Only animals have benefited from the muscle cell transformation so far but further studies are intended to see if the humans would experience the same benefits.

The studies have been performed on 12 weeks old rats that are considered to be young adults. Transformed stem cells have been turned into cartilage to treat damage caused by osteoarthritis.

The rats benefited from the transformed cells for as long as 24 weeks but the scientists are trying to extend that benefit up to 48 weeks.
Stem cells in skeletal muscle were given a boost with a bone protein called morphogenetic protein-4 (BMP-4), which made skeletal cells turn into cartilage cells. This protein has been used previously to make bone cells.

Person that needs the treatment would be taken biopsy in order to obtain muscle stem cells. The cells would be then grown in culture to create patches for the damaged cartilage.

For the time being, muscle stem cells are being tested for another condition in humans-bladder dysfunction. It is still not known when the muscle stem cells will be tested for cartilage repair.