A pioneering trial to treat knee arthritis by using patients’ own stem cells to regrow worn out cartilage is to start in the UK later this year; if successful the new technique offers hope to millions of people who suffer with the pain and stiffness of osteoarthritis, although the researchers warn that the treatment is unlikely to remove the need for joint replacement surgery.
The trial will take place at the Robert Jones and Agnes Hunt Orthopaedic Hospital in Oswestry, Shropshire, already renowned for being the first in the world to use stem cells to mend fractured bone.
Study leaders include Professor Sally Roberts and Professor James Richardson from Keele University’s Institute for Science and Technology in Medicine (ISTM), who also work at the Robert Jones and Agnes Hunt Hospital.
When cartilage in joints like the knees and hips wears down, the exposed hard bones rub against each other and cause inflammation, stiffness and pain, and sometimes also structural damage in the joint as the bones deform each other.
The human body, along with other mammals, has a natural reserve of stem cells for healing bone. The cells are called mesenchymal stem cells (MSCs) and they are stored in the bone marrow. Previous studies have already shown it is possible to grow them in the lab and also to form bone in animals and patients.
The team at Robert Jones and Agnes Hunt Hospital has also succeeded in taking patients’ own MSCs, growing them in a culture of the patients’ own serum, then put them back in the patient to repair fractured bone.
About 70 patients with knee osteoarthritis are expected to take part in the trial. After the operation the, researchers will then follow their progress for another 12 months to monitor the state of the cartilage and changes in their day to day living.
To remove the stem cells, a surgeon inserts a needle in the back of the patient’s pelvis and aspirates a mixture of blood and cells (this can be done under local or general anasthetic). The stem cells are then taken to the lab for separation and culturing. There can be as few as 20 cells to begin with, but over a few weeks these multiply to several million.
The cultured cells are then injected into the affected joint, where it is hoped they will eventually produce chondrocytes, the cells that make up cartilage, and reduce the inflammation and pain in the joint.
The researchers said the treatment, if successful, should be available in the next five to ten years, but people should not view it as a cure for osteoarthritis.
Richardson told the Daily Mail that the procedure may not remove the need for a joint replacement, but it may “prevent the need for a revision joint replacement”.
Roberts was also keen to stress that people realize the limitations of the treatment. She said stem cells have “huge potential”, and we need to learn how to harness them properly, but they won’t give you back the joints you had when you were a teenager. Also, they don’t “solve the underlying problem of osteoarthritis which still needs to be addressed”, she told the paper.
Another application mentioned on the Robert Jones and Agnes Hunt Hospital website is using stem cells in conjunction with the ACTIFIT artificial meniscus, to repair torn cartilage or meniscus tears, one of the most common knee injuries. The patient’s own cultured stem cells are added at the time of surgery to help regenerate tissue at the affected site.
Sources: Daily Mail, Robert Jones and Agnes Hunt Orthopaedic Hospital, AAOS.
Written by: Catharine Paddock, PhD