While many new and amazing therapies for rheumatoid arthritis have been developed in recent years, very little progress has been made in the treatment of osteoarthritis.
Osteoarthritis (OA) is the most common form of arthritis and affects approximately 30 million Americans. OA is a disease of articular cartilage, the gristle that caps the ends of long bones. Cartilage has both gliding as well as shock absorbing properties.
It is this flexibility of function that enables a joint to work properly.
Normal cartilage is composed of cells called chondrocytes that sit inside a matrix consisting of collagen and glycosaminoglycans... much like grapes inside Jello.
Osteoarthritis develops when the chondrocyte begins to malfunction and starts to produce destructive enzymes. At the same time water content inside the matrix changes making it more susceptible to stress. Small cracks, called "fissures" develop. Also, local inflammation involving the lining of the joint- called the synovium- begins. The end result is a gradual and premature wearing away of cartilage.
This process is most apparent in weight-bearing areas such as the neck, low back, hips, and knees.
Current approaches to the treatment of OA involve the use of analgesics (pain-relieving medicines), non-steroidal anti-inflammatory drugs (NSAIDS), physical therapy, proper weight management, exercises, injections of steroids, injections of viscosupplements (lubricants), and surgery.
While many of the above treatments help relieve pain, they do nothing to prevent cartilage loss... and more importantly, they do nothing to restore cartilage.
Orthopedic techniques such as chondrocyte transplantation and cartilage plug surgery are helpful for discrete, relatively small areas of cartilage loss but are generally reserved for younger people who have had traumatic injuries to cartilage. But what about the older person who suffers from osteoarthritis?
In recent years there has been much interest in the role of regenerative techniques to rebuild cartilage.
The topic of much study are stem cells. Stem cells are pluripotential cells, meaning they are cells that can become any kind of tissue, given the right stimulus. Stem cells can be obtained from embryonic tissue, which is a source of much controversy. Or they can be obtained from adults. The adult body has a small number of stem cells in many tissues. They are activated by injury or illness. Adult stem cells, as a rule, do not have the ability to differentiate as well as embryonic stem cells.
However, in recent years, techniques have been developed to harvest mesenchymal stem cells- stem cells found in the bone marrow. These mesenchymal stem cells cells, when properly prepared and concentrated, have the ability to differentiate into cartilage and bone.
Stem cells are harvested from the the patient's iliac crest bone marrow using local anesthetic and a special type of biopsy needle. The stem cells are then specially concentrated.
After the stem cells are prepared, the physician, using ultrasound guidance and local anesthetic, finds the area of arthritis involvement and irritates the area using a special large needle. This irritation is important because it initiates an inflammatory reaction which is the prelude to healing and regeneration. The areas that are irritated include the capsule, tendon insertions, pericapsular soft tissue, as well as cartilage.
Blood is drawn from the patient and spun in a special centrifuge in order to obtain platelet rich plasma. Platelets are blood cells that contain multiple growth and healing factors.
Once the irritation has been completed, stem cells as well as the platelet rich plasma are injected into the prepared area.
The growth factors within the platelet rich plasma act on receptors found on the surface of stem cells and cause the stem cells to differentiate and multiply.
The end result is cartilage regeneration as well as lessening of pain. While the data is preliminary, the early results appear to be very promising.
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