Stem cell therapy of tendinopathies: suggestions from veterinary medicine.

The ideal strategy for tendon healing has not been identified to date. Recently, the use of stem cells based therapy has been proposed, due to their ability to proliferate and to differentiate towards specific connective tissues lineages. Embryonic stem cells should be considered the ideal cell source for regenerative therapies, but ethical factors limit their use in humans. Mesenchymal stem cells are more easily available and can be obtained by different sources. Amnion derived stem cells can differentiate towards all three germ layers, and can be used for allogeneic transplantation and stored thanks to cryopreservation. In veterinary medicine, stem cells have been used with encouraging results for the treatment of the Superficial Digital Flexor tendinopathy in the horses. Considering that Superficial Digital Flexor tendinopathy is similar for pathogenesis and histopathology to Achilles tendinopathy in man, this experience can provide supportive data to encourage the use of regenerative therapy in humans.