Stem Cell Injections

About

Over recent years, a lot of attention has been focused on the potential for stem cells to treat osteoarthritis. This attention was largely due to claims that stem cells could regenerate the articular cartilage. This has certainly been received with enthusiasm by OA patients, eager for any scientific breakthrough that may alleviate their suffering or potentially reverse the arthritic process.

It is a complex subject, and it is very important to understand the basic science and the level of scientific evidence-in-support before electing to undergo stem cell treatment. Patients must consider the health risks and the price of such treatments, which are typically around $9000 out-of-pocket.

Scientists will refer to stem cells as ‘mesenchymal stem cells’ (MSC’s), and will often add words like ‘multipotent’ or ‘pluripotent’ in front of these terms. All this means is that the stem cells are immature cells that have yet to decide what to become. For instance, with the right stimulation and environment, a stem cell could become a bone cell, a cartilage cell, a liver cell or a skin cell. This process is called ‘differentiation’.

The stem cells that are offered for injection into arthritic joints are usually sourced from bone marrow or fatty (adipose) tissue. If these harvested stem cells are not in high enough numbers, they can be placed in growth factors to culture and multiply before injection into the joint.

Once the cells are injected into the joint, the first question is whether they will differentiate into articular cartilage cells? Remember, no new cartilage cells have been formed since childhood. In an attempt to increase the chances of this occurring, the stem cells are often injected with Platelet Rich Plasma (PRP), which contains some of the growth factors and proteins that are thought to stimulate differentiation into cartilage.

If the cells do differentiate into cartilage cells, the next question is whether these cells will stick to the remaining bone or cartilage and generate new articular cartilage?

Here we must consider that patients typically keep walking and carrying out their normal daily lives after the injection, with many times their bodyweight being put through the knee joint. The friction and load on the area where the cells are meant to adhere is high, and the generation of new cartilage is uncertain in such an environment. We must rely on the quality of scientific evidence to tell us whether stem cell technology should currently be selected for the treatment of knee arthritis. With the costs of treatment so high and with bias in research publications being common in this new area, assessing the quality of the evidence in support is critical.

Be Aware

Leading Australian scientists and physicians have expressed concerns that stem cell treatments for osteoarthritis and other diseases are being marketed to vulnerable people in Australia without sufficient evidence or regulation. This is made possible due to the loophole in the Australian Therapeutic Goods Administration Act which allows the use of any material derived from a patient’s body as therapy for that same patient.

The National Health and Medical Research Council (NHMRC) and other Federal Government health authorities have issued warnings about unproven stem cell treatments, criticised direct-to-consumer advertising, the lack of safety and clinical evidence, and the hefty price tags. Many see the use of stem cells for OA as human experimentation on a large scale.

This is not to say that stem cells will not have a role in the future treating of OA, however the relatively unknown risks and benefits, and the significant cost, should be carefully weighed against other treatment options.