The knee meniscus : investigating the regenerative potential of meniscal cartilage exposed to recombinant growth factors in vitro
Meniscal tears are common debilitating injuries that can have dramatic consequences especially for young athletes. Healing of meniscal tears following surgical repair is essentially only feasible for tears within the peripheral vascular zone. By comparison, tears that occur within the inner avascular zone do not heal and most commonly are treated by excision. This in turn greatly increases the potential for secondary osteoarthrosis. Clearly, there is a clinical need to augment surgical techniques, extending meniscal repair to the avascular zone. In this study, monolayer cell cultures were prepared from the inner, middle, and outer zones of the lateral menisci of sheep and from humans obtained following total knee arthroplasty and partial meniscectomy. Various concentrations of Platelet Derived Growth Factor (PDGF-AB), Insulin-like Growth Factor type I (IGF-I), and basic Fibroblast Growth Factor (bFGF) were used individually to assess their effects upon cell proliferation and extracellular matrix formation. This study found that the growth factors under investigation stimulated the fibrochondrocytes, both human and sheep, in a similar dose dependent fashion, although the specifics and extent of stimulation differed for each of the growth factors, and for each species. Interestingly, fibrochondrocytes cultured from the avascular zone were stimulated in a similar fashion to those cultured from the vascular zone. The action of the growth factors was not dependent upon serum being present. Therefore, the results of this study are an encouraging first step towards enhancing the regeneration and potentially the repair of injured meniscal tissue.