This is the common perception of knee osteoarthritis in our country, where primary hip osteoarthritis is rare. However, in the recent past, it has been realized that not only the elderly are at definite risk of osteoarthritis, but also many more middle-aged and even young people. Osteoarthritis is the most common form of joint disease (arthritis) and is one of the leading causes of disability in older people in India and in many countries. It is the common perception that the inevitable wear and tear with aging only leads to osteoarthritis, but this is not the whole truth. As we will see, not only the elderly, but others are also vulnerable to osteoarthritis.
Osteoarthritis (OA) in the peripheral joints most often affects the knee joint, and the disease can affect one or more of the three compartments of the knee. The knee joint acts to transfer force from the thigh muscles to the leg to move the body. The loads exerted on the knee surfaces during normal daily activities are two to seven times the body weight. Therefore, it is not surprising that the knee is so vulnerable to wear and tear (osteoarthritis). Osteoarthritic changes in the joint decrease the effectiveness of load transfer during these activities. General health is affected and OA of the knee has been shown to cause more limitations in walking, climbing stairs or other daily activities than any other disease. The form of the disease in the elderly is called primary osteoarthritis, while the affliction of the young and middle-aged is called secondary osteoarthritis. Let’s take a look at the risk factors for developing secondary osteoarthritis, which spans other age groups of people in the general population.
These are of two categories, General or systemic and local risks.
General risks
Evolution
The man along with two other mammals, the elephant and the bear, are the only animals that have straight knees. Evolutionarily straight knees are invaluable in minimizing energy expenditure when walking so that the body does not lean from side to side as it would if the knees were bent in a two-legged creature. The price or secondary effect of the upright posture is the transmission of weight through the inner half of the knee joint. Therefore, the inner half of the knee is susceptible to wear and tear over the normal course of time.
Genetic factors
These play an important role in a widespread form of the disease that is known to affect some communities and families. Research is ongoing to identify the exact genetic location that increases susceptibility to OA.
Diet
Many degenerative diseases such as osteoarthritis are the result of tissue damage from the attack of “oxygen free radicals”. Normal cartilage cells are known to reduce free radicals. Antioxidants such as vitamins A, C, and E have the potential to protect against such tissue damage. People who consume high amounts of vitamin C were found in one study to have a 60 to 70 percent reduction in the risk of progressive OA. High levels of vitamin C intake were also associated with a lower risk of knee pain according to the same study.
Vitamin D plays an important role in bone mineralization. The results of the above study show that high levels protect against disease progression.
bone mineral density
About three decades ago, surgeons who removed the head of the upper end of the thigh bone from elderly patients with hip fractures in partial hip replacement surgery noted that the end of the bone rarely showed arthritic changes. Since then, numerous studies have confirmed the inverse relationship between osteoporosis and osteoarthritis. Research is currently underway to determine if prescription osteoporosis drugs, such as calcitonin and bisphosphonates, prevent the x-ray changes of OA and prevent cartilage breakdown.
Female hormone deficiency (estrogen)
The incidence of knee osteoarthritis is increased in postmenopausal women, suggesting that estrogen deficiency could be a risk factor and that postmenopausal women are more susceptible to osteoarthritis. Despite the obvious correlation, more research is needed to understand the relationships between bone mineral density, estrogen, and OA. Since women are the predominant sex suffering from OA of the knee, female-specific knee implants or prostheses have been developed for total knee replacement, since the majority (two-thirds) of people who undergo knee replacement knee are women.
Local risk factors
obesity
Increased body weight contributes to an increase in the load transmitted through the weight-bearing knees by a factor of three to seven times the body weight and leads to accelerated wear of the articular cartilage. The relationship between obesity and osteoarthritis is stronger for bilateral than for unilateral disease and is greater in women than in men. Since the load transmitted to the knees varies between three and seven times the body weight, a one-time reduction in weight leads to a three to seven-fold decrease in pressure on the knees. Additionally, knee alignment can affect the impact of body weight on the knee joint. Bow-legged knees are more stressed by body weight, resulting in more severe medial compartment arthritis.
Physical activity
There is no evidence that participation in light or moderate levels of physical activity (walking, running, dancing, bicycling, gardening, and outdoor sports) throughout the life cycle increases a person’s risk of developing osteoarthritis of the knee. This means that even middle-aged people can safely participate in these activities without the risk of developing osteoarthritis.
However, participation in high-intensity contact sports is strongly related to the development of knee osteoarthritis in elite athletes. Many tennis players, runners, and professional soccer players are more likely to have knee arthritis and patellofemoral OA than age-matched controls.
occupational activity
Men in occupations that require repetitive overuse of the knee joint, eg carpenters, painters, miners, dock workers, are at increased risk of developing knee osteoarthritis. Bending, kneeling, squatting, climbing stairs, and lifting heavy loads place abnormal joint load on the knee joint and lead to cartilage damage. Risk factors are similar in both men and women.
Injury
Several studies in Europe and America have confirmed that knee injury is a strong predictor of the development of OA of the knee. Most knee injuries involve the ACL (anterior cruciate ligament) and ACL tears are often associated with meniscal damage or a tear in the medial collateral ligament. ACL injuries occur after two-wheeler accidents, accidents At home and outdoors.Both ACL deficiency and meniscus tears are strongly related to early degenerative arthritic changes.Although it is currently unclear to what extent the common ACL reconstruction operation can delay the onset of arthritis , some studies show that early meniscus-sparing ACL reconstruction without meniscectomy provides the greatest protection after knee injuries is seen in patients who have undergone partial or total meniscectomy, an operation commonly performed by surgeons Meniscal suturing and meniscal transplantation are ways to protect against osteoarthritis.The first op eration is available, but the second has not started yet. early teething problems. A meniscus transplant facility was announced in Chennai last year, but the supply of grafts has not arrived.
Mechanical environment of the knees.
It’s easy to understand how any joint or bearing can wear out quickly when you understand what happens to your car’s tires if the alignment and balance aren’t perfect, or if the tire pressure is too high or too low. The treads on the overloaded part of the tire wear the most. The same analogy applies to the knees. Knees that have a flex like the one pictured will wear out faster. Increased joint laxity, an accompaniment of age, contributes to OA.
muscular strength
It is a well-known observation that people with OA have weakness in the quadriceps muscles. Decreased muscle strength was assumed to be the result of disuse atrophy secondary to knee pain; however, it has recently been observed that many patients with asymptomatic knee arthritis have weak muscles. Therefore, it makes sense to build thigh muscles to prevent arthritis or improve symptoms after it develops, but it should be noted that increasing muscle strength will not stop the progression of the disease.
In summary, knee osteoarthritis, once considered a consequence of aging, is now recognized as multifactorial, resulting from the interaction of a variety of general and local factors such as age, genetic predisposition, unavoidable obesity, trauma, and the mechanical properties of the joint. The traditional surgical treatment of OA “a total knee replacement” is the best long-term cost-effective solution. However, other operations such as an osteotomy to correct the alignment of the bones around the knee, ACL reconstruction, cartilage surgery, and medications are available for different groups of affected patients. They will not doom the patient to develop osteoarthritis at a younger age and become a candidate for a total knee replacement.
