Meniscus tears are very common. Surgery to remove the torn part of the meniscus is also very common. Unfortunately, many people who have torn their meniscus, or who have the torn piece removed will go on to develop osteoarthritis. Until recently, a person with persistent pain following meniscus surgery had very few options. They could undergo a meniscus transplant, or simply try medications or injections to treat the pain.
In January 2014 a preliminary, but exciting study revealed that a single injection of stem cells may help certain patients regrow a portion of the meniscus which was removed at the time of surgery. This study also showed that pain relief was higher in the stem cell-treated meniscus tear group. 
Each knee contains two menisci. The meniscus functions as a shock absorber. It also helps distribute your weight across the knee joint to minimize the stress on the bones and articular cartilage. A torn meniscus is not capable of functioning normally. This results in abnormal stresses around the knee which can lead to arthritis, further loss of cartilage and pain.
There was evidence of meniscus regeneration and improvement in knee pain following treatment with allogeneic human mesenchymal stem cells. These results support the study of human mesenchymal stem cells for the apparent knee-tissue regeneration and protective effects.
What are stem cells?
Stem cells are unique cells within our body. They are “immature” which means that they haven’t grown into a skin cell, a cartilage cell, or a heart cell yet. Stem cells have the ability to grow into almost any type of cell within our body. Each tissue in our body has unique chemical compounds. Those chemicals can cause stem cells to start the process of maturing and becoming a fully developed cell. Theoretically.. if a stem cell is placed in the knee, the chemicals present in the knee will lead the stem cells to mature into cartilage cells.
Can Stem Cells Treat A Meniscus Tear?
The study quoted above was the first (to my knowledge) to show that stem cells, injected into the knee can regrow a portion of the meniscus which was removed at the time of surgery. The study showed that some patients regrew up to 20% of the torn part of the meniscus. More importantly, this study showed that patients who received the stem cells after their surgery felt better and had better pain scores.
This is the first in what will likely be a number of studies to determine whether or not stem cells possess the ability to completely regrow a meniscus after a portion of it is removed. Further studies will be needed to see if two or more treatments can improve the amount of the meniscus that grew back. Further study is also needed to see if these results stand the test of time. Will the new meniscus tissue last?
This is a very exciting time. Can stem cells treat meniscus tears? Should you receive stem cells after your meniscus surgery? These are very important questions and it is something you need to discuss with your doctor.
Please keep in mind that this is still considered experimental.
Bob says
Dr Luke,
I am 76 years old . It was recommended for me to have the bilateral torn portion of the meniscus removed and clean out as much of the arthritis as possible and inject stem cells. The findings of my MRI shows obliquely oriented full-thickness tear involving body and posterior horn medial meniscus. No evidence of displaced meniscal fragments. ACL, PCL and MCL are intact as well as the tendons of quadriceps and patellar are intact with both the lateral and retinacular patellar also intact. What a Mouth Full . . . Please give me your opinion / recommendation for my situation and what I should do. Gratefully Yours,
Bob
Howard J. Luks, MD says
Bob… At your age, and with arthritis in addition to degenerative meniscus tears the research in this area is pretty clear. THere appears to be no benefit to surgery over physical therapy, injections, compression sleeves, etc.
eduardo cavanagh says
I just want to compliment Dr. Luks for his objective answers, in these days where medical marketing on stem cells claims wonders but yet without scientific proof. Your comments help many of us to make the right choices. Many thanks,
Eduardo.
ANDREW says
Hello Doc , i saw your post on youtube as i was going through different videos about meniscus tear , and am glad on how you discuss meniscus tear , because i did MRI recently and i was told that i have one . Actually , i live in China with my family . Meanwhile, the doctor told me that i need to do surgery but i don’t really want to do that ,as am scared . Also , i had felt the pains on my left knee on and off for 6 months now after taken medication , but , recently after the revelation through MRI that i have meniscus tear , i began to feel better through some exercises that i found out that i can do on my knee for my meniscus and through prayers too , as i believe with God all things are possible , because he is the perfect healer . My questions are :
1. Can my torn meniscus heal by itself through the different knee exercises am doing ?
2. How do i know if i have inner or outside torn meniscus ? Because , the doctor didn’t tell me which one is it ,he just said i need to do surgery .
3. As i don’t feel pains again , can the pain resurface again as i get older ? Because am gonna be 39 years in May .I hope to receive your reply soon .Thanks and God bless you. Andrew from China
Howard J. Luks, MD says
Andrew .. the pain from a meniscus tear often calms down with Physio. Only the MRI can tell you where the tear is. No other way to tell. Surgery is only considered if we know that we can repair it… or suture the torn ends back together. Many, many tear patterns are repairable these days.
Andrew says
Thanks ,Dr .Howard for your prompt reply . The issue is that i don’t know the part of my meniscus that was torn , although ,i had done the MRI but the Doctor didn’t tell me , so how do i know if is medial or … ?That is, inner tear or outside tear , because the my MRI report was written in chinese language . Although , i still open for surgery during my summer vacation if the slight pain didn’t stop . Thanks
Andrew says
Thanks ,Dr .Howard for your prompt reply . The issue is that i don’t know the part of my meniscus that was torn , although ,i had done the MRI but the Doctor didn’t tell me , So , when is the right time to do surgery on torn menisucs ? Also , i hope after the surgery it not gonna trigger arthritis or other serious damage on my knee ?Thanks and hope to hear from you