Cartilaginous transdifferentiation of rat tenosynovial cells under the influence of bone morphogenetic protein in tissue culture.

In an in vitro system cartilage tissue was formed from the patellar ligament of young adult rats in the crevices of bone matrix gelatin (BMG) under the influence of bone morphogenetic protein (BMP). The rate of cartilage induction was 75% (six of eight) for the explants using patellar ligaments of rat knee joints. Almost the same rate was observed, 67% (four of six), for explants of ligament with fatty tissue. Tenosynovial cells and synovial cells from the surface of ligaments are potent responders to BMP, and this property may be applied to accelerate the biologic attachment of excised tendons and ligaments in clinical practice.