What is Abnormal Cartilage Functioning?

Tampa, Saint Petersburg and Clearwater, Fl

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Most people never give a second thought to whether their cartilage is normal or not.

When it is abnormal and pain, stiffness, and loss of mobility and function occur they become acutely aware there is a problem. In order to understand this a frame of reference of what is normal and then abnormal is useful in understanding the spectrum of joint dysfunction. Normality in a joint sense begins with the cell biology of cartilage. The basic structure of cartilage is a cartilage cell (chondrocyte) and it’s surrounding known as the extracellular matrix. The matrix is comprised of collagen (protein in links that give strength) and it’s support known as proteoglycans) the proteoglycans are comprised of chondroitin sulfate, keratin, and hyaluronon. The chondroitin is popular in over the counter supplements, and hylauronic acid is used in joint injections to give viscosity or lubrication. Aging increases the keratin sulfate which is not fully understood.

Normal joints just like skin are in a constant state of turnover. This is a dynamic process that in an equal state the turnover is stable and as molecules are broken down they are replaced in a consistent fashion and there is no net gain or loss, a equilibrium is achieved. This is true of skin and bone as well. Taking this into account, if the net turnover in the net is negative, a loss of cartilage volume occurs or there is a catabolic or breakdown occurring. If the knee remains in this state over time the minute changes add up and the net loss can be readily appreciated on an x-ray as visible reduction in joint space, manifested as narrowing space between the bones separating the knee. By the time this is readily appreciable on x-rays significant knee joint cartilage is lost and osteoarthritis has set in. Simplistically stated, if cartilage break down exceeds cartilage repair, degeneration occurs.  This process may be adversely affected by accumulated wear and tear, genetics, the aging process or inflammatory states of the body. The local control of these responses are under signals from inflammatory molecules called cytokines. These cytokines are under a complicated pathway of interwoven loops of feedback and inhibition. Unfortunately, the commonly prescribed anti-inflammatory medications do not successfully disrupt this process. These medications only exert an effect at an end product enzyme. This Cox2 enzyme produces a mediator known as Prostaglandin E2. This mediator is responsible for the pain associated with joint degeneration or arthritis. The trade off for pain relief has a most undesirable effect, by inhibiting this enzyme with medications, the buildup of cytokines which initiated the inflammatory response continues and more cartilage is broken down.   Equally troubling is that cartilage cells (Chondrocytes) produce more Prostaglandin E2 and another repair cytokine in response to degeneration as an attempted repair mechanism. Thus, the Prostaglandin E2 is necessary for feedback inhibition of the starting cytokines of the inflammatory cascade.  Another model for addressing the abnormally functioning joint is to circumvent the degenerative response with signals that initiate a repair response. Regenerative medicine incorporates the use of anabolic signals which initiate the repair mode and turn off or inhibit the breakdown mode. Biologics, Platelet-Rich-Plasma (PRP) and Stem Cell Therapy modulate this repair pathway. Biologic medications which address these cytokines have been approved for the treatment of Rheumatoid Arthritis. Unfortunately these expensive medications are not approved or covered for other uses such as Osteoarthritis. Additionally, these medications do not exert a precise effect and can impair the body’s ability to fight off infection. Local therapy such as Platelet-Rich-Plasma (PRP) or Stem Cell Therapy can be administered into a joint like a knee or hip directly without affecting the body’s ability to fight infections. The use of Regenerative Medicine therapies may be the equalizing event for abnormal joint functioning. Stem cells have been called the great balancers, and by balancing the normal joint remodeling process no negative breakdown occurs, and accordingly there is not abnormal joint activity.

 

Dr. Dennis Lox serves patients in the greater Tampa Bay area, including, Clearwater, St. Petersburg, Tampa, New Port Richey, Sarasota, and Spring Hill. He has been pleased to accommodate the needs of patients throughout Florida, the United States, the Western Hemisphere, and Europe, as well. Located in the 33765 and 33765 areas, our offices can be reached at (727) 462-5582 (Clearwater) and (727) 817-1909 (New Port Richey). Call to schedule your visit today.