Hello, Dr. H here! Sunday afternoon! So I’ve been asked “what is so important about the meniscus that you are trying to re-grow them in pigs?”
Well, first let’s talk about the meniscus. In a knee there are two, one on each side of the knee. The meniscus functions to cushion and protect the joint where the thigh bone and shin bone meet. With trauma or age, the meniscus can tear; once torn, they cause pain, swelling and mechanical symptoms such as popping, catching or giving way in the knee. (The torn meniscus is sort of like a hang nail that is snagging on things inside the knee. Usually like a hang nail, the meniscus does not heal itself, and unlike a fingernail, it does not re-grow.) These symptoms fortunately are easily treated by surgically removing the torn portion.
However, over time (15-20 years) the knee will develop arthritis which is dependent on how much of the meniscus is removed. This can be a real tragedy in someone who has a lot of meniscus removed at 20 years old. This person then might need a knee replacement at 40. There is a lot of research to find a meniscal substitute or an implant that can be inserted to replace a meniscus. We can even transplant a meniscus, but these treatments have not been shown to prevent arthritis.
What we are doing at McNeese State University is to see if we can re-grow the meniscus in pigs after having a portion of their meniscus removed. We first grow stem cells from fat then inject the cells into the knee after surgery. The initial research we did at MSU shows that pigs develop arthritis in the knee very fast after meniscal surgery. What takes 20 years in humans only takes about 6 months in pigs. We discovered that right here at MSU, pretty cool.
The whole idea is to develop the right approach that would make this idea possible for humans. Wouldn’t that be great to be able to inject the knee after surgery and re-grow the removed portion of meniscus? Who knows if this stem cell injection would work to re-grow the removed meniscus? We could even try to get the meniscal tears to heal with injection only, without having surgery.