How to diagnose knee osteoarthritis? Treatment should be divided into stages!

Author: Guo Xiaozhong, Chief Physician, First Affiliated Hospital of Tsinghua University

Reviewer: Li Jun, Chief Physician, Peking University First Hospital

Knee osteoarthritis is a degenerative disease. As people age, the cartilage of the knee joint gradually wears away, and eventually obvious lesions occur. In addition to age, it is also related to factors such as trauma and overwork.

Knee osteoarthritis first causes knee pain, which is the primary complaint. When it develops to a certain extent, it may also cause functional limitations, such as the inability to bend the knee. As the cartilage wears out more severely, severe knee valgus or knee varus deformity may occur.

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How to diagnose knee osteoarthritis? First, ask about the patient's medical history, such as the time when the pain started and lasted, and the degree of pain. Then perform a physical examination to check whether the knee joint is swollen or deformed, whether the movement is restricted, whether there is fluid accumulation in the joint cavity, and whether the ligaments and menisci are damaged. Combined with the medical history and physical examination, the next step is to perform targeted imaging and laboratory tests.

X-rays can be used to see if there are any changes in the bones, mainly to see if there are signs of wear and tear of the articular cartilage, whether there is narrowing of the joint space, and whether bone hyperplasia and loose bodies have occurred. In addition, a CT scan can be performed to see if there are any obvious changes in the bone and joint structure, whether there are loose bodies, and whether there are subchondral injuries such as cystic changes or subchondral bone sclerosis. Further examination requires a knee joint MRI, which can show in detail the degree of damage to the articular cartilage, whether the synovium is hyperplastic, the amount of fluid in the joint cavity, and can clearly observe the wear or damage of the meniscus and the integrity of the cruciate ligament.

Blood tests are done to see if there are any inflammatory changes, such as whether the white blood cell count, C-reactive protein, and erythrocyte sedimentation rate are elevated; whether there are any abnormalities in the rheumatoid factor, and whether there are any abnormalities in the test indicators of other connective tissue diseases, such as systemic lupus erythematosus; whether the uric acid level is high, and to rule out other lesions that may cause knee joint inflammation.

By taking medical history, physical examination, imaging examination and laboratory tests, and after a relatively detailed and systematic examination, other possible lesions can be excluded and a more accurate and clear diagnosis can be made.

The treatment of knee osteoarthritis adopts different treatment measures according to the different stages of development. We call it sequential treatment or step-by-step treatment of knee osteoarthritis.

In the early stages of knee osteoarthritis, the pain is sometimes mild and sometimes severe and does not last very long. There is no obvious degeneration and wear of the knee cartilage and conservative treatment can be used, such as rest, medication, physical therapy and other measures. The symptoms can generally be well relieved.

As age increases or other factors induce it, the condition continues to worsen, the articular cartilage shows obvious degeneration, and even valgus and varus deformity occurs. At this time, surgery is required to correct the deformity. Generally, osteotomy is performed in the area where the deformity is more obvious, restoring the force line of the lower limbs, reducing the force of the abnormal force-bearing parts, and significantly reducing the pressure on the knee joint, thereby restoring the normal function of the knee joint. For example, for varus deformity of the knee, osteotomy is mostly performed on the tibia; for valgus deformity of the knee, osteotomy is mostly performed on the femur.

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As the disease progresses, especially when there is severe wear of the medial unicompartment or unicompartment, cartilage stripping exposing the subchondral bone, and wear and rupture of the meniscus, a unicompartmental replacement can be performed for the medial wear, replacing only the damaged joint surface, which usually significantly reduces the patient's pain, and the operation is relatively small and the effect is good. If the knee joint disease continues to progress and involves both the medial and lateral compartments, that is, both sides of the femoral condyle and tibial plateau are significantly worn, and even the patella is damaged, then a simple unicompartmental replacement is no longer applicable. At this time, it is necessary to remove the hyperplastic tissue and damaged cartilage, and use total knee replacement, that is, replace an artificial total knee joint, which is an effective treatment for patients with advanced knee osteoarthritis.

In general, different treatment measures are taken at different stages of knee osteoarthritis to maximize the relief of the disease, eliminate symptoms, and return to normal life and work.

What are the commonly used drugs for early-stage knee osteoarthritis? If the pain is more obvious, you can take nonsteroidal anti-inflammatory drugs orally to eliminate the pain symptoms; if the joints are swollen and the synovium is inflamed, use drugs to eliminate swelling and treat synovitis; when the knee joint symptoms are obvious, you can also use some anti-inflammatory, analgesic, and blood-activating external drugs to improve the symptoms, such as plasters. In addition, you can also use some drugs that increase cartilage nutrition, such as glucosamine.

Nonsteroidal anti-inflammatory drugs have certain side effects, so this type of drug cannot be used for a long time. Use it when it hurts, and stop taking it as soon as possible when it doesn't hurt. Drugs that nourish joints are relatively less harmful to the human body, but they cannot be relied upon to treat osteoarthritis. Take it for 3 months and then stop for 1 month. Drugs for the treatment of synovitis and some topical medications are also not recommended for long-term use.

In addition to medication, there are many physical therapy methods for treating knee osteoarthritis, such as electrotherapy, magnetic therapy, heat therapy, ultrasound therapy, and drug introduction therapy. These methods can relieve symptoms, and the effects vary from person to person.

Knee osteoarthritis can generally be improved in the early stages through medication and physical therapy, and the condition can be controlled and no longer progress. However, as some patients age or suffer trauma, they will develop typical osteoarthritis, which is also called late-stage osteoarthritis, and surgical treatment may be required.