WHY ARE STEM CELLS SPECIAL?
Stem cells are located throughout the body. What makes stem cells special is that they can divide and duplicate into different cell types. Stem cells are known to transform to accommodate a certain need when placed in a certain environment. For example, stem cells in the vicinity of damaged cartilage are thought to develop into cartilage tissue. There are two basic forms of stem cell – the embryonic stem cell and adult stem cell. Adult stem cells, which are also known as mesenchymal stem cells or MSCs are of great interest to researchers, scientists and surgeons alike. MSCs are free of the controversy that surrounds the embryonic stem cells and yet have the potential to form new tissues. At our centre, we use the MSCs. This gives us the ability to repair and regenerate tissues such as cartilage and bone more effectively.
HOW ARE STEM CELLS USED FOR ARTHRITIS TREATMENT?
Stem cells may be applied during surgery (such as surgery to repair a torn knee meniscus) or directly into the arthritic joint through injections. Sometimes medical imaging, such as ultrasound is used to deliver cells precisely to the site of cartilage damage when administering stem cell injections
WHO CAN HAVE STEM CELL THERAPY FOR ARTHRITIS?
Stem cell therapy is available for most people who suffer with arthritis. Most published research indicates that younger patients who have relatively mild to moderate osteoarthritis or cartilage damage see the most benefit. According to some evidence, people with severe arthritis can also benefit from stem cell therapy.
WHERE DO THE STEM CELLS COME FROM?
The stem cells are harvested autologously – directly from the patients. Consequently, there is no risk of disease transmission, rejection or ethical controversy that can exist using cells from an unrelated donor. All humans have a supply of MSCs in various tissues and these can be harvested using specialised techniques.
The most common type of stem cells used for treating arthritis are mesenchymal stem cells. Mesenchymal stem cells are usually collected from the patient’s fat tissue, blood or bone marrow.
The process of collecting cells is often called harvesting.
Adipose (fat) stem cells are harvested using surgery or liposuction.
Peripheral blood stem cells, found in the bloodstream, are harvested by taking a blood sample from the patient.
Bone marrow stem cells are harvested from one of the patient’s bones, which is processed and the stem cells prepared are used as an injection.
Bone marrow is usually taken from the pelvic bone using a needle and syringe, a process called bone marrow aspiration. The patient is given a quick short general anaesthetic or sometimes a local anaesthetic with a sedative during the procedure.
WHERE CAN STEM CELLS BE USED?
Stem cells can be used in a variety of degenerative conditions to help in the repair and regeneration of damaged tissues and structures. In joint preservation, one role of stem cells is in the treatment of arthritis of the affected painful joint. Most frequently involved joints to which stem cell therapy is given are the hip, knee, shoulder and ankle but other smaller joints can also be treated. This can potentially be accomplished by regeneration of cartilage tissue (gristle). In simple terms, the gristle on the joint surface is the barrier to arthritis. Once this layer is damaged, the joint is likely to progress to frank arthritis, which presents as pain, stiffness and loss of function. Stem cell therapy may be used in an attempt to encourage regeneration of this gristle layer.
The procedure is designed to help preserve the natural joint cartilage and perhaps delay or prevent the need for more major operations such as joint replacement procedures.
Another area of particular interest for stem cell therapy in the hip and knee is to help with the regeneration of dead bone. In a condition called avascular necrosis, or AVN, there is death of a segment of the bone near the joint. This can sometimes progress onwards to become severe arthritis. Early reports of the use of stem cells to regenerate bone in AVN are encouraging.
There are many other reasons why stem cells might be used. These techniques may be relevant to different patients and are employed as required
WHAT DOES THE PROCEDURE INVOLVE?
The injection is done as a day case procedure under a short general anaesthetic. Patients often ask whether stem cell therapy involves surgery on two separate occasions. For the techniques that we use, only a single operation is normally required. This is normally carried out as day-case procedure with or without an arthroscopy alongside. Once the patient is under general anaesthesia, an aspirate of their blood and/or marrow is taken with a special needle. This is taken most commonly from the hip bone. The aspirate is then processed in the operating theatre, and the stem cell injection injected into the joint. If a key hole procedure is required this is performed prior to the injection. The surgeon uses specialist arthroscopy techniques to prepare the tissue bed so that it is ready to receive the stem cells. The harvested stem cells, sometimes alongside a suitable scaffold, are then injected through the same keyholes that are routinely used for the arthroscopy.
WHAT ARE THE SIDE EFFECTS?
Any surgical intervention carries a degree of risk however the surgical procedures used for stem cell therapy are the same as those for routine hip or knee arthroscopy operations. There is a theoretical risk of infection, but this is low and surgery is in any event covered by antibiotic treatment. As for the stem cells, these are derived from the patient’s own blood or marrow, so there is no risk of rejection or disease transmission.
WHAT IS THE EVIDENCE FOR STEM CELL THERAPY?
Stem cell therapy is a relatively new procedure. However, it has created so much interest worldwide that extensive research has been taking place in this field. Animal and human studies have been published that have suggested a safe and favourable response to stem cell therapy in hips, knees, ankles and even smaller joints. Our practice routinely collects outcome data on almost all patients who undergo surgical treatment under our care; assessment questionnaires are periodically sent to those who have undergone surgery. This is an invaluable source of information that helps us to inform our patients, publish in the literature, and to train others who are interested in the techniques we undertake.
Through many trials and research around the world scientists have injected osteoarthritis patients with Bone marrow derived cells in different occasions. Their results have been thoroughly compared by peers and patients, evaluating pain scores and walking ability post treatments. Some of the trials showed that in patients with knee OA treated with intra-articular injection of autologous bone marrow-derived stem cells (BM-SCs) observed that the patients demonstrated rapid and progressive improvement of their functional indices and pain by 1 year and also showed a highly significant decrease of poor cartilage areas with improvement of cartilage quality.
Another study carried out in injections of BM-SCs in knee OA was shown to improve pain, functional status of the knee, and walking distance without any adverse events. An increase in cartilage thickness and a considerable decrease in the size of damaged sub-chondral bone were noticed.
A trial in Germany showed a good defect filling and repair of tissue with BM-SCs in patients with knee OA and a significant clinical improvement. Another study reported that BMSCs in patients with medial femoral condyle lesions, could result into normal arthroscopic appearance.
POST TREATMENT CARE
Routine follow up appointment at 3 months with ongoing support and care for your condition through our helpline and clinic.
If you have a good response to the injection it does not need to be repeated often and should give you pain relief and improved function for 2-3 years, if not longer.
We recommend repeating the MRI scan on a yearly basis to assess cartilage healing but this is not mandatory.