纤颤），2期（白色纤颤散射），3期（部分覆盖，伴白色纤颤），4期（白色纤维软骨过度生长），阶段5（甚至覆盖有白色纤维软骨）。活检标本显示出不同的细胞类型和染色模式之间的浅区与梭形纤维软骨，类细胞和中深层圆形分布的透明软骨样细胞。纤维软骨样细胞胞浆及细胞周基质内可见反型胶原，透明软骨样细胞胞浆及细胞周基质内可见番红0、反型胶原及S-100蛋白。IGF-1 mRNA杂交显示再生软骨表面细胞呈阳性。

High tibial osteotomy (HTO) was performed 127 osteoarthritic knees. Regeneration of the articular cartilage after HTO was observed and classified.Macroscopic findings at the time of plate removal were compared to those of the initial HTO.The averaged interval between these two operations was 25 months. The biopsy specimens were taken from the medial femoral condyle in 28 knees.At the time of the initial high tibial osteotomy the weight bearing portion of the articular surface was markedly degenerated in the medial femoral condyle. At the time of the plate removal, regeneration of the articular cartilage in the medial femoral condyle classified into the stages as Stage 0 (no regenerative change), Stage 1 (pink and yellowish fibrillation), Stage 2 (white fibrillation scattering), Stage 3 (partial coverage with white fibrillation), Stage 4 (overgrowth of white fibrocartilage), Stage 5 (even coverage with white fibrocartilage).The biopsy specimens showed different cell types and staining patterns between superficial zone with spindle shaped fibrocartilage-like cells and middle to deep zone with round shape distributed hyaline cartilage-like cells. Anti type collagen was observed in the cyteplasma and pericellar matrix of fibrocartilage-like cells while Safranin-0, anti-type collagen and S-100 protein was observed those area of hyaline cartilage-like cells. In the hybridization for mRNA of IGF-1 revealed that cells in the surface of regenerated cartilage were positive.