• Stem cells from umbilical tissue or a person’s own adipose fat are the most effective stem cells for relieving knee osteoarthritis pain and loss of function, according to a new meta-analysis.
• The meta-analysis found that, in all the studies included, stems cells helped safely alleviate knee joint pain.
• Nearly half of all people develop knee osteoarthritis over the course of their lives.

Among the most promising treatments for knee pain and loss of function from osteoarthritis is the injection of stem cells into the knee.

A new meta-analysis purports to have identified the best sources of stem cells for this purpose so far.

The best stem cells for knee pain and loss of knee function are those derived from donors’ umbilical cord tissue or a patient’s own adipose fat cells.

The meta-analysis collates the results of stem cell of knee osteoarthritis trials involving 875 patients across 16 studies. There were 336 men in the studies. Participants ranged in age from 51 to 69 years. Stem cells were received by 441 people, and 436 people served as controls.

Overall, people being treated with any of the stem cells experienced a significant decrease in knee pain starting at three months of treatment, underscoring the potential of the therapy for knee osteoarthritis.

The study is published in the Journal of Orthopoedic Research.

The knee is the joint that is most commonly affected by osteoarthritis. According to the World Health Organization (WHO), knee osteoarthritis currently affects about 365 million people worldwide.

Older studies have found that the lifetime risk of developing symptomatic knee osteoarthritis is about 40% in men and 47% in women.”

Knee osteoarthritis occurs when the cartilage in one’s knee breaks down, causing the joint’s bones to rub directly together, creating friction.

The reduction in physical activity that may occur as a result of pain can lead to other health issues such as obesity, diabetes, and cardiovascular disease.

Some causes of knee osteoarthritis include:

• joint injuries, fractures, strains, and repeated stress on the joint
• joint diseases
• metabolic diseases, such as diabetes
• obesity, causing the joint to carry excess weight, as well as systemic inflammation, and metabolic issues
• sex — women develop osteoarthritis more often than men
• genetics

Dr. Gendai Echezona, of Premier Pain Care and Wellness, not involved in the current research, noted that regenerative medicine for the knee is not something new. She noted that regenerative therapy includes stem cell therapy as well as injections of platelet-rich plasma.

“This particular study,” she said, “focuses on the newer treatment of mesenchymal stem cell therapy as a treatment for knee osteoarthritis. Mesenchymal stem cells may be bone-marrow derived, derived from adipose tissue (from fat), or umbilical-cord derived.”

Mesenchymal cells are stem cells that can develop into many types of connective tissue. They have large nuclei and are spindle-shaped.

“Although there are studies evaluating various stem cells and comparing these treatments to platelet rich plasma, few studies directly compare different types of stem cells for treatment of knee osteoarthritis,” said Dr. Echezona.

“This study,” said Skidmore College’s Dr. Paul Arciero, also not involved in the research, “provides a systematic review comparison of the different types of stem cell therapies and their overall effectiveness on alleviating knee joint pain, restoring knee joint function, and minimizing knee joint trauma.”

Dr. Echezona listed the currently available options for treating knee osteoarthritis.

Stem-cell treatment of knee osteoarthritis is not currently approved by the Food and Drug Administration (FDA) in the United State, noted Dr. Echezona.

“Many therapies for osteoarthritis of the knee involve lifestyle modifications such as exercise, weight loss if appropriate, and diets rich in anti-inflammatory foods. Physical therapy is a great option to increase strength, improve range of motion and flexibility, and even reduce pain.”

In addition, Dr. Echezona said:

“There are many classes of medications which may be used topically (e.g., anti-inflammatory agents, lidocaine, CBD), orally (e.g., acetaminophen, anti-inflammatory agents, duloxetine), or even injected (e.g., hyaluronic acid, steroids) to treat pain. If none of these treatments are helping your pain, surgery may be an option.”

“Stem cell implantation may potentially repair affected tissue, develop new cartilage, decrease inflammation, and slow down further degeneration,” explained Dr. Echezona.

“This leads to decreased pain and improved functionality, which can contribute to joint strengthening,” she said.

The studies and meta-analysis use several scoring systems for assessing individuals’ pain levels.

“As patient pain scores are improved,” said Dr. Arciero, “restoration of function, including increased mobility/movement and subsequent strengthening and flexibility will follow. This allows for return to activities of daily living and enhanced well-being.”

“Exercise,” predicted Dr. Echezona, “is appropriate and will likely be encouraged with stem cell implants.”

Both Drs. Echezona and Arciero cautioned that individuals who receive stem cell therapy should closely consult their physicians regarding subsequent exercise.

Dr. Echezona warned that “[w]hat we all have to keep in mind is that there is a lack of standardization in treatment protocols, especially regarding the cell type, cell source, cell quality, cell dose, and criteria used to evaluate treatment outcomes and safety.”

“Despite this, the treatments show excellent potential, so we look forward to future studies to support efficacy and safety,” said Dr. Echezona.

The authors of the meta-analysis concluded by prioritizing stem cells by effectiveness: first, mesenchymal stem cells from umbilical tissues, second, stem cells extracted from patient’s own adipose fat, and finally, mesenchymal stem cells from bone marrow.