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

采用胫骨高位截骨术治疗膝骨性关节炎127例。观察和分类HTO术后关节软骨的再生情况，并将钢板取出时的大体观察结果与初次HTO时的大体结果进行比较。两次手术之间的平均间隔为25个月。活检标本取自28膝股骨内侧髁，初次胫骨高位截骨术时，股骨内侧髁关节面承重部分明显退变。摘除钢板时，股骨内侧髁关节软骨再生分为0期(无再生改变)、1期(粉黄色纤颤)、2期(白色纤颤散在)、3期(部分覆盖白色纤颤)、4期(白色纤维软骨过度生长)、5期(均匀覆盖白色纤维软骨)。活检标本显示浅层梭形纤维软骨样细胞和中至深层圆形分布透明软骨样细胞不同的细胞类型和染色模式。纤维软骨样细胞胞浆和胞周基质中可见抗型胶原，透明软骨样细胞中可见藏红花素-0、反型胶原和S-100蛋白。IGF-1mRNA杂交显示再生软骨表面细胞呈阳性反应。

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.