Gonarthrosis. Knee prosthetics

Degenerative changes in the knee joint begin with the destruction of the articular cartilage (hard elastic, smooth covering of the bone in the area of the articular surfaces). After some time, the process of degeneration can begin both in soft tissues (for example, in the joint bag, ligaments) and in the bones.

Gonarthrosis begins slowly and at first proceeds almost imperceptibly. Later, the disease can develop rapidly, accompanied by increasing pain and significant limitation of mobility in daily life.

The cause of degenerative diseases is, as a rule, an uneven mechanical load in varus and valgus deformities, the so-called "X" and "O"-shaped legs, or a decrease in cartilage elasticity during joint changes caused by inflammation (rheumatism).

Causes

Cartilage is nourished by joint fluid. This joint fluid delivers nutrients to the cartilage cells found in the ground substance of the cartilage and removes decay products. Inflammatory diseases of the joint worsen the properties of the joint fluid, thereby disrupting the nutrition of the cartilage. In the loading phase, the cartilage behaves like a sponge: during loading, the cartilage tissue secretes fluid, and at rest, the fluid is absorbed. Too much load, for example, with axial deformity of the legs, as well as an insufficient level of load due to low motor activity, disrupts the nutrition of the cartilage. Lack of movement reduces the elastic properties of cartilage.

The human knee joint is resistant to stress, but at the same time very sensitive. The work of the bone levers of the femur and lower leg bone, as well as the movement of muscles when walking or running, create a load on the knee joint of 3-4 kg for every kilogram of weight. If the part of the joint responsible for the transfer of force is half worn out due to congenital diseases or acquired problems of uneven loading, then the pressure on the knee joint increases four times.

Changing the load on the knee joint with "X-" and "O-shaped legs". With an O-shaped leg, the inner side of the knee joint experiences an increased load, and the outer side suffers from its lack. With X-shaped legs, everything happens the other way around. Simultaneously with this or independently of this, the articular surface between the patella and the thigh may suffer. Also, damage to the meniscus (an elastic cartilaginous shock absorber between the thigh and lower leg), its removal or joint instability due to ligament rupture disrupts the load balance, which leads to the progression of the disease. Excess weight, heavy physical labor or repetitive movement processes accelerate the course of the disease.

Prevention

The cartilage is nourished during the movement of the joint, at the same time, excessive load must be avoided. Only the joint that regularly "works", i.e. is in motion, thanks to which the cartilage receives sufficient nutrition, remains elastic and is able to withstand sudden overloads without loss. Extreme stress on the joint, such as lifting and carrying heavy objects, should be avoided whenever possible in daily life.

You can independently carry out a set of preventive measures that will help you prevent the onset of the disease or slow down the development of the disease in the initial stages.

Do you have to sit a lot due to the nature of your professional employment?

• Stretch your legs repeatedly.
• Get up as often as possible and walk a couple of steps.

Practice certain sports.

• Especially recommended are cycling, swimming, Nordic Walking and cross-country skiing;
• sports with a sharp transition from movement to standing and vice versa are not recommended, such as tennis and table tennis, squash, badminton, as well as team sports: handball, football, volleyball, etc.

Make movements in the joints in full!

• Do gymnastics regularly
• Strengthen muscles, increase their elasticity
• Do exercises to stretch the joint capsules and ligaments

If there are early signs of illness or previously identified injuries, avoid carrying heavy loads. 

• "Kilogram in hand, and two on the stomach!" - means 2-3 kilograms of weight per hip joint
• When shopping in a supermarket, use a trolley instead of a basket
• Use the escalator or elevator when moving goods.
• Use a cane to reduce stress on the joint

If there is damage to the knee, it makes sense to use escalators and elevators. Physical activity is important, of course, but stairs should be avoided.

Symptoms

The following complaints should serve as a reason for you to reconsider your daily movement pattern and possibly take preventive measures or resort to one or another treatment.

• The first symptom: Feeling tired after long walks, pain is still absent, but the desire to take a break visits more and more often.
• You feel tired after a long walk. There are no pains yet, but the need for rest arises more and more often.
• With progressive degeneration of the joint, drawing pains, a feeling of pressure, slight pains in the groin area, in the thigh or knee joint are observed.
• At the onset of the next phase of the disease, you feel pain when walking for a long time, when walking over rough terrain and / or when climbing stairs.
• Typical is the so-called "pain during the run-up": when getting up after a long sitting or after getting out of bed, the first movements are painful. You need to "break up".
• In the later stages, there are pains at rest and night pains.
• The more often the pain occurs, the more you will try to avoid movements that cause pain. As a result, shortening and tension of muscle fibers occur, you try to take a sparing position, constantly bending the leg slightly in the hip joint, the joint capsule and ligamentous apparatus wrinkle. In the end, the amplitude of movements in the hip joint decreases, the final phase of movements becomes painful.

X-ray results

With the progression of coxarthrosis, changes in the hip joint become noticeable on x-rays.

• First, the articular cartilage is damaged and thinned. It is impossible to see it on an x-ray, but it is projected as a dark border between light bone surfaces, this is the so-called “articular gap” (which does not block x-rays). With the breakdown of cartilage tissue, the “joint gap” becomes narrower, eventually the bone surfaces come into contact with each other.
• Under heavy loads, the bone tissue also reacts. In the area of loading, thickening of the bone tissue occurs. On an x-ray, sclerosis (compaction) looks like a light strip (which does not transmit x-rays). Unstressed bone appears more transparent than normal bone.
• Excessive formation of osteophytes (bone outgrowths) occurs at the edges of the joints.
• In the area of increased load, point blood supply disorders occur, the bone tissue dies in these places, and small cysts (hollow spaces) form in its place. Often they occur in pairs on adjacent and opposite bone surfaces.

Diagnostics

The first step is the anamnesis, a systematic description of the patient's medical history. This takes into account recent complaints, life circumstances (eg occupational stress), past health status (eg existing diseases), special risk factors (eg allergies), genetic (hereditary) risk. The following questions are typical for taking an anamnesis:

• Since when, how often and what kind of pain do you have?
• The reason for their occurrence, and how do you remove them (load, sport)?
• Did you self-medicate (home remedies), what did the doctor prescribe (medication, therapeutic exercises)?
• Do you suffer from other diseases?
• What medications do you take regularly?