The pathogenic factors of osteoarthritis of the bones and joints are not single, and changes in collagen, proteoglycan, chondrocytes, cartilage, synovium, etc., can affect other components, so the pathological forms of degenerative changes in joint cartilage are also varied.
1. Ageing:Ageing is the strongest risk factor for the development of osteoarthritis. According to post-mortem data, about 5% of people have degenerative changes in their joints from the age of 20, and by the age of 40, almost 90% of weight-bearing joints have varying degrees of osteoarthritis changes. Professor Zhang Naijing and others conducted an epidemiological survey of knee osteoarthritis among 2063 adults in the suburbs of Beijing and found that among those aged 16-30, 31-40, 41-50, 51-60, and over 60 with knee pain, the positive rates of osteophytes were 10.6%, 14.8%, 29.1%, 51.8%, and 78.5%, respectively, increasing with age.
2. Gender:According to the data analysis of Professor Zhang Naijing and others, the incidence rate of women is twice that of men before the age of 50, but it is basically equal between the two genders after the age of 50.
3. Occupation:Osteoarthritis is related to occupation. The long-term and repeated use of certain joints can increase the incidence of these joints. For example, the elbows and shoulders of foundry workers, the spine and knees of miners, the knee and ankle joints of loaders and unloaders, the shoulders of drivers, the wrist joints of repairmen and weavers, the metatarsophalangeal joints of ballet dancers, the cervical joints of those who engage in long-term embroidery, typing, and sedentary work, and the calcaneus of textile workers, salespersons, receptionists, and honor guards who work in a standing position for a long time. These parts, due to the long-term and repeated performance of a single action, cause the joints to be worn out frequently and lead to osteoarthritis. The 1994 edition of the 'Annals of Rheumatology' pointed out that a comparison of 109 male and female patients aged 50 or over with osteoarthritis with 218 people without osteoarthritis showed that those who spend more than 30 minutes a day in a squatting or kneeling position or climb more than 10 floors a day have a significantly higher incidence of knee osteoarthritis.
4. Genetic factors of race and ethnicity:The incidence rate is highest in the British and lowest in West Africa; the incidence rate in whites is higher than in blacks; for women with Heberden's nodes, their mothers and sisters are 2 to 3 times more likely to have the disease than the general population. Moreover, the detection rate of HLA-A1 and HLA-B8 in patients with osteoarthritis is increased.
5. Physiological factors:Weight gain makes the already worn-out and degenerated joints plus the additional burden even more likely to be damaged, so osteophytes often occur in areas with heavy load, such as the hip, knee, calcaneus, and lumbar spine. Additionally, due to joint pain, patients unconsciously limit their activities, leading to weight gain, which further exacerbates joint lesions. A study published in the American Journal 'Today's Arthritis' indicates that people who are 20 pounds overweight compared to the standard weight have a 3.5 times higher chance of developing osteoarthritis than those with normal weight. The most common sites are the hip and knee joints.
6. Poor posture:The incidence of cervical spondylosis in those who work at a desk for a long time, have poor sleeping posture, or use unsuitable pillows is particularly high. This is due to the imbalance of paravertebral muscles, ligaments, and joints, where the side with high tension is prone to varying degrees of fatigue, and due to the continuous tension of some muscles in the cervical spine, these muscles may eventually develop static injuries, leading to degenerative changes in the cervical spine and causing osteophytes. It is also related to the long-term uneven stress on the cervical spine joints, causing excessive stress on a certain part of the joint and damaging the joint.
7. Bone venous stasis and bone hypertension:Abnormal bone blood flow characterized by bone venous stasis and bone hypertension, which leads to a decrease in the difference between arterial and venous pressure, a reduction in the blood flow of nutrient vessels, and nutritional disorders that can cause the necrosis of trabecular bone, and the necrosis of bone cells may be one of the causes of arthritis.