Arthritis is a term used to describe more than 100 different conditions. The most common type of arthritis is osteoarthritis, a form of wear and tear that is often associated with the aging process. What is ironic is that there is abundant evidence that osteoarthritis begins much earlier in life, possibly as early as the teen years.
With osteoarthritis, there is a complex interaction of inflammation, degeneration, and aging that leads to cartilage deterioration.
Cartilage is the gristle that caps the ends of long bones. The function of cartilage is 6to provide shock absorption and gliding mechanisms for joints.
Cartilage consists of a matrix made up of collagen and proteoglycans- proteins and sugars. Also, cartilage is high in water content. In addition to matrix, chondrocytes, cells that are responsible for production of matrix. Imagine grapes inside a gelatin mold.
What causes arthritis is poorly understood. There appears to be a change in chondrocyte function stimulated by inflammatory changes that occur in the synovium, the lining of the joint.
With these changes, the matrix begins to develop cracks and starts to wear away as the chondrocyte makes enzymes that cause destruction rather than construction of matrix.
The Holy Grail of treatment of osteoarthritis has been to develop treatments that help not only with symptoms but also cause retardation of cartilage wear and tear.
That is where stem cells come in.
Various attempts at inducing cartilage healing with stem cells have met with mixed results. The results appear to be highly dependent upon the following factors: age of the patient, body mass index (BMI), extent of cartilage loss, and the technical expertise of the center performing the procedure.
Cartilage is avascular meaning that blood flow is extremely limited. Limited blood flow restricts the ability of cartilage to heal after injury.
Multiple attempts in the past to heal cartilage have met with dismal results. These have included cartilage cell implants (Carticel), mosaicplasty, as well as microfracture. While these procedures have enabled the formation of fibrocartilage, this type of cartilage is not the same as the hyaline cartilage that has been injured and worn away.
The goal is to try and make hyaline cartilage that can withstand the day to day pounding of daily life. However, there has been encouraging evidence that stem cells can overcome the treatment gap.
The use of autologous stem cells has been reported in a recently published paper.
(Wei N, Beard S, Delauter S, Bitner C, Gillis R, Rau L, Miller C, Clark T. Guided Mesenchymal Stem Cell Layering Technique for Treatment of Osteoarthritis of the Knee. J Applied Res. 2011; 11: 44-48)
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