The dogs were sacrificed respectively at 16 and 24 weeks after operation.The patellar cartilage were observed with HE, Safranin O, and Toluidine Blue staining under the light microscopes.

• 16、24周后取髌股关节软骨，经HE、番红花、甲苯胺蓝染色，观察其病理变化，同时采用电镜观察其超微结构改变。