Articular cartilage has a very limited capacity for self repair and usually, once damaged, results in progressive degeneration of the underlying and surrounding cartilage until the ability to shield the underlying bone is non functional leading to small areas of localised arthritis, with symptoms of pain swelling. Similarly, where larger areas of cartilage have been worn away, the knee will begin to experience degenerate symptoms including aches, pains and swelling but will also begin to develop stiffness and eventually progressive deformity, in a common pattern of wear and tear or osteoarthritis. Other arthritic symptoms include difficulty arising from a seated position, squatting, kneeling, negotiating stairs or sleeping at night. Various non-surgical solutions currently exist for arthritic knees include weight loss, activity modification, natural anti-inflammatories (fish oil, krill), simple analgesia (Panadol, Panadol Osteo), non-steroidal anti-inflammatories (NSAIDs), physiotherapy, orthotics, braces, walking aids and in many cases, combinations of these treatments will help patients to achieve a pain managed state. Where non-surgical treatment options have been unsuccessful, consideration of surgical techniques such as arthroscopy including microfracture, cartilage transplant, osteotomies and knee replacements can be considered.
It is hoped that stem cell therapy will become a useful tool to help improve the results of some of these smaller operations such as microfracture and cartilage transplant and also to help delay or avoid altogether some of these larger operations such as osteotomies and knee replacements. Stem cells are from one of two main groups – adult stem cells which are found in all tissues of the body and when derived from connective tissue (mesenchyme) are referred to as mesenchymal stem cells (MSCs) or the alternate source being embryonic stem cells that are derived from the inner cell mass of early stage embryos. Currently stem cell therapy for the knee has been performed using adult stem cells from autologous donors (patients donating from their own bodies to themselves) where the MSCs are derived from one of two main sites, bone marrow or adipose tissue. Bone marrow derived mesenchymal stem cells (BMSCs) requires a bone marrow biopsy to be performed from either the patient’s pelvis (iliac crest) or distal femur (knee), whereas adipose derived mesenchymal stem cells (AMSCs) are harvested using liposuction from the abdomen, with both techniques able to be performed under local anaesthesia with light sedation as a day surgery type procedure. The regenerative stem cells are prepared in laboratory conditions on the same day as they were harvested into an injectable medium, which is then injected into the knee under sterile conditions using local anaesthetic.
Stem cell therapy is still an experimental treatment, which may provide symptomatic improvement for the arthritic knee but as yet, has not successfully regenerated durable functioning articular cartilage within the human knee in a reliable and reproducible manner in a non laboratory setting. It has been hypothesised but not yet proven that stem cell treatment has a dual benefit of acting as both a powerful anti-inflammatory and either regenerating or helping to slow the rate of wear of cartilage in the knee. Whilst, as with any new procedure, theoretical concerns exist about potential complications such as tumour growth or infection, stem cell therapy has been shown in recent studies to be safe with an acceptable very low risk of such complications. Its role at the present remains unclear, and Dr Gallagher is undertaking his own research to see if it does reverse or slow the rate of wear and / or alleviate some of the symptoms of the arthritic knee before employing its use therapeutically. Thus, it remains an exciting area of modern medicine with many potential applications and Dr Gallagher remains committed to studying the effects of stem cell therapy in the knee, and, when and where it is likely to reliably provide preventative or restorative benefit to the knee, commence performing stem cell therapy in the future.