Osteoarthritis (OA) is the most common form of arthritis and affects more than 20 million Americans. Commonly associated with aging, OA affects
weight-bearing areas of the musculoskeletal system such as the neck, low back, hips, and knees. It also affects joints that are highly mobile such as the base of the thumb and the big toe joint.
While OA was considered to be primarily a condition affecting the elderly, it is now believed that OA can begin early- within the second decade of life. OA is a disease that affects cartilage, the gristle that lines the ends of long bones.
Cartilage consists of a matrix that is composed of a mixture of collagen and proteoglycans. Within this matrix, cells that make new cartilage, called chondrocytes, sit... much like grapes inside jello.
Biochemical changes occur that lead to alterations in the matrix of cartilage making it more susceptible to early degeneration. As a result, the cartilage begins to wear away prematurely. Small cracks- called fissures- begin to form. The fissures eventually grow to the point that the cartilage actually flakes away. At the same time, inflammation develops and this accelerates the wearing away of cartilage.
It is difficult to estimate the number of people who have OA but who are not yet symptomatic. However, as we learn more about this disease, it is clear that cartilage changes and symptoms do not necessarily go hand-in-hand.
The treatment of OA then needs to take into consideration both the symptoms of pain that occur along with the biochemical changes that lead to cartilage deterioration.
A number of investigators have devoted much time and effort towards developing medicines called disease-modifying osteoarthritis
drugs... or DMOADS.
Unfortunately, DMOAD discovery is extremely difficult since cartilage damage is hard to quantitate. Scientists have used many different methods to measure cartilage thickness in response to drugs including magnetic resonance imaging, ultrasound, standard x-ray, and arthroscopy. Arthroscopic retrieval of cartilage specimens offers the most hope as far as a definitive marker of effect but is technically difficult.
Currently, the treatment of osteoarthritis is primarily symptomatic. Rheumatologists generally start with non-drug therapies including patient education, dietary counseling, and specific exercises.
Over-the-counter non-steroidal anti-inflammatory
drugs (NSAIDS) such as ibuprofen (eg, Advil) or naproxyn (eg, Aleve) and analgesics such as acetaminophen (eg, Tylenol) sometimes are effective.
Most patients with more than mild OA will require prescription medications such as prescription NSAIDS (Motrin, Naprosyn, Lodine, Relafen, Daypro, Mobic, and Celebrex, to name a few.) These medicines are usually effective but also carry with them potential side-effects including damage to the gastrointestinal system, kidney damage, and an increased risk of cardiovascular events such as heart attack and stroke.
A food-based anti-inflammatory compound called flavocoxib (Limbrel) appears to be effective for some patients and appears to be safer than traditional NSAIDS.
Prescription analegesics such as tramadol (Ultram) may be useful. However, the use of stronger narcotics sometimes is called for in severe cases.
Topical agents such as Myorx (an OTC preparation), Voltaren gel, and patches such as Flector (a patch containeing Voltaren) and Lidoderm (a patch containing lidocaine, a local anesthetic) can also be useful adjuncts.
Since OA tends to affect weight-bearing joints the most, the hip and knee are often the symptomatic areas that bring patients in to see the rheumatologist.
Injections of corticosteroid ("cortisone") or viscosupplements (lubricants derived from rooster combs or other sources... examples being Hyalgan, Supartz, Synvisc, Euflexxa)) can be helpful for symptomatic relief.
The most exciting and promising therapy aimed at both pain relief as well as cartilage regeneration appears to be the use of combined treatment using stem cells and platelet rich plasma. The technique involves the use of autologous stem cells, meaning cells that are harvested from the patient, and given back to the patient... therefore mitigating the ethical concerns associated with fetal stem cells.
Stem cells are harvested using a biopsy needle from the iliac crest (pelvic bone) of the patient. At the same time, blood is drawn and the blood is spun down to produce platelet rich plasma. Platelets are cells in the blood that contain many growth and healing factors. A small gauge needle is then inserted into the joint (knee or hip) using local anesthetic and the area of concern (cartilage, bone spur, and tendon attachments) are mildly irritated with the needle. The stem cells and platelet rich plasma are then injected into the joint.
Preliminary results appear very promising not only for symptom relief but also for chondrocyte and cartilage regeneration.
by Nathan Wei
