The effect of locally applied vascular endothelial growth factor on meniscus healing:: gross and histological findings

Introduction: Tears in the peripheral part of the menisci have a better healing potential than tears in the central part, because the central two-thirds of the menisci are avascular. We hypothesized that healing of meniscus tears in the avascular zone can be promoted by the local application of the angiogenic factor vascular endothelial growth factor (VEGF). Materials and methods: A tear was created in the avascular zone of the medial meniscus in 18 merino sheep. The tear was then repaired with an uncoated suture (group 1), a suture coated with PDLLA (group 2), and by a suture coated with PDLLA/VEGF (group 3). Results: After 6 weeks, we observed increased immunostaining for factor VIII in the VEGF-treated group 3. However, in this treatment group no meniscus healed completely. In the uncoated suture group and in the PDLLA-coated-suture group, partial healing was observed in three animals and complete healing in three animals, respectively. Conclusion: In this experiment the local application of VEGF via PDLLA-coated sutures did not promote meniscus healing. Growth factors might not always be a promising tool for tissue repair.