Regenerative therapy is an alternative treatment option for knee injury patients. Minimally invasive procedures like stem cell and platelet-rich plasma therapies involve an outpatient procedure performed under local anesthesia in the doctor’s office, using the patient’s own adult stem cells to help the knee heal.
Adult stem cell treatments are used to treat a host of conditions including leukemia and similar blood and bone cancers. Pain doctors use regenerative therapy in treating the knee because there are fewer chances of complications.
In This Article:
- Types of Knee Injuries?
- What Is Stem Cell Therapy for Knee Injuries?
- Stem Cell Therapy for Knee Injuries
- Platelet-Rich Plasma (PRP) Therapy for Knee Injuries?
- Knee Osteoarthritis Treated with PRP
- Prolotherapy for Knee Injuries?
- Regenerative Therapy is Not for All Knee Injuries
- Novus Spine & Pain Center
- Stem Cell Therapy for Knee Injuries Resources
Types of Knee Injuries
Perhaps the most common joint disease is Osteoarthritis, which is a type of knee injury common among older Americans and a leading cause of chronic disability. Osteoarthritis, a degenerative form of arthritis, causes bone cartilage to breakdown. Cartilage is the smooth tissue covering bones and cushions joints allowing joint bones to glide smoothly. However, because it’s not supplied with blood vessels, cartilage doesn’t self-repair.
Other types of knee injuries include:
- Meniscus Tear. A common knee injury caused by sudden twists of the knee. The meniscus is cartilage in the knee that cushions and stabilizes the knee and protects the bones from wear.
- Chondromalacia (also called Patellofemoral Syndrome). One of the most common causes of chronic knee pain. The condition is an abnormal softening of the cartilage on the underside of the kneecap (patella).
- Pes Anserine Bursitis. An inflammation of the bursa (small, fluid-filled sacs that cushion bones and soft tissue) located between the shinbone (tibia) and three tendons of the hamstring muscle at the inside of the knee.
- Baker’s Cyst. A protrusion on the back of the knee caused by excess joint fluid compressed by body weight between the bones of the knee joint.
- Patellar Tendonitis. An injury to the tendon connecting the kneecap (patella) to the shinbone. It is most common among athletes whose sports involve frequent jumping.
Most treatments for osteoarthritis of the knee address only the symptoms which can create other challenges. Doctors often suggest weight loss and exercise programs for their osteoarthritis patients. However, these are often difficult for people to follow successfully, partially because side effects of pain medications may cause other health problems. Researchers looking for less risky and more accessible, effective options are turning to regenerative therapy solutions because of their potential to improve knee osteoarthritis symptoms.
What Is Stem Cell Therapy for Knee Injuries?
Regenerative therapy uses the patient’s own body to help stimulate healing. The patient’s own adult stem cells (also mesenchymal stem cells) have the potential to develop into musculoskeletal cells, such as fat, bone, or cartilage.
Stem cells are found throughout the body and have the potential to become any type of cell—including those found in cartilage. They can help the body regenerate tissue by stimulating healing and reducing the painful effects of osteoarthritis. And furthermore, researchers believe adult stem cells can repair and replace cartilage as well as other tissue damaged by arthritis.
Platelet-rich plasma (PRP) therapy is a process of concentrating platelets that include growth factors and injecting them into an injured area of the body, thereby causing new tissues to form. When these growth factors interact with local cells, new tissue formation begins.
Adult stem cells and PRP are both considered safe because the cells are collected from the patient, minimizing the risk of an unwanted reaction. There is evidence that people with severe arthritis can benefit from stem cell therapy. Most research indicates that younger patients who have relatively mild osteoarthritis or cartilage damage see the most benefit.
Stem Cell Therapy for Knee Injuries
In 2011, doctors at the University of Aberdeen published research in the journal Arthritis and Rheumatism the first evidence that the number of stem cells in the knee, after an injury, increase and begin to turn themselves into cartilage. Their research has since been cited in more than 40 medical studies.
Researchers then tried to determine why the knee does not rebuild cartilage on its own, if there is an abundance of stem cells in the knee after an injury. The University of Calgary in 2012 found that in cases of osteoarthritis, stem cells already in the knee do not heal because of improper communication between the cells. Instead of healing, the environment in the knee became degenerative. Their research suggests that the development of a therapy resulting in the stem cells properly communicating again would create a new strategy in healing.
The stem cell communication failure was confirmed in 2016 at Tehran University for Medical Sciences. Researchers there found that despite their more significant numbers, native stem cells acted chaotically and were unable to repair bone, cartilage, and other knee tissues. The research found the introduction of bone marrow stem cells into the chaotic environment stimulated the native stem cells to perform healing functions. As a result, the joint stem cells change from chaotic to healing because of communication.
The 2012 Calgary research was supported in a December 2017 study published in Nature Reviews Rheumatology. The 2017 paper reported they found sufficient stem cells in the knee. The problem was how to get those cells to activate to repair and heal the knee.
A research team in Australia was able to confirm how the change in the joint environment works. Their research showed the new stem cells create a new communication network and signal the native stem cells and other growth factors to regroup. The stem cells then began regenerating cartilage and repairing damaged joints.
Stem cell therapy results are impressive. About 85 percent of patients treated show significant improvement within a year.
Platelet-Rich Plasma (PRP) Therapy for Knee Injuries
Platelet-rich plasma (PRP) is a relatively low-pain, low-risk procedure that uses the patient’s own blood to stimulate growth in injured tissues. Recent evidence suggests that PRP may be an effective treatment for managing pain associated with knee osteoarthritis. PRP can also be used with other pain management methods for knee osteoarthritis.
PRP has been used in surgeries to promote cell regeneration since 1987. Furthermore, a growing body of evidence shows it is a viable treatment for tendinosis (chronic tendinitis). Not until recently, though, have experts researched and debated about the efficacy of PRP injections for treating osteoarthritis.
Nearly all of the research investigating the use of PRP to treat osteoarthritis and other cartilage defects has been done since 2000, and the vast majority of research articles on the topic have been published since 2010.
A 2017 meta-analysis of 14 randomized, controlled trials with a total of 1,423 participants found PRP appears to be effective in the management of pain associated with knee osteoarthritis. Researchers noted that, compared with placeboes, PRP injections significantly reduced pain scores at 3-, 6-, and 12-month follow-ups. And compared with controls, PRP significantly improved physical function at these follow-ups.
Knee Osteoarthritis Treated with PRP
Researchers studying PRP and osteoarthritis often work with patients who have knee osteoarthritis.
One clinical study published in 2013 involved 78 patients suffering from osteoarthritis in both knees (156 knees). Each knee received one of three treatments: 1 PRP injection, 2 PRP injections, or 1 placebo saline injection. Researchers evaluated the subjects’ knees at 6-weeks, 3-months, and 6-months following the treatment. Patients receiving 1 or 2 PRP injections reported a reduction in pain and stiffness as well as improvement in knee function at 6-weeks and 3-months. At the 6-month mark, positive results declined, though pain and function were still better than before PRP treatment. The group receiving the placebo injections reported a small increase in pain and stiffness and a decrease in knee function.
A second, smaller study examined patients with mild knee pain for an average of 14 months. Each arthritic knee underwent an MRI to evaluate joint damage and then received a single PRP injection. The study patients then had their knees assessed 1-week, 3-months, 6-months and 1-year after treatment.
In addition, the participants had a second MRI on their knees one year following the initial PRP treatment. Researchers found most patients receiving the PRP treatment had less pain than the previous year, although the pain had not necessarily disappeared completely. The follow-up MRIs showed that that the degenerative process had not progressed in the majority of knees.
Prolotherapy Therapy for Knee Injuries
Prolotherapy is the injection of an irritating solution (often dextrose, a form of sugar water) into the affected joints, ligaments, and tendons. A typical program of treatment involves a series of injections given monthly over a three- to four-month period. Occasionally, follow-up injections may be needed.
Although the use of the therapy began in the 1920s, researchers and doctors still aren’t sure how prolotherapy improves pain and other symptoms. David Rabago, MD, an associate professor of family medicine at the University of Wisconsin-Madison School of Medicine and Public Health, says one theory is that prolotherapy injections trigger a natural healing process, stimulating repair of damaged tissues.
In a randomized, double-blind controlled trial, Dr. Rabago placed 90 people with knee osteoarthritis into one of three groups. The first group received prolotherapy, a second group received inactive salt-water shots, and the third was given a series of knee exercises to do at home three times a week.
For the first two groups, doctors injected a solution into the knee joint targeting points of pain and swelling. This procedure was performed on three occasions, four weeks apart (with the possibility of two additional treatments, if needed). The third group doing exercises was included in the trial to rule out the possibility of mistaking a placebo effect (in either injection group) for a genuine therapeutic response.
The study used the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) to measure the effectiveness of the treatment. Researchers compared participants’ WOMAC score for levels of pain, stiffness and physical function both before treatment and a year after the beginning of the study.
The WOMAC score of those receiving prolotherapy improved 24 percent, compared with an 11-percent improvement in the salt-water group. The exercise group had a 12-percent improvement. The changes in the prolotherapy group versus the comparison groups were great enough that researchers could rule out the possibility of chance findings.
Regenerative Therapy is Not for All Knee Injuries
Not everyone is a candidate for regenerative therapy. If the knee is bone-on-bone or the osteoarthritis is severe enough, the recommendation is most likely knee replacement surgery. Artificial joints typically last only a few decades, so they are not an ideal solution for patients younger than 50.
There are no professional medical guidelines for who can and cannot receive regenerative therapy for knee injuries. For now, the decision about who gets stem cell, PRP therapy, or prolotherapy treatments is up to patients and their doctor. Most doctors and pain management specialists make recommendations on a case-by-case basis.
Novus Spine & Pain Center
Novus Spine & Pain Center is in Lakeland, Florida, and specializes in stem cell therapy for knee injuries. By using a comprehensive approach and cutting-edge therapies, we work together with patients to restore function and regain an active lifestyle, while minimizing the need for opiates.
Stem Cell Therapy for Knee Injuries Resources
Can Stem Cell Therapy Save Your Knees? (Ski Magazine)
Stem Cells for Knees: Promising Treatment or Hoax? (WebMD)
The Importance of Stem Cell Numbers in Stem Cell Therapy (Stem Cell Institute)
Efficacy of Platelet-Rich Plasma Injections (Arthritis Heath)
Is Platelet-Rich Plasma (PRP) a Safe and Effective Treatment for Osteoarthritis of the Knee? (Healthline)
Pros and Cons of Using PRP for Tendon Injuries (Sports Health)
PRP Injections for Pain (American Association of Orthopaedic Medicine)
Prolotherapy for Knee Osteoarthritis (Arthritis Foundation)
Is Stem Cell Therapy for Arthritis Safe and Effective? (Arthritis Health)
Knee osteoarthritis prevalence, risk factors, pathogenesis and features: Part I (PubMed)
What is Osteoarthritis? (Arthritis.org)
Meniscus Tear Knee Injury (WebMD)
Chondromalacia Patella (Patellofemoral Syndrome) (MedicineNet)
Pes Anserine (Knee Tendon) Bursitis (OrthoInfo)
Baker’s Cyst (Popliteal Cyst) (MedicineNet)
Patellar Tendinits (Mayo Clinic)
Synovial Fluid Progenitors Expressing CD90+ from Normal but Not Osteoarthritic Joints Undergo Chondrogenic Differentiation without Micro-Mass Culture (PubMed)
Mesenchymal stem cell therapy: a new trend for cell therapy (PubMed)
The temporal effect of platelet-rich plasma on pain and physical function in the treatment of knee osteoarthritis: systematic review and meta-analysis of randomized controlled trials (PubMed)
Treatment with platelet-rich plasma is more effective than placebo for knee osteoarthritis: a prospective, double-blind, randomized trial. (PubMed)
Clinical and MRI outcomes after platelet-rich plasma treatment for knee osteoarthritis (PubMed)
The History of Prolotherapy (Practical Pain Management)
Dextrose prolotherapy for knee osteoarthritis: a randomized controlled trial. (PubMed)