Effects of different bone marrow stimulation techniques on avascular zone meniscal defects

Abstract

OBJECTIVES: In this study, we sought to investigate the effect of different amounts of Bone Marrow-Derived Mesenchymal Stem Cells (BMSCs), obtained by different BMSCs, on the healing of avascular zone meniscal defects. BACKGROUND: Treating avascular zone meniscal injuries has gained popularity. BMSCs contribute to the healing of avascular zone meniscal defects. The amount of BMSCs derived from different bone marrow stimulation techniques (BMSTs) varies, which could affect the therapeutic efficacy of this treatment. METHODS: Fifty-four skeletally mature female New Zealand White rabbits were used after local ethical committee approval. A full thickness, 1.5 mm diameter defect was produced in the inner two-thirds of the anterior portion of the medial meniscus avascular zone using a biopsy punch. Animals were enrolled into three different groups according to BMST (0.8 mm, 1.5 mm, and 4 mm). Medial menisci were harvested and prepared for histomorphometric, histologic and immune-histologic analyses. RESULTS: Larger bridging tissues across the defect were detected in the 1.5-mm and 4-mm groups at 4 weeks (p < 0.05). The best quality score at the 1-,4- and 12-week endpoints was in 0.8 mm, 4 mm and 0.8 mm, 1.5 mm, respectively (p < 0.05). Immunostaining of experimental and control knees at the 1-week endpoint revealed diffuse staining within the bridging tissue for PDGA, TGFβ-3, BMP-2 and IGF. HSCORE for these pro-regenerative cytokines did not reach statistical significance at the 1-week endpoint (p > 0.05) CONCLUSION: The largest amount of BMSCs did not correlate with best quality and largest quantity of bridging tissue at the avascular zone in meniscal defects.