Promoting the Proliferative and Synthetic Activity of Knee Meniscal Fibrochondrocytes Using Basic Fibroblast Growth Factor in Vitro

Background: Meniscal tears situated within the inner avascular region do not heal despite suturing. New approaches need to be developed to augment surgical repair.

Hypothesis: To demonstrate that basic fibroblast growth factor, used as a single agent or in combination with serum, stimulates the activity of fibrochondrocytes by enhancing proliferation and extracellular matrix synthesis in all meniscal zones, including the inner (avascular) zone of the meniscus.

Study Design: Controlled laboratory study.

Methods: Monolayer cell cultures were prepared from the inner, middle, and outer zones of the lateral meniscus. Various concentrations of basic fibroblast growth factor were used in the presence or absence of 10% fetal calf serum. The authors measured the uptake of radiolabeled thymidine to assess cell proliferation and radioactive sulfur and proline to assess extracellular matrix formation.

Results: Overall, basic fibroblast growth factor-stimulated cells from all meniscal zones to proliferate and to form new extra-cellular matrix (P <.05). The basic fibroblast growth factor (in the absence of serum) increased DNA formation and protein synthesis by cells from the inner meniscal zone by 7- and 15-fold, respectively (P <.001).

Conclusions: These results indicate that meniscal cells and, more important, cells from the avascular zone are capable of responding favorably to the addition of basic fibroblast growth factor by expressing their intrinsic potential to proliferate and generate new extracellular matrix.

Clinical Relevance: The results suggest that it may be possible to augment surgical repair of the meniscus in the future.