Regenerative medicine is a branch of translational research in tissue engineering and molecular biology which deals with the process of replacing, engineering or regenerating human cells, tissues or organs to restore or establish normal function. This field holds the promise of engineering damaged tissues and organs by stimulating the body’s own repair mechanisms to functionally heal previously irreparable tissues or organs.
Regenerative medicine also includes the possibility of growing tissues and organs in the laboratory and implanting them when the body cannot heal itself. If a regenerated organ’s cells would be derived from the patient’s own tissue or cells,this would potentially solve the problem of the shortage of organs available for donation, and the problem of organ transplant rejection.
The National Institutes of Health defines regenerative medicine as “the process of creating living, functional tissues to repair or replace tissue or organ function lost due to age, disease, damage, or congenital defects. The hope is to restore damaged tissue that will not adequately heal on its own.
Regenerative medicine treatments can be divided into three categories
- Cellular therapies – facilitate healing by injecting or placing live cells into the patient. Examples of cellular therapy include PRP and stem cell therapies, which can be used to treat tendinopathy and other sports injuries. Cellular therapy is sometimes called cell therapy or cytotherapy.
- Tissue engineering – replaces or repairs damaged tissue with natural tissue, man-made tissue, or a combination of both. In sports medicine, tissue engineering techniques may be used to treat cartilage injuries.
- Other therapies – that attempt to trigger the body’s natural ability to heal tissues without introducing new cells or tissues. Prolotherapy is an example of this is type of therapy.
How Is Regenerative Medicine Used for Sports Injuries?
In sports medicine, regenerative medicine treatments are typically used to repair or replace damaged cartilage, tendon, and ligament tissues.
Physicians who recommend regenerative medicine treatments for sports injuries hope to:
- Amplify the body’s natural healing abilities
- Encourage the growth of new tendons, ligaments, or cartilage tissue
The goal is to reduce pain and improve function.
Rest, physical therapy, bracing, and taping
Regenerative medicine is not a substitute for traditional nonsurgical treatments, such as rest, bracing, taping, and/or physical therapy to improve flexibility and strength. Regenerative medicine and traditional treatments can be used together to optimize healing.
Other applications for regenerative medicine
Regenerative medicine is not limited to treating sports injuries. For example, tissue engineering allows skin tissue to be created for burn victims. Other applications, such as developing artificial organs, are being researched.
Does Regenerative Medicine Work?
Clinical research studies of regenerative medicine treatments have shown mixed results but are generally encouraging. Most studies have been relatively small. More large-scale, high-quality clinical studies are needed before scientists can know exactly if and how regenerative medicine treatments help heal sports injuries such as tendinopathy.
Interest in regenerative medicine has grown, particularly as some doctors and researchers look for a way to treat patients without NSAIDs or cortisone. As time passes, individual doctors learn and share information, improving the application of these treatments.
Until more is known, regenerative medicine treatments are not considered standard practice and insurance plans typically do not cover them. Many patients are willing to pay out-of-pocket.
Stem cell injections, platelet rich plasma (PRP), prolotherapy, and cartilage regeneration techniques are examples of regenerative medicine treatments physicians use to treat sports injuries. This page describes those treatments.
Regenerative medicine treatments may be used independently or together. For example, PRP can be used alone in a therapeutic injection or applied during cartilage regeneration surgery.
4 Types of Regenerative Medicine Treatments
All of these treatments are outpatient procedures and may not be covered by insurance. More than one treatment session may be required before results are felt and, as with any treatment, results are not guaranteed.
1. Stem Cell Treatments
A stem cell does not serve a specific bodily function, but it can develop into a cell that does, such as a cartilage cell or a tendon cell. Physicians who use stem cell therapy believe that, when placed into a certain environment, stem cells can transform to meet a certain need. For example, stem cells that are placed near a damaged Achilles tendon are hypothesized to develop into healthy Achilles tendon cells.
Physicians usually collect the stem cells used for treatment from the patient’s fat, blood, or bone marrow. Some companies sell doctors stem cells from amniotic fluid, placenta- or cord-tissue, but without close oversight these cells usually die during storage and transport—making the product ineffective.
Many experts believe that the natural healing properties found in the blood’s platelets and plasma can be used to facilitate the healing and repair of sports injuries. PRP can be injected or applied to the injured area during a surgery
To make PRP, blood is taken from the patient and then processed—often using a centrifuge—to create a concentrated solution of platelets and plasma (PRP).
All PRP is not the same. PRP therapy varies, depending on factors such as differences in patients’ blood, the method of blood processing, and the use of other substances, such as anesthetics (e.g. lidocaine).
Inflammation increases blood flow and attracts cells—granulocytes, monocytes, macrophages and fibroblasts—that can repair and heal damaged tissues. Sports injuries usually cause inflammation, but in some cases inflammation subsides before the injury has healed. During prolotherapy, a physician injects an irritant into the injured area, which temporarily increases inflammation. The hope is that the additional inflammation will facilitate further healing.
Prolotherapy sometimes uses PRP as an irritant, but prolotherapy is not by definition a cellular therapy. In fact, the most commonly used irritant is dextrose, a simple sugar. Substances such as glycerine or saline may also be used.
Note: Compared with other regenerative medicine treatments, such as stem cell and PRP injections, there is not a lot of clinical research regarding prolotherapy and its effectiveness.
4. Surgeries for Cartilage Regeneration
Because cartilage does not contain blood vessels, it does not have a reliable blood supply, which prevents damaged cartilage from healing well naturally. Different techniques may be used to try to repair cartilage, including but not limited to:
- Making small cuts or abrasions in the bone directly below the cartilage injury. The aim is that the blood from the damaged bone will facilitate new cartilage cell growth.
- Transplanting cartilage from another part of the patient’s body, a donor, or animal.
- Implanting engineered tissue made from stem cells and an artificial scaffold—a sort of microscopic netting that holds the cells until they mature and grow.
Note: These techniques are typically used to treat damaged articular cartilage, which covers bone at the joints, not other types of cartilage, such as the knee meniscus.
When considering regenerative medicine treatment for a sports injury, people have lots of choices regarding types of treatment and where to get it. The abundance of choices, along with the uncertainties about efficacy and lack of formal professional medical guidelines, can be overwhelming.
To help make the decision, patients are encouraged to ask their doctors about their training, the recommended procedure, cost, and potential side effects.
Considering Cost of Regenerative Medicine
In most cases, insurance does not cover regenerative medicine treatments and patients must pay out-of-pocket. Prices vary considerably depending on the specific treatment, region, and doctor and/or hospital.
For example, the cost of a single PRP injection typically ranges from $500 to $2,000. Bone marrow stem cell injections range from $2,000 to $5,000 or more. Therapeutic injections and prolotherapy, which can cost $100 to $500, often require more than one treatment, raising the overall cost.
Physician Training and Details About the Procedure
When selecting a physician for any type of regenerative medicine therapy, patients may want to ask:
- What training does the doctor have in performing the treatment? Some experts recommend that a doctor offering any regenerative medicine therapy complete a formal training course or have extensive one-on-one training with an experienced doctor.
- Does the doctor have experience treating this problem with the proposed regenerative medicine treatment? What is his or her success rate?
- If stem cells or PRP is being used, is a blood analysis (hemodialysis) done before treatment?
- Are the stem cells or PRP cells being used live cells? How is their viability verified?
- Are any anesthetics or additives used during the procedure? How might these affect the treatment outcome?
- If an injection will be given, does the doctor use ultrasound, fluoroscopy, or computed tomography (CT scan) to guide injections? Does the doctor have training or certification to use these imaging technologies? Some experienced orthopedic and sports medicine physicians are able to make accurate injections to certain tendons without the need for imaging; however, proper use of imaging technologies can ensure that the injections are administered precisely.
A patient might worry that questions about a doctor’s training and experience could offend the doctor. However, a doctor should be able to answer these questions openly and freely.
Potential Risks, Benefits, Recovery Times
Most regenerative medicine treatments are considered safe and have few potential side effects, but side effects do occur. Before providing any treatment, a doctor should also explain the:
- Potential risks
- Possible benefits
- Steps of the procedure
- Follow-up protocol, which should include at least one follow-up appointment
- Expectations for recovery and time frame for healing
The patient may be asked to sign an informed consent form that the therapy is an elective procedure with certain risks and side effects.