Untersuchung des Einflusses von Wachstumshormon HGF auf die Regenerationsfähigkeit des Gelenkknorpels nach Implantation autologer Knorpel-Knochen-Transplantate am Beispiel des Kniegelenkes des Schafes

Objectives: In recent years more and more studies tried to evaluate possible influences of different growth factors on hyaline cartilage regeneration. In a rabbit model, hepatocyte growth factor (HGF) was proven to increase the amount of hyaline-like chondrocytes in a mixed fibro-cartilaginous regenerate of small defects. The aim of the current study was to evaluate, whether intraarticular administration of HGF influences the ingrowth of osteochondral grafts in a sheep model. Methods: Both knee joints of eight sheep were opened surgically and osteochondral grafts were harvested and simultaneously transplanted to the contralateral compartment. The sheep were divided into two groups, resulting in 16 grafts per group. In one group HGF was administered by intraarticular injections given three times a week for four weeks. The control group received isotonic sodium chloride injections. The animals were sacrificed after three months. Results: Histological evaluation showed a complete ingrowth of the osseous part of the osteochondral grafts. A healing or ingrowth at the level of the cartilage could not be observed. Anyway, histological evaluation of the transplanted grafts according to Mankin revealed, that the cartilage of the HGF group showed less signs of degeneration than the control group. In the HGF group less cloning of chondrocytes and less irregularities of the articular surface were observed. No deleterious effects, such as osteophyte formation, cartilage thickening or synovial proliferation, were observed. Conclusion: In conclusion, HGF positively influenced the structure of the transplanted osteochondral graft, but could not diminish the fissures in the marginal zone of the grafts.