Osteophytes--an alternative source of chondrocytes for transplantation?

The aim of this research was to evaluate the possibility of using osteophyte-derived chondrocytes for autologous chondrocyte implantation by comparing the behaviour of these chondrocytes with that of normal articular cartilage-derived chondrocytes in monolayer culture.

The scrapings from the cartilage mantle of osteophytes harvested during routine total knee replacement for osteoarthritis were enzymatically digested and grown in monolayer culture. Articular cartilage scrapings obtained from visually normal area of the femoral condyle (usually from the posterior cuts) were also enzymatically digested as for the cartilage from the osteophytes. The behaviours of these two sets of chondrocytes were evaluated in monolayer culture, by their gross appearance, matrix protein elaborated and collagen types with the articular cartilage-derived chondrocytes acting as controls.

Osteophyte-derived chondrocytes confluenced earlier than normal articular cartilage-derived chondrocytes. The osteophyte-derived chondrocytes elaborated cartilaginous matrix as evidenced by positive staining for Toluidine blue and the cells were immunoreactive positive for collagen types I, II and III.

Osteophyte-derived chondrocytes are similar to normal articular cartilage-derived chondrocytes in monolayer culture. Since osteophytes are expendable tissues and often found in association with full thickness articular cartilage defects, they may provide an alternative source of chondrocytes for transplantation in cases where autologous chondrocyte transplantation (implantation) is embarked upon.