If you are a patient suffering with long-term knee problems caused by a damaged or surgically removed meniscus, you have likely been made aware that your meniscus, or what remains of it, has a limited capacity to repair itself. You may have also been made aware that meniscus related surgery also has a limited capacity to improve your situation.
If you were given a realistic assessment of your meniscus situation, you were told that osteoarthritis, degenerative knee disease, and possibility of knee replacement were the ultimate outcomes.
This is why researchers are looking at regenerative injections for degenerative knee conditions included wear an tear meniscus damage
Stem cell therapy can be a highly effective treatment in which stem cells are injected into an injured area. At the Magaziner Center, we use Mesenchymal stem cells (MSCs) for our stem cell therapy injections. These stem cells are responsible for rebuilding and regenerating soft tissue repair in the body, they do this by transforming themselves into many different types of tissue, and are therefore able to differentiate into ligaments, tendons, bone, nerve, and cartilage.
How stem cell injections addresses meniscus injury
The problem with the meniscus is that it is divided into zones. The outer area that gets a steady blood supply (Red Zone) and has a capacity for healing. The middle area the “Red-White” zone that has limited blood supply and is more challenging to heal, and the avascular zone or the “White zone,” which is thought that repair cannot be made because it has no direct blood supply.
In a recent study, doctors write: “The repair of meniscus tissue in the avascular zone (without blood vessels to bring healing components) remains a great challenge, largely owing to their limited healing capacity.” The answer they suggest to heal this area lies with stem cell based tissue engineering. Stem cells, they write, “provide a promising treatment option for damaged meniscus because of their multiple differentiation potential (their ability to change into meniscal and cartilage cells).”(1)
In research, scientists looked at rabbits with massive meniscal defects. Their goal was to see if a single stem cell injection would improve the defect. This is what the researchers wrote: “(stem cells) injected into the knee adhered around the meniscal defect, and promoted meniscal regeneration in rabbits.” This also lead to a preservation of the articular cartilage and subchondral bone.(2)
Before you think, that is an animal study from a few years ago, this research is being built on by a May 2021 research presentation (3) by the same researchers now working in humans. Here they write:
“We have been studying mesenchymal stem cells (MSCs) in synovial fluid and the intra-articular injection of synovial MSCs in osteoarthritis knees. Here, mainly based on our own findings, we overview the characteristics of endogenous (native stem cells) MSCs in the synovial fluid of osteoarthritis knees and their mode of action when injected exogenously into osteoarthritis knees. Many MSCs similar to synovial MSCs were detected in the synovial fluid of human osteoarthritis knees, and their number correlated with the radiological osteoarthritis grade. Exogenous synovial MSCs can promote anti-inflammation, lubrication, and cartilage matrix synthesis in osteoarthritis knees. Based on our findings, we have initiated a human clinical study of synovial MSC injections in osteoarthritis knees.”
Doctors at Harvard University found unique characteristics in the stem cells of mice meniscus that could be reawakened by stem cell augmentation. The findings were so optimistic that the Harvard team declared that studying the mouse meniscal stem cells would provide essential information for enhancing therapeutic strategies for treating knee joint injury and disease.(4)
This agrees with other research which strongly supports Stem Cell Therapy as a means to regrow meniscal tissue. From the American Journal of Bone and Joint Surgery:(5)
There are limited treatment options for tissue restoration and the prevention of degenerative changes in the knee.
Stem cells have been a focus of intense preclinical research into tissue regeneration but limited clinical investigation.
In a randomized, double-blind, controlled study, the safety of the intra-articular injection of human mesenchymal stem cells into the knee, the ability of mesenchymal stem cells to promote meniscus regeneration following partial meniscectomy, and the effects of mesenchymal stem cells on osteoarthritic changes in the knee were investigated.
There was evidence of meniscus regeneration and improvement in knee pain following treatment with mesenchymal stem cells.
These results support the study of human mesenchymal stem cells for the apparent knee-tissue regeneration and protective effects.
PRP and stem cells in humans
A June 2021 case history presentation paper (6) suggests meniscus regeneration with PRP and stem cell injections.
“Conventional pharmacological and surgical treatments are effective in treating the condition; however, do not result in regeneration of healthy tissues. In this report, we highlight the role of cell-based therapy in the management of medial and lateral meniscal and anterior cruciate ligament tears in a patient who was unwilling to undergo surgical treatment. We injected autologous mesenchymal stem cells obtained from the bone marrow and adipose tissue and platelet-rich plasma into the joint of the patient at the area of injury, as well as intravenously. The results of our study corroborate with those previously reported in the literature regarding the improvement in clinical parameters and regeneration of meniscal tissue and ligament. Thus, based on previous literature and improvements noticed in our patient, cell-based therapy can be considered a safe and effective therapeutic modality in the treatment of meniscal tears and cruciate ligament injury.”
Native stem cells within all the meniscus’ zones
A paper from January 2021 (7) suggests that native stem cells can be found within all the meniscus zones implying that non-surgical repair may be possible. The zones of the meniscus are the red-red (RR), red-white (RW) and white-white (WW) zones. Especially revealing was the presence of native stem cells in the white-white zone, a zone considered unrepairable because it lacks direct blood circulation.
Platelet Rich Plasma therapy (PRP) for meniscus damage
An August 2019 study (8) offers us a good introduction and understanding of how Platelet Rich Plasma injections or PRP therapy can help a patient with meniscus tears.
“Platelet-rich plasma (PRP) is an autologous concentration of platelets that contain a large number of growth factors. These growth factors play a role in the regeneration, repair, and acceleration of the biochemical process, thereby reducing the pain associated with injuries of the articular cartilage and meniscus.”
In this study the researchers evaluated the effect of PRP in the treatment of knee joint cartilage injuries and degenerative meniscus lesions as well as pain relief in 126 patients. Three treatments were given and then the patient’s condition was evaluated up to 6 months. The researchers concluded: “The results showed considerable improvement 3 months after the PRP application, and 6 months after the application the results remained approximately identical.” (The treatment was sustainable).
Is stem cell therapy an option for you? If you would like to explore more information, please contact our office so we can start a conversation with you.
1. Hana Yu, Adetola B Adesida and Nadr M Jomha1. Meniscus repair using mesenchymal stem cells – a comprehensive review. Stem Cell Research & Therapy 2015, 6:86 doi:10.1186/s13287-015-0077-2
2. Hatsushika D, Muneta T, Horie M, Koga H, Tsuji K, Sekiya I. I Intraarticular injection of synovial stem cells promotes meniscal regeneration in a rabbit massive meniscal defect model. J Orthop Res. 2013 Sep;31(9):1354-9. doi: 10.1002/jor.22370. Epub 2013 Apr 17.
3 Sekiya I, Katano H, Ozeki N. Characteristics of MSCs in Synovial Fluid and Mode of Action of Intra-Articular Injections of Synovial MSCs in Knee Osteoarthritis. Int J Mol Sci. 2021 Mar 11;22(6):2838. doi: 10.3390/ijms22062838. PMID: 33799588; PMCID: PMC8001624.
4 Gamer LW, Shi RR, Gendelman A, et al. Identification and characterization of adult mouse meniscus stem/progenitor cells.Connect Tissue Res. 2016 Dec 22:1-8. doi: 10.1080/03008207.2016.1271797.
5 Kopf S, Sava MP, Stärke C, Becker R. The menisci and articular cartilage: a life-long fascination. EFORT Open Reviews. 2020 Oct;5(10):652-62.
6 Mahajan PV, Subramanian S, Parab SC, Mahajan S. Autologous Minimally Invasive Cell-Based Therapy for Meniscal and Anterior Cruciate Ligament Regeneration. Case Reports in Orthopedics. 2021 Jun 25;2021.
7.Vangsness CT Jr, Farr J , Boyd J et al. Adult human mesenchymal stem cells delivered via intra-articular injection to the knee following partial medial meniscectomy: a randomized, double-blind, controlled study. J Bone Joint Surg Am. 2014 Jan 15;96(2):90-8. doi: 10.2106/JBJS.M.00058.
8 Mitev K, Longurov A. Intra-articular Platelet-Rich Plasma Injections for Treating Knee Pain Associated with Articular Cartilage and Degenerative Meniscal Lesions. Open Access Maced J Med Sci. 2019 Aug 12;7(15):2484-2487. doi: 10.3889/oamjms.2019.674. PMID: 31666852; PMCID: PMC6814463.