Osteoarthrosis is a chronic joint disease characterized by localized articular cartilage degeneration, bone loss, joint edge spur formation and joint deformity and subchondral bone denseness, also known as osteoarthritis, degenerative osteoarthrosis, proliferative arthritis, and age-related arthritis. The disease affects the quality of life of middle-aged and elderly patients to varying degrees.
Etiology
The cause of the disease is still unclear, but it is thought to be closely related to ageing, and may also be related to excessive joint activity (e.g., frequent strenuous joint activity), joint overload (e.g., obesity), joint trauma, genetics, intraosseous hypertension, osteoporosis, and metabolic and endocrine abnormalities. In recent years, it has been found that the disease may be associated with T-2 toxin infection.
Pathogenesis
It is also unclear at present. However, it is believed that the disease is mainly caused by joint degeneration due to aging and joint strain, which is a natural manifestation of aging, just like the wrinkled skin of the elderly. The degeneration occurs first in the cartilage, causing changes in the cartilage composition, resulting in a decrease in cartilage elasticity or even loss of cartilage. The load-bearing cartilage surface changes from a normal smooth state to a broken cotton wool state, with the subchondral bone exposed and the bone surface becoming smooth and ivory-like due to constant friction, while the non-load-bearing cartilage surface is repaired, new bone is formed, and bone spurs are formed at the joint edge. In addition the entire course of the disease involves the ligaments, joint capsule, synovial membrane and periarticular muscles, ultimately leading to joint pain and loss of function.
Clinical features
The disease can occur in all joints of the body, but it is more likely to occur in the knee and hip joints, the spine, and the finger joints, which are heavily weight-bearing. The knee and hip joints are particularly affected.
Classification
1.Primary: The cause of the disease is unclear, the patient has no history of trauma, infection, congenital deformity, no genetic defects, no systemic metabolic and endocrine abnormalities and other reasons. Mostly seen in obese people over 50 years old.
2.Secondary: It refers to the joint destruction or joint structure change due to some known causes, such as joint trauma, surgery or other obvious factors.
Clinical symptoms
1.Pain: Almost all cases have varying degrees of pain, which progresses slowly with the course of the disease. The pain is obvious when the joint starts to move, and it decreases after a little activity, however, when there is too much weight bearing and joint activity, the pain increases again, which is characteristic of osteoarthrosis. Sometimes the pain can be radiated, such as hip pain can be radiated to the inner thigh, near the knee joint.
2.Mobility disorders: In the early stage, joint stiffness can be seen, such as when the knee joint is in a certain position for a long time, the movement is unfavorable and it is difficult to start; later, joint instability gradually appears, the range of motion of joint flexion and extension decreases and the walking ability decreases, especially the ability to go up and down steps, squat, run and jump decreases more obviously.
Clinical signs
1. Joint swelling: The eyes of both knees are full, and in severe cases the suprapatellar capsule (suprapatellar area of the knee) is obviously swollen, and the knee joint is swollen in the shape of a crane’s knee. In addition to acute infection, there is usually no redness or fever in the joint.
2. Peri-articular pressure pain: most commonly in the medial knee joint.
3. Restriction of joint movement: manifests as difficulty in joint flexion and extension, and difficulty in squatting.
4, joint friction sounds and friction sensation: friction sensation can be palpated and friction sounds can be heard when flexing and extending the joint.
5.Muscle atrophy: Long-term osteoarthrosis does not heal due to joint wasting and muscle atrophy around the joint. Most commonly, the quadriceps muscle of the thigh is atrophied, resulting in weakness in knee extension.
6. Deformity: It is seen in advanced patients, with inversion of the knee being the most common. The “O” shaped leg, as seen in some patients, is the result of internal derangement of the knee.