Cell-based therapy for meniscal repair: a large animal study.

Background: The avascular portion of the meniscus cartilage in the knee does not have the ability to repair spontaneously.
Hypothesis: Cell-based therapy is able to repair a lesion in the swine meniscus.
Study Design: Controlled laboratory study.
Methods: Sixteen Yorkshire pigs were divided into four groups. A longitudinal tear was produced in the avascular portion of the left medial meniscus of 4 pigs. Autologous chondrocytes were seeded onto devitalized allogenic meniscal slices and were secured inside the lesion with two sutures. Identical incisions were created in 12 other pigs, which were used as three separate control groups: 4 animals treated with an unseeded scaffold, 4 were simply sutured, and 4 were left untreated. Meniscal samples were collected after 9 weeks, and the samples were analyzed grossly, histologically, and histomorphometrically.
Results: Gross results showed bonding of the lesion margins in the specimens of the experimental group, whereas no repair was noted in any of the control group specimens. Histological and histomorphometrical analysis showed multiple areas of healing in the specimens of the experimental group.
Conclusions: This study demonstrated the ability of seeded chondrocytes to heal a meniscal tear.
Clinical Relevance: Cell-based therapy could be a potential tool for avascular meniscus repair.