Osteoarthritis of the knee is a common disease that causes knee pain, aching and swelling. Osteoarthritis of the knee develops most commonly in overweight people especially women past menopause. It is more likely in people who have suffered traumatic injuries to their knees and in those with a family history of the disease.
The Epidemiology of Osteoarthritis of the Knee
Osteoarthritis of the knee most commonly develops in adult women, especially those who are post-menopausal. It is thought that the loss of sex hormone in women plays a key role.
Osteoarthritis of the knee is the leading cause of disability worldwide in both men and women. It affects 15% of adults over age 50 years. For many people, stem cell therapy has the potential to improve, if not restore, knee-joint function. The combination of this therapy together with simple common sense methods and practices are powerful tools to effectively manage this crippling disease without resorting to knee replacement surgery. This represents a revolutionary development in medical therapy.
Knee Osteoarthritis affects some people much worse than it does others. In fact, the vast majority of people with OA of the knee do fairly well despite their aches and pains. They do not require orthopedic surgery or stem cell therapy to live normal happy lives. Genetics is one of the factors that can cause OA to be worse for some people. Unfortunately, your genetics cannot be changed but most of the other factors involved are things that you can have some control over. This includes injuries, your diet, exercise, and loss of key hormones due to aging. Many can be altered positively in ways that will lower the impact arthritis of the knee has on your life today and its effect on you in the future.
Osteoarthritis of the Knee Is an Inherited Disease
There are a number of indicators that prove arthritis is in-part inherited but the process is far from simple. The first clue is found by the higher incidence of arthritis among close relatives of people with this condition than those without the condition. In genetic studies in identical twins, 60% of both have OA of the knee.
Obesity and Risk for Osteoarthritis of the Knee
There is a growing weight problem in America and the prevalence of obesity in women is higher than in men. 30% percent of American adults are obese and another 30% are overweight and these numbers are increasing. The growing obesity epidemic is why OA of the knee is becoming more common.
There are at least two important reasons obesity contributes to arthritis. The first is simple mechanics. Overweight people place increased stress on the joint cartilage during regular activities of daily life. Over time, this results in damage leading to progressive scarring of the articular cartilage that comprises the joint surfaces and causes painful arthritis.
The second comes from recent basic research into fat cell function. These fat cells are scientifically known as the adipocyte. Adipocytes produce inflammatory hormones into the blood that are identical to cytokines released from immune cells that cause inflammation. These include the interlukins (IL1, IL 6 and IL 9) as well as tumor necrosis factor alpha (TNF α). As they circulate through the body they travel to the knee joint and cause arthritis, pain, stiffness.
Aging, Gender, Menopause, and Osteoarthritis of the Knee
Women experience OA of the knee about twice as often as men. The knee is particularly vulnerable in adult women past menopause. The reason why is unclear but it is likely related to a decreased ability of the joint tissues to repair and replace themselves normally due to sex hormone deficiency and a higher prevalence of being overweight and obese after menopause.
The two principle hormones lost at menopause in women are estrogen and androgens. Traditionally physicians and patients have focused mainly upon estrogen replacement therapy after menopause. While this treatment has been shown to prevent osteoporosis it does not prevent OA of the knee or prevent obesity. Androgens influence and are required for mesenchymal stem cells that form bone, joint, and muscle tissue to differentiate or change into these healthy tissues. In the absence of androgens, these stem cells change into fat.
Mesenchymal stem cells are the cells that we harvest from the abdominal fat reservoir and transplant into the knee joint that change into cartilage cells to resurface your damaged joint surface. The presence of the androgen hormone testosterone is necessary for the transformation of these stem cells into cartilage. When androgens are absent, these stem cells transform into fat, which does not contribute to your joint health. For this reason, androgen loss with aging in both genders and menopause in women impairs the normal repair of joint tissue contributing to the development of OA of the knee.
Men also lose androgens with aging but more gradually than women and do not have an equivalent sudden precipitous 50% loss of circulating androgens as occurs at menopause. This gender difference may partially explain why there are twice as many postmenopausal women with OA of the knee than similarly aged men.
It is simple and easy to replace androgens in both men and women using pharmaceutical grade micronized DHEA. I use this hormone judiciously and carefully in each patient and monitor them both clinically and biochemically for unwanted androgenic side effects.
Knee Joint Injuries and Osteoarthritis
Adults, who later in life experience the signs and symptoms of arthritis, commonly report knee cartilage and ligament sports injuries suffered during adolescence and young adulthood. It is very common to hear, “My knee pain all started when…. ”. The follow up to this statement typically has to do with some event that occurred while playing football, rugby, basketball, tennis, soccer, volleyball, or running, etc. The usual cause of injury to the medial or lateral meniscus is when a severe twisting strain is placed on the joint.
The menisci cushion the contact points between the femur above and tibia below that comprise the knee joint. The menisci are pads that sit upon the articular cartilage that attach firmly to the bone that make up the joint. It is this padding that is commonly torn during sporting injuries. A severely injured but repaired joint and one that has sustained non-surgical mild to moderate injury repeatedly will express scar tissue on the articular cartilage joint surfaces and sometimes useless fragments of what remains of previously healthy tissue. Both promote progressive damage to opposing healthy joint tissue. When the cumulative damage exceeds the joints ability to repair it, arthritis is the result. The accumulated damage occurs over time and is one of the reasons that arthritis of the knee is considered a chronic, progressive disease. In other words, in the average person with OA of the knee, the condition usually becomes worse with time.
Trauma that causes the knee to buckle can tear one of the 4 supportive ligaments that help to keep the joint in place by stabilizing the two bones in their proper anatomic position. These ligaments are called the anterior and posterior cruciate ligaments and the lateral and medial collateral ligaments.
In many people when the damage is modest, the injury heals fairly quickly. Mesenchymal stem cells that naturally reside within the joint are one of the key players in normal joint repair and maintenance. These stem cells form a reserve of tissue that is called upon to repair cell damage and replace cells that pass on after reaching their natural life span. The mesenchymal stem cell reserve is reduced when the demand to repair damaged cartilage exceeds the available supply. High levels of inflammatory chemicals and cells present within the joint and also impair the function and activity of the stem cells that remain.
Autologous stem cell therapy restores the depleted stem cell pool by adding many millions of healthy vigorous cells. These cells exert an immunomodulatory effect on the inflammatory cells meaning that in the joint they tamp down the immune cell’s release of inflammatory chemicals and activities. The platelet-rich plasma we administer during stem cell therapy contains large quantities of reparative growth factors that stimulate division, growth, and differentiation of mesenchymal stem cells into mature cartilage that resurfaces the damaged articular cartilage. Platelet-rich plasma also has an anti-inflammatory effect on the inflammatory cells present in the joint independent of the stem cells that are beneficial to patients with osteoarthritis of the knee.
Until the advent of stem cell therapy, there were no disease-modifying therapies that could alter the natural history of osteoarthritis of the knee.