Millions of American suffer from damaged menisci (the protective lining of the knee) and this can lead to debilitating arthritis. There are few solutions for a damaged meniscus. Small tears can be sewn but larger tears can only be solved by removal of the meniscus (which reduces pain in the patient) but this leaves the knee without its natural shock absorber between the femur and tibia. Without the meniscus the knee is prone to very bad arthritis. There have been attempts to replace the meniscus using tissue from other parts of the body or from cadavers but this is has a very low success rate.

However, there may be good news on the horizon. Researchers at the Columbia University Medical Center have found a way to regenerate the meniscus in sheep. They start by taking a scan of the healthy knee and then 3d print a scaffold in the exact shape of the undamaged meniscus. It takes about 30 minutes to print and is made from a biodegradable polymer. Once printed the meniscus is infused with two human proteins: connective growth factor and transformative growth factor. By releasing these proteins in a specific order researchers were able to get the body to attract existing stem cells to the body and transform in to meniscus tissue.

(Right) Regenerated meniscus tissue in sheep (Left) control.

Image credit: http://newsroom.cumc.columbia.edu

After the meniscus scaffold is placed in the sheep a new meniscus is formed in about four to six weeks. The scaffold eventually dissolves and is eliminated from the body. This is just the beginning phase of testing so it is not certain how long lasting the meniscus is or what the long term effect may be. But it is revolutionary in its potential to help meniscus damaged patients (both human and animal) and because it works with stem cells inside the body. Previously work with stem cells involved the cells being removed from the body and manipulated in a lab.

Main Image Credit: http://newsroom.cumc.columbia.edu