Stem Cell Therapy Following Meniscus Knee Surgery Reduces Pain and Regenerates Meniscus


According to a new study published in the January issue of the Journal of Bone and Joint Surgery (JBJS), a single stem cell injection after meniscus knee surgery can provide pain relief and aid in meniscus regrowth.

In the US alone, over one million knee arthroscopy procedures are performed each year. These surgeries are usually prescribed to treat tears to the wedge-shaped piece of cartilage on either side of the knee called the “meniscus.” The meniscus acts as an important shock absorber between the thighbone (femur) and the shinbone (tibia) at the knee-joint.

Knee-Ligament-Pain-and-Strains-Meniscus-Tear-and-Pain

This novel study, “Adult Human Mesenchymal Stem Cells (MSC) Delivered via Intra-Articular Injection to the Knee, Following Partial Medial Meniscectomy,” examined 55 patients who had undergone a surgical removal or all or part of a torn meniscus (known as a partial medial meniscectomy). Each patient was randomly assigned to one of three treatment groups: Groups A, B and C. The 18 patients in group A received a “low-dose” injection of 50 million stem cells within seven to 10 days after their meniscus surgery. Another 18 patients in group B received a higher dose of 150 million stem cells seven to ten days after their knee surgery. The controls group consisted of 19 patients who received injections of sodium hyaluronate only (no stem cells). All patients were evaluated to determine the safety of the procedure, the degree of meniscus regeneration (i.e. with MRI and X-ray images), the overall condition of the knee-joint, and the clinical outcomes through two years. Most of the patients enrolled in this study had some arthritis, but patients with severe (level three or four) arthritis, were excluded from the study.

Most of the patients who had received stem cell treatments reported a significant reduction in pain. 24 percent of the patients in one MSC group and 6 percent of the other showed at least a 15 percent increase in meniscal volume at one year. Unfortunately, there was no additional increase in meniscal volume at year two.

“The results demonstrated that high doses of mesenchymal stem cells can be safely delivered in a concentrated manner to a knee-joint without abnormal tissue formation,” said lead study author C. Thomas Vangsness, Jr., MD. “No one has ever done that before.” In addition, “the patients with arthritis got strong improvement in pain” and some experienced meniscal regrowth.

The key findings of this study are that there no abnormal (ectopic) tissue formation or “clinically important” safety issues identified. Also, 24 percent of the patients in the low-dose injection group (A) and six percent of the high-dose injection group (B) at one year showed “significantly increased meniscal volume,” as determined by an MRI, and this increase did not continue into the second year, but remained stable (should future studies try a second injection of MSCs?). Third, none of the patients in the control group (non-MSC group) showed significant meniscus regrowth. Finally, patients with osteoarthritis experienced a reduction in pain in the stem cell treatment groups, but there was no reduction in pain in the control (non-MSC group).

“The results of this study suggest that mesenchymal stem cells have the potential to improve the overall condition of the knee joint,” said Dr. Vangsness. “I am very excited and encouraged” by the results. With the success of a single injection, “it begs the question: What if we give a series of injections?”

Clinical Study Evaluates Healing of Knee Cartilage With Stem Cells


The biotechnology company InGeneron will test its patented Transpose RT system in a clinical study that examined the ability of regenerative cells from a patient’s own fat to enhance cartilage healing after knee surgery.

Qualified patients are being recruited through the Fondren Orthopedic Group in Houston. According to the American Orthopedic Society for Sports Medicine, over 4 million knee arthroscopies are performed worldwide each year. Damaged knee cartilage is very difficult to treat and can lead to chronic pain and long-term disability.

Robert Burke, who is serving as the principal investigator of this clinical study, is an orthopedic surgeon with the Fondren Orthopedic Group in Houston. Burke thinks that stem cells taken from a patient’s own fat may enhance cartilage healing. He studied adding patient-derived regenerative cells to the knee during arthroscopic surgery for particular patients, and compared them to patients who had arthroscopic surgery without added fat-derived stem cells.

Arthroscopic surgery is a common procedure is commonly used to treat damaged cartilage, and the patients who had received arthroscopic surgery were randomly chose to either receive fat-derived stem cells or not receive them. Burke, will then monitor these patients for the next 12 months after surgery to determine if the added cells improved cartilage healing.

According to Burke, “Articular cartilage, the smooth surface covering the joints at the ends of bones, has no good way of healing on its own. The body doesn’t create enough new cartilage of the same type to repair the damage.” Better treatments would use various techniques to help the body make new cartilage.

“Stem cells and other regenerative cells that we can obtain fat have the potential to do that,” said Burke. Such regenerative cells can divide and mature to form several types of cells and tissues. and are found in multiple places in the body. Fat that lies just below the skin is one of the easiest places to obtain stem cells.

The InGeneron Transpose RT System uses a small amount of fat, which is removed and processed to separate out the regenerative cells. The separated adipose tissue-derived mesenchymal stem cells are then immediately placed into the area of damaged cartilage during knee surgery. Once in the knee, these cells may divide to make new cartilage cells.

This kind of biological activity has been seen in laboratory studies and veterinary medicine. However, Burke’s study will be one of the first to test the technology in humans for treating cartilage damage. Like other types of stem cell-based therapies, the treatment is not currently licensed for human use in the United States but it is registered in Europe, Mexico, and other countries. Following the Texas Medical Board’s rules about the use of stem cells for treatment, this study is under the supervision of the research review board at Texas Orthopedic Hospital, where all of the patients will undergo surgeries.

This is a two-year study.