Cartilage repair and motor function recovery in knee joint during articular cartilage defects at different directions / 中国组织工程研究

ABSTRACT

BACKGROUND:At present, there are many researches about repairing articular cartilage defects. In particular, the microfracture technique has been widely used. OBJECTIVE:To observe recovery of knee joint motor function and morphological changes in tissue repair during articular cartilage defects with different directions (coronal position and sagittal position). METHODS:Articular cartilage fracture models with 2 mm-thick medial femoral condyles of rabbit knee joint were established. According to incision directions, models were assigned to coronal and sagittal groups. At 5, 10 and 20 weeks after model induction, general observation was performed. Specimens were sliced into paraffin sections, and subjected to hematoxylin-eosin staining and col agen staining. Tissue repair at the articular cartilage defects was observed using optical microscope and immunohistochemical method. After model induction, range of motion of rabbit joints was regularly examined in the two groups.RESULTS AND CONCLUSION:A white line was seen across the femoral condyles at defects in the two groups. Articular surface at defect repair was at the level of in situ cartilage, and reached a bone union. Knee joint treated by operation did not affect function. Under light microscope, partial reconstruction of subchondral bone was seen in the two groups, mainly fibrocartilage repair. The level of bony remodeling was lower than tidal line of adjacent in situ cartilage. Immunohistochemical method exhibited that type I col agen staining gradual y reduced at defects of specimens, but type II col agen staining gradual y increased. These results suggested that there was no significant difference in the recovery of motor function of knee joint and the repair of articular cartilage with different directions (coronal and sagittal position).